Abdominal Trauma: Nonoperative Management and Postoperative Considerations

FIGURE 57.1 A thorough history and physical examination in the intensive care unit including imaging, termed the tertiary survey, can be documented on a standardized form to facilitate communication among care providers.

TABLE 57.1 Indications for Surgeon Evaluation in the Intensive Care Unit

Massive transfusion protocols, often initiated in the ED, may be continued in the ICU. Trauma-induced coagulopathy is now well recognized, and underscores the importance of preemptive blood component administration (12). The resurgent interest in viscoelastic hemostatic assays (TEG, ROTEM) has facilitated the appropriate and timely use of clotting adjuncts including the prompt recognition of fibrinolysis. The traditional thresholds for blood component replacement in the patient manifesting a coagulopathy have been INR over 1.5, PTT more than 1.5 normal, platelet count above 50,000/μL, and fibrinogen over 100 mg/dL. However, these guidelines have been replaced by TEG or ROTEM criteria in many trauma centers (Table 57.2). Such guidelines are designed to limit the transfusion of immunologically active blood components and decrease the risk of transfusion-associated lung injury and multiple organ failure (12).

TABLE 57.2 Transfusion Triggers Using Either Thromboelastography-Based Resuscitation or Traditional Methods

Adequate resuscitation is mandatory, and often determines when the surgeon can safely return the patient to the operating room (OR) after initial operative intervention. Specific goals of resuscitation include a core temperature higher than 35°C, base deficit less than –6, and normal coagulation indices. Hyperchloremia associated with normal saline administration and exogenous bicarbonate, occasionally given if the serum pH is below 7.2 to improve cardiovascular function and response to vasoactive agents, obfuscates the acid–base balance and lactate in general is considered a more reliable indicator of adequate tissue perfusion. Although correction of base deficit and lactate values is desirable, how quickly this should be accomplished requires careful consideration. Adverse sequelae of aggressive crystalloid resuscitation include increased intracranial pressure, worsening pulmonary edema, and intra-abdominal visceral and retroperitoneal edema resulting in secondary ACS as well as extremity compartment syndrome (13,14). Therefore, it should be the overall trend of the resuscitation rather than a rapid reduction of the base deficit that is the goal.

NONOPERATIVE MANAGEMENT OF TRAUMA

Blunt Liver and Spleen Injuries

The liver and spleen are the most commonly injured solid organs, occurring in 10% to 15% of all trauma patients (Fig. 57.2). The liver’s large size makes it the most susceptible organ injured in blunt trauma, and it is frequently involved in upper torso penetrating trauma. Blunt trauma to the left upper quadrant, often with associated rib fractures, should raise the concern for a splenic injury. Although the liver is more frequently injured, recurrent bleeding from splenic injuries is more common. Nonoperative management of solid-organ injuries is pursued in hemodynamically stable patients who do not have overt peritonitis or other indications for laparotomy (15–25). The clinician should consider the following elements when reviewing the CT scan: the American Association for the Surgery of Trauma (AAST) grade of injury (Table 57.3), the amount of free fluid within the abdomen, the presence of contrast extravasation indicating ongoing arterial bleeding, and evidence of pseudoaneurysms (Fig. 57.3). High-grade injuries, a large amount of hemoperitoneum, contrast extravasation, and pseudoaneurysms are not absolute contraindications for nonoperative management; however, these patients are at high risk for failure and are more likely to need angioembolization (26–29). There is no age limit for consideration of nonoperative management for solid-organ injuries, but elderly patients do not tolerate secondary bleeding as well (30–32).

FIGURE 57.2 Representative solid-organ injuries; American Association for the Surgery of Trauma grading includes evidence of grade III and IV hepatic injuries (**A, B**) and grade III and IV splenic injuries (**C, D**) and parenchymal lacerations.

