3
Preoperative Preparation
David McAneny, MD
INTRODUCTION
The preoperative management of any patient is part of a continuum of care that extends from the surgeon’s initial consultation through the patient’s full recovery. While this ideally involves a multidisciplinary collaboration, surgeons lead the effort to assure that correct care is provided to all patients. This involves the establishment of a culture of quality care and patient safety with high, uniform standards. In addition, the surgeon is responsible for balancing the hazards of the natural history of the condition if left untreated versus the risks of an operation. A successful operation depends upon the surgeon’s comprehension of the biology of the patient’s disease and keen patient selection.
This chapter will consider preoperative preparation from the perspectives of the patient, the operating room facility and equipment, the operating room staff, and the surgeon.
PREPARATION OF THE PATIENT
History & Physical Examination
The surgeon and team should obtain a proper history from each patient. The history of present illness includes details about the presenting condition, including establishing the acuity, urgency, or chronic nature of the problem. Inquiries will certainly focus on the specific disease and related organ system. Questions regarding pain can be guided by the acronym OPQRST, relating to Onset (sudden or gradual), Precipitant (eg, fatty foods, movement, etc), Quality (eg, sharp, dull, or cramps), Radiation (eg, to the back or shoulder), Stop (what offers relief?), and Temporal (eg, duration, frequency, crescendo-decrescendo, etc). The presence of fevers, sweats, or chills suggests the possibility of an acute infection, whereas significant weight loss may imply a chronic condition such as a tumor. The history of present illness is not necessarily confined to the patient interview. Family members or guardians provide useful information, and outside records can be indispensable. Documents might include recent laboratory or imaging results that preclude the need for repetitive, costly testing. The surgeon should request CD-ROM disks of outside imaging, if appropriate. In the case of reoperative surgery, prior operative reports and pathology reports are essential (eg, when searching for a missing adenoma in recurrent primary hyperparathyroidism).
The past medical history should include prior operations, especially when germane to the current situation, medical conditions, prior venous thromboembolism (VTE) events such as deep vein thromboses (DVT) or pulmonary emboli (PE), bleeding diatheses, prolonged bleeding with prior operations or modest injuries (eg, epistaxis, gingival bleeding, or ecchymoses), and untoward events during surgery or anesthesia, including airway problems. One must secure a list of active medications, with dosages and schedule. Moreover, it is beneficial to inquire about corticosteroid usage within the past 6 months, even if not current, to avoid perioperative adrenal insufficiency. Medication allergies and adverse reactions should be elicited, although knowledge about environmental and food allergies is also valuable and should be recorded so that these exposures are avoided during the hospital stay. Some anesthesiologists are reluctant to use propofol in patients with egg allergies, and reactions to shellfish suggest the possibility of intolerance of intravenous iodinated contrast agents.
The social history classically involves inquiries into tobacco, alcohol, and illicit drug usage, but this moment also offers the opportunity to establish a personal relationship with patients (and their loved ones). It is fun and often stimulating to learn about patients’ occupations, avocations, exercise, interests and accomplishments, fears and expectations, and family lives. Patients’ regular activities offer insight into physiologic reserve; an elite athlete should tolerate nearly any major operation, whereas a frail, sedentary patient can be a poor candidate for even relatively minor operations.
A family history includes queries pertinent to the patient’s presenting condition. For example, if a patient with a colorectal cancer has relatives with similar or other malignancies, genetic conditions such as familial adenomatous polyposis or hereditary nonpolyposis colorectal cancer could be indicted. This scenario would have screening implications for both the patient and family members. In addition, one should also elicit a family history of VTE complications, bleeding disorders, and anesthesia complications. For example, a sudden and unexpected death of a relatively young family member during an operation could suggest the possibility of a pheochromocytoma, particularly in the setting of a medullary cancer or related endocrine disorder. A strong family history of allergic reactions might imply hypersensitivity to medications.
A review of systems assesses the patient’s cardiovascular, pulmonary, and neurologic status, including questions about exertional chest pain or dyspnea, palpitations, syncope, productive cough, or central nervous symptoms. It is also important to have a basic understanding of the patient’s symptoms relative to other major organ systems. For example, while one might not necessarily expect an orthopedic surgeon to have an interest in a patient’s gastrointestinal or genitourinary habits or problems, these issues may bear grave consequences if a patient experiences postoperative incontinence following joint replacement. Regardless of degree of specialization, surgeons and their designated teams are capable of identifying and investigating potentially confounding conditions.
A thorough physical examination is also an essential part of the patient assessment. Even if the surgeon already knows from imaging that there will be no pertinent physical findings, human touch and contact are fundamental to the development of a trusting physician-patient relationship. In addition to the traditional vital signs of pulse, blood pressure, respiratory rate, and temperature, for many operations it is also important to record the patient’s baseline oxygen saturation on room air, weight, height, and body mass index (BMI). The physical examination includes an assessment of general fitness, exercise tolerance, cachexia, or obesity, as well as focusing on the patient’s condition. Additional observations may detect findings such as cardiopulmonary abnormalities, bruits, absent peripheral pulses or bruits, adenopathy, skin integrity, incidental masses, hand dominance, neurologic deficits, or deformities. A thorough abdominal examination may include digital anorectal and pelvic examinations. The surgeon should also appreciate potential airway problems, particularly if general anesthesia is anticipated.
Preoperative Testing
Laboratory and imaging investigations are tailored to the individual patient’s presenting condition, as discussed in later chapters. However, there should be no “routine” battery of preoperative laboratory studies for all patients. In fact, published data do not support an association between routine studies and outcome. In addition, laboratory tests are costly and may result in harm due to false-positive and fortuitous findings. Instead, tests should be selected based upon the patient’s age, comorbidities, cardiac risk factors, medications, and general health, as well as the complexity of the underlying condition and proposed operation. For example, children uncommonly require preoperative laboratory tests for most operations. On the other hand, a complete blood count, chemistries, and an electrocardiogram are proper for high-risk patients before complex operations. Algorithms and grid matrices are available to individualize the selection of preoperative tests (Table 3–1). Importantly, each system should establish a practice for managing abnormal test results, whether germane to the patient’s active condition or a serendipitous finding.
Table 3–1. Sample preoperative testing grid.
A complete blood cell count and basic chemistries are reasonable for some operations, but their likelihood of predicting abnormal or meaningful results should be considered. Coagulation factors such as prothrombin time (PT), international normalized ratio (INR), and partial thromboplastin time (PTT) are not routinely indicated but should be pursued when patients report prolonged bleeding or the usage of anticoagulants. Moreover, INR and PTT may be warranted for operations that have little threshold for intraoperative or postoperative bleeding, such as those on the brain, spine, or neck. Bile duct obstruction, malnutrition, or an absent terminal ileum can affect vitamin K absorption, and a preoperative assessment of INR is important in those instances as well. A pregnancy test (eg, urine beta-human chorionic gonadotropin [beta-HCG]) should be performed shortly before surgery on women with childbearing potential. Other laboratory testing will be dictated by specific conditions, including liver chemistries, tumor markers, and hormone levels. A blood bank specimen should be selectively submitted in advance of operations that are associated with significant hemorrhage or in the setting of anemia with prospects for further blood loss. The preparation of blood for transfusion is costly, so blood-typing alone may suffice without actual cross-matching.
Routine preoperative testing of blood glucose is an intriguing concept, given the relationship between elevated blood sugars and surgical site infections (SSIs), although hemoglobin A1C levels have not correlated with postoperative infections. Some reckon that nondiabetic patients comprise 30%-50% of cases with perioperative hyperglycemia, perhaps constituting an argument for measuring preoperative glucose levels in all candidates for major operations. While it is accepted that diabetic patients require close monitoring of perioperative glucose levels, including immediately before the operation, the value of doing this for all patients is evolving and warrants thoughtful investigation.
Some investigators have advocated routine nasal swab screening to identify carriers of Staphylococcus aureus. The results can guide decontamination measures such as intranasal application of antibiotic ointment (eg, mupirocin) and local hygiene with 2% chlorhexidine showers for 5 days before surgery. Patients with methicillin-resistant S aureus (MRSA) receive appropriate antibiotic prophylaxis and contact precautions. Although the issue of routine MRSA screening is not fully resolved, this practice may be ideal at least for immunocompromised patients and for those undergoing open cardiac operations and implantations of foreign bodies, particularly in orthopedics and neurosurgery. Prospective wound or abscess culture results should also influence decisions about perioperative antibiotics.
