Principles of surgery

PART I
Basic Considerations

CHAPTER 7
Trauma

CLINICAL QUESTIONS

1. What are the “ABCs” of the primary survey?

A. Assess (stability of patient), Begin (treatment), Cervical spine (don’t forget to stabilize the cervical spine)

B. Airway, Breathing, Circulation

C. Accident (history), Background (patient’s past medical history), Community (family medical history)

D. Assess, Begin (to treat), Complete (evaluation of all injuries)

Answer: B

The first step in patient management is performing the primary survey, the goal of which is to identify and treat conditions that constitute an immediate threat to life. The ATLS course refers to the primary survey as assessment of the ‘ABCs’ (Airway with cervical spine protection, Breathing, and Circulation). Although the concepts within the primary survey are presented in a sequential fashion, in reality they often proceed simultaneously. Life-threatening injuries must be identified (Table 7-1) and treated before advancing to the secondary survey. (See Schwartz 9th ed., pp 136-137.)

TABLE 7-1 Immediately life-threatening injuries to be identified during the primary survey


Airway

Airway obstruction

Airway injury

Breathing

Tension pneumothorax

Open pneumothorax

Flail chest with underlying pulmonary contusion

Circulation

Hemorrhagic shock

Massive hemothorax

Massive hemoperitoneum

Mechanically unstable pelvis fracture

Extremity losses

Cardiogenic shock

Cardiac tamponade

Neurogenic shock

Cervical spine injury

Disability

Intracranial hemorrhage/mass lesion


2. Which of the following would mandate elective intubation in a patient with a normal voice, normal oxygen saturation, and no respiratory distress?

A. Airway bleeding

B. Stab wound to the neck with mild swelling in the left lateral neck

C. Localized right lateral subcutaneous emphysema

D. Bilateral mandibular fracture

Answer: A

In general, patients who are conscious, do not show tachypnea, and have a normal voice do not require early attention to the airway. Exceptions are patients with penetrating injuries to the neck and an expanding hematoma; evidence of chemical or thermal injury to the mouth, nares, or hypopharynx; extensive subcutaneous air in the neck; complex maxillofacial trauma; or airway bleeding. Althoughthese patients may initially have a satisfactory airway, it may become obstructed if soft tissue swelling, hematoma formation, or edema progresses. In these cases, elective intubation should be performed before evidence of airway compromise. Patients with stab wounds to the neck do not necessarily require elective intubation, nor do patients with localized subcutaneous emphysema. Bilateral mandibular fracture without airway compromise does not require intubation. (See Schwartz 9th ed., pp 136-137.)

3. What is the most common indication for intubation in a trauma patient?

A. Altered mental status

B. Inhalation injury

C. Facial injury

D. Cervical hematoma

Answer: A

Establishment of a definitive airway (i.e., endotracheal intubation) is indicated in patients with apnea; inability to protect the airway due to altered mental status; impending airway compromise due to inhalation injury, hematoma, facial bleeding, soft tissue swelling, or aspiration; and inability to maintain oxygenation. Altered mental status is the most common indication for intubation. Agitation or obtundation, often attributed to intoxication or drug use, may actually be due to hypoxia. (See Schwartz 9th ed., p 137.)

4. Which of the following trauma patients with airway compromise and failed endotracheal intubation should undergo emergency tracheostomy (rather than a cricothyroidotomy)?

A. An 84-year-old male with blunt trauma to the neck

B. A 65-year-old female with a stab wound to the submandibular region

C. A 16-year-old male with a gunshot wound to the neck

D. A 6-year-old female with a crush injury to the face

Answer: D

In patients under the age of 8, cricothyroidotomy is contraindicated due to the risk of subglottic stenosis, and tracheostomy should be performed.

Emergent tracheostomy is indicated in patients with laryngotracheal separation or laryngeal fractures, in whom cricothyroidotomy may cause further damage or result in complete loss of the airway. This procedure is best performed in the OR where there is optimal lighting and availability of more equipment (e.g., sternal saw). In these cases, often after a ‘clothesline’ injury, direct visualization and instrumentation of the trachea usually is done through the traumatic anterior neck defect or after a collar skin incision.

