Penetrating Trauma to the Chest, Abdomen, and Extremities Case File

Penetrating Trauma to the Chest, Abdomen, and Extremities Case File

Eugene C. Toy, MD, Barry C. Simon, MD, Terrence H. Liu, MD, MHP, Katrin Y. Takenaka, MD, Adam J. Rosh, MD, MS

Case 8

An intoxicated 25-year-old man was brought to the emergency department (ED) by paramedics after he was involved in an altercation and sustained several stab wounds to the torso and upper extremities. His initial vital signs in the ED showed pulse rate of 100 beats per minute, blood pressure of 112/80 mm Hg, respiratory rate of 20 breaths per minute, and Glasgow coma scale of 13. A 2-cm stab wound is noted over the left anterior chest just below the left nipple. Additionally, there is a 2-cm wound adjacent to the umbilicus, and several 1- to 2-cm stab wounds are noted in right arm and forearm, near the antecubital fossa. The abdominal and chest wounds are not actively bleeding and there is no apparent hematoma associated with these wounds. However, one of the wounds in the right arm is associated with a 10-cm hematoma that is actively oozing. 

⯈ What are the next steps in the evaluation of this patient?

⯈ What are the complications associated with these injuries?

ANSWER TO CASE 8:

Penetrating Trauma to the Chest, Abdomen, and Extremities

Summary: A 25-year-old hemodynamically stable, intoxicated man presents with stab wounds to the chest, abdomen, and upper extremities.

• Next step: Assess ABCDE: airway, breathing, circulation, disability, and exposure. After completing this survey, consider probing knife wounds (except chest wounds) to see whether they are superficial or deep.

• Potential complications from injuries:

    • Chest wound: Pericardial effusion/tamponade, pneumothorax, hemothorax, diaphragmatic injury

    • Abdominal wound: Hollow viscus, vascular, or urinary tract injury

    • Extremities: Vascular, nerve, or tendon injury

ANALYSIS

Objectives

1. Be able to classify penetrating injuries by location, including chest, thoracoabdominal region, abdomen, flank, back, and “cardiac box.”
2. Learn the priorities involved in the initial management of penetrating injuries.
3. Become familiar with the treatments of penetrating truncal and extremity injuries.

Considerations

A systematic approach must be undertaken in the evaluation of this patient. The clinician must guard against being distracted by injuries not immediately threatening to loss of life or limb. Likewise, young healthy individuals, particularly those who are intoxicated, may have significant injuries and not manifest many physical examination findings or hemodynamic changes. Advanced trauma life support (ATLS) guidelines stress the initial primary survey to identify and address potentially life-threatening injuries. The primary survey consists of the ABCDEs (airway, breathing, circulation, disability, and exposure). Exposure (removing all of the patient’s clothing and rolling the patient to examine the patient’s backside) is particularly important in a patient with penetrating trauma because puncture wounds may be hidden in axillary, inguinal, and gluteal folds.

Following the primary survey, preliminary labs, plain x-rays, and a bedside ultrasound should be obtained as clinically indicated. In this case, an upright chest x-ray (CXR), preferably at end expiration will be needed to assess for pneumothorax and hemothorax. A focused abdominal sonogram for trauma (FAST) examination should be performed to evaluate for pericardial and intraperitoneal free fluid. This patient is hemodynamically stable and possesses minimal abdominal examination findings. Therefore, a reasonable strategy is to perform local wound exploration to determine the depth of the puncture wound. A wound that does not penetrate the abdominal fascia may be irrigated and closed without further diagnostic requirement. However, it is important to note that in an intoxicated patient, the physical examination may not be very sensitive.

Approach To:

Penetrating Trauma

DEFINITIONS

CHEST: Area from clavicles to costal margins, 360 degrees around.

“CARDIAC BOX”: Anatomical region bordered by the clavicles superiorly, bilateral midclavicular lines laterally, and the costal margins inferiorly. This box includes the epigastric region between the costal margins. Eighty-five percent of penetrating cardiac stab wounds originate from a puncture to the “box.”