Electrocardiograms are not routinely performed but are justified for patients older than 50 years; those having vascular operations; and those with a history of hypertension, cardiac disease, significant respiratory disease, renal dysfunction, and diabetes mellitus. Chest radiographs are no longer performed on a regular basis but are primarily reserved for patients with malignancies or perhaps with significant pulmonary disease. Further special tests are selectively obtained when clinically indicated and often with guidance from consultants; these tests may include echocardiography, cardiac stress testing, baseline arterial blood gases, and pulmonary function tests. Carotid ultrasonography may be valuable in patients with carotid bruits or histories of cerebrovascular accidents or transient ischemia attacks. Noninvasive venous studies may be considered in patients who have had prolonged immobility and/or hospital stays before surgery.
PREOPERATIVE PROCESS
At its simplest, the process of preparing a patient for an operation can involve a rapid assessment in the clinic or emergency room followed by an expeditious trip to the operating room. However, like most care in the contemporary health care system, the process is more commonly complex and involves a formal series of integrated steps to assure best outcomes. It is incumbent upon the surgery team to create an efficient and cost-effective preoperative system and scheduling protocol that result in optimally prepared patients, rare cancellations of operations, and few disruptions of the operating room schedule. A systemic approach to patient preparation focuses upon risk assessment and reduction, as well as education of the patient and family. This effort begins during the first encounter with the surgeon and continues through the moments before the operation. Ideal preoperative systems assign risk based upon evaluations that are derived from sound published evidence and best practices and driven by standardized algorithms to identify and then modify hazards before operations.
Risk Assessment & Reduction
Overview
The essence of preparing a patient for an operation regards considering whether the benefits of the operation justify the risks of doing harm, along with deciding how to minimize or eliminate those hazards. The American Society of Anesthesiologists (ASA) classification system (Table 3–2) stratifies the degree of perioperative risk for patients. While somewhat rudimentary, this system has faithfully served anesthesiologists and surgeons in predicting how well patients might tolerate operations, and the scores have been validated by several recent publications. The Acute Physiology and Chronic Health Evaluation (APACHE II and III) is an example of a severity of illness scoring system that may be applied to intensive care unit patients to predict mortality. The value of such assessments lies in numerically designating the severities of patients’ conditions, permitting comparisons of outcomes.
Table 3–2. American Society of Anesthesiologists (ASA) classification system.
The University Health Systems Consortium (UHC) analyses derive from inpatient administrative and financial datasets to predict risk-adjusted outcomes for mortality, lengths of stay, and cost of care. The vagaries of medical coding can result in discrepancies, and the UHC system does not monitor patients after hospital discharge. Nevertheless, UHC data can identify deficiencies in practice. Although clinical databases are more costly and challenging to implement than commercially available products such as the UHC program, they provide more robust risk-adjusted outcomes data. Examples of clinical databases include those from the Society of Thoracic Surgeons (STS) and the National Surgical Quality Improvement Program (NSQIP). In NSQIP, dedicated nurses prospectively collect and validate an established panel of defined patient variables, comorbidities, and outcomes, and they pursue surveillance for 30 days after hospital discharge. The NSQIP analysis considers patient factors, effectiveness of care, and random variation, and logistic regression models calculate risk-adjusted 30-day morbidity and mortality. These data are reported as odds ratios for comparison with expected outcomes, allowing for the severity of the patients’ illnesses. Immediate benefits of NSQIP present the ability to identify true risk-adjusted data and local opportunities for improvement. For example, Veterans Administration (VA) surgeons reduced postoperative mortality from 3.2% in 2003 to 1.7% in 2005, while the complication rate declined from 17% to 10% (p < 0.0001). This effort focuses upon systems of care, providing reliable data to assess and reduce risks associated with operations. When compared to UHC, NSQIP is much more likely to identify complications because of its surveillance of patients 30 days beyond their hospitalizations.
The NSQIP program has also generated a tremendous repository of data to develop “risk calculators” for a variety of operations and conditions, allowing preoperative risk assessments and hopefully facilitating significant reductions of preoperative hazards. Finally, NSQIP participants have fostered a culture of sharing best practices and processes, both within the published literature and through formal and personal collaborations.
Beyond the obvious physical and emotional implications of adverse outcomes for patients and their families, the financial costs of postoperative complications to the health care system are staggering. It has been postulated that a major postoperative complication adds over $11,000 to the cost of the hospital care of an affected individual and significantly extends the duration of the inpatient confinement. In fact, the total cost of care increases by more than half when a complication develops. Notably, respiratory complications may increase the cost of care by more than $52,000 per patient. Strikingly, data from NSQIP have demonstrated that the occurrence of a serious complication (excluding superficial wound infections) after major operations is an independent risk factor for decreased long-term survival. Therefore, it is crucial that efforts focus upon reducing and eliminating postoperative complications.
Well-designed, systematic preoperative assessment programs can prospectively identify predictors of various complications and drive the ability to attenuate risks and improve outcomes. The perspective of teams of surgeons, physicians, nurses, and others with expertise managing standardized, algorithm-driven preoperative evaluations, often with checklists, is a departure from traditional care that primarily involved solitary surgeons with disparate practices. The new paradigm recognizes that variability in practice is the enemy of efficiency.
The financial dividends appreciated from enhanced results and diminished death and complication rates more than compensate for the expenditures associated with quality improvement efforts and participation in auditing programs such as NSQIP. It is essential that surgeons monitor their patients’ outcomes, preferably in a risk-adjusted fashion, to understand their practices and to demonstrate opportunities for improvement.
Cardiovascular
In 1977, Goldman published a multifactorial index for assessing cardiac hazards among patients undergoing noncardiac operations. The same group issued a Revised Cardiac Risk Index (RCRI) in 1999, reporting six independent predictors of cardiac complications. These include a history of ischemic heart disease, congestive heart failure, cerebrovascular disease, a high-risk operation, preoperative treatment with insulin, and a preoperative serum creatinine greater than 2.0 mg/dL. The likelihood of major cardiac complications increases incrementally with the number of factors present. Contemporary NSQIP data have led to the development of a risk calculator to predict postoperative cardiac complications. A multivariate logistic regression analysis demonstrated five prognostic factors for perioperative myocardial infarction (MI) or cardiac arrest: the type of operation, dependent functional status, abnormal creatinine, ASA class, and increasing age. The analysis has been validated and has led to the composition of an interactive risk calculator. Another multivariate model demonstrated criteria that predict adverse cardiac events among patients who have had elective vascular operations, and it also suggests improved predictive accuracy among these patients compared to the RCRI. Independent hazards include increasing age, smoking, insulin-dependent diabetes, coronary artery disease, congestive heart failure (CHF), abnormal cardiac stress test, long-term beta-blocker therapy, chronic obstructive pulmonary disease, and creatinine ≥1.8 mg/dL. Conversely, the analysis demonstrated a beneficial effect of prior cardiac revascularization. There is obviously overlap among the factors identified in these models.
The determination of an increased chance of a patient developing postoperative cardiac complications will certainly influence the tenor of preoperative discussions with patients and their family members, especially if the surgeon can present validated data regarding the actual likelihood of a cardiac complication or death. In addition, correctable hazards may be addressed, including smoking cessation, optimal control of diabetes, hypertension, and fluid status, and assurance of compliance with medical measures. Finally, formal risk assessments guide cardiologists with respect to cardiac stress testing, echocardiography, and coronary catheterization among higher-risk patients. Selected patients may be candidates for preoperative revascularization, either with coronary artery stent placement or surgical bypass.
The American College of Cardiology (ACC) Foundation and the American Heart Association (AHA) periodically issue joint recommendations about the cardiac evaluation and preparation of patients in advance of noncardiac operations. These guidelines are evidence based, include an explanation of the quality of the data, and provide comprehensive algorithms for the propriety of testing, medications, and revascularization to assure cardiac fitness for operations. As important as preoperative cardiac risk stratification is, a cardiology consultation also lays the groundwork for postoperative risk assessment and later modifications of coronary risk factors.
