BASIC SCIENCE QUESTIONS
1. Which one of the following high-risk organizations has achieved an exceptionally low accident and error rate?
A. Navy nuclear submarine program
B. U.S. Postal Service
C. Auto manufacturing industry
D. Food services industry
The nuclear submarine program is an excellent example of an organization that has achieved the distinction of being considered a ‘high reliability organization.’ High reliability organization theory, which was developed by a group of social scientists at the University of California at Berkeley, recognizes that there are certain high-risk industries and organizations that have achieved very low accident and error rates compared to what would be expected given the inherent risks involved in their daily operations (Fig. 12-1). Other examples of industries or organizations that are regarded as having achieved high reliability status include aircraft carrier flight decks, nuclear power plants, and the Federal Aviation Administration’s air traffic control system. In fact, one reason why nuclear power plants have such an excellent reliability record may be that their operators are often former naval submarine officers whose previous experience and training within one highly reliable organization are easily transferable to other organizations. The other three industries listed have all been identified as having a higher error rate (lower quality). (See Schwartz 9th ed., p 314, and Fig. 12-1.)
FIG. 12-1. Cross-industry comparison of size, productivity, and efficien cy. (Reproduced with permission from the Advisory Board Company, 2005.)
2. A serious medical error is committed by the chief resident. The best way to teach him or her and his or her fellow residents about this situation is
A. To make the resident personally accountable in a public forum such as morbidity and mortality conference
B. To make the resident personally accountable in a one-on-one discussion with his or her attending
C. To have the resident meet with risk management to understand the potential medicolegal implications of the error
D. To use the error to analyze the system that allowed it to happen, and make suggestions for prevention of the error in the future
One of the assumptions underlying the science of high reliability organizations is the following observation made by Weick in 1987: Humans who operate and manage complex systems are themselves not sufficiently complex to sense and anticipate the problems generated by the system. This introduces another important idea undergirding the science of patient safety: the concept of normal accident theory. Instead of attributing accidents to individual error, this theory states that accidents are intrinsic to high-volume activities and even inevitable in some settings; that is, they are ‘normal’ and should be expected to occur. Accidents should not be used merely to identify and punish the person at fault. As Reason states, even the ‘best people can make the worst errors as a result of latent conditions.’ (See Schwartz 9th ed., p 314.)
3. Which of the following characteristics is typically seen in a high-reliability (low error) surgical service?
A. Personal accountability is stressed in a public forum such as a morbidity and mortality conference on a regular (usually weekly) basis
B. Hierarchical responsibility is imposed, with final authority resting with the attending surgeon
C. Friendly open relationships exist between all members of the surgical team including nurses and clerical staff
D. The culture of the work environment stresses following established protocols.
High reliability organization theory suggests that proper oversight of people, processes, and technology can handle complex and hazardous activities and keep error rates acceptably low. Studies of multiple high reliability organizations have revealed that they share the following common characteristics:
• People are supportive of one another.
• People trust one another.
• People have friendly, open relationships emphasizing credibility and attentiveness.
• The work environment is resilient and emphasizes creativity and goal achievement, providing strong feelings of credibility and personal trust.
Developing these characteristics is an important step toward achieving a low error rate in any organization. (See Schwartz 9th ed., p 314.)
4. The number of medical errors which kill patients in the United States is the equivalent of one jumbo jet crashing every
D. 3 months
The Institute of Medicine (IOM) report shocked the health care community by concluding that between 44,000 and 98,000 deaths and over 1 million injuries occurred each year in American hospitals due to medical error. In fact, the number of deaths attributed to medical error is the aviation equivalent of one jumbo jet crash per day. (See Schwartz 9th ed., p 315.)
5. The culture of an organization is an important component of safety. Which of the following characteristics of the traditional surgical culture helps improve safety in the operating room?
A. Hierarchical structure with the surgeon responsible for the final outcome
B. Personal accountability at the weekly morbidity and mortality conference
C. Ability to work equally well under nonstressful and stressful conditions
D. The ability to solve a problem once the problem is clearly identified.
Surgeons have a culture that encourages them to quickly and decisively identify issues and solve problems. This characteristic can easily be applied to improving safety in the operating room.
The hierarchical structure of the operating room, tendency to assess “blame” to a surgeon at a morbidity and mortality conference, and the perception most surgeons have of their ability to work equally well in stressful and nonstressful situations DECREASE safety in the operating room.
