Chapter 26: Abdominal Trauma

Initial reports from the field tend to be brief and consist of bare essentials to alert the receiving facility. The field staff focus on major presenting signs and symptoms that can be managed or temporized while preparing for and implementing transport to the hospital. Interventions such as splinting, intubation, IV placement, and, in some communities, drug administration are performed. Review and advice from the receiving physician or facility is often sought. The current paradigm emphasizes "scoop and run," or rapid transport to a definitive facility rather than aggressive and prolonged management in the field.¹ Some would even advocate against placement of IVs prior to beginning transport in urban areas, since the time to place IVs may be equivalent to the time of transport. Location and time of transport probably have a major effect on level and outcomes of care. Advanced life support (ALS) providers are more prevalent in the urban than the rural setting, which is probably the opposite of what is required. Interestingly, however, ALS has not been shown to provide benefit in the EMS setting, and the use of EMS causes delays in time of transport owing to advanced interventions for severe trauma. More concerning, ALS measures, particularly endotracheal intubation, worsened outcomes for patients with initial Glasgow Coma Scale (GCS) scores of less than 9.^2,3

Estimated time of arrival (ETA) and information about the nature of the injury and patient help the receiving facility prepare personnel and resources appropriately. Further exchange of information might consist of requests for guidance from the receiving physician; otherwise, the EMS staff will focus on transport and patient stability. Transport, IV placement, and directly applied pressure to the head wounds along with vital signs and basic patient observation are the key at this time, which is known as the prehospital phase.

This patient may arrive in stable condition with minor injuries that you can easily manage, or could decompensate at any point from overt or occult causes. A room or area should be set aside for this patient, with space for equipment and personnel. Nursing and support staff, including radiology, should be on standby. Endotracheal intubation equipment (laryngoscopes and endotracheal tubes of different sizes, a bag-mask device, end-tidal Co₂ confirmation device, oral or nasal airways, and suction at a minimum) should be prepared and checked. Warm IV fluid sets should be prepared. Standard monitors including noninvasive blood pressure, pulse oximetry, and continuous electrocardiography (ECG) must be present. The blood bank should be informed and asked to have un–cross-matched type O blood available if needed. Universal precautions must be observed; therefore, gowns, gloves, and eye/face protection should be donned. The surgeon should be called in. Arrangements for possible transfer to a higher level care facility should be initiated.

You can begin a simple initial assessment as the patient rolls in. Is the patient conscious? Is he in distress? Does he have any gross injuries? Is your team assembled and prepared? EMS will give you a brief but fuller summary than performed over the radio. Details such as mechanism of injury, restrained versus unrestrained, time of extraction, and events during transport provide insight into likely sites and severity of injuries.

A simple and systematic approach is emphasized by the advanced trauma life support (ATLS) guidelines. Many of the steps can be performed in parallel by the team. Coordination by a team leader is essential, along with communication among team members.

A rapid primary survey is followed by treatment of abnormal vital functions. A secondary survey follows, and then definitive care.

ATLS guidelines reduce initial trauma management to ABCDE:

1. Airway maintenance with cervical spine protection

2. Breathing and ventilation

3. Circulation with hemorrhage control

4. Disability: neurologic status

5. Exposure/environmental control: completely undress the patient but prevent hypothermia⁴

You should be concerned about this patient. He suffered a high-energy impact without restraint and has a head injury along with signs of chest or abdominal injury. Table 26-1 outlines typical patterns of injury based on injury mechanism. The lack of severe abdominal pain and relative lack of physical findings can be masked by altered mental status. Furthermore, patients, particularly the young, can compensate for initial injury for some time before abruptly deteriorating. Significant injuries can remain relatively occult, dictating continued patient reassessment. The relative blood pressure stability provides no reassurance; hypotension is a late sign of decompensation.⁵ The tachycardia is nonspecific but may portend ongoing blood loss or impending hemodynamic compromise.

You have performed a rapid primary survey and should now address vital functions while beginning a secondary survey. Fluid administration is indicated. The tachycardia could be due to pain, anxiety, or more likely ongoing blood loss. There is little or no disadvantage to a fluid bolus at this point. One to 2 L of normal saline or Ringer's lactate, warmed, should be given rapidly. A nasogastric tube (since there is no facial or skull base injury, the nasal route is appropriate) for lavage and a urinary catheter are important. You should also address the most obvious injury and source of blood loss; that is, the scalp lacerations. Scalp wounds can cause significant blood loss. The wound should be inspected gently but not probed. Depressed skull fracture or foreign material should be identified if possible. Leakage of clear fluid indicates cerebrospinal fluid (CSF) leak. Staples or sutures can quickly stop blood loss; since the scalp is highly vascular, infection is unlikely.