Noninvasive and invasive preoperative testing should be performed only when the results will influence patient care. Noninvasive stress testing before noncardiac operations is indicated in patients with active cardiac conditions (eg, unstable angina, recent MI, significant arrhythmias, or severe valvular disease), or in patients who require vascular operations and have clinical risk factors and poor functional capacity. Good data support coronary revascularization before noncardiac operations in patients who have significant left main coronary artery stenosis, stable angina with three-vessel coronary disease, stable angina with two-vessel disease and significant proximal left anterior descending coronary artery stenosis with either an ejection fraction < 50% or ischemia on noninvasive testing, high-risk unstable angina or non–ST-segment elevation MI, or acute ST-elevation MI. However, current data do not support routine preoperative percutaneous revascularization among patients with asymptomatic coronary ischemia or stable angina.
The role of beta-blockers for cardiac protection is evolving, and these agents are no longer empirically advised for all high-risk patients due to potential adverse consequences. Beta-blockers should be continued perioperatively among those patients who are already taking them and among those having vascular operations and at high cardiac risk, including known coronary heart disease or the presence of ischemia on preoperative testing. The role of beta-blockers is uncertain for patients with just a single clinical risk factor for coronary artery disease. Cardiac complication risk calculators may become beneficial in the stratification of patients who should receive beta-blockers to reduce perioperative cardiac complications.
Preoperative aspirin usage should continue among patients at moderate to high risk for coronary artery disease, unless the risk of resultant hemorrhage definitely outweighs the likelihood of an atherothrombotic event. Thienopyridines, such as ticlopidine or clopidogrel, are administered in concert with aspirin as dual antiplatelet therapy following placement of coronary artery stents. They are intended to inhibit platelet aggregation and resultant stent thrombosis, although they certainly increase the risk of hemorrhage. Therefore, if an operation can be anticipated, the surgeon and cardiologist must coordinate efforts regarding the sequence of the proposed operation and coronary stenting, weighing the hazards of operative bleeding while on antiplatelet therapy for a stent versus potential postoperative coronary ischemia. Elective operations with a significant risk of bleeding should be delayed 12 months before the discontinuation of the thienopyridine in the presence of a drug-eluting stent, at least 4-6 weeks for bare-metal stents, and 4 weeks after balloon angioplasty. Therefore, if a patient requires percutaneous coronary artery intervention prior to noncardiac surgery, bare-metal stents or balloon angioplasty should be employed rather than drug-eluting stents. Even when thienopyridines are withheld, aspirin should be continued, and the thienopyridine is to be resumed as soon as possible after the operation. In circumstances such as cardiovascular surgery, the dual antiplatelet agents are continued throughout the perioperative course to minimize the likelihood of vascular thrombosis.
Pulmonary
Postoperative pulmonary complications (PPC), such as the development of pneumonia and ventilator dependency, are debilitating and costly. They are associated with prolonged lengths of hospital stay, an increased likelihood of readmission, and increased 30-day mortality. Therefore, it is critical to identify patients at greatest risk for PPC. Established risk factors for PPC include advanced age, elevated ASA class, congestive heart failure, functional dependence, known chronic obstructive pulmonary disease, and perhaps malnutrition, alcohol abuse, and altered mental status. In addition, hazards are greater for certain operations (eg, aortic aneurysm repair, thoracic or abdominal, neurosurgery, head and neck, and vascular), prolonged or emergency operations, and those done under general anesthesia. A risk calculator was devised to predict the likelihood of PPC occurrence, indicating seven independent risk factors. These include low preoperative arterial oxygen saturation, recent acute respiratory infection, age, preoperative anemia, upper abdominal or thoracic operations, duration of operation over 2 hours, and emergency surgery.
A multivariable logistic regression has affirmed that active smoking is significantly associated with postoperative pneumonia, SSI, and death, when compared to nonsmokers or those who have quit smoking. Moreover, this is a dose-dependent phenomenon, predicated upon the volume and duration of tobacco consumption. The benefits of preoperative smoking cessation seem to be conferred after an interval of at least 4 weeks. Conversely, the risk of developing PPC is the same for current smokers versus those who quit smoking for less than 4 weeks before an operation. Smoking cessation also confers favorable effects on wound healing. Therefore, patients should be encouraged to stop smoking at least 1 month before operations, ideally with programmatic support through formal counseling programs and possibly smoking cessation aids such as varenicline or transdermal nicotine.
A recent analysis of patients having general surgery and orthopedic operations demonstrated that sleep apnea is an independent risk factor for the development of PPC. A simple “STOP BANG” questionnaire can screen patients for sleep apnea. The acronym queries Snoring, Tired during day, Obstructed breathing pattern during sleep, high blood Pressure, BMI, Age over 50 years, Neck circumference, and male Gender. Patients with sleep apnea may be managed with continuous positive pressure (CPAP) or bilevel positive airway pressure (BiPAP) devices, both before and after operations. The presence of sleep apnea may also influence anesthesia techniques.
Patients identified as being at highest risk for the development of PPC may benefit from preoperative consultations with respiratory therapy and pulmonary medicine experts. Pulmonary function tests and baseline arterial blood gas tests guide the care of select patients, especially those anticipating lung resections. In addition to smoking cessation, asthma should be medically controlled. Patient education focuses upon inspiratory muscle training (including the usage of incentive spirometry), the concepts of postoperative mobilization, deep inspiration, and coughing, along with oral hygiene (tooth brushing and mouth washes). Respiratory therapists can provide expertise with CPAP and BiPAP systems for patients with sleep apnea. Surgeons and anesthesiologists should collaborate regarding plans for neuromuscular blocking agents and strategies to reduce pain, including the administration of epidural analgesics and the consideration of minimally invasive techniques to avoid large abdominal or thoracic incisions. Finally, formal intensive care unit protocols can promote liberation from ventilator support.
Venous Thromboembolism
Venous thromboembolism (VTE) events such as DVT or PE are major complications that can lead to death or serious long-term morbidity, including chronic pulmonary hypertension and postthrombotic limb sequelae. Scoring systems stratify patients by their probability of developing a postoperative VTE to guide preventative measures. In the 2012 American College of Chest Physicians (ACCP) recommendations, the patient’s score selects the alternatives of early ambulation alone (very low risk), mechanical prophylaxis with intermittent pneumatic compression (IPC) devices (low risk), options of low-molecular-weight heparin (LMWH) or low-dose unfractionated heparin or IPC (moderate risk), and IPC in addition to either LMWH or low-dose heparin (high risk). Furthermore, an extended course (4 weeks) of LMWH may be indicated among patients undergoing resections of abdominal or pelvic malignancies. Of course, the surgeon must entertain the hazards of pharmacologic prophylaxis when bleeding poses even greater harm than VTE, in which case IPC alone may suffice. Heparin prophylaxis is associated with a 4%-5% chance of wound hematomas, 2%-3% incidence of mucosal bleeding and the need to stop the anticoagulation, and a 1%-2% risk of reoperation. The ACCP 2012 guidelines do not advocate routine vein surveillance with ultrasonography or the insertion of inferior vena cava filters for primary VTE prevention. Notably, antiembolism graduated compression stockings (GCS) do not promote venous blood flow from the leg and can violate skin integrity and result in the accumulation of edema. The efficacy of stocking for VTE prevention is unproven.
Caprini has developed a more elaborate risk calculation that has been validated in a variety of clinical settings and specialties, and is adaptable to standardized order sets (Figure 3–1). This scoring system acknowledges the gravity of individual hazards, including personal and family histories of VTE, the diagnosis of a malignancy, a history of obstetrical complications or known procoagulants, and prolonged operations, among several other factors. It also identifies patients who may either entirely avoid anticoagulation or benefit from an extended duration of LMWH. There is no doubt that the cumulative incidence of VTE extends many weeks after operations, particularly for malignancies and in an era when the duration of hospital stays (and inpatient prophylaxis) has declined. In fact, about one-third to half of patients who manifest a postoperative VTE after cancer surgery do so following hospital discharge. Therefore, regimens of pharmacologic prophylaxis should be maintained after the discharge of patients who have elevated risk scores. The ACCP and Caprini systems are two among several VTE risk assessment tools, each of which has advantages and disadvantages. The system adopted in any hospital or surgery center will be a function of local resources and culture, but it is ideal that surgeons develop and maintain a local standard to minimize the threat of postoperative VTE.