Cricothyroidotomy (Fig. 7-1) is performed through a generous vertical incision, with sharp division of the subcutaneous tissues and strap muscles. Visualization may be improved by having an assistant retract laterally on the neck incision using army-navy retractors. The cricothyroid membrane is verified by digital palpation through the space into the airway. The airway may be stabilized before incision of the membrane using a tracheostomy hook; the hook should be placed under the thyroid cartilage to elevate the airway. A 6.0 tracheostomy tube (maximum diameter in adults) is then advanced through the cricothyroid opening and sutured into place. (See Schwartz 9th ed., p 137.)

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FIG. 7-1. Cricothyroidotomy is recommended for emergent surgical establishment of a patent airway. A vertical skin incision avoids injury to the anterior jugular veins, which are located just lateral to the midline. Hemorrhage from these vessels obscures vision and prolongs the procedure. When a transverse incision is made in the cricothyroid membrane, the blade of the knife should be angled inferiorly to avoid injury to the vocal cords. A. Use of a tracheostomy hook stabilizes the thyroid cartilage and facilitates tube insertion. B. A 6.0 tracheostomy tube or endotracheal tube is inserted after digital confirmation of airway access.

5. Which of the following is the most appropriate initial treatment of a sucking chest wound?

A. Occlusive dressing taped on 3 out of 4 sides

B. Chest tube placed through the wound, cover wound (and chest tube) with occlusive dressing

C. Chest tube placed in a clear area, closure of the wound

D. Closure of the wound, intubation of the patient, sedation

Answer: A

An open pneumothorax or ‘sucking chest wound’ occurs with full-thickness loss of the chest wall, permitting free communication between the pleural space and the atmosphere (Fig. 7-2). This compromises ventilation due to equilibration of atmospheric and pleural pressures, which prevents lung inflation and alveolar ventilation, and results in hypoxia and hypercarbia. Complete occlusion of the chest wall defect without a tube thoracostomy may convert an open pneumothorax to a tension pneumothorax. Temporary management of this injury includes covering the wound with an occlusive dressing that is taped on three sides. This acts as a flutter valve, permitting effective ventilation on inspiration while allowing accumulated air to escape from the pleural space on the untaped side, so that a tension pneumothorax is prevented. Definitive treatment requires closure of the chest wall defect and tube thoracostomy remote from the wound.

Placing the chest tube through the wound would increase infectious complications and would result in inadequate closure and healing of the wound. Closing the wound with a remotely placed chest tube is the definitive treatment, which is usually done in the operating room, rather than as initial treatment in the ED. Closing the wound without a chest tube could result in a tension pneumothorax and is contraindicated. (See Schwartz 9th ed., p 138.)

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FIG. 7-2. A. Full-thickness loss of the chest wall results in an open pneumothorax. B. The defect is temporarily managed with an occlusive dressing that is taped on three sides, which allows accumulated air to escape from the pleural space and thus prevents a tension pneumothorax. Repair of the chest wall defect and tube thoracostomy remote from the wound is definitive treatment.

6. A 4-year-old is brought hypotensive to the ED after an MVA. Peripheral IV access is attempted but is unsuccessful. The next best access is

A. Cordis introducer in the internal jugular vein

B. Single lumen subclavian venous catheter

C. Double lumen femoral venous catheter

D. Intraosseous catheter

Answer: D

In hypovolemic patients under 6 years of age, an intraosseous needle can be placed in the proximal tibia (preferred) or distal femur of an unfractured extremity (Fig. 7-3). Flow through the needle should be continuous and does not require pressure. All medications administered IV may be administered in a similar dosage intraosseously. Although safe for emergent use, the needle should be removed once alternative access is established to prevent osteomyelitis. A Cordis introducer would be excessively large for even central veins in a 4-year-old child. Both the single and double lumen catheters would be less effective than the interosseous for resuscitation. According to Poiseuille’s law, the flow of liquid through a tube is proportional to the diameter and inversely proportional to the length; therefore, venous lines for volume resuscitation should be short with a large diameter. (See Schwartz 9th ed., p 139.)

