Abdominal injuries are potentially life-threatening and should be approached with caution. Following trauma, the abdomen may be a sanctuary for a broad spectrum of injuries that, if not discovered and corrected expeditiously, may lead to deleterious consequences. Traditionally these injuries are classified as either blunt trauma or penetrating injuries. The majority of blunt abdominal trauma is secondary to motor vehicle collisions, whereas the majority of penetrating injuries is predominantly secondary to gunshot or stab wounds. Patients with abdominal trauma require rapid assessment, stabilization, and early surgical consultation when indicated to maximize the chances of a successful outcome.

Assessment

Initial management of all trauma patients is the same, and abdominal trauma is no exception. Following ATLS protocols, begin the assessment with a rapid primary survey, including evaluation of the airway, breathing, circulation, disability, and exposure.

Airway

Assess the airway while maintaining cervical spine immobilization until potential injury is ruled out. Jaw thrust without head extension can be used to open the airway of a trauma patient. Administer high-flow oxygen, and intubate the patient if indicated.

Breathing

First assess breathing by auscultating for breath sounds. Diminished or absent breath sounds should raise clinical suspicion for a possible pneumothorax. Next, inspect for asymmetry of chest wall movement, open wounds, or flail segments. Then palpate the chest wall carefully. Palpable crepitus may indicate a pneumothorax or rib fractures. Rapidly perform needle decompression or tube thoracostomy when indicated (See Chapter 24). Pulse oximetry and capnography may be useful.

Circulation

Assess circulation. If gross external hemorrhage is present, control with direct pressure. Assess pulses, capillary refill, and blood pressure. Obtain intravenous access, preferably with at least two large-bore (≥16-gauge) peripheral catheters. If peripheral intravenous access is inadequate or unattainable, place a central venous catheter or interosseous line. Begin fluid resuscitation. The FAST examination is important at this stage of the evaluation, especially in hemodynamically unstable patients, where a positive FAST exam would be an immediate indication for emergency laparotomy.

Disability

To assess disability, complete a brief and focused neurologic examination to document the patient’s current mental status. The examination should include an assessment of pupillary size and reactivity, a determination of the patient’s Glasgow Coma Scale score, and notation of any focal neurologic deficits such as unilateral weakness or poor muscle tone. Ideally, assessment of disability should be performed before administering pain medications, sedatives, or paralytics.

Exposure

In order to complete a thorough secondary survey, the patient must be fully exposed. Completely undress the patient while taking precautions to prevent or recognize and correct associated hypothermia. Begin a more thorough secondary survey, including logrolling the patient and examining all skin folds, the back, and axillae for any signs of trauma (eg, contusions, hematomas, abrasions, or penetrating wounds). Attempt to identify all wounds and document their location. To help identify the trajectory of bullets, place a radiopaque marker (eg, paper clip) at the wound site prior to obtaining X-rays. Do not remove impaled foreign bodies because they may be providing hemostasis from a vascular injury. Most foreign body removal should be performed with surgical consultation in a more controlled setting. Describe each wound, and avoid using terms such as entrance or exit wound on initial presentation, because it is often difficult to correctly make this assessment visually. These determinations are best left to a forensic pathologist.

Any penetrating injury below the level of the nipple line warrants evaluation for intra-abdominal injury. For patients involved in motor vehicle collisions, carefully examine the chest and abdomen looking for ecchymosis or erythema in the area of the clavicles or across the abdomen. The classic “seat-belt sign” or linear bruising across the lower abdomen is a marker for intra-abdominal injury, present in approximately 25% of patients with this finding. Examine the abdomen for any tenderness, distention, rigidity, or guarding. It is often difficult to assess bowel sounds at this stage of the examination. Evaluate the pelvis for anteroposterior or lateral instability with gentle pressure; this does not require much force and should not be repeatedly performed. Examine the genitalia and look for blood at the urethral meatus, especially in males. Perform digital rectal examination in any patient with abdominal trauma to look for gross blood, assess sphincter tone, identify a high-riding prostate, and to note any other evidence of trauma. There is no role for occult blood testing acutely in a trauma. If blood at the urethral meatus or a high-riding prostate is present, placement of a urinary catheter is contraindicated and a retrograde urethrogram is required to evaluate for potential urethral injury.