Figure 3–1. Sample order set page with “Caprini” calculation of venous thromboembolism risk. The total value of checked-off factors indicates the proper preoperative and postoperative prophylaxis regimens, including upon discharge from hospital. (© Boston Medical Center Corporation 2012.)
Diabetes Mellitus
Patients with diabetes mellitus are more likely to undergo operations than are those without diabetes, and their care is associated with longer lengths of hospital stay, increased rates of postoperative death and complications, and relatively greater utilization of health care resources. It has been established that elevated postoperative blood glucose levels in diabetic patients translate to progressively greater chances of SSIs following cardiac operations, as well as a greater likelihood of postoperative infections and prolonged hospital stays in patients with noncardiac operations. In fact, increased perioperative glucose levels have correlated with a higher risk of SSIs in general surgery, cardiac surgery, colorectal surgery, vascular surgery, breast surgery, hepatobiliary and pancreas surgery, orthopedic surgery, and trauma surgery. The relative risk of an SSI seems to incrementally increase in a linear pattern with the degree of hyperglycemia, with levels greater than 140 mg/dL being the sole predictor of SSI upon multivariate analysis. In one study, the likelihood of an adverse postoperative outcome increased by 30% for every 20 mg/dL increase in the mean intraoperative glucose level. Interestingly, about one-third of patients with perioperative hyperglycemia are not diabetics. Furthermore, the risk of death relative to perioperative hyperglycemia among patients undergoing noncardiac operations has been shown to be greater for those without a history of diabetes than for those with known diabetes. Nevertheless, these data pertain to intraoperative and postoperative blood sugars, not preoperative values.
Current recommendations for desirable glucose ranges in critically ill patients are commonly about 120-180 mg/dL, but the best range for perioperative glucose levels is not yet established, and low levels may result in harm when clinicians try to achieve “tight” control of blood sugars. In fact, trials and meta-analyses have failed to prove a clinical benefit of maintaining glucose levels in the normal laboratory reference range (80-110 mg/dL). Although preoperative blood sugar and hemoglobin A1C levels have not clearly correlated with adverse outcomes, good control of glucose before operations likely facilitates blood sugar management during and after operations. An abundance of data support postoperative glucose control as a major determinant of postoperative complications, with emerging data also indicating an adverse effect of intraoperative hyperglycemia. Interestingly, surgeons may actually be more influential than are patients’ primary care physicians in terms of encouraging preoperative compliance with diabetes medications, at least in the short term. Patients are commonly motivated to attend to medical conditions such as diabetes to enhance chances of postoperative success.
Patients having operations that require fasting status are advised about oral antihyperglycemic medications on the day of surgery in accordance to Table 3–3. Injectable medications such as exenatide and pramlintide are not administered on the day of surgery, and insulin therapy is determined by the duration of action of the particular preparation, as outlined in Table 3–4. Patients with type 1 diabetes require basal insulin at all times. Patients with insulin pumps may continue their usual basal rates.
Table 3–3. Instructions for preoperative management of oral antihyperglycemic medications.
Table 3–4. Instructions for preoperative management of injectable antihyperglycemic medications and insulin.
Multidisciplinary teams, including endocrinologists, surgeons, anesthesiologists, nurses, pharmacists, information technology experts, and others, have developed formal protocols and algorithms for perioperative glycemic control, and an example of a preoperative order set is illustrated in Table 3–5. A typical protocol is nurse-driven and involves checking glucose levels on all diabetic patients in the holding area shortly before an operation. As an example of one protocol, glucose values ≤180 mg/dL are satisfactory and require no treatment. Glucose levels of 181-300 mg/dL prompt the nurse to begin an infusion of intravenous (IV) insulin before the operation, along with a 5% dextrose solution to minimize the chances of hypoglycemia. Endocrinologists are automatically consulted to assist with postoperative insulin management in these patients and in those with insulin pumps. In general, insulin pump therapy is continued along with the infusion of a dextrose solution. Patients with pumps may also require the addition of IV insulin, as per the protocol.
Table 3–5. Example of adult perioperative glycemic control protocol.
Patients with glucose levels > 300 mg/dL are assessed for ketones or for acidosis prior to starting an insulin infusion. Markedly elevated preoperative blood sugars warrant special deliberation by all involved. Matters to be considered include the urgency of the operation, whether the underlying condition itself may be contributing to hyperglycemia, metabolic consequences such as the presence of ketoacidosis, the risks of proceeding with an operation at that moment, the likelihood of establishing better control at a later date, and the dangers imposed by postponing the operation. Dramatic elevations (eg, > 300 mg/dL) are typically indicative of chronic poor glucose control, but the clinician often does not have the luxury of perfectly managing diabetes before operations.
Intravenous insulin is best for perioperative glucose control due to its rapid onset of action, short half-life, and immediate availability (as opposed to subcutaneous absorption). Insulin may be administered with an IV bolus technique or via continuous IV infusion, but regular glucose monitoring (eg, hourly for continuous insulin infusions) is necessary in either system to assure adequate control and to avoid hypoglycemia. The insulin administration method before, during, and after an operation (infusion vs bolus) is a function of local resources (eg, glucose meters, blood sample processing, and staffing), as well as the patient’s individual circumstances. After the operation, a patient should be assessed for an insulin infusion regimen if being transferred to a critical care setting, a basal-bolus insulin program, or the resumption of the patient’s usual diabetes medications.
Surgical Site Infection
Surgical site infections (SSIs) are major contributors to postoperative morbidity and can be monitored and reduced by multiple complex interventions that are institution-specific. Excellent surgical technique is obviously a major factor in eliminating SSIs, and this involves limiting wound contamination, blood loss, the duration of the operation, and local tissue trauma and ischemia (eg, using sharp dissection rather than excessive electrocoagulation). However, a variety of adjuvant preoperative measures, beyond glycemic control described above, also contribute to the prevention of SSIs. Antibiotics should be administered within the 1-hour period before incision for certain clean operations and for all clean-contaminated, contaminated, and dirty operations. In addition, further dosages of the antibiotics should be infused about every two half-lives during the operation (eg, every 4 hours for cefazolin). Correct antibiotic selection is determined by several factors, such as the bacterial flora that are most likely to cause an infection, local bacterial sensitivities, medication allergies, the presence of MRSA, and the patient’s overall health and ability to tolerate an infection. In clean operations with low rates of infections, the surgeon should contrast the cost and hazards of antibiotics with the likelihood, cost, and morbidity of a postoperative infection. Antibiotic choices for prophylaxis against SSIs are cited inTable 3–6 for a variety of operations. Operations that involve bacteroides should prompt the addition of metronidazole to the regimen, and operations with a dirty wound classification may be guided by culture results and hospital-specific bacteria sensitivities. When antibiotics are administered for SSI prophylaxis rather than for treatment of an established or suspected infection, they are typically not continued after surgery, except in special circumstances such as vascular grafts, cardiac surgery, or joint replacements. Even then, prophylaxis should expire within one to two days. Order sets, automated reminders, and team vigilance are essential to assure the consistent usage of the correct antibiotics at the right time and for the proper duration.
Table 3–6. Examples of prophylactic antibiotic selections for various operations.a
Wound perfusion and oxygenation are also essential to minimize the likelihood of SSIs. A sufficient intravascular blood volume provides end-organ perfusion and oxygen delivery to the surgical site. The maintenance of perioperative normothermia also has salutary effects on wound oxygen tension levels and can consequently reduce the incidence of SSIs. Therefore, the application of warming blankets immediately prior to the operation may support the patient’s temperature in the operating room, especially for high-risk operations such as bowel resections that often involved a prolonged interval of positioning and preparation when a broad surface area is exposed to room air. Similarly, some data support hyperoxygenation with Fio2 ≥80% during the first 2 hours after a major colorectal operation.