Culture is to an organization what personality is to the individual—a hidden, yet unifying theme that provides meaning, direction, and mobilization. Organizations with effective safety cultures share a constant commitment to safety as a top-level priority, a commitment that permeates the entire organization. These organizations frequently share the following characteristics:
• An acknowledgment of the high-risk, error-prone nature of an organization’s activities
• A nonpunitive environment where individuals are able to report errors or close calls without fear of punishment or retaliation
• An expectation of collaboration across ranks to seek solutions to vulnerabilities
• A willingness on the part of the organization to direct resources to address safety concerns
Traditional surgical culture stands almost in direct opposition to the values upheld by organizations with effective safety cultures for several reasons. Surgeons are less likely to acknowledge their propensity to make mistakes or to admit these mistakes to others. Surgeons tend to minimize the effects of stress on their ability to make decisions, and often claim that their decision making is equally effective in emergency and normal situations. The surgical culture, especially in the operating room (OR), is traditionally rife with hierarchy. Intimidation of other OR personnel, by surgeons was historically accepted as the norm. This can prevent nurses and other OR staff from pointing out potential errors or mistakes by surgeons. (See Schwartz 9th ed., p 316.)
6. The most common cause of a sentinel event such as wrong-site surgery is
A. Inadequate training of personnel involved
B. Poor communication
C. Inadequate patient assessment prior to the procedure
D. Critical information unavailable at the time of the procedure
According to the Joint Commission, communication breakdown is the most common root cause of sentinel events such as wrong-site surgery (Fig. 12-2). Poor communication contributed to nearly 70% of sentinel events reported to the Joint Commission on Accreditation of Healthcare Organizations in 2006. Good communication is an essential component of teamwork and should be emphasized in any organization wishing to create a culture of patient safety. It especially is important in the OR, one of the most complex work environments in health care. (See Schwartz 9th ed., p 316.)
FIG. 12-2. Root causes of sentinel events 1995–2002. (Data from http://www.jointcommission.org/Sentinel Events/Statistics: Sentinel Event Statistics. Joint Commission website [accessed February 6, 2008].)
1. A patient with a right popliteal occlusion is scheduled for bypass. The initial incision is made on the left leg. The error is recognized and no further dissection is carried out. The bypass is performed uneventfully on the right (correct) leg. This situation is
A. An adverse event
C. A sentinel event
D. All of the above
This constitutes “an injury caused by medical management” (an adverse event), “care falling below the standard of care” (negligence), and “an unexpected occurrence involving death or serious physical or psychological damage” (sentinel event). (See Schwartz 9th ed., p 315, and Table 12-1.)
TABLE 12-1 Types of medical error
• Injury caused by medical management rather than the underlying condition of the patient
• Prolongs hospitalization, produces a disability at discharge, or both
• Classified as preventable or unpreventable
• Care that falls below a recognized standard of care
• Standard of care is considered to be care a reasonable physician of similar knowledge, training, and experience would use in similar circumstances
• An error that does not result in patient harm
• Analysis of near misses provides the opportunity to identify and remedy system failures before the occurrence of harm
• An unexpected occurrence involving death or serious physical or psychological injury
• The injury involves loss of limb or function
• This type of event requires immediate investigation and response
• Other examples
• Hemolytic transfusion reaction involving administration of blood or blood products having major blood group incompatibilities
• Wrong-site, wrong-procedure, or wrong-patient surgery
• A medication error or other treatment-related error resulting in death
• Unintentional retention of a foreign body in a patient after surgery
Reproduced with permission from Woreta TA, Makary MA: Patient safety, in Makary M (ed): General Surgery Review. Washington, DC: Ladner-Drysdale, 2008, p 553.
2. Which of the following is a risk factor for a retained surgical sponge?
A. Surgery which takes longer than 6 hours
B. Use of >30 sponges
C. Pelvic surgery
D. Unplanned change in procedure
An unplanned change in procedure is one of the risk factors for retained surgical sponge. The length of the procedure, unless it involves nurses from more than one shift, is not a risk factor, nor is pelvic surgery. There is no increased risk with an increased number of sponges. (See Schwartz 9th ed., p 325, and Table 12-2.)