THORACOABDOMINAL: Area from the inframammary crease (women) or nipples (men), down to the costal margins, 360 degrees around. The clinical significance of a penetrating wound to this region is that there is a risk of injury to the intrathoracic and intra-abdominal contents, as well as to the diaphragm.

ANTERIOR ABDOMEN: Area bordered by the costal margins superiorly, the bilateral midaxillary lines laterally, and by the inguinal ligaments inferiorly.

FLANK: Area from the coastal margin down to the iliac crest, and between the anterior and posterior axillary lines.

BACK: Area between the posterior axillary lines. Because of thick musculature over the back, only about 5% of stab wounds to the back lead to significant injuries.

CLINICAL APPROACH

Initial Management

The primary survey, or ABCDEs, should be addressed first (see Table I–2 in Section I). The clinician should not be distracted by eye-catching but not immediately life-threatening injuries. In an unstable patient, treatment decisions often need to be made before obtaining diagnostic tests. For example, a patient with a stab wound to the chest and rapidly dropping oxygen saturations will require tube thoracostomy (“B” breathing) prior to confirmatory CXR. Bleeding, even if profuse, is most effectively controlled by direct hand pressure to the bleeding site. Gauze and pressure dressings are generally less effective. All patients should have immediate placement of large-bore IV access at two sites. Volume repletion should be initiated with warm IV fluids. After completion of the primary survey, a systematic search for other injuries (secondary survey) should be undertaken. Diagnostic tests should be performed expeditiously after the primary survey and often concurrent with the secondary survey (Table 8–1).

In general, gunshot wounds are more likely to cause greater tissue destruction and life-threatening injuries than stab wounds. This is due to the unpredictable path of the bullet which can lead to significant tissue destruction. Hence, it is not safe to assume that a bullet has taken a direct path between the entrance and exit wounds.

The management of patients with penetrating injuries has undergone significant evolution over the past two decades. During the 1980s and 1990s, most patients underwent invasive diagnostic evaluations, including exploratory laparotomy and angiography based solely on mechanism and location. Currently, selective treatment for some penetrating injuries is acceptable. Selective treatment may involve close observation, and additional minimally invasive diagnostic studies such as ultrasonography, laparoscopy, and thoracoscopy. This option has led to a significant reduction in unnecessary operations. However, selective treatment must be tailored to the clinical situation and balanced against the risk of delay to diagnosis and definitive operative intervention. The decision to proceed with selective treatment is best

determined by a qualified surgeon, after the initial evaluation.

Specific Anatomical Regions

Chest Injuries Generally, 10% to 15% of patients with penetrating chest trauma require urgent operative intervention. Fortunately the majority of these patients can be identified within the first minutes by initial hemodynamic instability, the presence of a large hemothorax on CXR, or high chest tube output. The remaining 85% to 90% of patients may require only close observation, diagnostic imaging, and tube thoracostomy.

The upright chest x-ray (CXR) has adequate sensitivity to evaluate for pneumothorax and hemothorax. Obtaining an end-expiratory film may increase the likelihood of detecting a small pneumothorax. In a patient with a high risk mechanism, the absence of a pneumothorax should be confirmed by a repeat upright CXR in 4 to 6 hours or by computed tomography (CT). CT of the chest is highly sensitive for the detection of pneumothorax. A small pneumothorax visualized by CT and missed by CXR is referred to as an “occult pneumothorax.” An occult pneumothorax should be reevaluated for progression in 4 to 6 hours by CXR.

Local wound exploration of a chest injury is not recommended because the procedure itself can penetrate the pleura and cause a pneumothorax. Pneumo- or hemothorax found by CXR is treated by placement of a 36- or 40-French chest tube. Smaller tubes clot easily with blood and are not indicated in the setting of trauma. If the pneumo- or hemothorax does not resolve with one chest tube, then a second chest tube should be placed. There has not been a consensus on the size of traumatic pneumothorax that warrants tube thoracostomy, although recent literature has shown a push towards more invasive procedures especially when the pneumothorax is 20% or greater. However, if the injury requires mechanical ventilation then a chest tube should be placed, regardless of size, to prevent a worsening of the pneumothorax or a tension physiology from the positive pressure ventilation. The best initial treatment of a tension pneumothorax is needle decompression followed immediately by the placement of a chest tube. Considerations for operative thoracotomy include initial output of 1500 mL of blood, or 200 mL/h over the next 4 hours.

