Abdominal trauma

INTRODUCTIONEpidemiologyAbdominal injuries are common in patients who sustain major trauma. Unrecognized abdominal injuries are frequently the cause of preventable death. Abdominal injuries rank third as a cause of traumatic death preceded by head and chest injuries. Abdominal trauma results in a mortality rate of 13 to 15%. Patients with multiple abdominal organ injuries (with or without an injury to another body system) have significantly higher mortality rates than those with an isolated abdominal injury. Approximately one-fifth of all traumatized patients requiring operative intervention have sustained trauma to the abdomen. The distribution of patients with abdominal trauma varies based on triage patterns of trauma systems, geography, and socioeconomic status.

Mechanisms of Injury and BiomechanicsThe abdomen is vulnerable to injury since there is minimal bony protection for underlying organs. Because of the retroperitoneal location of certain organs and vascular structures (e.g., vena cava, aorta, pancreas, and duodenum), these structure are less frequently injured. The physical examination of the abdomen may not be successful inIdentifying intra-abdominal pathology; therefore, a description of the mechanism of injury is importantThe most common mechanism of blunt abdominal injury is a motor vehicle crash.' Firearms, stabbings, and physical assaults are associated with penetrating abdominal trauma. Injuries to the abdomen can result from acceleration, deceleration, or a combination of both forces. The abdominal viscera may be compressed or directly impacted. Crushing forces may compress the duodenum or the pancreas against the vertebral column. During energy transfer, abdominal structures attached by either ligaments or blood vessels may be stressed at their attachment points. Forces applied to a solid organ can rupture a surrounding capsule and injure the parenchyma as well. Safety restraint devices, particularly three-point safety belts, provide significant protection; however, if they are improperly positioned, they can cause deceleration injuries to the lower Lap belt use has been associated with injury to the hollow organs, particularly the small bowel and colon, lumbar spine, and abdominal wall.' Frontal impact crashes with a bent steering wheel and broken windshield are associated with spleen and liver injuries as well as head and chest trauma. Depending on the side of the impact, side impact crashes can result in injuries to the liver and spleen. Rear impact crashes can result in neck or abdominal injuries in unrestrained drivers who hit the steering column. Ejected motorcyclists may sustain pelvic fractures or intra-abdominal trauma from collisions with the handlebars or ground.

Types of InjuriesBlunt and penetrating abdominal injuries may be associated with extensive damage to the viscera resulting in massive blood loss. Blunt or penetrating abdominal injuries are related to the: • Type of force applied • Tissue density of structure injured (e.g., fluid-filled, gas-filled, solid, or encapsulated)The liver and spleen are the most commonly injured organs from blunt trauma.

1

The organs of the abdomen are vulnerable to penetrating injury not only through the anterior abdominal wall, but through the back, flank area and lower chest." Patients with penetrating abdominal injuries may present with single or multiple wounds. The liver, small bowel and stomach are the most commonly injured organs from penetrating trauma.

Usual Concurrent InjuriesBecause of their anatomical location, fractures of the lower rib cage are often associated with spleen or liver injures. The patient with abdominal trauma, particularly esophageal and gastric injuries, may have associated chest trauma. Patients with pelvic fractures frequently have associated intra-abdominal trauma (e.g., bladder laceration). Patients with penetrating wounds at the nipple line interiorly or at the inferior border of the scapula posterior are considered to be at risk for intra-abdominal injury.

PATHOPHYSIOLOGY AS A BASIS FOR SIGNS AND SYMPTOMSPatient manifestations of abdominal trauma are frequently subtle. The abdomen may sequester large amounts of fluid without apparent distention.

Signs and symptoms of blood loss: Abdominal tenderness Specific pain patterns Absent bowel sounds are associated with abdominal injury.

Blood LossInjuries to organs or abdominal blood vessels may lead to extensive hemorrhage. Some abdominal organs are semi-fixed by ligaments, such as the mesenteric attachments of the intestines. When these organs are stressed at their points of attachment, tears often occur at the point where the vessels enter the organ. The spleen and the liver have a rich blood supply and store blood. Rapid loss of large blood volumes from their parenchymal or vascular structures can occur. Because they are encapsulated, compression of the abdomen may rapidly increase pressure within the capsule, resulting in rupture and hemorrhage. In addition, the consistency of the tissues makes hemostasis difficult. Recently, however, there has been a trend toward nonoperative management of patients with splenic and hepatic injuries if the patient is hemodynamically stable. Bleeding from organs in the anterior abdomen is usually confined to that cavity. Bleeding from structures in the retroperitoneum leads to hemorrhage in the retroperitoneum, which is more difficult to evaluate and diagnose

PainPain, rigidity, guarding, or spasms of the abdominal musculature are classic signs of intra-abdominal pathology. Sudden movement of irritated peritoneal membranes against the abdominal wall causes rebound tenderness and guarding of the abdominal muscles.