Current practice has incorporated the FAST (Focused Assessment with Sonography in Trauma) examination into trauma care worldwide. The basic premise of FAST is to identify fluid in the pericardium or peritoneum. An extended FAST (eFAST) examination is used at some centers; this protocol uses ultrasound to look for pathologic fluid or air in the thorax.

The FAST examination has four views (Figure 26-1); eFAST adds thoracic views.⁶ The examination is usually performed initially with the patient supine. The patient can be moved, if clinically appropriate, to improve sonographic windows; for example, to the right lateral position to demonstrate fluid in the right upper quadrant. There is no established, widely accepted certification in FAST; however, United States surgical and emergency medicine residencies now promote training in this technique.

Evidence supports the widespread adoption of FAST. Ultrasound in abdominal trauma has been shown to improve patient outcomes, reduce the use of diagnostic peritoneal lavage (DPL) and computed tomography (CT), and shorten time to the operating room (OR).⁷ Cost savings are significant; more than enough to pay for the cost of the ultrasound machine.⁸ Scoring based on fluid depth in the abdomen correlates with need for laparotomy.⁹ FAST can detect as little as 250 mL of free fluid in the abdomen, with an average positive FAST at 619 mL.¹⁰

Classic diagnostic tools for abdominal trauma are the DPL and the CT scan. DPL is sensitive for blood in the abdomen but is somewhat time consuming; requires operator experience; has reduced effectiveness or application in the pregnant, obese, or postsurgical patient; and is invasive. Use of the DPL has decreased with the advent of FAST. CT scan is sensitive not only for free fluid but also for solid organ injury and free air, and is now widely available. However, it is costly and time consuming, as well as requiring transport of a potentially unstable patient out of a highly monitored setting (Table 26-2).¹¹

FAST equipment is small and portable. It can be performed at the bedside by a member of the trauma team while initial review and resuscitation efforts are under way. ATLS guidelines recommend a repeat FAST examination 30 minutes after the first scan to demonstrate developing hemoperitoneum in slowly bleeding patients or patients close to the time of injury.⁴

DPL is 98% sensitive for intraperitoneal bleeding but does not detect pericardial pathology. It is best performed by an experienced operator. The open or closed infraumbilical approach can be used. After NG tube and urinary catheter placement, the lower abdominal surface is made sterile. In the open technique, the infraumbilical area is locally anesthetized if indicated, a vertical incision is made, and then the soft tissue is dissected at the midline down to the peritoneum. The peritoneum is punctured and a peritoneal dialysis catheter or other appropriate tube is passed into the peritoneal cavity. The closed technique employs a catheter passed over a needle that is inserted into the peritoneum over a wire—essentially a Seldinger technique. If initial aspiration is negative for blood, gastrointestinal (GI) contents, or other foreign material, 1 L of warmed crystalloid is instilled. The fluid is distributed throughout the abdomen by gentle manipulation of the patient. The fluid should remain for a few minutes if conditions allow. The fluid is then drained. More than 30% return is adequate. The fluidshould be sent for Gram stain, red blood cell (RBC) and white blood cell (WBC) counts. More than 100,000 RBCs/cc, more than 500 WBCs/cc, or positive Gram stain for bacteria or food fibers indicates the need for laparotomy. Note that the DPL does not detect retroperitoneal injury or diaphragmatic tears. The pregnant patient or prior surgical patient may require a supraumbilical approach. Potential complications of the DPL include bleeding, peritonitis from enteric perforation, urinary bladder injury, solid organ injury, and wound infection.⁴

FAST, DPL, and CT are not mutually exclusive tests and can be used to complement management. There is no absolute standard of care when choosing among these tests, but clearly their availability and timing must be considered. An initial FAST examination for every trauma patient is standard at many centers.