Any patient with an injury within the cardiac box should undergo prompt FAST examination of the heart by an experienced sonographer. The subxiphoid view may be complemented by a parasternal view. The experienced sonographer can detect pericardial blood with up to 100 percent sensitivity (Figure 8–1). Hemopericardium is an indication for pericardial exploration in the operating room.

Resuscitative (or so-called emergency department) thoracotomy is reserved for patients who are in extremis or who have lost vital signs in the ED or within a few minutes prior to arrival. This procedure is associated with a great deal of controversy. The practitioner must bear in mind that mortality exceeds 97%. In addition, this intervention may expose healthcare providers to unnecessary accidental injury and infectious agents. The best outcomes occur when this procedure is performed in properly selected patients by an experienced physician and in a medical center with the capability to provide definitive treatment.

Figure 8–1. FAST examination imaging the subxiphoid region for pericardial fluid.

Thoracoabdominal Thoracoabdominal wounds are of particular interest because injuries to the diaphragm are difficult to detect. Unless the diaphragmatic defect is large, herniation of stomach or intestines is rarely visualized by CXR in the ED. Moreover, CT is not sensitive enough to detect small diaphragmatic injures. Surgical consultation should be obtained when diaphragmatic injury is suspected because the definitive diagnostic study is surgical evaluation by laparoscopy or thoracoscopy. If these injuries go untreated, herniation of intra-abdominal contents into the chest may eventually occur due to the presence of negative intrathoracic pressure.

Anterior Abdomen Immediate indication for laparotomy includes evidence of shock (hypotension, tachycardia, cold and clammy skin, or diaphoresis), peritonitis, gun-shot wound with a suspected course through the abdominal cavity, or evisceration of abdominal contents. In the absence of these findings, further radiographic evaluation or observation is indicated.

Local wound exploration is the best initial evaluation for a stable patient with an abdominal stab wound. This procedure is performed after preparing the skin with an antiseptic agent, creating a sterile field and anesthetizing the skin and soft tissues. The skin laceration is enlarged, and the wound tract is gently followed until either its termination or its violation of the anterior abdominal fascia. An intact fascia makes it highly unlikely that there is an intra-abdominal injury, and therefore the wound may be irrigated and closed.

If the anterior abdominal fascia has been penetrated, then it is critical that a surgeon becomes involved in the patient’s care in order to help facilitate observation  with serial abdominal examinations or surgical intervention. Historically, diagnostic peritoneal lavage (DPL) was performed at the bedside to further investigate potential intra-abdominal injuries. However, DPL has been largely replaced by CT scan or diagnostic laparoscopy in the hemodynamically stable patient and by laparotomy in the unstable patient.

Back/Flank The physical examination, FAST, and DPL are insensitive in diagnosing injuries to the retroperitoneum, including the colon, kidneys, and ureters. The only clue to a retroperitoneal process irritating the psoas muscles may be the patient’s need to flex their hips. Hematuria is the most reliable sign of injury to the kidneys, ureters, and bladder. If gross or microscopic hematuria is present or if a high degree of suspicion exists for possible injury, further evaluation is needed. CT with delayed images, intravenous pyelography (IVP), and perhaps retrograde cystography are useful imaging modalities. Recent literature suggests that most renal injuries without associated hemodynamic compromise or urinary collection system leaks do not mandate exploration. These patients require hospital admission, bedrest, and serial laboratory studies. Laparotomy may be necessary for high-grade renal lacerations in an unstable patient.

Extremities The six Ps of arterial insufficiency (pain, paralysis, parasthesias, pallor, pulselessness, and poikilothermia) and the hard signs of vascular injury (pulsatile bleeding, expanding hematoma, absent distal pulses, palpable thrill, or audible bruit) should be evaluated. Their presence is an indication for immediate operative or angiographic evaluation. A careful pulse examination should be performed to look for a deficit. If pulses are not palpable, then Doppler can be used to identify arterial flow. Sites of injury should be auscultated for a bruit that can represent a traumatic arteriovenous fistula. Ankle-brachial indexes (ABI) can be a useful measurement for evaluating lower extremity vascular trauma. An ABI value of <0.9 may represent vascular injury and, therefore, warrants further investigation. However, in long-standing diabetics, ABIs are less sensitive due to stiffened diseased vasculature leading to spurious values. Additionally, a motor or sensory deficit can represent nerve or tendon injury that is best evaluated and treated in the operating room.