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FIG. 7-3. Intraosseous infusions are indicated for children 6 years of age in whom one or two attempts at IV access have failed. A. The proximal tibia is the preferred location. Alternatively, the distal femur can be used if the tibia is fractured. B. The needle should be directed away from the epiphyseal plate to avoid injury. The position is satisfactory if bone marrow can be aspirated and saline can be easily infused without evidence of extravasation.

7. Which of the following is a life-threatening compromise to circulation and must be identified during the primary survey?

A. Unstable pelvic fracture

B. Pericardial effusion

C. 40% pneumothorax

D. Femoral artery injury

Answer: D

During the circulation section of the primary survey, four life-threatening injuries that must be identified are (a) massive hemothorax, (b) cardiac tamponade, (c) massive hemoperitoneum, and (d) mechanically unstable pelvic fractures. A pericardial effusion (without tamponade) is not immediately life threatening, nor is a pneumothorax or a peripheral arterial injury. (See Schwartz 9th ed., p 140.)

8. Which of the following is defined as a massive hemothorax?

A. 1600 ml of intrathoracic blood in a 100-kg woman

B. 900 m of intrathoracic blood in a 70-kg man

C. 800 ml of intrathoracic blood in a 50-kg woman

D. 200 ml of intrathoracic blood in a 20-kg boy

Answer: A

A massive hemothorax is defined as >1500 mL of blood or, in the pediatric population, one third of the patient’s blood volume in the pleural space. Blood volume can be quickly estimated by multiplying body weight (in kg) × 70. So, the 20-kg child would have a total blood volume of 1400 ml. One third of his blood volume (the amount necessary to be classified as a massive hemothorax) would be 466 ml. (See Schwartz 9th ed., p 140.)

9. Which of the following is the best initial treatment for acute traumatic pericardial tamponade in a patient with a systolic blood pressure of 90 mmHg?

A. Immediate ER thoracotomy with pericardiotomy and repair of the injury

B. ER thoracoscopy for pericardial drainage

C. Fluid resuscitation to stabilize blood pressure during transfer to the operating room for definitive repair

D. Ultrasound guided placement of a pericardial catheter

Answer: D

Early in the course of tamponade, blood pressure and cardiac output will transiently improve with fluid administration. In patients with any hemodynamic disturbance, a pericardial drain is placed using ultrasound guidance (Fig. 7-4). Removing as little as 15 to 20 mL of blood will often temporarily stabilize the patient’s hemodynamic status, prevent subendocardial ischemia and associated lethal arrhythmias, and allow transport to the OR for sternotomy. Pericardiocentesis is successful in decompressing tamponade in approximately 80% of cases; the majority of failures are due to the presence of clotted blood within the pericardium. Patients with a SBP 70 mmHg warrant emergency department thoracotomy (EDT) with opening of the pericardium to address the injury. Thoracoscopy is not considered a reasonable treatment for traumatic chest wounds with hypotension. This patient does not warrant an ER thoracotomy because the systolic BP is >70 mmHg. The best initial treatment is ultrasound guided placement of a pericardial catheter followed by transfer to the operating room for definite treatment. (See Schwartz 9th ed., pp 140-141.)

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FIG. 7-4. Pericardiocentesis is indicated for patients with evidence of pericardial tamponade. A. Access to the pericardium is obtained through a subxiphoid approach, with the needle angled 45 degrees up from the chest wall and toward the left shoulder. B. Seldinger technique is used to place a pigtail catheter. Blood can be repeatedly aspirated with a syringe or the tubing may be attached to a gravity drain. Evacuation of unclotted pericardial blood prevents subendocardial ischemia and stabilizes the patient for transport to the operating room for sternotomy.

10. Which of the following is an indication for emergency department thoracotomy (EDT)?

A. Witnessed cardiac arrest after a stab wound to the chest with 25 min of CPR

B. Witnessed cardiac arrest after blunt trauma to the chest with 10 min of CPR

C. Profound hypotension (systolic BP 70) following a stab wound to the chest

D. Cardiac arrest in the ED following closed head injury

Answer: C

The utility of EDT has been debated for many years. Current indications are based on 30 years of prospective data (Table 7-2). EDT is associated with the highest survival rate after isolated cardiac injury; 35% of patients presenting in shock and 20% without vital signs (i.e., pulse or obtainable blood pressure) are resuscitated after isolated penetrating injury to the heart. For all penetrating wounds, survival rate is 15%. Conversely, patient outcome is poor when EDT is done for blunt trauma, with 2% survival among patients in shock and 1% survival among those with no vital signs. A is incorrect because there was more than 15 min of CPR following a penetrating injury. B is incorrect because there was more than 5 min of CPR following a blunt injury. D is incorrect; there is no indication for EDT after isolated head injury. (See Schwartz 9th ed., pp 140-142, and Fig. 7-5.)