TABLE 57.3 American Association for the Surgery of Trauma Solid-Organ Injury Grading Scales

The AAST developed a grading scale to provide a uniform definition of solid-organ injuries based upon the magnitude of anatomic disruption (33–35). The grading of solid-organ injuries permits accurate relay of information between care providers, a predictive value on the incidence of nonoperative failure, and information for appropriate monitoring (Table 57.4). Most patients with liver or spleen injuries, regardless of grade, can be managed nonoperatively (16,23). A multidisciplinary approach including angiography with selective angioembolization and endoscopic retrograde cholangiopancreatography (ERCP) with stenting has resulted in higher rates of successful nonoperative management and improved survival in liver (26,27,36) and splenic injuries (28,29,37–40). Splenic angioembolization has been employed as an adjunct to nonoperative therapy, with reported salvage rates of 98% (40). Patients with contrast extravasation who are hemodynamically stable should likely undergo splenic embolization (28,29,38,39). Additionally, patients with splenic artery pseudoaneurysms or arteriovenous (AV) fistulae within the spleen are also candidates (41). If a patient is going to fail nonoperative management (Fig. 57.4), the time to failure is different for liver versus spleen injuries. Typically liver injuries rebleed within the first hours of admission, while splenic lacerations may have delayed rupture or bleeding weeks following the original injury. With high failure rates reported for grade V splenic injuries, empiric immunization for encapsulated organisms should be considered but may not be mandatory (42). Similarly, patients who undergo angioembolization of the spleen should also receive immunizations. Repeat imaging within 7 days is performed for high-grade injuries (43); hepatic injuries can be evaluated with ultrasound while splenic injuries undergo CT scanning. Patients with liver trauma and evidence of right upper quadrant fluid collections on ultrasound or clinical deterioration (increasing abdominal pain, worsening liver function tests, unexplained fever) should undergo CT scanning.

TABLE 57.4 Appropriate Monitoring and Nonoperative Management Failure Rates for Solid-Organ Injuries by Grade

FIGURE 57.3 Contrast blush noted on CT scan imaging of the liver (A) suggestive of active arterial bleeding; postinjury pseudoaneurysms of the spleen are likewise demonstrated with contrasted CT imaging (B).

FIGURE 57.4 Rates of nonoperative failure for solid-organ injuries.

Pancreatic Injuries

Historically, injuries to the pancreas were managed with operative intervention (44). With the recent evolution of nonoperative management for solid-organ injuries, a nonresectional management schema has been developed for most pancreatic injuries (45,46). Observation of pancreatic contusions, particularly those in the head of the pancreas that may involve ductal disruption, includes serial examinations and monitoring of serum amylase. Patients with pancreatic injuries involving the major ducts, originally a strict indication for operative intervention, may be managed with ERCP and stenting in selected patients; durability of this approach is currently under investigation (47).

Duodenal Hematomas

Following blunt trauma, patients may develop hematomas in the duodenal wall that obstruct the lumen. Clinical examination findings include epigastric pain associated with either emesis or high nasogastric tube (NGT) output; CT scan imaging with oral contrast failing to pass into the proximal jejunum is diagnostic (Fig. 57.5). Patients with suspected associated perforation, suggested by clinical deterioration or imaging with retroperitoneal free air or contrast extravasation, should be explored operatively. Nonoperative management includes continuous NGT decompression and nutritional support with total parenteral nutrition (TPN) (48,49). A marked drop in NGT output heralds resolution of the hematoma, which typically occurs within 2 weeks. Repeat imaging to document these clinical findings may be helpful before initiating an oral diet. If the patient does not improve clinically or radiographically within 2 to 3 weeks, operative evaluation is warranted.