The right upper quadrant view looks at the Morrison pouch and thus for fluid in the right paracolic gutter between the liver and right kidney. The left upper quadrant view examines the space between the spleen and the left kidney; that is, the left paracolic gutter. Notably, the right paracolic gutter is longer than the left and tends to have more fluid in it during pathologic states since the phrenocolic ligament on the left side diverts fluid to the right. The rectovesical pouch in males or the pouch of Douglas in females is the most dependent intrapelvic space in the supine patient, and is thus the target of the FAST pelvic view. The pericardium, typically through the subxiphoid or subcostal view, is seen on the fourth view. Assessment of the diaphragms and pleural spaces bilaterally is performed in the eFAST.¹¹ Figure 26-2 is a sample left upper quadrant FAST view.

Recurrent tachycardia after resolution with fluid along with developing FAST findings suggests intraperitoneal bleeding. The lack of change in physical examination and lack of acute anemia should not reassure you. Circulating hemoglobin concentration does not change acutely with rapid hemorrhage.

ATLS guidelines recommend a low threshold for transfer of trauma patients to higher levels of care. You have stabilized and already begun resuscitation of this patient; further management requires the OR. At this point, you must decide between transfer to another, higher level of care facility or await arrival of your OR staff. This choice must be made using your knowledge of the resources at hand and time of transport to the next facility, as well as the patient's stability. You have already initiated arrangements with a team at a trauma center 40 minutes away by ground, which has 24-hour OR readiness. You and the surgeon decide that transfer is best for this patient (Table 26-3).

Further studies will delay transfer and definitive care for this patient. While other pathology might be revealed by the scan, you have already identified his most threatening problem—hemoperitoneum—and its treatment—laparotomy. Further studies are not indicated pending resolution of his primary problem, and could worsen his condition. Even the entirely stable patient's transfer should not be delayed. This particular patient, however, is not stable and needs laparotomy as soon as possible (Table 26-4).

ABCDE (see above), the treatment of abnormal vitals, and repeated assessment of traumatized patients.

This patient needs to be in a c-collar since we do not know if she suffered another injury, and she likely is unresponsive because of medications used to intubate, if not from injury. She needs a complete primary survey, which includes looking at the back, perineum, and rectum. Endotracheal tube position should be confirmed by breath sounds and end-tidal carbon dioxide (ETCo₂) concentration. A FAST examination can be done after she is turned. The room should be warmed and fluids made warm. Blood should be available, and labs sent. An oral gastric tube for lavage and a urinary catheter should be placed.

She is bleeding somewhere and needs resuscitation with fluid and probably blood. If cross-matched blood is available, give several units in anticipation of ongoing blood loss; otherwise, you must use un–cross-matched but typed blood if she is already typed, or type O blood if you do not know the blood type. Since she is female, she may have been exposed to Rh antigens during pregnancy and, therefore, you should not use O+ blood if at all possible. Fresh-frozen plasma (FFP) should be given as well; recent trauma literature supports use of FFP to blood in a 1:1 ratio, although this is not a universal standard.¹² Another large-bore IV would prove to be useful.

Not if she fails to respond to fluids and blood. She would need to go directly to the OR for laparotomy. In fact, some experts would take any patient with penetrating wounds to the abdomen and hemodynamic instability to the OR immediately. A secondary survey should be repeated. Points of interest would be the chest, looking for pneumothorax, hemopneumothorax or a pericardial effusion, all of which can cause tachycardia, hypotension, and acute anemia. The left anterior chest wound, since it is below the nipple, could have caused an intra-abdominal injury. If she responds to the fluid and blood products, then a judgment can be made about conservative, expectant management (observation and studies) versus immediate laparotomy.

Gunshot wounds are high energy; stab wounds are low energy. Gunshot wounds to the abdomen typically mandate exploratory laparotomy since significant intraperitoneal injury will reach nearly 90%. Gunshots can also fragment or ricochet off bony structures, worsening injury. Small bowel, colon, liver, and vascular structures are the more common injured organs. Stab wounds to the abdomen are less likely to require exploratory laparotomy and, if the patient is stable, can be explored at the bedside. Organs injured by stab wounds are typically the liver, small bowel, diaphragm, and colon.⁴ Indications for exploratory laparotomy in abdominal trauma are listed in Table 26-5. Gunshot wounds can vary widely depending on site of entry, type of bullet, and victim position. Entry and exit sites are not always identifiable. The projectile path within the body is not necessarily linear as the bullet can tumble prior to stopping, and it can subsequently migrate. CT scan, while highly useful in the stable patient with penetrating abdominal injury, does not obviate the need for serial observation or exploratory laparotomy.¹³

This patient is probably developing intra-abdominal hypertension (IAH) with signs of abdominal compartment syndrome in the setting of fecal peritonitis, bowel injury, and large fluid resuscitation. You should check a bladder pressure, and while that is obtained, call the surgeon, who will likely elect to open the abdomen. See Chapter 28 for more details regarding assessment and management of IAH. The CVP is elevated because of transmission of the high intra-abdominal pressures to the inferior vena cava (IVC). Similarly, catheter-measured cardiac filling pressures would be elevated, with a low cardiac output and stroke volume. This patient requires the fluid for resuscitation; the bowel edema is part of the natural history of her disease process and will have to be managed conservatively until resolution.