TABLE 12-2 Risk factors for retained surgical sponges
• Emergency surgery
• Unplanned changes in procedure
• Patient with higher body-mass index
• Multiple surgeons involved in same operation
• Multiple procedures performed on same patient
• Involvement of multiple operating room nurses/staff members
• Case duration covers multiple nursing “shifts”
3. Which of the following can be used to decrease the risk of a retained sponge?
A. Limiting the use of sponges by liberal use of suction
B. Routine radiographs in patients undergoing multiple procedures
C. Delaying wound closure until the count is completed
D. Routine radiograph in patients with a BMI >40
The benefit of performing surgical counts to prevent the occurrence of retained surgical items is controversial. The increased risk of a retained surgical item during emergency surgery in the study by Gawande and colleagues appeared to be related to bypassing the surgical count in many of these cases, suggesting that the performance of a surgical count can be useful in reducing the incidence of this sentinel event. However, the ‘falsely correct count,’ in which a count is performed and declared correct when it is actually incorrect, occurred in 21 to 100% of cases in which a retained surgical item was found. This type of count was the most common circumstance encountered in all retained surgical item cases, which suggests that performing a surgical count in and of itself does not prevent this error from taking place. The counting protocol also imposes significant demands on the nursing staff and distracts them from focusing on other primarily patient-centered tasks.
Although there is no single tool to prevent all errors, the development of multiple lines of defense to prevent retained surgical items and universally standardizing and adhering to OR safety protocols by all members of the surgical team will help reduce the incidence of this never event. Surgeons should take the lead in the prevention of retained surgical items by avoiding the use of small or nonradiologically detectable sponges in large cavities, by performing a thorough wound inspection before closing any surgical incision, and by having a vested interest in the counting procedure performed by nursing staff to keep track of sponges, needles, instruments, and any other potential retained surgical item. The value of routine radiography in the setting of emergency cases or when multiple major procedures involving multiple surgical teams are being performed to prevent a retained surgical item is becoming more apparent. (See Schwartz 9th ed., p 325.)
4. Which of the following increases the risk of wrong-site surgery?
A. Surgery late in the day
B. Thin patient (BMI 22)
C. Surgeon running multiple rooms
D. Multiple surgeons involved in the same operation
Multiple surgeons involved in the operation has been identified as a risk factor for wrong-site surgery. Morbidly obese patients are at higher risk; thin patients have no increased risk for wrong-site surgery. Although “time pressure” is a risk factor for wrong-site surgery, running multiple rooms in and of itself is not considered a risk factor.
There is a one in four chance that surgeons who work on symmetric anatomic structures will be involved in a wrong-site error sometime during their careers. No surgical specialty is immune.
The risk of performing wrong-site surgery increases when there are multiple surgeons involved in the same operation or multiple procedures are performed on the same patient, especially if the procedures are scheduled or performed on different areas of the body. Time pressure, emergency surgery, abnormal patient anatomy, and morbid obesity are also thought to be risk factors. Communication errors are the root cause in more than 70% of the wrong-site surgeries reported to the Joint Commission. Other risk factors include receiving an incomplete preoperative assessment because documents are either unavailable or not reviewed for other reasons; having inadequate procedures in place to verify the correct surgical site; or having an organizational culture that lacks teamwork or reveres the surgeon as someone whose judgment should never be questioned. (See Schwartz 9th ed., p 326.)
5. Which of the following increases the risk of a complication while placing a central line?
A. Placing a central line at the request of another surgeon
B. Placement by a lower level (PGY3) resident
C. Failure to place the patient in Trendelenburg position
D. Changing a line when infected, rather than on a protocol set schedule
Failure to ensure that the central line is indicated is a key cause of complications after placing central lines. This most often occurs when the line is placed at the request of another surgeon. Lines should be placed by trained and competent personnel. At a PGY3 level most residents are well trained in this technique. Trendelenburg position is controversial. Lines should only be changed when indicated, not on a routine schedule. (See Schwartz 9th ed., p 327.)
Steps to decrease complications include the following:
• Ensure that central venous access is indicated.
• Experienced (credentialed) personnel should insert the catheter, or should supervise the insertion.
• Use proper positioning and sterile technique. Controversy exists as to whether or not placing the patient in the Trendelenburg position facilitates access.
• Central venous catheters should be exchanged only for specific indications (not as a matter of routine) and should be removed as soon as possible.
6. If air embolism is suspected during placement of a central line, the patient should be placed in which of the following positions?
C. Right lateral decubitus
D. Left lateral decubitus
Although estimated to occur in only 0.2 to 1% of patients, an air embolism can be dramatic and fatal. Treatment may prove futile if the air bolus is larger than 50 mL. Auscultation over the precordium may reveal a “crunching” noise, but a portable chest xray is required for diagnosis. If an embolus is suspected, the patient should immediately be placed into a left lateral decubitus Trendelenburg position, so the entrapped air can be stabilized within the right ventricle. Aspiration via a central venous line accessing the heart may decrease the volume of gas in the right side of the heart, and minimize the amount traversing into the pulmonary circulation. Subsequent recovery of intracardiac and intrapulmonary air may require open surgical or angiographic techniques. Prevention requires careful attention to technique. (See Schwartz 9th ed., p 328.)