Penetrating Wounds

Patients with abdominal gunshot wounds (GSWs) violating the peritoneum usually undergo emergent laparotomy due to an approximate 90% visceral injury rate. Selected patients with isolated low-energy GSWs to the right upper quadrant are observed (50); CT scan imaging must delineate the tract of the bullet, which should be confined to the parenchyma of the liver, and the patient must be hemodynamically stable with a benign clinical examination. Recently, several trauma centers have extended this policy to all abdominal GSWs without CT evidence of a hollow visceral injury (51,52). Patients with abdominal stab wounds to the back or flank with negative CT imaging or an isolated kidney injury are also managed nonoperatively (53). Similar to patients with right upper quadrant GSWs, individuals with stab wounds and a CT scan showing the tract of injury confined to the liver are usually observed (53). In some cases, laparoscopy will be done to assess the penetrating liver injury and ensure that hollow viscera are not violated. Regardless of the trauma surgeon’s decision for operative versus nonoperative management, it is essential that these patients undergo repeated abdominal examination. Observation for a missed bowel injury is critical; clinical findings in such patients include a rising white blood cell (WBC) count, fever, tachycardia, and increasing abdominal pain or diffuse abdominal tenderness. In patients with isolated liver injuries, complications are similar to those for patients with blunt injuries, namely, bleeding, bile leaks, or biliary sepsis.

COMPLICATIONS OF NONOPERATIVE INJURY MANAGEMENT

Following hepatic injuries, the most common complication is a bile leak or biloma, occurring in up to 20% of patients with major injuries (grade III or higher) (Fig. 57.6) (54,55). Clinical presentation includes abdominal distention, intolerance of enteral feeds, and elevated liver functions tests. CT scanning effectively diagnoses the underlying problem, and the vast majority is treated with percutaneous drainage and ERCP with sphincterotomy. Occasionally, laparoscopy or laparotomy with drainage of biliary ascites is indicated, particularly if the patient fails to resolve their ileus and fever (56). Hemobilia, manifested by the triad of right upper quadrant pain, jaundice, and upper gastrointestinal bleeding, is a rare complication indicative of a communication between a tributary of the hepatic artery and biliary system. Delayed rupture of a subcapsular hematoma with hemorrhage is another infrequent complication but the diagnosis is usually obvious. Patients undergoing angioembolization for liver trauma must be carefully monitored for hepatic necrosis, and may occasionally require delayed formal hepatic resection (Fig. 57.7).

FIGURE 57.5 Duodenal hematomas are diagnosed radiographically by direct identification of a hematoma (A) or failure to pass oral contrast past the third portion of the duodenum on computed tomography scan (B) or upper gastrointestinal series (C).

The most common problem in patients with splenic injuries is delayed bleeding. Patients undergoing splenic embolization can experience rebleeding, with up to 15% of patients requiring splenectomy (57). Moreover, those undergoing successful angioembolization typically have significant ischemic pain, and some may develop splenic abscesses. In centers that advocate splenic autotransplantation to prevent overwhelming postsplenectomy sepsis (OPSS), recognition of CT scan findings of normal splenic implants versus infected splenic implants is critical in patients with clinical deterioration (58) (see Fig. 57.7).

ONGOING EVALUATION FOR INJURIES: HOW TO AVOID A MISSED INJURY

With the paradigm shift from operative to nonoperative management of trauma, the clinician must have a heightened sense of awareness to identify an occult injury.

Missed bowel injuries are the most commonly pursued injury, not due to their frequency (<5% of blunt trauma) but rather their associated morbidity. Diagnosing a hollow viscus injury is notoriously difficult (59), and even short delays in diagnoses result in increased morbidity (60,61). CT scan imaging is not 100% accurate; repeat CT scan imaging, diagnostic peritoneal lavage (DPL), ultrasound, and even laparotomy may be necessary for definitive evaluation. If a patient’s initial CT scan of the abdomen shows free fluid without evidence of a solid-organ injury to explain such fluid, patients are monitored closely for evolving signs of peritonitis suggestive of a bowel injury (62–64). If patients have a significant closed head injury or cannot be examined serially, DPL should be performed to exclude bowel injury. DPL should also be considered in a patient if there is increasing intra-abdominal fluid on bedside ultrasound in patients with a solid-organ injury but a stable hemoglobin, and/or in patients with unexplained clinical deterioration. When pursuing a diagnosis of bowel injury using DPL, particular attention should be paid to elevations in bilirubin, alkaline phosphatase, and amylase (65,66) (Table 57.5). The specific type of injury may be either bowel perforation due to ischemia from an avulsed mesentery, a direct antimesenteric blowout injury, or an extensive serosal injury (Fig. 57.8). One should not assume that drugs, alcohol, or their associated withdrawal syndromes are the primary source of a patient’s clinical deterioration.