Several other adjuvant measures are employed at the surgical site to reduce the incidence of SSIs. Protocols with mupirocin nasal ointment application and chlorhexidine soap showers have reduced the incidence of SSIs among patients colonized with methicillin-sensitive S aureus. During an operation, wound protectors may be deployed to minimize the chances of a superficial or deep SSI developing. Some surgeons (and their teams) change gloves and gowns, and may use a separate set of instruments (that have not come into contact with potential contaminants) for wound closure.
Fluid & Blood Volume
Likely out of concerns about incurring renal insult, surgeons and anesthesiologists have traditionally advocated liberal perioperative fluid resuscitation during recent decades, often overestimating insensible and “third space” fluid losses. As a result, patients can develop significant volume overload that is associated with serious complications. Recent data instead support goal-directed (or protocol-based) fluid restriction as likely resulting in a decreased incidence of cardiac and renal events, pneumonia, pulmonary edema, ileus, wound infections, and anastomosis and wound healing problems, as well as shorter durations of hospital stay. Unfortunately, traditional vital signs, including even central venous pressure, do not reliably correlate with intravascular volume or cardiac output. Moreover, pulmonary artery catheterization has actually been associated with increased mortality, and its implementation for the optimization of hemodynamic status is rarely required. Pulmonary artery catheterization is valuable for few, highly selected patients who exhibit clinical cardiac instability along with multiple comorbid conditions. Newer, minimally invasive modalities for monitoring cardiac output offer promise to determine optimal preload volume and tissue oxygen delivery before and during operations, including esophageal Doppler and analyses of stroke volume variation and pulse pressure variation. The precise standards of goal-directed volume resuscitation remain elusive, but surgeons and anesthesiologists should prospectively collaborate regarding plans for both volume resuscitation and the selection of the type of anesthesia. This is especially so during the management of challenging problems such as pheochromocytomas, when patients require preoperative vasodilatation and then intravascular volume expansion. Another clinical dilemma involves patients with end-stage renal failure. Dialysis should be performed within about 24-36 hours before an operation to avoid electrolyte disturbances, but the surgeon should confer with the nephrologist to minimize intravascular blood volume depletion.
Blood transfusions may be necessary before operations, especially in the setting of active hemorrhage or profound anemia. However, transfusions have been associated with increased operative mortality and morbidity, decreased long-term survival, greater lengths of hospital stay, and higher chances of tumor recurrence due to immunosuppressive effects imparted by transfused blood. The benefits of transfusions must be balanced against their hazards. Of course, bleeding diatheses require preoperative correction, including transfusions of blood products such as fresh frozen plasma, specific clotting factors, or platelets. Hematology consultations are invaluable when blood incompatibilities or unusual factor deficiencies are present.
Nutrition
Preoperative nutritional status bears a major impact on outcome, especially with respect to wound healing and immune status. A multivariate analysis recognizes hypoalbuminemia (albumin < 3.0 mg/dL) as an independent risk factor for the development of SSIs, with a fivefold increased incidence versus patients with normal albumin levels, corroborating the results of previous studies. Among moderately to severely malnourished patients, efforts may be focused upon preoperative feedings, ideally via the gut, although at least 1 week of the regimen is necessary to confer benefit. Total parenteral nutrition is an option for select patients in whom the gut cannot be used, but it conveys potential hazards. Immune modulating nutrition (IMN), with agents such as L-arginine, L-glutamine, ω-3 fatty acids, and nucleotides, can enhance immune and inflammatory responses. A recent meta-analysis of randomized controlled trials suggests that perioperative IMN with open, elective gastrointestinal operations is associated with fewer postoperative complications and shorter lengths of hospital stay compared to results for patients with standard enteral nutrition. However, the value of preoperative IMN is not firmly established.
At the other end of the spectrum, investigators have demonstrated that severe obesity is associated with increased rates of postoperative mortality, wound complications, renal failure, and pulmonary insufficiency, as well as greater durations of operative time and hospital stays. The AHA has issued guidelines for the assessment and management of morbidly obese patients, including an obesity surgery mortality score for gastric bypass. Unfavorable prognostic elements include BMI ≥50 kg/m2, male sex, hypertension, PE risks (eg, presence of a VTE event, prior inferior vena cava filter placement, history of right heart failure or pulmonary hypertension, findings of venous stasis disease), and age ≥45 years. Bariatric surgeons typically enforce a preoperative regimen of weight reduction before proceeding with surgery to enhance outcomes and to assure the patient’s commitment to the process.
Endocrine
Endocrine deficiencies pose special problems. Patients may have either primary adrenal insufficiency or chronic adrenal suppression from chronic corticosteroid usage. Inadequate amounts of perioperative steroids can result in an Addisonian crisis, with hemodynamic instability and even death. The need for perioperative “stress” steroid administration is a function of the duration of steroid therapy and the degree of the physiologic stress imposed by the operation. Supplemental corticosteroids should definitely be administered for established primary or secondary adrenal insufficiency, for a current regimen of more than the daily equivalent of 20 mg of prednisone, or for those with a history of chronic steroid usage and a Cushingoid appearance. Perioperative steroids should be considered if the current regimen is 5 to 20 mg of prednisone for 3 weeks or longer, for a history of more than a 3-week course of at least 20 mg of prednisone during the past year, for chronic usage of oral and rectal steroid therapy for inflammatory bowel disease, or for a significant history of chronic topical steroid usage (> 2 g daily) on large areas of affected skin. Increased amounts of corticosteroids are not necessary for patients who have received less than a 3-week course of steroids. Patients having operations of moderate (eg, lower extremity revascularization or total joint replacement) and major (eg, cardiothoracic, abdominal, central nervous system) stress should receive additional corticosteroids as outlined in Table 3–7. Minor or ambulatory operations, including those under local anesthesia, do not require supplemental steroids. Excessive amounts of steroids can have adverse consequences, including increased rates of SSIs, so hydrocortisone should not be indiscriminately prescribed. Of course, glucose levels should be closely monitored while patients receive steroids. Conversely, patients with advanced Cushing syndrome require expeditious medical and perhaps surgical treatment due to the potential for rapid deterioration, including fungal sepsis. Cushing syndrome and pheochromocytomas are separately addressed in Chapter 33.
Table 3–7. Recommendations for perioperative corticosteroid management.
Thyrotoxicosis must be corrected to avoid perioperative thyroid storm. Management includes antithyroid medications (eg, methimazole or propylthiouracil) and beta-blockers; saturated solution of potassium iodide controls hyperthyroidism and reduces the vascularity of the gland in patients with Graves disease. On the other hand, significant hypothyroidism can progress to perioperative hypothermia and hemodynamic collapse and thus requires preoperative hormone replacement. This is normally accomplished with daily oral levothyroxine, but greater doses of IV thyroid hormone may be necessary to acutely reverse a significant deficit. Large goiters can affect the airway and require collaboration between surgeon and anesthesiologist, possibly including a review of imaging to demonstrate the extent and location (eg, substernal) of the goiter. When possible, computed tomography contrast should be avoided in patients with significant goiters as the iodine load may provoke thyrotoxicosis.
Geriatric Patients
As the elderly demographic expands, surgeons are confronted with increasingly frail patients who have multiple comorbidities. Simple, noninvasive, yet focused elements from the patient’s history and physical examination serve as prognostic factors based upon the patient’s well-being or frailty. Makary has reported graded scores (allowing for BMI, height, and gender) that are predicated upon degree of weight loss, diminished dominant grip strength, self-reported description of exhaustion levels, and weekly energy expenditure in the course of routine activities, along with walking speed. Preoperative frailty is predictive of an increased chance of postoperative complications, prolonged lengths of hospital stay, and discharge to a skilled or assisted-living facility after having previously lived at home. A recent multivariate analysis demonstrated that among more than 58,000 patients undergoing colon resection, independent predictors of major complications were an elevated frailty index, an open (vs laparoscopic) operation, and ASA Class 4 or 5, but interestingly not wound classification or emergency status. The care of the elderly requires thoughtful considerations of their diminished physiologic reserve and tolerance of the insult of an operation. Interventions may include preoperative and early postoperative physical therapy, prospective discharge planning, and the introduction of elder-specific order sets. Simple scoring systems can provide valuable information for the surgeon to present to the patient and family so that they can anticipate the nature of the postoperative care and recovery, including potential transfer to a rehabilitation facility and long-term debility.