7. During placement of a Swan Ganz catheter, the patient coughs up a significant amount of blood. The initial step to manage this complication is
B. Inflate the balloon on the Swan Ganz catheter
C. Intubate the patient
D. Emergent thoracotomy
Flow-directed, pulmonary artery (‘Swan-Ganz’) catheters can cause pulmonary artery rupture due to excessive advancement of the catheter into the pulmonary circulation. There usually is a sentinel bleed noted when a pulmonary artery catheter balloon is inflated, and then the patient begins to have uncontrolled hemoptysis. Reinflation of the catheter balloon is the initial step in management, followed by immediate airway intubation with mechanical ventilation, an urgent portable chest x-ray, and notification of the OR that an emergent thoracotomy may be required. If there is no further bleeding after the balloon is reinflated, the x-ray shows no significant consolidation of lung fields from ongoing bleeding and the patient is easily ventilated, then a conservative nonoperative approach may be considered. This approach might include observation alone if the patient has no signs of bleeding or hemodynamic compromise; however, more typically a pulmonary angiogram with angioembolization or vascular stenting is required. Hemodynamically unstable patients rarely survive because of the time needed to perform the thoracotomy and identify the branch of the pulmonary artery that has ruptured. (See Schwartz 9th ed., p 328.)
8. 4 days following placement of a tracheostomy tube in the ICU, a significant amount of blood is suctioned from the tracheostomy. The most appropriate next step is
B. Gentle repeat suctioning until clear
C. Bedside bronchoscopy
D. Bronchoscopy in the operating room
The most dramatic complication of tracheostomy is tracheoinnominate artery fistula (TIAF). This occurs rarely (~0.3%), but carries a 50 to 80% mortality rate. TIAFs can occur as early as 2 days or as late as 2 months after tracheostomy. The prototypical patient is a thin woman with a long, gracile neck. The patient may have a sentinel bleed, which occurs in 50% of TIAF cases, followed by a most spectacular bleed. Should a TIAF be suspected, the patient should be transported immediately to the OR for fiberoptic evaluation. If needed, remove the tracheostomy, and place a finger through the tracheostomy site to apply direct pressure anteriorly for compression of the innominate artery. (See Schwartz 9th ed., p 329.)
9. Which of the following should be used to prepare a patient with mild renal insufficiency (BUN 38, Creatinine 1.5) for angiography?
B. Oral hydration (3 liters) during the 24 hours before the procedure
C. Intravenous hydration for 12 hours after the procedure
Renal complications of angiography occur in 1 to 2% of patients. Contrast nephropathy is a temporary and preventable complication of radiologic studies such as CT, angiography, and/or venography. Some studies suggest a benefit of N-acetylcysteine for this condition. For the patient with impaired renal function or dehydration before contrast studies, twice-daily dosing 24 hours before and on the day of the radiographic study is suggested. Nonionic contrast also may be of benefit in higher-risk patients. IV hydration before and after the procedure is the most efficient method for preventing contrast nephropathy. (See Schwartz 9th ed., p 329.)
10. Which of the following may help prevent ototoxicity in a patient receiving vancomycin?
C. Ferrous sulfate
Ototoxicity due to aminoglycoside administration occurs in up to 10% of patients, and is often irreversible. Recent data show that iron chelating agents and alpha-tocopherol may be protective against ototoxicity. Vancomycin-related ototoxicity occurs about 3% of the time when used alone, and as often as 6% when used with other ototoxic agents, but is self limiting. (See Schwartz 9th ed., p 329.)
11. On the third day after a carotid endarterectomy, a 68-year-old patient develops atrial fibrillation with a heart rate of 160 and a blood pressure of 96/58. The initial treatment should be
C. A beta blocker
D. An alpha blocker
Atrial fibrillation is the most common arrhythmia and occurs between postoperative days 3 and 5 in high-risk patients. This is typically when patients begin to mobilize their interstitial fluid into the vascular fluid space. Contemporary evidence suggests that rate control is more important than rhythm control for atrial fibrillation. The first-line treatment includes beta blockade and/or calcium channel blockade. Beta blockade must be used judiciously, because hypotension, as well as withdrawal from beta blockade with rebound hypertension, is possible. Calcium channel blockers are an option if beta blockers are not tolerated by the patient, but caution must be exercised in those with a history of congestive heart failure. Although digoxin is still a faithful standby medication, it has limitations due to the need for optimal dosing levels. Cardioversion may be required if patients become hemodynamically unstable and the rhythm cannot be controlled. (See Schwartz 9th ed., p 332.)