FIGURE 57.6 Bilomas are the most common complication following hepatic trauma (A), while angioembolization for unremitting postinjury liver hemorrhage may result in partial hepatic necrosis (B).

FIGURE 57.7 A: Splenic implants are autotransplanted into the greater omentum to prevent overwhelming postsplenectomy sepsis. Follow-up computed tomography can differentiate between “normal” implants (B) and infected implants (C).

Missing a rectal injury may be life threatening in patients with pelvic fractures. Although some patients have clear findings on physical examination, ranging from hematochezia to overt degloving of the perineum, others may have smaller injuries that are missed on initial evaluation in the trauma bay. In fact, the rectal examination may have been omitted in the trauma bay, so the intensivist should ensure that this has been done. Flexible sigmoidoscopy is the easiest diagnostic procedure for the clinician to perform at the bedside in the ICU; endoscopic evaluation should search for blood within the canal, ischemic mucosa, as well as intestinal perforation (67).

TABLE 57.5 A Positive Diagnostic Peritoneal Lavage Following Blunt Trauma Defined by Specific Laboratory Values

Pancreatic contusions, with or without associated ductal disruption, are difficult to diagnose in patients with blunt abdominal trauma (68). Patients at risk include those with high-energy mechanisms suggested by a seatbelt sign on physical examination, or a direct blow to the epigastrium (69). The initial CT scan may show nonspecific stranding of the pancreas. Associated fluid around the pancreas should prompt further studies such as ERCP or magnetic resonance cholangiopancreatography (MRCP) to rule out a biliary or pancreatic duct injury. With a tentative diagnosis of a pancreatic contusion, one may consider following serial determinations of amylase/lipase; although these laboratory studies do not have a reliable sensitivity (70), increasing values over time combined with an alteration in clinical examination should prompt a repeat CT scan, a duodenal C-loop study, a DPL, or an ERCP depending upon the suspected lesion.

FIGURE 57.8 Bowel injuries following blunt trauma include perforation due to ischemia from an avulsed mesentery (A), a direct antimesenteric blowout injury (B), and a blunt serosal injury (C).

POSTOPERATIVE MANAGEMENT OF SPECIFIC INJURIES

In addition to resuscitation of the trauma patient, ICU care includes management of injuries found at operative exploration. Communication between the operating surgeon and the intensivist is critical, and should include intraoperative findings and procedures, any tenuous operative repairs, anticipated problems or complications, the need for repeat operative exploration, and location of drains. The intraoperative estimated blood loss (EBL) and associated blood product transfusion requirements are essential data to anticipate events in the postoperative period. The transfusion information should include whether a massive transfusion protocol was initiated, or if evidence of clinical coagulopathy was identified during operative treatment. Finally, all clinicians caring for the patient should remember that injuries can be missed even with prior operative intervention.

Liver and Spleen Injuries

Although the majority of patients with solid-organ injuries are successfully managed nonoperatively, hemodynamically unstable patients or those with associated injuries may require urgent operation. Life-threatening hepatic bleeding is most often controlled with perihepatic packing or sometimes with additional Foley catheter tamponade of deep lacerations (Fig. 57.9). The most immediate concern in the postoperative period is rebleeding; this is heralded by a falling hemoglobin, blood or blood clots accumulating under a temporary abdominal closure dressing, and bloody output from intra-abdominal drains. Substantial hemorrhage is reflected in hemodynamic instability and continued acidosis. Patients with recurrent hemorrhage may be treated with angioembolization or may necessitate repeat operative packing depending on the rate of bleeding (27). Postoperative hepatic ischemia is usually due to either a prolonged intraoperative Pringle maneuver or hepatic artery ligation or embolization; patients with the former should have an elevation but subsequent resolution of their transaminases while those with the latter may have frank hepatic necrosis. Patients are returned to the OR for pack removal 24 to 48 hours after initial injury. Other long-term sources of morbidity are similar to patients undergoing nonoperative management, and include intra-abdominal abscess, biloma, and hemobilia. Although patients should be evaluated for infectious complications, patients with severe liver trauma (grade IV or V) have intermittent “liver fever” for the first 5 postinjury days (71).

