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Emergency and Acute Medicine – Penetrating Abdominal Trauma
Overview and Mechanism of Injury
Penetrating abdominal trauma results from injury caused by knives, gunshots, or other foreign objects breaching the abdominal wall. Damage to solid organs most often leads to significant hemorrhage, whereas hollow viscus injuries may cause leakage of bowel contents with subsequent peritonitis and sepsis. Injuries are frequently complex, and combined thoracic and abdominal involvement occurs in approximately one-quarter of cases.
Etiology and Injury Patterns
Penetrating trauma carries a high risk of intra-abdominal injury. Approximately 80% of gunshot wounds and 20–30% of stab wounds result in significant abdominal pathology. Commonly injured structures include the liver, small bowel, stomach, colon, major vascular structures, retroperitoneum, and mesentery or omentum. Less frequently affected organs include the spleen, diaphragm, kidneys, pancreas, duodenum, and biliary system.
Clinical Presentation
Patients present with an obvious penetrating wound and may range from having localized pain to overt peritoneal signs and hemodynamic instability. High-velocity projectiles can cause extensive tissue destruction through direct injury, secondary missiles (bone or bullet fragments), and temporary cavitation. Exit wounds may be larger than entrance wounds, but small or inconspicuous entry and exit sites can mask severe internal injury.
Clinicians must remember the full anatomic boundaries of the abdomen, which extend from the nipples anteriorly and the inferior scapular tips posteriorly down to the inferior gluteal folds.
Initial Evaluation and Essential Workup
Gunshot wounds to the abdomen are generally assumed to have caused intra-abdominal injury and are typically managed with operative exploration.
For stab wounds to the anterior abdomen, local wound exploration is essential. If the anterior fascia is violated, further evaluation with diagnostic peritoneal lavage or bedside ultrasonography is indicated.
Diagnostic laparoscopy is particularly useful for identifying diaphragmatic injuries and selected liver or splenic lacerations and may help avoid unnecessary laparotomy in stable patients.
CT imaging is valuable for evaluating suspected retroperitoneal injuries in stable patients but is unreliable for detecting hollow viscus or diaphragmatic injuries.
Diagnostic peritoneal lavage remains useful in select cases. A red blood cell count of 10,000/mm³ or greater is an indication for laparotomy. Patients with lower counts should be closely observed for 8–24 hours for evolving peritoneal signs.
Diagnostic Tests and Interpretation
Laboratory evaluation includes serial hemoglobin or hematocrit measurements to assess ongoing blood loss, urinalysis to screen for genitourinary injury, arterial blood gas analysis to evaluate hypovolemia, and blood typing with cross-matching for patients with suspected significant injury.
Imaging studies may include plain radiographs with external markers to localize foreign bodies, identify fractures, or detect free air. Intravenous pyelography may be used when renal injury is suspected. Focused abdominal sonography for trauma (FAST) can rapidly identify intraperitoneal fluid, while CT with intravenous contrast is reserved for stable patients in experienced centers.
Differential Diagnosis
Upper abdominal penetrating wounds may involve intrathoracic structures, while lower thoracic injuries can extend into the abdominal cavity. Both possibilities should always be considered during evaluation.
Prehospital Management
Fluid resuscitation should be carefully titrated to clinical response. Military antishock trousers are not recommended. Open wounds should be covered with sterile dressings, and eviscerated bowel should be protected with moist sterile dressings. Impaled objects must be stabilized in place and never removed in the field.
Initial Stabilization and Therapy
Management begins with high-flow oxygen and placement of two large-bore intravenous lines for crystalloid infusion. If there is no response after 2 liters of crystalloid, transfusion of packed red blood cells is indicated, using O-negative blood initially if the patient is unstable. Type-specific and cross-matched blood should be administered as soon as available.
Pediatric Considerations
Children in hypovolemic shock should receive crystalloid boluses of 20 mL/kg. Severe shock requires transfusion of packed red blood cells at 1 mL/kg. Diagnostic peritoneal lavage is relatively contraindicated in children younger than 8 years.
Emergency Department Procedures
A nasogastric tube should be placed to reduce aspiration risk and decompress the stomach prior to diagnostic peritoneal lavage. This may also relieve respiratory distress caused by diaphragmatic injury with herniation of abdominal contents.
A Foley catheter should be inserted after excluding urethral injury to assist in detecting genitourinary trauma and monitoring urine output. Tetanus prophylaxis should be administered when indicated.
Medications
Broad-spectrum intravenous antibiotics with gram-negative and anaerobic coverage are required due to the high risk of contamination. Acceptable regimens include second-generation cephalosporins, beta-lactam/beta-lactamase inhibitor combinations, or combination therapy with aminoglycosides and anaerobic agents. Tetanus toxoid and tetanus immunoglobulin should be given as appropriate.