TABLE 7-2 Current indications and contraindications for emergency department thoracotomy


Indications

Salvageable postinjury cardiac arrest:

Patients sustaining witnessed penetrating trauma with 15 min of prehospital CPR

Patients sustaining witnessed blunt trauma with 5 min of prehospital CPR

Persistent severe postinjury hypotension (SBP ≤60 mmHg) due to:

Cardiac tamponade

Hemorrhage—intrathoracic, intra-abdominal, extremity, cervical

Air embolism

Contraindications

Penetrating trauma: CPR >15 min and no signs of life (pupillary response, respiratory effort, motor activity)

Blunt trauma: CPR >5 min and no signs of life or asystole


CPR = cardiopulmonary resuscitation; SBP = systolic blood pressure.

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FIG. 7-5. Algorithm directing the use of emergency department thoracotomy (EDT) in the injured patient undergoing cardiopulmonary resuscitation (CPR). ECG = electrocardiogram; OR = operating room; SBP = systolic blood pressure.

11. Management of suspected blunt cardiac injury includes which of the following?

A. Mandatory admission to an intensive care unit

B. Cardiac catheterization

C. Continuous monitoring if EKG abnormalities are noted

D. Cardiac enzymes

Answer: C

Although as many as one third of patients sustaining significant blunt chest trauma experience blunt cardiac injury, few such injuries result in hemodynamic embarrassment. Patients with electrocardiographic (ECG) abnormalities or dysrhythmias require continuous ECG monitoring and anti-dysrhythmic treatment as needed. Unless myocardial infarction is suspected, there is no role for measurement of cardiac enzyme levels—they lack specificity and do not predict significant dysrhythmias. The patient with hemodynamic instability requires aggressive resuscitation and may benefit from the placement of a pulmonary artery catheter to optimize preload and guide inotropic support. Echocardiography may be indicated to exclude pericardial tamponade or valvular or septal injuries. It typically demonstrates right ventricular dyskinesia but is less helpful in titrating treatment and monitoring the response to therapy unless done repeatedly. Patients with refractory cardiogenic shock may require placement of an intra-aortic balloon pump to decrease myocardial work and enhance coronary perfusion. Admission to an intensive care unit is determined by whether or not there is need for continuous monitoring and/or any hemodynamic instability. It is not mandatory for all patients with blunt cardiac injury. Cardiac catheterization is not used in the diagnosis or treatment of blunt cardiac injury. Cardiac enzymes are not specific for blunt cardiac injury and do not help in the management of these patients. (See Schwartz 9th ed., p 143.)

12. A patient presents with stable vital signs and respiratory distress after a stab wound to the chest. Chest tubes are placed and an air leak is noted. The patient is electively intubated. The patient arrests after positive pressure ventilation is started. What is the most likely diagnosis?

A. Unrecognized hemorrhage in the abdomen

B. Tension pneumothorax

C. Pericardial tamponade

D. Air embolism

Answer: C

Air embolism is a frequently overlooked or undiagnosed lethal complication of pulmonary injury. Air emboli can occur after blunt or penetrating trauma, when air from an injured bronchus enters an adjacent injured pulmonary vein (bronchovenous fistula) and returns air to the left heart. Air accumulation in the left ventricle impedes diastolic filling, and during systole air is pumped into the coronary arteries, disrupting coronary perfusion. The typical case is a patient with a penetrating thoracic injury who is hemodynamically stable but experiences arrest after being intubated and placed on positive pressure ventilation. The patient should immediately be placed in Trendelenburg’s position to trap the air in the apex of the left ventricle. Emergency thoracotomy is followed by cross-clamping of the pulmonary hilum on the side of the injury to prevent further introduction of air (Fig. 7-6). Air is aspirated from the apex of the left ventricle and the aortic root with an 18-gauge needle and 50-mL syringe. Vigorous massage is used to force the air bubbles through the coronary arteries; if this is unsuccessful, a tuberculin syringe may be used to aspirate air bubbles from the right coronary artery. Once circulation is restored, the patient should be kept in Trendelenburg’s position with the pulmonary hilum clamped until the pulmonary venous injury is controlled operatively. (See Schwartz 9th ed., p 144.)