Irritation may be because of the presence of free blood or gastric contents in the peritoneal cavity. Manifestations of pancreatic and duodenal injury are related to hemorrhage in the area and the effect of active enzymes on their surrounding tissues. The resultant "chemical peritonitis" from the enzymes released into the retroperitoneum and the significant tissue swelling may not appear as signs and symptoms for several hours after injury.

2

The patient with pancreatic and duodenal injury may also complain of diffuse abdominal tenderness and pain radiating from the epigastric area to the back.

PeristalsisFollowing abdominal injury, bowel sounds are frequently hypodynamic. Blood in the abdominal cavity, direct bowel injury, or any number of conditions including stress may decrease peristaltic activity; however, hypoactive or absent bowel sounds combined with tenderness and guarding should be viewed with a high index of suspicion.

SELECTED ABDOMINAL INJURIES- Hepatic InjuriesBecause of its size and location, the liver is frequently injured when force is applied to the abdomen. The severity of hepatic injuries ranges from a controlled subcapsular hematoma and lacerations of the parenchyma to a severe vascular injury of the hepatic veins, retrohepatic cava, and/or hepatic avulsion The friability of liver tissue, the extensive blood supply, and the blood storage capacity cause hepatic injury to result in profuse hemorrhage. These types of injuries require surgical control of bleeding.The success of nonoperative management for hepatic injuries is predicted on adherence to rigid criteria for patient selection. These include hemodynamic stability; the absence of peritoneal signs: neurologic integrity; precise CT delineation of the injury, degree of free intraperitoneal blood, and absence of associated intra-abdominal injuries: need for no more than two hepatic-related blood transfusions; and CT scan documented improvement or stabilization with time.SIGNS AND SYMPTOMS• Upper right quadrant pain• Abdominal wall muscle rigidity, spasm, or involuntary guarding• Rebound tenderness• Hypoactive or absent bowel sounds• Signs of hemorrhage and/or hypovolemic shock

- Splenic InjuriesInjury to the spleen is usually associated with blunt trauma, but may also be associated with penetrating trauma. Fractures of the left 10th to 12th ribs are associated with underlying damage to the spleen. Injuries to the spleen range from laceration of the capsule or a nonexpanding hematoma to ruptured subcapsular hematomas orparenchymal laceration. The most serious splenic injury is a severely fractured spleen or vascular tear, producing splenic ischemia and massive blood loss. In cases of minor, blunt trauma, the treatment approach is generally less invasive and dependent on the patient's age and other clinical factors. Nonoperative management of the patient with an isolated splenic injury mandates that the patient be hem dynamically stable This may involve bed rest and possibly blood transfusions (Classes I and II shock only); however, observation or surgical management should be directed at eliminating the need for transfusion."

"SIGNS AND SYMPTOMS• Signs of hemorrhage or hypovolemic shock• Pain in the left shoulder (Kehr's sign)• Tenderness in the upper left quadrant• Abdominal wall muscle rigidity, spasm, or involuntary guarding

3

- Hollow Organ InjuriesForces causing trauma to hollow organs may result in either blunt or penetrating injuries. The small bowel is the hollow organ most frequently injured. Deceleration may lead to shearing, which causes avulsion or tearing of the small bowel. The areas of the small bowel most commonly affected are the areas relatively fixed or looped. Lap seat belts causing compression have resulted in rupture of the small bowel or colon.2

SIGNS AND SYMPTOMS• Peritoneal irritation manifested by abdominal wall muscle rigidity, spasm, involuntary guarding, rebound tenderness, and/or pain• Evisceration of the small bowel or stomach• Diagnostic Peritoneal Lavage (DPL) may show presence of bile, feces, or food fibers

Renal InjuriesThe most common injury to the kidney is a blunt contusion, Suspect renal injury if there are fractures of the posterior ribs or lumbar vertebrae. Renal parenchyma can be damaged by shearing and compression forces causing lacerations or contusion. The deeper the laceration the more serious the bleeding. Rupture of the kidney is not usually associated with hypovolemia unless laceration of a renal artery has occurred. Deceleration forces may cause vascular damage to the renal artery. Since there is little collateral circulation in the area of the renal artery, any ischemia is serious and may lead to acute tubular necrosis.