Illicit Drug & Alcohol Usage
The value of routine testing for the presence of illicit drugs, at least among patients with suggestive histories, is uncertain. The presence of drugs in blood or urine might result in a cancellation of an operation, particularly if it is not immediately required. Conversely, some clinicians are not concerned about proving recent drug usage as long as the patient does not exhibit current evidence of toxicity or a hypermetabolic state. The confirmation of illicit drug usage obviously heightens awareness about the possibility of postoperative withdrawal. In general, patients should be advised to refrain from taking illicit drugs for at least a couple of weeks before an operation. Similarly, a history of heavy alcohol consumption raises the possibility of a postoperative withdrawal syndrome, which can be associated with significant morbidity and even death. It is ideal if patients can cease drinking alcohol for at least one week before an operation. Regardless of whether the patient can suspend alcohol consumption, the surgeon must closely monitor for symptoms of withdrawal among these patients and consider the regular administration of a benzodiazepine during recovery to prevent or treat acute withdrawal.
Cancer Therapy
Many patients undergo neoadjuvant therapy for malignancies involving the breast, esophagus, stomach pancreas rectum, soft tissues, and other sites. The surgeon is responsible for restaging the tumor before proceeding with a resection. In general, the interval between the completion of the external beam radiation and the operation is commensurate with the duration of the radiation therapy. Similarly, a reasonable amount of time should elapse after systemic therapy to permit restoration of bone marrow capacity and nutrition, to the extent possible. Angiogenesis inhibitors such as bevacizumab disrupt normal wound perfusion and healing. The duration of time between biological therapy and an operation is not firmly established. However, it is probably best to allow 4 to 6 weeks to elapse after treating with bevacizumab before proceeding with an operation, and the therapy should not be resumed until the wound is fully healed, perhaps 1 month later.
Emergency Operations
Emergency operations generally permit little time for risk reduction, although fluid and blood resuscitation can be instituted and antibiotics administered. Emergency operations among patients who have undergone chemotherapy within the past month are associated with increased rates of major complications and death. In patients with profound neutropenia, operations should be deferred to the extent possible due to severely impaired wound healing and the likelihood of irreversible postoperative sepsis.
INFORMED CONSENT
The informed consent process is far more that a signed document or “permission slip.” Consent involves a conversation between the surgeon and patient (and perhaps family members or a legal guardian) that extends from the initial consultation through subsequent clinic visits or correspondence and into the preoperative holding area. The discussion addresses indications for the operation and its expected outcome, alternative treatments, the natural history of the underlying condition without intervention, the basic mechanics and details of the operation, potential risks, the impact of the operation on the patient’s health and quality of life, the extent of hospitalization and recuperation (including possible rehabilitation care), the timing of resumption of normal activities, and residual effects. The informed consent process may also indicate that a resident will participate in the patient’s care, under the supervision of the teaching surgeon and with the appropriate level of competence. Spouses and other family members should be included in the consent process for major operations that present chances of death or major debilitation.
In some circumstances, the patient may not be able to provide consent and no family members or guardians may be available. The surgeon should consider the acuity of the patient’s condition and whether it requires an immediate operation. If emergency surgery is indicated, the surgeon should document the situation and advise a hospital administrator, if possible. Some unusual, nonacute scenarios may require seeking legal consent for an operation through the judicial process.
PREOPERATIVE INSTRUCTIONS
In some settings, all preoperative preparation is conducted through surgeons and their office staffs. Conversely, more robust systems may employ an elaborate process to prepare patients for operations. Regardless of the preoperative process, education constitutes a major component. In addition to learning about the actual operation, patients (and family members or caretakers) need to understand both preparation for and recovery from the operation.
Consistent information should be provided about how long a patient should fast and what medications are to be taken on the morning of the operation. The ASA has issued guidelines about preoperative fasting. To minimize retained gastric volume and maximize gastric pH, anesthesiologists advise adults and children to refrain from drinking clear liquids for at least 2 hours before general anesthesia, regional anesthesia, or sedation/analgesia (vs 4 hours for infants taking breast milk, or 6 hours for infant formula). Patients should avoid eating light meals for at least 6 hours and fatty meals for 8 hours before receiving anesthetics or sedatives.
In general, it is ideal for patients to continue to take their usual critical medications with a sip of water on the morning of an operation, including beta-blockers, calcium channel blockers, nitrates, and other hypertension control agents, alpha agonists or alpha antagonists, statins, hormones such as levothyroxine, psychotropic agents, oral contraceptives, and medications for cardiac rhythm problems, chronic obstructive pulmonary disease, gastroesophageal reflux, peptic diatheses, and neurologic disorders. Some surgeons and anesthesiologists advise patients to not take angiotensin-converting enzyme (ACE) inhibitors on the day of surgery due to the possibility of patients developing refractory hypotension during general anesthesia, although ACE inhibitors should be resumed shortly after the operation. Similarly, diuretics are commonly withheld on the morning of operations that involve potentially significant amounts of fluid losses and resuscitation. Of course, these recommendations are tempered by individual circumstances and clinical judgment; for example, patients probably should take their ACE inhibitors and diuretics before operations that do not require general anesthesia or involve much intravenous fluid, and when inadequately controlled hypertension could postpone the operation. Glucose and corticosteroid management have already been addressed.
Chronic narcotics (eg, methadone) are continued on the day of surgery to avoid possible withdrawal. Monoamine oxidase (MAO) inhibitors are associated with drug interactions with indirect sympathomimetics such as ephedrine (resulting in severe hypertension) or with phenylpiperidine opioids such as meperidine, tramadol, methadone, dextromethorphan, and propoxyphene (causing a serotonin syndrome with potential coma, seizures, or even death). Acute withdrawal of MAO inhibitors can provoke major depression, so they can be continued preoperatively, but without the concomitant usage of confounding medications.
The management of aspirin and thienopyridines for active coronary (or cerebrovascular) disease was reviewed earlier. Aspirin taken for other reasons, nonsteroidal anti-inflammatory agents, herbal preparations, and vitamin E can disrupt normal coagulation and should be stopped one week before an operation. Epoprostenol is a prostaglandin that is used to treat pulmonary hypertension; it also inhibits platelet aggregation and behaves like “liquid aspirin.” The discontinuation of epoprostenol will provoke pulmonary hypertension, so it is best to continue the infusion, accepting possible oozing from surgical sites that can be controlled with standard measures. Estrogen receptor antagonists (eg, tamoxifen) can be associated with an increased risk of VTE. Therefore, the surgeon should consider stopping such medications 2-4 weeks before an operation and resuming them after a similar postoperative interval, especially in patients at a heightened risk of developing VTE.
Patients receiving anticoagulants require consideration of the indication for this therapy, the potential hazards of thrombosis developing while the anticoagulation is suspended, and the dangers of perioperative hemorrhage. Stopping warfarin 5 days before the operation will ordinarily allow normalization of INR, and the surgeon will determine if a “bridge” of a quickly reversible infusion of unfractionated heparin or LMWH injections is necessary to minimize the duration of time during which anticoagulation is withheld.
Patients should bring asthma inhalers to the hospital for usage shortly before being anesthetized. Similarly, eye drops, particularly those with beta-blockade properties, should be taken in accordance with their usual schedule.
Additional preoperative instructions include skin hygiene (eg, preoperative chlorhexidine showers, although their benefit is not absolutely proven), local care of preexisting wounds or ulcers, and discussions about tobacco, drug, or alcohol cessation, glucose management, and nutrition. Nurses may mark potential sites for bowel stomae. Some patients will require vaccinations when a splenectomy is possible.
Education also addresses what patients can expect during convalescence. This includes the importance of early postoperative mobilization and ambulation, pulmonary toilet, oral care, wound care, diet, physical therapy, rehabilitation, later adjuvant care, and even complementary or alternative options. Patients may be shown videos or provided brochures, which can be available in multiple languages. The team should definitely provide details about the logistics of the operation, including when and where the patient will report for preoperative visits and tests and for the operation itself. Finally, patients should know whom to contact with questions.