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FIG. 7-6. A. A Satinsky clamp is used to clamp the pulmonary hilum to prevent further bronchovenous air embolism. B. Sequential sites of aspiration include the left ventricle, the aortic root, and the right coronary artery.

13. Which of the following is the expected blood loss in a patient with 6 rib fractures?

A. 240 ml

B. 480 ml

C. 750 ml

D. 1500 ml

Answer: C

For each rib fracture there is approximately 100 to 200 mL of blood loss; for tibial fractures, 300 to 500 mL; for femur fractures, 800 to 1000 mL; and for pelvic fractures, >1000 mL. Although no single injury may appear to cause a patient’s hemodynamic instability, the sum of the injuries may result in life-threatening blood loss. (See Schwartz 9th ed., p 145.)

14. A 25-year-old man presents following blunt trauma to the abdomen. FAST exam shows injury to the spleen. His HR is 110, RR is 25 and he is mildly anxious. What percentage of his blood volume do you estimate he has lost?

A. 15%

B. 15-30%

C. 30-40%

D. >40%

Answer: B

He has class II hemorrhagic shock (based on his vital signs) with a loss of between 15% and 30% of his blood volume. (See Schwartz 9th ed., p 145, and Table 7-3.)

TABLE 7-3 Signs and symptoms of advancing stages of hemorrhagic shock

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15. A 40-year-old man is struck in the head. A CT scan is obtained, which is shown below. What is the diagnosis?

A. Subdural hematoma

B. Subarachnoid hemorrhage

C. Intraparenchymal hemorrhage

D. Epidural hematoma

Answer: C

This is an epidural hematoma. Epidural hematomas have a distinctive convex shape on computed tomographic scan, whereas subdural hematomas are concave along the surface of the brain. (See Schwartz 9th ed., p 148, and Fig. 7-7.)

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FIG. 7-7. Epidural hematoma. A distinctive convex shape on computed tomographic scan.

16. A 27-year-old man presents to the ED after receiving blows to the head. He opens his eyes with painful stimuli, is confused, and localizes to pain. What is his Glasgow Coma Score?

A. 13

B. 11

C. 9

D. 7

Answer: B

His score is 2 (eye) + 4 (verbal) + 5 (motor) = 11. (See Schwartz 9th ed., p 145, and Table 7-4.)

TABLE 7-4 Glasgow Coma Scalea

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17. A 75-year-old woman presents to the ED following an MVA. She has decreased strength and sensation in her arms. She has normal strength and sensation in her legs. The most likely diagnosis is

A. Brown-Séquard syndrome

B. Anterior cord syndrome

C. Central cord syndrome

D. Posterior cord syndrome

Answer: C

There are several partial or incomplete spinal cord injury syndromes. Central cord syndrome usually occurs in older persons who experience hyperextension injuries. Motor function and pain and temperature sensation are preserved in the lower extremities but diminished in the upper extremities. Some functional recovery usually occurs but is often not a return to normal. Anterior cord syndrome is characterized by diminished motor function and pain and temperature sensation below the level of the injury, but position sensing, vibratory sensation, and crude touch are maintained. Prognosis for recovery is poor. Brown-Séquard syndrome is usually the result of a penetrating injury in which the right or left half of the spinal cord is transected. This rare lesion is characterized by the ipsilateral loss of motor function, proprioception, and vibratory sensation, whereas pain and temperature sensation are lost on the contralateral side. Posterior cord syndrome does not exist. (See Schwartz 9th ed., p 150.)

18. The appropriate treatment of an asymptomatic patient with a stab wound to Zone III of the neck is

A. Observation

B. CT of the neck

C. Angiography

D. Operative exploration

Answer: A

Zone III is the superior portion of the neck, above the angle of the mandible. Asymptomatic patients can be observed. Zone III injuries that are symptomatic should be evaluated with angiography and, if necessary, embolization of bleeding vessels. (See Schwartz 9th ed., pp 150-151, and Figs. 7-8 and 7-9.)