12. Which of the following is the best method to decrease the risk of renal failure in a patient with myoglobinuria?
A. IV hydration to maintain good urine output
B. Sodium bicarb to maintain urine pH >8
The treatment of renal failure due to myoglobinuria in severe trauma patients has shifted away from the use of sodium bicarbonate for alkalinizing the urine, to merely maintaining brisk urine output of 100 mL/h with crystalloid fluid infusion. Mannitol and furosemide are not recommended as long as the IV fluid achieves the goal rate of urinary output. (See Schwartz 9th ed., p 334.)
13. Ischemic changes to the skin can lead to decubitus ulcers. This ischemia occurs after what period of time in the same position?
A. 10 minutes
B. 30 minutes
C. 1 hour
D. 2 hours
Decubitus ulcers are preventable complications of prolonged bedrest due to traumatic paralysis, dementia, chemical paralysis, or coma. Ischemic changes in the microcirculation of the skin can be significant after 2 hours of sustained pressure. Routine skin care and turning of the patient helps ensure a reduction in skin ulceration. This can be labor intensive and special mattresses and beds are available to help with this ubiquitous problem. (See Schwartz 9th ed., p 334.)
14. The most common virus transmitted by transfusion is
A. Hepatitis A
B. Hepatitis B
C. Hepatitis C
D. Human Immunodeficiency Virus (HIV)
Hepatitis B is the most common virus transmitted by blood transfusion, followed by hepatitis C and then HIV. Hepatitis A is transmitted through contaminated food. (See Schwartz 9th ed., p 335, andTable 12-3.)
TABLE 12-3 Rate of viral transmission in blood product transfusionsa
15. Intra-abdominal hypertension is defined by a bladder pressure greater than
A. 10 cm H2O
B. 15 cm H2O
C. 20 cm H2O
D. 25 cm H2O
Measurement of abdominal pressures is easily accomplished by transducing bladder pressures from the urinary catheter after instilling 100 mL of sterile saline into the urinary bladder. A pressure greater than 20 mmHg constitutes intra-abdominal hypertension, but the diagnosis of ACS requires intra-abdominal pressure greater than 25 to 30 mmHg, with at least one of the following: compromised respiratory mechanics and ventilation, oliguria or anuria, or increasing intracranial pressures. (See Schwartz 9th ed., p 335.)
16. Which of the following has been shown to decrease wound infections in a clean contaminated wound (e.g., nonperforated appendicitis)?
A. Antibiotic impregnated plastic drape placed prior to skin incision
B. Irrigation of the wound with saline solution prior to closure
C. Irrigation of the abdomen with antibiotic solution prior to closure
D. 24 to 28 hours of antibiotics after surgery
There exist no prospective, randomized, double-blind, controlled studies that demonstrate that antibiotics used beyond 24 hours in the perioperative period prevent infections. There is a general trend toward providing a single preoperative dose, as antibiotic prophylaxis may not impart any benefit at all beyond the initial dosing. Irrigation of the operative field and the surgical wound with saline solution has shown benefit in controlling wound inoculum. Irrigation with an antibiotic-based solution has not demonstrated significant benefit in controlling postoperative infection. Antibacterial-impregnated polyvinyl placed over the operative wound area for the duration of the surgical procedure has not been shown to decrease the rate of wound infection. Although skin preparation with 70% isopropyl alcohol has the best bactericidal effect, it is flammable, and could be hazardous when electrocautery is used. The contemporary formulas of chlorhexidine gluconate with isopropyl alcohol or povidone-iodine and iodophor with alcohol are more advantageous. (See Schwartz 9th ed., p 335.)
17. At the conclusion of an operation for a colostomy closure, the patient is noted to have a HR of 130, temp of 102, and elevated expired pCO2. The most appropriate treatment is
A. Irrigation of the abdominal cavity to remove cytokines and lower temperature
B. Careful exploration to rule out a missed bowel injury
C. Tylenol per rectum at the end of the procedure and careful observation
D. Ice packs and intravenous dantrolene
Malignant hyperthermia occurs after exposure to agents such as succinylcholine and some halothane-based inhalational anesthetics. The presentation is dramatic, with rapid onset of increased temperature, rigors, and myoglobinuria related to myonecrosis. Medications must be discontinued immediately and dantrolene administered (2.5 mg/kg every 5 minutes) until symptoms subside. Aggressive cooling methods are also implemented, such as an alcohol bath, or packing in ice. In cases of severe malignant hyperthermia, the mortality rate is nearly 30%. (See Schwartz 9th ed., p 339.)