There is no evidence supporting antibiotic use in the patient with penetrating abdominal trauma sensu stricto.¹⁴ However, patients undergoing exploratory laparotomy should receive one dose of antibiotic with gram-positive and gram-negative coverage prior to incision. Patients with evident hollow viscus injury should receive at least 1 day of such antibiotic. Our patient, who has fecal peritonitis, is more complex and will require several days of antibiotic treatment for gram-positives, gram-negatives, anaerobes, and possibly fungal pathogens as well since the patient is critically ill. The Infectious Disease Society of America/Surgical Infection Society guidelines recommend 4 to 7 days of treatment for complicated intra-abdominal infections; less than 24 hours of antibiotic are required for simple perforated bowel cases. These guidelines also detail antibiotic regimens.¹⁵

The tertiary survey should be performed. This is essentially the final phase of the evaluation that began in the trauma bay. The patient's injuries and status should be reviewed literally from head to toe. A physical examination should be performed and a history elicited from the patient if possible. Laboratory and radiologic studies should be thoroughly reviewed. In this way, missed injuries or trauma sequelae can be identified. The tertiary survey typically takes place 24 hours after admission, and some centers repeat the tertiary survey prior to discharge.^16,17

Hepatic injury manifests as hypovolemic shock. Hemorrhage can be rapid enough that anemia is not seen on initial laboratory investigation. CT is sensitive for liver injury and can provide the basis for triage, but these images have not been found to correlate well with intraoperative findings. FAST is typically not useful for defining liver parenchymal injury. Surgical management can include direct ligation of vessels, debridement, or partial resection if indicated. Packing is performed for hard to control bleeding. Identification and control of bleeding can be challenging since the liver has three sources of blood: the hepatic artery, portal vein, and back bleeding from the hepatic veins. Injury at the hepatic veins or hepatic IVC can be especially hard to manage.¹⁸ A common grading system for hepatic injury is given in Table 26-6. Traumatic hepatic injury even with high-grade liver laceration can be managed conservatively without operation with close observation, having cross-matched blood available, and fluid restriction with the aim of a low CVP to reduce venous bleeding.

Pancreatic injury. This patient suffered blunt trauma to the epigastric area, energetic enough to cause thoracic spine fracture. Absence of hyperamylasemia on initial presentation does not rule out traumatic pancreatitis; conversely, not all elevations of amylase in trauma patients are caused by pancreatitis, a finding that is not well understood but may be due to translocation into the bloodstream.¹⁹ In any case, traumatic pancreatitis must be assessed by serial CT if necessary. Management can range from observation to debridement, depending on CT findings and patient condition.

Transfuse blood products—The patient likely has ongoing blood loss.

Retroperitoneal bleed from the pelvic fracture should be uppermost. These can be quite difficult to control, but there are several interventions to stabilize the bleeding. In the first place, do no harm. Do not worsen the fracture and potentially the bleeding by rocking the pelvis to determine stability. Instead, if retroperitoneal hemorrhage from pelvic fracture is suspected, the pelvic bone should be stabilized with a commercial purpose-built device or by cinching a sheet around the patient's hips. Management can be expectant or can involve interventional radiology for embolization versus intraoperative management. The latter can lead to worse blood loss since the bleeding source can be difficult to identify and control in the OR. In such cases, packing and stabilization of the bony structures, then embolization, can be done.²⁰ Retroperitoneal hemorrhage can occur with both blunt and penetrating abdominal injuries, with or without bony involvement. Other concerns in the differential are pulmonary embolus (fat, air, or thrombotic), pericardial tamponade, pneumothorax, or great vesselinjury. Neurogenic shock from a high spinal injury is less likely, given the tachycardia. Ongoing assessment of vital signs, imaging, or surgical exploration is indicated.