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FIG. 7-8. For the purpose of evaluating penetrating injuries, the neck is divided into three zones. Zone I is up to the level of the cricoid and is also known as the thoracic outlet. Zone II is located between the cricoid cartilage and the angle of the mandible. Zone III is above the angle of the mandible.

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FIG. 7-9. Algorithm for the selective management of penetrating neck injuries. CT = computed tomography; CTA = computed tomographic angiography; GSW = gunshot wound; IR Embo = interventional radiology embolization.

19. Which of the following is an indication for CT of the chest to rule out a thoracic aortic injury?

A. Left hemopneumothorax

B. Respiratory distress with multiple rib fractures

C. High speed head-on MVC with normal chest radiograph

D. Left scapular pain

Answer: C

At least 7% of patients with a descending torn aorta have a normal chest radiograph. Therefore, screening spiral CT scanning is performed based on the mechanism of injury: high-energy deceleration motor vehicle collision with frontal or lateral impact, motor vehicle collision with ejection, falls of >25 ft, or direct impact (horse kick to chest, snowmobile or ski collision with tree). The CXR finding of a left apical cap is suggestive of a thoracic aortic injury. Multiple rib fractures or scapular pain alone are not suggestive of a thoracic aortic injury. (See Schwartz 9th ed., p 151, and Table 7-5.)

TABLE 7-5 Findings on chest radiograph suggestive of a descending thoracic aortic tear


1. Widened mediastinum

2. Abnormal aortic contour

3. Tracheal shift

4. Nasogastric tube shift

5. Left apical cap

6. Left or right paraspinal stripe thickening

7. Depression of the left main bronchus

8. Obliteration of the aorticopulmonary window

9. Left pulmonary hilar hematoma


20. A 20-year-old young man presents with an left anterior 8th intercostal space stab wound. He is in no distress and a chest x-ray is normal. A diagnostic peritoneal lavage is perfomed and has a RBC count of 8,000/μl and a WBC count of 300/μl. Which of the following is the best treatment for this patient?

A. Observation only

B. CT scan

C. Laparoscopy

D. Exploratory Laparotomy

Answer: C

Occult injury to the diaphragm must be ruled out in patients with stab wounds to the lower chest. For patients undergoing DPL evaluation, laboratory value cutoffs are different for those with thoracoabdominal stab wounds and for those with standard anterior abdominal stab wounds (see Table 7-6). An RBC count of >10,000/μL is considered a positive finding and an indication for laparotomy; patients with a DPL RBC count between 1000/μL and 10,000/μL should undergo laparoscopy or thoracoscopy. (See Schwartz 9th ed., pp 153-155.)

TABLE 7-6 Criteria for “positive” finding on diagnostic peritoneal lavage

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21. A 45-year-old, otherwise healthy woman presents after a moving vehicle accident. She is hemodynamically stable and with only minimal tenderness in her right upper quadrant. A FAST exam (focused abdominal sonographic test) is positive with fluid seen in the hepatorenal fossa and the pelvis. Which of the following is the next best step in her management?

A. Observation only

B. CT scan

C. Laparoscopy

D. Exploratory laparotomy

Answer: B

Patients with fluid on FAST examination, considered a ‘positive FAST,’ who do not have immediate indications for laparotomy and are hemodynamically stable undergo CT scanning to quantify their injuries. Injury grading using the American Association for the Surgery of Trauma grading scale (Table 7-7) is a key component of nonoperative management of solid organ injuries. Because of the risk of a solid organ injury, observation is not indication. If she has an isolated liver or spleen injury, the correct treatment is most likely observation; therefore, both laparoscopy and laparotomy would not be indicated. (See Schwartz 9th ed., pp 155-157, and Fig. 7-10.)

TABLE 7-7 American Association for the Surgery of Trauma grading scales for solid organ injuries

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FIG. 7-10. Algorithm for the initial evaluation of a patient with suspected blunt abdominal trauma. CT = computed tomography; DPA = diagnostic peritoneal aspiration; FAST = focused abdominal sonography for trauma; Hct = hematocrit.

