Scott A. Keeney and Jose L. Pascual

Initial Assessment

Patients presenting with known or suspected abdominal trauma require a detailed physical examination of the abdomen, which should include inspection, making careful note of cutaneous ecchymosis from seat belts, tire marks, and bullet or stab wounds. Abdominal distention may suggest intra-abdominal hemorrhage, whereas a scaphoid abdomen suggests a ruptured diaphragm. Palpation should focus specifically on the presence or absence of masses or areas of tenderness. Auscultation of the abdomen should be performed as well in order to rule out any pathologic vascular murmurs.

Initial laboratory work should include a complete blood count, serum electrolytes, renal function, coagulation studies, blood typing, urinalysis, and a pregnancy test in women. Other beneficial studies may include tests of liver function, amylase and lipase, serum ethanol level, and a toxicology screen.

Routine radiologic studies obtained in patients with major blunt trauma should include a supine chest radiograph and a pelvic radiograph. Abdominal radiographs are rarely helpful in the assessment of blunt abdominal trauma but are essential in cases of penetrating abdominal trauma. All foreign bodies must be accounted for by abdominal radiologic imaging and also in adjacent images of the thorax, pelvis, and extremities. Entrance and exit sites should be identified with radiopaque markers applied to the patient prior to exposure of the film in order to help determine missile trajectory and potentially injured organs. Trajectory delineation in the initial assessment may quickly determine the need for operative intervention.

Many patients have absolute indications for surgery that are apparent early in the evaluation (Box 97.E1).

Most instances of hypotension in the immediate peri-trauma period should be treated aggressively with volume, using saline or blood products as needed. Although a secondary survey is always necessary, in the setting of life-threatening injuries requiring immediate transfer to the operating room, the exam may have to be delayed until the patient arrives to the intensive care unit (ICU). On arrival to the ICU and after the patient is hemodynamically stable, it is imperative to review all identified injuries and complete the physical exam and diagnostic workup. The tertiary survey should also be performed in the ICU, generally within 24 to 48 hours after admission to identify any missed injuries. In severely injured patients, the secondary survey is often hindered by life-threatening priorities, and a missed injury rate of 0.3% to 12% has been reported. Although these missed injuries are rarely life threatening, they may be clinically debilitating and can significantly impact the patient’s long-term outcome.

All patients with either blunt or penetrating abdominal trauma should be given tetanus prophylaxis if they have not received it in the previous 10 years. If an exploratory laparotomy is planned, a preoperative dose of broad-spectrum antibiotics covering gram-negative aerobes, gram-positive cocci, and anaerobic organisms should be given 30 to 60 minutes prior to incision. If no enteric contamination has occurred, no further antibiotics are required postoperatively. With enteric spillage, however, a 24-hour postoperative course of antibiotics is warranted. As a precautionary measure, all intravascular lines placed in the trauma admitting area should be removed within 24 hours of arrival in the ICU and new vascular access should be established in a sterile manner.

Diagnostic Evaluation of the Patient with Blunt Abdominal Trauma

In the hemodynamically stable patient with blunt abdominal trauma, additional diagnostic studies are often necessary to assess the need for less urgent operative intervention. The choice of study may depend on the availability of equipment, the information sought, and the preference of the clinician (Table 97.1). Diagnostic evaluation, however, should never delay operative intervention in patients with a clear indication for urgent abdominal exploration.

Ultrasonography: The Focused Assessment of Sonography for Trauma (FAST)

Ultrasonography has increased in popularity for the rapid assessment of trauma patients and is now part of the initial resuscitation as directed by Advanced Trauma Life Support (ATLS) protocols. This is in part due to easy bedside acquisition and the immediate availability of the information it yields, in addition to the lack of radiation exposure. The Focused Assessment of Sonography for Trauma (FAST) is a quick, reproducible, easily learned technique that evaluates the torso for the presence of abnormal fluid collections. The exam involves interrogation of the chest, looking for pericardial fluid as well as hemo/pneumothoraces, and examination of the abdomen, looking for fluid in dependent areas (the hepatorenal recess, the splenorenal recess, and the pelvis). When used as a rapid triage tool by experienced operators, the technique has been validated in multiple studies with sensitivities in the 70% and high 80% range and specificities reported up to 100% in patients with blunt abdominal trauma and hypotension.