SIGNS AND SYMPTOMS• Ecchymosis over the flank• Flank or abdominal tenderness elicited during palpation• Gross or microscopic hematuria—the absence of hematuria does not rule out renal injury

Bladder and Urethral InjuriesThe majority of bladder injuries are blunt. Normally, the bladder lies below the level of the symphysispubis, but when full, it rises above the pubis into the abdominal cavity. If the bladder is not full when the rupture occurs, urine may leak into the surrounding pelvic tissues, vulva, or scrotum. If a distended bladder ruptures are perforated, urine is likely to extravasate into the abdomen. Most ruptures of the bladder occur in association with pelvic fractures. Urethral trauma is more common in males than females because the male urethra is longer and less protected. The presence of an anterior pelvic fracture should raise the index of suspicion for a concomitant urethral injury. Urethral injury in females is almost always associated with pelvic fractures. Injury to the penile portion of the urethra in males is most commonly caused by straddle trauma. Prostatic (posterior) urethral injury is usually caused by pelvic fractures and frequently leads to incontinence and impotenceSIGNS AND SYMPTOMS• Suprapubic pain• Urge, but inability to urinate• Hematuria (may be microscopic) Blood at the urethral meatus• Blood in scrotum• Rebound tenderness

4

• Abdominal wall muscle rigidity, spasm, or involuntary guarding• Displacement of prostate gland

NURSING CARE OF THE PATIENT WITH ABDOMINAL TRAUMAAssessmentHISTORYRefer to Initial Assessment, for a description of general information that should be collected regarding every trauma victim. Only pertinent questions specific to patients with abdominal injuries are described below.• Was the patient wearing any restraints or protective devices? Inappropriately positioned lap belts may injure lower abdominal structures. The use of a lap belt without a shoulder belt is associated with hyperflexion injury to the lumbar spinet• What are the location, intensity, and quality of pain?• Is nausea or vomiting present?• Does the patient feel an urge to defecate or urinate?

PHYSICAL ASSESSMENTRefer to Initial Assessment, for a description of the assessment of the patient's airway, breathing, circulation, and disability.Inspection• Observe the contour of the abdomen (i.e., flat or distended)• Inspect the lower chest, abdomen, flanks, and back for seat belt abrasions or other soft tissue injuries• Ecchymosis over the upper left quadrant suggests soft tissue trauma or splenic injury• Ecchyrnosis around the umbilicus suggests intraperitoneal bleeding, and ecchymosis of the flank suggests retroperitoneal bleeding.' Ecchymotic signs such as these may take hours or days to develop and may not be noted on initial presentation.• Inspect gunshot and stab wounds. Wounds should be described by size, appearance, and location.Wounds should NOT be labeled as entrance and exit, but clearly identified and numbered.• Inspect the pelvic area for soft tissue bruising• Inspect the perineum for hematomas, bloody drainage from the urethral meatus, and vaginal or rectal bleedingAuscultation• Auscultate all four quadrants of the abdomen for bowel sounds. Absence of bowel sounds in combination with abdominal distention and guarding are highly indicative of visceral injury.• Auscultate the chest. If bowel sounds are heard in the chest, it is an indication of diaphragmatic rupture with heriation of the stomach or small bowel into the thoracic cavity.PercussionPercuss the abdomen for hyperresonance or dullness. Hyperresonance indicates air while dullness indicates fluid accumulation.Palpation• Begin palpating in an area where the patient has not complained of pain. Gently palpate each of the four quadrants separately for involuntary guarding, rigidity, spasm, and localized pain. Press on the abdomen and quickly release to determine the presence of rebound tenderness. Any positive findings of involuntary guarding, rigidity, pain. or spasm during palpation indicate peritoneal irritation. These signs may be absent if the patient has:

5

• Competing pain from another injury• Retroperitoneal hematoma• Spinal cord injury• Ingested alcohol or narcotics• Decreased level of consciousness• Palpate the pelvis for bony instability, asymmetry', or pain, which indicate possible dislocations or fractures• Palpate the. Flanks for tenderness• Palpate the anal sphincter for presence or absence of tone