22. After CT scan, she is shown to have a liver laceration as shown below. There is a 4-cm laceration into the right lobe with a 10-cm subcapsular hematoma (see Fig. 7-11). What grade liver injury does she have?

Image

FIG. 7-11.

A. Grade I

B. Grade II

C. Grade III

D. Grade IV

Answer: C

Because she has a laceration >3 m in depth, she has a Grade III liver injury. (See Schwartz 9th ed., p 157.)

23. A stable patient with a Grade III splenic laceration has the following laboratory results 2 hours after admission: Hg/Hct 8.7/29 Plt 70,000 INR 1.3.

A. No transfusions are indicated

B. Transfuse PRBCs only

C. Transfuse PRBCs and platelets

D. Transfuse PRBCs, platelets, and FFP

Answer: B

Although current critical care guidelines indicate that PRBC transfusion should occur once the patient’s hemoglobin level is 7 g/dL, in the acute phase of resuscitation the endpoint is 10 g/dL. Fresh-frozen plasma is transfused to keep the patient’s International Normalized Ratio (INR) less than 1.5 and partial thromboplastin time (PTT) 45 seconds. Primary hemostasis relies on platelet adherence and aggregation to injured endothelium, and a platelet count of 50,000/μL is considered adequate if platelet function is normal. With massive transfusion, however, platelet dysfunction is common, and therefore a target of 100,000/μL is advocated. If fibrinogen levels drop below 100 mg/dL, cryoprecipitate should be administered. This patient, who is in the acute phase of resuscitation, should receive PRBCs because the Hg is less than 10. Because platelets are >50,000 and INR is 1.5, transfusions of platelets and/or FFP are not indicated. (See Schwartz 9th ed., p 158.)

24. Which of the following is an indication for operative intervention in a patient with an isolated duodenal hematoma?

A. Hematoma >3 cm in diameter

B. Total or near total occlusion of the duodenum by the hematoma

C. Failure to resolve 10 days after admission

D. Contained retroperitoneal leak

Answer: D

The majority of duodenal hematomas are managed nonoperatively with nasogastric suction and parenteral nutrition. Patients with suspected associated perforation, suggested by clinical deterioration or imaging with retroperitoneal free air or contrast extravasation, should undergo operative exploration. A marked drop in nasogastric tube output heralds resolution of the hematoma, which typically occurs within 2 weeks; repeat imaging to confirm these clinical findings is optional. If the patient shows no clinical or radiographic improvement within 3 weeks, operative evaluation is warranted. The size of the hematoma is not a criterion for operative intervention, nor is the degree of initial occlusion by the hematoma. Patients with persistent duodenal occlusion after 3 weeks should undergo operative exploration. Any sign of perforation is an indication for exploration. (See Schwartz 9th ed., p 179.)

25. Which of the following is an indication for a lower leg fasciotomy?

A. >35-mmHg difference in diastolic pressure and the compartment pressure

B. >35-mmHg difference in mean arterial pressure and the compartment pressure

C. >25mmHg difference in systolic pressure and the compartment pressure

D. >25-mmHg compartment pressure, regardless of blood pressure

Answer: A

In conscious patients with compartment syndrome, pain is the prominent symptom, and active or passive motion of muscles in the involved compartment increases the pain. Paresthesias may also be described. In the lower extremity, numbness between the first and second toes is the hallmark of early compartment syndrome in the exquisitely sensitive anterior compartment and its enveloped deep peroneal nerve. Progression to paralysis can occur, and loss of pulses is a late sign. In comatose or obtunded patients, the diagnosis is more difficult to secure. In patients with a compatible history and a tense extremity, compartment pressures should be measured with a handheld Stryker device. Fasciotomy is indicated in patients with a gradient of 35 mmHg (gradient = diastolic pressure – compartment pressure), ischemic periods of >6 hours, or combined arterial and venous injuries. In the absence of clinical signs such as pain and paresthesias, compartment pressures are used to determine the need for fasciotomy. The difference between the diastolic blood pressure and the compartment pressure is measured. Patients with a gradient >35 mmHg should undergo a fasciotomy. (See Schwartz 9th ed., p 185, and Fig. 7-12.)