COMPREHENSION QUESTIONS

8.1 A 23-year-old man is involved in an altercation in the parking lot after a baseball game. He suffers a single stab wound 2-cm medial and superior to the left nipple. His blood pressure is 110/80 mm Hg and heart rate is 80 beats per minute. Which of the following management options is most appropriate for this patient?

A. CXR, wound exploration, and ECG

B. CXR and CT scan of the abdomen

C. CXR and echocardiography

D. CXR, echocardiography, and laparoscopy

8.2 For which of the following patients is CT imaging an appropriate diagnostic option?

A. A 38-year-old man with diffuse abdominal pain, involuntary guarding, and a 6-in knife impaled just below the umbilicus

B. A 22-year-old man with a single stab wound to the back, pulse rate of 118 beats per minute, blood pressure of 94/80 mm Hg, and gross hematuria

C. A 16-year-old adolescent boy with a single stab wound 2 cm above the left inguinal crease, with heart rate of 120 beats per minute and blood pressure of 90/78 mm Hg

D. A hemodynamically stable, 34-year-old woman, who is 26 weeks pregnant and has a single stab wound to the back and no other abnormalities on physical examination

8.3 A 34-year-old man is brought into the emergency department after a motor vehicle accident. He complains of dyspnea and initially had an oxygen saturation of 88%. On examination, he has decreased breath sounds of the right chest and now has an oxygen saturation of 70% on room air. Which of the following is the most appropriate next step?

A. Chest radiograph

B. CT of the chest

C. Tube thoracostomy

D. Heparin anticoagulation

ANSWERS

8.1 C. CXR is sensitive in identifying hemothorax and pneumothorax, while echocardiography is useful in identifying pericardial fluid. Wound exploration of the chest wound is not recommended because the information gained is limited and the procedure is associated with the potential of producing pneumothorax. An ECG provides limited information regarding cardiac injury and is generally not done. A stab wound above the nipple line is rarely associated with intraabdominal injury, therefore, CT scan of the abdomen or diagnostic laparoscopy is unnecessary.

8.2 D. CT of the abdomen may be useful in identifying injuries to the retroperitoneal structures in a patient with a stab wound to the back. That the patient is 26-week pregnant does not contraindicate CT scan. Further diagnostic study would not be beneficial in patients listed in choices A, B, and C because these patients are exhibiting signs of significant injury that would necessitate urgent exploratory laparotomy.

8.3 C. The constellation of clinical signs points toward a pneumothorax. The presence of significant hypoxia requires immediate placement of a chest tube prior to chest radiograph confirmation as further delay may progress to cardiovascular collapse.

CLINICAL PEARLS

⯈ The systematic approach to the trauma patient is ABCDE (airway, breathing, circulation, disability, exposure).

⯈ A wound that does not penetrate the abdominal fascia may be irrigated and closed without further diagnostic studies.

⯈ Penetrating trauma to the chest below the nipple line may cause thoracic, intra-abdominal, and occult diaphragmatic injuries.

⯈ The FAST (focused abdominal sonogram for trauma) is fairly accurate in assessing intraperitoneal free fluid.

⯈ Approximately 85% of penetrating cardiac stab wounds originate from a puncture to the “cardiac box.”

References

Cameron JL, ed. Current Surgical Therapy. 7th ed. St. Louis, MO: Mosby; 2001. 

Townsend CM, Beauchamp RD, Evers BM, Mattox KL, eds. Sabiston Textbook of Surgery. 16th ed. Philadelphia, PA: W.B. Saunders; 2001. 

Trunkey DD, Lewis FR, eds. Current Therapy of Trauma. 4th ed. St. Louis, MO: Mosby; 1999.

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