DIAGNOSTIC PROCEDURESRefer to Initial Assessment, for frequently ordered radiographic and laboratory' studies.Additional studies for patients with abdominal trauma are listed below.Radiographic Studies• Computerized tomography (CT)An abdominal CT scan may be performed to identify solid organ lacerations, hematomas, or small amounts of blood or air in the abdominal cavity. Computerized tomography of the abdomen is most commonly and appropriately used in the patient who is deemed hemodynamically stable and does not have other injuries requiring immediate diagnostic or therapeutic intervention that would be delayed by CT examination of the abdomen.• Intravenous pyelogram (IVP)Extravasation of the contrast media into surrounding tissues indicates a disruption in the integrity of the kidney, ureters, or bladder.• Flat plate, lateral, or upright abdominal radiographic studiesThese studies are used to:• Visualize foreign bodies and associated visceral damage• Identify the path of penetrating objects• Visualize free air in the abdomen indicating disruption of the gastrointestinal tract• Cystogram/urethrogram• Diagnostic ultrasound or sonogram• Ultrasonography may be used to detect the presence of hemoperitoneum. Indications for this procedure are the same as for diagnostic peritoneal lavage (DPL).• Angiography, as indicatedLaboratory Studies• Serum amylase• Liver function studies• Analysis of urine, stool, or gastric contents for blood• Pregnancy testing for females of childbearing ageOther StudiesDiagnostic peritoneal lavage (DPL)• DPL is one method used to detect intra-abdominal bleeding (see Fig 21). A diagnostic peritoneal lavage is not useful for identifying retroperitoneal bleeding." After decompressing the bladder with an indwelling catheter and the stomach with a gastric tube to avoid inadvertent puncture, a peritoneal catheter is inserted into the abdomen (usually below the umbilicus). The catheter is introduced via a puncture or a small incision. Withdrawal of gross blood from the catheter is considered a positive finding. If gross blood is not initially aspirated, a liter of warmed lactated Ringer's solution or normal saline is rapidly infused through the catheter. The lavage fluid is then allowed to drain out via

6

gravity and analyzed for the presence of red or white blood cells, bile, amylase, food fiber, or feces. DPL has a 98% accuracy rate in correctly identifying intra-abdominal bleedine.' A positive DPL requires a surgical consult.

• The American College of Surgeons Committee on Trauma recommends that a DPL be performed early to evaluate the severely injured, hypotensive patient, especially if the abdominal examination is':• Suggestive of injury• Unreliable (e.g., patient is unresponsive)

- Diagnostic peritoneal lavage may be contraindicated in the following circumstances':• When the decision has already been made to perform abdominal surgery• When the patient has had previous abdominal surgery increasing the potential for adhesions• When the patient has known cirrhosis of the liver• When the patient obese, making technical performance of the procedure difficult• When the patient has a known medical history of coagulopathy

INTERVENTIONS• Cannulate two veins with large-bore, 14- or 16-gauge catheters, and initiate infusions of lactated Ringer's solution or normal saline• Administer blood, as indicated• Insert an indwelling urinary catheter An indwelling urinary catheter is inserted to minimize urine leakage into the abdomen or supporting tissues. If a urethral injury is suspected, consider catheterizing the bladder through a suprapubic approach.Frequently observe for and quantify the degree o hematuria with an indwelling urinary catheter. The initial urine obtained may have been in the bladder prior to the traumatic event. If hematuria is noted, this may be because of the placement of the urinary catheter. Measure and discard the initial urine specimen and test the subsequent urine specimen for the presence of blood.Suspected injury to the urethra (i.e., gross blood) is a contraindication to catheterization through the urethra.• Insert gastric tube and aspirate gastric contents, in order to: • Decompress the stomach and prevent aspiration • Prevent vagal stimulation and resultant bradycardia • Minimize gastric content leakage and subsequent contamination of the abdominal cavity • Test the gastric aspirate for the presence of blood• Cover open abdominal wounds with a sterile dressing. If evisceration of abdominal contents has occurred, place a sterile, moist dressing over the injury.• Stabilize impaled objects• Continue or apply a pneumatic antishock garment (PASG) for patients with severe hypotension because of hemorrhage. Although use of the garment is controversial, if used it may reduce intra abdominal hemorrhage• Administer antibiotics, as prescribed. Leakage of gastric and bowel contents will result in peritonitis and possibly sepsis.• Administer analgesics, as prescribed• Prepare the patient for operative intervention, hospital admission, or transfer, as indicated

7

Evaluation and Ongoing AssessmentRefer to Initial Assessment, for a description of the ongoing evaluation of the patient's airway, breathing, circulation, and disability. Additional evaluations include:• Monitoring cardiovascular status for changes suggestive of hypovolemic shock• Reassessing the abdomen frequently and thoroughly to detect subtle changes• Monitoring urinary elimination for changes suggestive of hypovolemic shock

SUMMARYAbdominal trauma is frequently associated with injuries to other body regions, including the chest, Because of the high vascularity of the solid organs and the presence of major vessels, abdominal trauma has the potential to produce hemorrhage and hypovolemic shock. Patients with abdominal injuries may not present with obvious signs and symptoms. Frequent assessments and ongoing evaluation are essential' components of the trauma nursing process to detect changes in the patient's condition. Unrecognizec abdominal trauma is a frequent cause of preventable death.The trauma nurse is part of a team who recognizes the nature of multisystem trauma and the need for an organized, standardized approach to the assessment, diagnosis, and interventions for the management the patient. The nurse, who is familiar with the anatomy of the abdomen, mechanisms and patterns of injury, and the pathophysiologic consequences of injury as a basis for signs and symptoms, contribute significantly to the collaborative efforts of the trauma team.

8