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FIG. 7-12. A. The anterior and lateral compartments are approached from a lateral incision, with identification of the fascial raphe between the two compartments. Care must be taken to avoid the superficial peroneal nerve running along the raphe. B. To decompress the deep flexor compartment, which contains the tibial nerve and two of the three arteries to the foot, the soleus muscle must be detached from the tibia.

26. Which of the following bladder pressures is an absolute indication for a decompressive laparotomy?

A. >5 mmHg

B. >15 mmHg

C. >25 mmHg

D. >35 mmHg

Answer: D

Generally, no specific bladder pressure prompts therapeutic intervention, except when the pressure is >35 mmHg. Rather, emergent decompression is carried out when intra-abdominal hypertension reaches a level at which endorgan dysfunction occurs. Mortality is directly affected by decompression, with 60% mortality in patients undergoing presumptive decompression, 70% mortality in patients with a delay in decompression, and nearly uniform mortality in those not undergoing decompression. Abdominal hypertension is classified by grade, with Grade I (mild) being >10 mmHg (≥13 cm H2O). Grade IV hypertension or >35 mmHg (≥48 cm H2O) is an absolute indication for decompressive laparotomy. (See Schwartz 9th ed., p 188, Table 7-8 and Fig. 7-13.)

TABLE 7-8 Abdominal compartment syndrome grading system

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FIG. 7-13. Abdominal compartment syndrome is defined by the end organ sequelae of intra-abdominal hypertension. CO = cardiac output; CVP = central venous pressure; ICP = intracranial pressure; PA = pulmonary artery; SV = stroke volume; SVR = systemic vascular resistance; UOP = urine output; VEDV = ventricular end diastolic volume.

27. Which of the following is a normal physiologic change during pregnancy?

A. Relative anemia

B. Decrease in circulating blood volume

C. Respiratory acidosis

D. Bradycardia

Answer: A

Pregnancy results in physiologic changes that may impact postinjury evaluation (Table 7-9). Heart rate increases by 10 to 15 beats per minute during the first trimester and remains elevated until delivery. Blood pressure diminishes during the first two trimesters due to a decrease in systemic vascular resistance and rises again slightly during the third trimester (mean values: first = 105/60, second = 102/55, third = 108/67). Intravascular volume is increased by up to 8 L, which results in a relative anemia but also a relative hypervolemia. Consequently, a pregnant woman may lose 35% of her blood volume before exhibiting signs of shock. Pregnant patients have an increase in tidal volume and minute ventilation but a decreased functional residual capacity; this results in a diminished PCO2 reading and respiratory alkalosis. Also, pregnant patients may desaturate more rapidly, particularly in the supine position and during intubation. Supplemental oxygen is always warranted in the trauma patient but is particularly critical in the injured pregnant patient, because the oxygen dissociation curve is shifted to the left for the fetus compared to the mother (i.e., small changes in maternal oxygenation result in larger changes for the fetus because the fetus is operating in the steep portions of the dissociation curve).

As noted earlier there is a relative anemia during pregnancy, but a hemoglobin level of 11 g/dL is considered abnormal. Additional hematologic changes include a moderate leukocytosis (up to 20,000 mm3) and a relative hypercoagulable state due to increased levels of factors VII, VIII, IX, X, and XII and decreased fibrinolytic activity. (See Schwartz 9th ed., pp 190-191.)

TABLE 7-9 Physiologic effects of pregnancy


Cardiovascular

Increase in heart rate by 10–15 bpm

Decreased systemic vascular resistance resulting in:

(a) Increased intravascular volume

(b) Decreased blood pressure during the first two trimesters

Pulmonary

Elevated diaphragm

Increased tidal volume

Increased minute ventilation

Decreased functional residual capacity

Hematopoietic

Relative anemia

Leukocytosis

Hypercoagulability

(a) Increased levels of factors VII, VIII, IX, X, XII

(b) Decreased fibrinolytic activity

Other

Decreased competency of lower esophageal sphincter

Increased enzyme levels on liver function tests

Impaired gallbladder contractions

Decreased plasma albumin level

Decreased blood urea nitrogen and creatinine levels

Hydronephrosis and hydroureter