PREOPERATIVE HOLDING AREA
The time in the preoperative holding unit offers a final opportunity to educate the patient and family and to coordinate care before proceeding into the operating room. Patients (and their loved ones) are often anxious before operations and will be reassured by an organized, professional, and collegial environment. Members of the surgery team should introduce themselves and discuss the proposed operation and the anticipated postoperative care and recovery, including the possibilities of transfer to an intensive care unit or later to a rehabilitation facility. Traditional vital signs are recorded, ideally including baseline oxygen saturation. Special instructions address postoperative mobilization and pulmonary care for those patients undergoing general anesthesia or at high risk for PPC and might involve breathingexercises with incentive spirometry. This setting is definitely a good moment to formally mark the correct site and laterality of the operation, when pertinent, and to confirm fasting status, medications taken during the past 24 hours (especially beta-blockers), allergies, recent corticosteroid usage, and pregnancy status. Checklists (Figure 3–2) have become an important mechanism to assure the application of standard practices, and a section can be devoted to the preoperative unit. In addition, order sets greatly contribute to the delivery of consistent and correct care, including the administration of prophylactic antibiotics, adequate VTE prophylaxis (including the application of compression boots), and hydrocortisone for those patients with a recent history of significant corticosteroid usage. The infusion of antibiotics is not necessarily begun in the holding area, as it may still be more than 1 hour before the actual incision, but antibiotics can be secured for delivery to the operating room with the patient. Glycemic control protocols are begun in the holding area, as outlined earlier. For patients having bowel resections, the effectiveness of the mechanical prep may be investigated, and warming blankets can be applied. Finally, surgeons and anesthesiologists have the chance to discuss blood volume status and strategies for fluid administration, which may begin in the holding area.
Figure 3–2. Sample of Universal Checklist for perioperative care. © Boston Medical Center Corporation 2012.
OPERATING ROOM
Preparation of the patient continues in the operating room, up to the moment of the incision. When local hair removal is necessary for exposure, this should be done immediately before the operation, with electric clippers. Razors traumatize skin and have been associated with a greater chance of infection. Most surgical site skin preparations contain iodine-based compounds or chlorhexidine, but the addition of isopropyl alcohol to either of these agents seems to confer the best outcomes. Regardless of the agent selected, it is important that the skin prep be applied in a standard fashion—ideally by an assigned, trained individual to assure consistency—and that it dries prior to the application of the sterile drapes. Iodine-impregnated adherent drapes can also be used to cover the skin surrounding the surgical site. The role of mechanical bowel preparations and antibiotic prophylaxis (oral and/or parenteral) in colorectal operations is addressed in another chapter. The placement of urinary catheters in the operating room merits special comment. Urinary tract infections (UTI) are costly and can be reduced in frequency by sterile placement and prompt postoperative removal. The routine practice of two people (one for exposure and one for insertion) catheterizing obese women can decrease the incidence of UTI.
Proper positioning of the patient for an operation is critical to enhance exposure, to protect potential pressure points or muscle compartments, and to avoid traction injuries to nerves. Surgeons, nurses, and anesthesia staff share responsibility for patient safety during operations and should concur about how the patient is situated on the operating room table.
PREPARATION OF THE OPERATING ROOM FACILITY
Beyond the hazards for SSIs discussed earlier, wound sepsis is also related to the bacteriologic status of both the hospital setting in general and the operating room in particular. The entire hospital environment must be protected from undue contamination to avoid colonization and cross-infection of patients with virulent strains of microorganisms that could invade surgical sites despite the practice of asepsis, antisepsis, and sterile surgical technique. All staff should diligently wash their hands before and after contact with patients, regardless of location (ie, in the operating room or elsewhere in the facility). Patients with especially dangerous or resistant organisms (eg, Clostridium difficile, MRSA, and vancomycin-resistant Enterococcus) may warrant special precautions such as isolation and staff wearing gowns and gloves during direct contact with the patient and secretions. Notably, alcohol-based hand sanitizers are not effective against C difficile.
In the United States, it is standard for members of the operating room team to wear issued “scrub” clothes, caps, shoe covers, and masks, although this practice is less dogmatic in other countries. Surgeons and staff who perform the operation and handle sterile instruments wear sterile gowns, protective eye gear, and gloves. “Universal precautions” are practiced for the safety of the team, under the presumption that any patient’s blood or fluids can convey communicable diseases such as human immunodeficiency virus (HIV) or hepatitis. Formal procedures and policies should be developed locally for injured staff or those exposed to blood or other potential hazards during operations.
Sterilization
Items used during an operation are sterilized to destroy microorganisms on the surface of the instrument or in a fluid. Current sterilization methods include steam autoclave, hydrogen peroxide gas plasma, gamma irradiation, ethylene oxide gas, and dry heat. An autoclave system uses saturated steam under pressure. This is the most widely used method due to its ability to rapidly sterilize devices while being relatively inexpensive and nontoxic. The two most common types of steam autoclaves are gravity displacement, which must reach temperatures of 121°C, and prevacuum sterilizers, which must reach temperatures of 132°C. Minimum exposure periods for wrapped devices are 30 minutes for the former technique and 4 minutes for the latter system. Of course, the implementation of steam is limited by its corrosive effect on heat-sensitive items.
Liquid hydrogen peroxide is a nontoxic sterilizing agent that initiates the inactivation of microorganisms on a heat-sensitive device within 75 minutes. Liquid hydrogen peroxide is vaporized and diffused through the sterilization chamber to contact the surfaces of the device. An electrical field is created within the chamber, changing the vapor to gas plasma. Microbicidal free radicals are generated in the plasma, rendering the device sterile.
Gamma sterilization utilizes Cobalt-60 radiation to inactivate microorganisms on single-use medical supplies, pharmaceuticals, and biological-based products, although the US Food and Drug Administration does not approve gamma irradiation in health care facilities. Liquid and gaseous ethylene oxide is a toxic, flammable sterilizing agent that initiates the inactivation of microorganisms on a heat-sensitive device within 1-6 hours, with 8-12 hours required for aeration. Ethylene oxide gas is diffused through the sterilization chamber at temperatures between 37°C and 63°C and a relative humidity of 40%-80%. The gas bonds with water molecules to reach the device surfaces and render the device sterile. Due to the extended aeration time requirement and high level of toxicity, ethylene oxide gas sterilization is being replaced with nontoxic processes that have shorter process times.
Dry heat sterilization utilizes heating coils to raise the temperature of the air inside the sterilization chamber to sterilize surfaces of devices. It is appropriate only for items that have a low moist heat tolerance but high temperature tolerance. The most common time-temperature relationships for dry heat sterilization are 170°C for 1 hour, 160°C for 2 hours, and 150°C for 2.5 hours.
Operating Room Plans
Surgeons should prospectively communicate with the operating room staff about what operation will be performed, including its anticipated duration and all necessary items, to enhance efficiency and avoid delays. “Case cards” contain information about standard equipment, devices, and sutures. Surgeons must also anticipate special needs such as unusual instruments or hardware, prosthetic materials for implantation, coagulation devices (eg, electrocautery, ultrasound or radiofrequency energy devices, lasers), intraoperative laboratory testing (eg, glucose, hematocrit, parathyroid hormone), imaging (eg, fluoroscopy, ultrasonography), nerve monitoring, and any other details specific to the operation. The primary surgeon is responsible for coordinating surgery teams when multiple consultants and allied professionals collaborate in a patient’s care, including surgeons, anesthesiologists, nurses, technicians, and others. A checklist hopefully promotes communication about these matters to assure that it is safe to proceed with an operation.
Preparations also include the development of contingency plans for a variety of dangerous scenarios. These could include environmental problems in the operating room (eg, a fire, the loss of humidity control or power, or computer failure), or threatening clinical conditions (eg, massive hemorrhage, cardiac arrest, air embolus, malignant hyperthermia, etc). Plans can be composed as algorithms and documented on paper or online and even projected on monitors for the entire team to review.
Preparation of the Surgery Team
Attention is being increasingly focused upon the development of teams in the operating room. Much of this work has been modeled upon the concepts of crew resource management (CRM), as promulgated by the aviation profession. Psychologists analyzed behaviors of flight crews in the 1970s and proposed measures to improve safety, including reducing the hierarchy of that time, empowering junior team members to express concerns about potential problems, and training senior crew members to listen to the perspectives of other team members while accepting questions as honest communication rather than insubordination. This approach encourages the crew to participate in the enterprise and offer their expertise and talents, while the captain remains the ultimate authority.