Operative intervention for splenic injuries includes splenectomy and splenorrhaphy. Postoperative hemorrhage may be due to the inadequate splenic hilar vessel ligation, a missed short gastric artery, or recurrent bleeding from the spleen if splenic repair was attempted. An early postsplenectomy increase in platelets and WBCs is normal; however, beyond postoperative day 5 a WBC count above 15,000 should prompt a thorough search for underlying infection (72). The role of antiplatelet therapy for thrombocytosis remains controversial; data are lacking on whether aspirin therapy yields a significant outcome benefit, and for which patient population. Therapy may be instituted when the platelet count exceeds 1,000,000/μL, if not contraindicated (e.g., cerebral trauma) due to evidence of platelet hyperactivity of more than 48 hours (73). Additional sources of morbidity include a concurrent but unrecognized iatrogenic injury to the pancreatic tail during splenectomy resulting in pancreatic ascites or fistula. Patients have an increased incidence of intra-abdominal abscesses in the left upper quadrant following splenectomy with concomitant gastrointestinal injury, but presumptive drainage does not prevent this complication. Routine care following splenectomy also includes immunizations for encapsulated organisms (Streptococcus pneumoniae, Haemophilus influenzae, and Meningococcus) usually just prior to discharge, optimally 2 to 3 weeks after splenectomy (74).

Gastrointestinal Injuries

Operative intervention for either penetrating or blunt gastrointestinal injuries entails primary repair, resection with primary anastomosis, or resection with a stoma diversion. Regardless of the type of operation or the type of anastomosis (stapled vs. sewn) (75), one should await resolution of the patient’s expected postoperative ileus before feeding. Return of bowel function is noted by a decrease in gastrostomy or NGT output and the passing of flatus. If an ileostomy or colostomy was required, one should inspect it daily to ensure it is pink without evidence of necrosis. Postoperative complications include anastomotic leak, prolonged ileus, and bowel obstruction. A leak with intra-abdominal contamination or sepsis presents with increasing abdominal pain, fevers, and respiratory compromise in the extubated patient, or persistent fevers and intolerance of enteral feeding in the intubated patient. CT scan is diagnostic and repeat operation is often required.

Important questions for the intensivist following operative intervention for pancreatic injuries include how much of the pancreas was resected, is there a pancreaticoenteric anastomosis, was the pancreatic stump closed securely, was the spleen preserved, and where were drains placed (76). Closed suction drains should remain in place until the patient is tolerating an oral diet or enteral nutrition, with the associated drain output being less than 30 mL/day. Postoperative complications include pancreatic fistula, pseudocyst, abscess, pancreaticoenteric leak, and pancreatitis. The most common of these is a pancreatic fistula, occurring in up to 20% of patients with isolated pancreatic trauma including the major duct, and in up to 35% of patients with combined pancreatic and duodenal injuries. Diagnosis in patients with drains in place is defined as output greater than 30 mL/day with an amylase level three times greater than serum value after postoperative day 5 (77). In patients without drains in place who have persistent abdominal pain, fevers, or intolerance of oral intake, CT scan imaging should be performed to evaluate for an intra-abdominal fluid collection. Drainage by interventional radiology (IR) is performed for fistula diagnosis and control. Pancreatic fistulae following trauma are managed in an identical fashion to those occurring following elective pancreatic resection (77).