Treatment

Fluid Resuscitation

Hemodynamic support is an early goal in the treatment of trauma patient. The use of crystalloids is currently recommended in trauma resuscitation but the concept of acute fluid resuscitation is evolving and may represent an area of some controversy. Animal and human studies have demonstrated deleterious effects of aggressive fluid resuscitation, particularly if penetrating trauma is present. Rapid infusion of large amounts of crystalloids may disrupt the formation of the soft clot and dilute the clotting factors, leading to increased bleeding. The results are less clear in the setting of blunt trauma. The amount of fluid given should be tailored to each individual patient. Also, blood pressure alone is not the best indicator of the level of shock. Attempts to make the patient normotensive are not recommended. A more reasonable goal may be to obtain systolic blood pressure of 80–90 mm Hg or a mean arterial pressure of 70 mm Hg. Crystalloids remain first-line fluids, followed by infusions of packed red blood cells. Other blood products, such as fresh frozen plasma and platelets, may be indicated in potentially uncontrollable hemorrhage (eg, deep truncal injury.) Recombinant Factor VIIa is used as an adjunct to other blood products in the setting of massive hemorrhage. The CRASH-2 trial, which tested an infusion of tranexamic acid, demonstrated a 9% reduction in death for traumatized patients with suspected hemorrhage whom were given the drug within 8 hours of injury. While certainly not standard of care at this time, this treatment may become widely adopted in next few years as another option to employ in treatment of significant hemorrhage in the setting of trauma.

Indications for Emergency Laparotomy

Most patients with penetrating abdominal injuries will also require laparotomy given the high incidence of intra-abdominal injury once the fascia has been violated. Hemodynamically unstable patients sustaining blunt or penetrating trauma with a positive screening test (such as focused assessment with sonography for trauma [FAST] examination or diagnostic peritoneal lavage [DPL]) require laparotomy to control hemorrhage and evaluate for intra-abdominal injuries. Although there is no debate that patients with peritonitis or hemodynamic instability should undergo urgent laparotomy after penetrating trauma to the abdomen, it is also clear that certain stable patients without peritonitis may be managed without operation. Routine laparotomy is NOT indicated in hemodynamically stable patients with knife stab wounds if there is no evidence of peritonitis or diffuse abdominal tenderness. Routine laparotomy is also NOT routinely indicated in stable patients with gunshot wounds if wounds are tangential and without peritoneal signs. Initially stable blunt trauma patients with identified abdominal injuries should be carefully observed so that if they become hemodynamically unstable they can rapidly receive operative intervention. Laparoscopy for certain penetrating injuries has helped in eliminating nontherapeutic laparotomies. Patients with obvious diaphragmatic injury noted on chest X-ray require emergency laparotomy. Patients considered to be at very low risk for having intra-abdominal injury (particularly intra-abdominal injury requiring acute intervention) have no hypotension, no GCS < 14, no costal margin tenderness, no abdominal tenderness, no hematuria ≥25 RBC/hpf, no hematocrit < 30, and no femur fracture.

Surgical Consultation

It is imperative to seek early surgical consultation in the management of patients with abdominal trauma, especially if the patient is hemodynamically unstable. Many stable patients with blunt abdominal injuries can initially be treated with nonoperative management. Not all blunt and penetrating abdominal injuries require immediate operative intervention but the majority will require observation and repeat examinations at a minimum.

Diagnostic Testing

Laboratory Evaluation

Initial laboratory evaluation in the traumatically injured patient should include hemoglobin, hematocrit, and platelet count to establish a baseline. A blood-type and screen should be ordered in case transfusion of packed red cells is needed. A lactate level may be obtained and, if elevated, is an excellent indicator of shock. Similarly, base deficit is another indicator of shock. The role of amylase or lipase in abdominal trauma is uncertain. Elevation of liver enzymes may indicate hepatic injury. Glucose and white blood cell count are often elevated in acute trauma and are nonspecific findings. Examination of the urine may reveal gross hematuria, which typically suggests significant injury to the urogenital tract (Chapter 26).

Other Diagnostic Modalities

Plain Radiography

Almost all major trauma patients require plain X-rays of the chest, pelvis, and cervical spine. Although rarely used today because of the ubiquity of computed tomography (CT) scanning, a one-shot intravenous pyelogram may be useful in patients with flank wounds or gross hematuria who are unable to undergo further diagnostic testing prior to operative intervention. Plain radiography of the abdomen is generally not helpful other than in penetrating trauma as a means of evaluating the trajectory of a retained intra-abdominal missile.

Diagnostic Peritoneal Lavage

Although DPL has largely been replaced by ultrasonography, clear indications still remain for its use. A positive DPL in hemodynamically unstable patients with potential multisystem trauma allows for expeditious interventions. A negative test in stab wounds supports observation and early discharge. The main concern regarding DPL is that it is overly sensitive for intra-abdominal blood, which has lead to a high rate of negative or nontherapeutic laparotomies. Recent literature, however, has advocated the use of DPL in conjunction with CT scanning or laparoscopy, particularly in low-velocity penetrating trauma (ie, stab wounds), to decrease the number of nontherapeutic laparotomies. If DPL is considered, it should be performed only after consultation with the trauma surgeon, who should perform this diagnostic study in most cases. Current guidelines emphasize the complimentary role of DPL, FAST, and CT scanning for trauma patients.

CT Scanning