As in the airline industry, the implementation of CRM in the operating room is supported by a series of activities before the main event. The ideal preoperative briefing establishes the team leader, facilitates communication, outlines the team’s work, and specifies protocols, responsibilities, expectations, and contingency plans. This collaboration can result in improved outcomes, greater patient satisfaction, and better morale among team members. Checklists should not merely be perfunctory recitations of goals; they should promote a culture of teamwork. These checklists can be modified to suit local circumstances, resources, and cultures, and they codify critical steps, such as having necessary materials and medications on hand as well as indicating the appropriate location and side of the operation in instances when wrong-site mistakes could be made. Simulation training is also becoming more readily available, particularly regarding rare, complex, or high-risk scenarios, as well as the introduction of new members to teams.
Preparation of the Surgeon
The professional development of a surgeon is a privilege and an enduring pursuit involving emotional and intellectual growth, discipline, creativity, dedication, equanimity, technical talent, and formal education. College, postgraduate, and medical school curricula are certainly preludes to accredited surgery residencies and fellowships. That certain personalities are drawn to different surgical specialties is part of the joy and diversity of the profession.
Board certification confirms that a surgeon has completed the requisite years of residency and passed a rigorous examination to indicate competence. Learning continues well beyond formal training, as exemplified by specialty board certification and the recent Maintenance of Certification program, instituted by the American Board of Surgery and 23 other member boards of the American Board of Medical Specialties to assure lifelong professional development. The surgeon must be familiar with contemporary literature and adapt to emerging technologies and operative techniques, building upon established knowledge and skills. Moreover, the surgeon critically assesses data to decide the wisdom and value of new developments for the individual patient, the surgeon, and the prevailing health care system. Fellowship in the American College of Surgeons (or comparable organizations outside the United States and Canada) endorses that the surgeon has successfully completed a thorough evaluation of professional competence and ethical fitness. The qualifications include board certification, commitment to the welfare of patients above all else, and pledges regarding appropriate compensation and the avoidance of unjustified operations.
The surgeon must also be versed in and a leader of quality improvement within the process of caring for patients. Naturally, the proficiency provided by performing large numbers of certain high-risk operations results in improved outcomes. This is a matter of designing excellent systems that support surgical care, rather than the exclusive talents of a solitary surgeon. Ideal care involves a coordinated series of steps and collaborations—bundles of care—among teams of professionals so that the system and culture are sustained despite the loss of any individual, and the surgeon is the leader of that team. Crew Resource Management, as described earlier, has defined seven characteristics of leaders of high-performance teams:
Leadership traits are not necessarily intuitive, and they require introspection, training, and practice. The surgeon remains the proverbial captain of the ship regarding the care of patients having operations, but as a consultative leader among trusted colleagues.
References
American Society of Anesthesiologists Committee. Practice guidelines for preoperative fasting and the use of pharmacologic agents to reduce the risk of pulmonary aspiration: application to healthy patients undergoing elective procedures. An updated report by the American Society of Anesthesiologists Committee on Standards and Practice Parameters. Anesthesiology. 2011;114:495-511.
Ata A, Lee J, Bestle SL, et al. Postoperative hyperglycemia and surgical site infection in general surgery patients. Arch Surg. 2010;145:858-864.
Bahl V, Hu HM, Henke PK, et al. A validation study of a retrospective venous thromboembolism risk scoring method. Ann Surg. 2010;251:344-350.
Bertges DJ, Goodney PP, Zhao Y, et al. The Vascular Study Group of New England Cardiac Risk Index (VSG-CRI) predicts cardiac complications more accurately than the Revised Cardiac Risk Index in vascular surgery patients. J Vasc Surg. 2010;52:674-683.
Bode LG, Kluytmans JA, Wertheim HF, et al. Preventing surgical-site infections in nasal carriers of Staphylococcus aureus. N Engl J Med. 2010;362:9-17.
Canet J, Gallart L, Gomar C, et al. Prediction of postoperative pulmonary complications in a population-based surgical cohort. Anesthesiology. 2010;113:1338-1350.
Corcoran T, Rhodes JEJ, Clarke S, et al. Perioperative fluid management strategies in major surgery: a stratified meta-analysis. Anesth Analg. 2012:114:640-651.
Darouiche RO, Wall MJ, Itani KMF, et al. Chlorhexidine-alcohol versus povidone-iodine for surgical-site antisepsis. N Engl J Med. 2010;362:18-26.
Frisch A, Chandra P, Smiley D, et al. Prevalence and clinical outcome of hyperglycemia in the perioperative period in noncardiac surgery. Diabetes Care. 2010;33:1783-1788.
Gould MK, Garcia DA, Wren SM, et al. Prevention of VTE in nonorthopedic surgical patients: antithrombotic therapy and prevention of thrombosis, 9th ed. American College of Chest Physicians evidence-based clinical practice guidelines. Chest. 2012; 141(suppl 2): e227S-e277S.
Gupta PK, Gupta H, Sundaram A, et al. Development and validation of a risk calculator for prediction of cardiac risk after surgery. Circulation. 2011;124:381-387.
Hawn MT, Houston TK, Campagna EJ, et al. The attributable risk of smoking on surgical complications. Ann Surg. 2011;254:914-920.
Hennessey DB, Burke JP, Ni-Dhonochu T, et al. Preoperative hypoalbuminemia is an independent risk factor for the development of surgical site infection following gastrointestinal surgery: a multi-institutional study. Ann Surg. 2010;252:325-320.
Makary MA, Segev DL, Pronovost PJ, et al. Frailty as a predictor of surgical outcomes in older patients. J Am Coll Surg. 2010;210:901-908.
Marimuthu K, Varadhan KK, Ljungqvist O, et al. A meta-analysis of the effect of combinations of immune modulating nutrients on outcome in patients undergoing major open gastrointestinal surgery.Ann Surg. 2012;255:1060-1068.
Memtsoudis S, Liu SS, Ma Y, et al. Perioperative pulmonary outcomes in patients with sleep apnea after noncardiac surgery. Anesth Analg. 2011;112:113-121.
Merkow RP, Bilimoria KY, McCarter MD, et al. Post-discharge venous thromboembolism after cancer surgery. Ann Surg. 2011;254:131-137.
Pannucci CJ, Bailey SH, Dreszer G, et al. Validation of the Caprini risk assessment model in plastic and reconstructive surgery patient. J Am Coll Surg. 2011;212:105-112.
Obeid NM, Azuh O, Reddy S, et al. Predictors of critical care-related complications in colectomy patients using the National Surgical Quality Improvement Program: exploring frailty and aggressive laparoscopic approaches. J Trauma Acute Care Surg. 2012;72:878-883.
Pannucci CJ, Bailey SH, Dreszer G, et al. Validation of the Caprini risk assessment model in plastic and reconstructive surgery patient. J Am Coll Surg. 2011;212:105-112.
Poirier P, Alpert MA, Fleisher LA, et al. Cardiovascular evaluation and management of severely obese patients undergoing surgery: a science advisory from the American Heart Association. Circulation. 2009;120:86-95.
Rutala WA, Weber DJ, the Healthcare Infection Control Practices Advisory Committee. Guideline for disinfection and sterilization in healthcare facilities, 2008.http://www.cdc.gov/hicpac/pdf/guidelines/disinfection_nov_2008.pdf.
Shuman AG, Hu HM, Pannucci CJ, et al. Stratifying the risk of venous thromboembolism in otolaryngology. Otolaryngol Head Neck Surg. 2012;146:719-724.
Swenson BR, Hedrick TL, Metzger R, et al. Effects of preoperative skin preparation on postoperative wound infection rates: a prospective study of 3 skin preparation protocols. Infect Control Hosp Epidemiol. 2009;30:964-971.
Wong J, Lam DP, Abrishami A. Short-term preoperative smoking cessation and postoperative complications: a systematic review and meta-analysis. Can J Anaesth. 2012; 59:268-279.
MULTIPLE CHOICE QUESTIONS