Disposition and Follow-Up
Patients requiring operative intervention must be admitted. Those with negative diagnostic studies should be observed for at least 8 hours with serial abdominal examinations and repeated hematocrit measurements.
Patients with stab wounds that do not penetrate the fascia may be discharged after a period of observation in the emergency department.
Clinical Pearls and Pitfalls
Permissive hypotension is increasingly supported during resuscitation to limit bleeding. Overaggressive crystalloid administration should be avoided. Complete exposure of the patient is essential to avoid missed injuries. Routine spinal immobilization is unnecessary unless there is clear evidence of spinal cord injury.
Overview and Mechanism of Injury
Penetrating abdominal trauma results from injury caused by knives, gunshots, or other foreign objects breaching the abdominal wall. Damage to solid organs most often leads to significant hemorrhage, whereas hollow viscus injuries may cause leakage of bowel contents with subsequent peritonitis and sepsis. Injuries are frequently complex, and combined thoracic and abdominal involvement occurs in approximately one-quarter of cases.
Etiology and Injury Patterns
Penetrating trauma carries a high risk of intra-abdominal injury. Approximately 80% of gunshot wounds and 20–30% of stab wounds result in significant abdominal pathology. Commonly injured structures include the liver, small bowel, stomach, colon, major vascular structures, retroperitoneum, and mesentery or omentum. Less frequently affected organs include the spleen, diaphragm, kidneys, pancreas, duodenum, and biliary system.
Clinical Presentation
Patients present with an obvious penetrating wound and may range from having localized pain to overt peritoneal signs and hemodynamic instability. High-velocity projectiles can cause extensive tissue destruction through direct injury, secondary missiles (bone or bullet fragments), and temporary cavitation. Exit wounds may be larger than entrance wounds, but small or inconspicuous entry and exit sites can mask severe internal injury.
Clinicians must remember the full anatomic boundaries of the abdomen, which extend from the nipples anteriorly and the inferior scapular tips posteriorly down to the inferior gluteal folds.
Initial Evaluation and Essential Workup
Gunshot wounds to the abdomen are generally assumed to have caused intra-abdominal injury and are typically managed with operative exploration.
For stab wounds to the anterior abdomen, local wound exploration is essential. If the anterior fascia is violated, further evaluation with diagnostic peritoneal lavage or bedside ultrasonography is indicated.
Diagnostic laparoscopy is particularly useful for identifying diaphragmatic injuries and selected liver or splenic lacerations and may help avoid unnecessary laparotomy in stable patients.
CT imaging is valuable for evaluating suspected retroperitoneal injuries in stable patients but is unreliable for detecting hollow viscus or diaphragmatic injuries.
Diagnostic peritoneal lavage remains useful in select cases. A red blood cell count of 10,000/mm³ or greater is an indication for laparotomy. Patients with lower counts should be closely observed for 8–24 hours for evolving peritoneal signs.
Diagnostic Tests and Interpretation
Laboratory evaluation includes serial hemoglobin or hematocrit measurements to assess ongoing blood loss, urinalysis to screen for genitourinary injury, arterial blood gas analysis to evaluate hypovolemia, and blood typing with cross-matching for patients with suspected significant injury.
Imaging studies may include plain radiographs with external markers to localize foreign bodies, identify fractures, or detect free air. Intravenous pyelography may be used when renal injury is suspected. Focused abdominal sonography for trauma (FAST) can rapidly identify intraperitoneal fluid, while CT with intravenous contrast is reserved for stable patients in experienced centers.
Differential Diagnosis
Upper abdominal penetrating wounds may involve intrathoracic structures, while lower thoracic injuries can extend into the abdominal cavity. Both possibilities should always be considered during evaluation.
Prehospital Management
Fluid resuscitation should be carefully titrated to clinical response. Military antishock trousers are not recommended. Open wounds should be covered with sterile dressings, and eviscerated bowel should be protected with moist sterile dressings. Impaled objects must be stabilized in place and never removed in the field.
Initial Stabilization and Therapy
Management begins with high-flow oxygen and placement of two large-bore intravenous lines for crystalloid infusion. If there is no response after 2 liters of crystalloid, transfusion of packed red blood cells is indicated, using O-negative blood initially if the patient is unstable. Type-specific and cross-matched blood should be administered as soon as available.
Pediatric Considerations
Children in hypovolemic shock should receive crystalloid boluses of 20 mL/kg. Severe shock requires transfusion of packed red blood cells at 1 mL/kg. Diagnostic peritoneal lavage is relatively contraindicated in children younger than 8 years.
Emergency Department Procedures
A nasogastric tube should be placed to reduce aspiration risk and decompress the stomach prior to diagnostic peritoneal lavage. This may also relieve respiratory distress caused by diaphragmatic injury with herniation of abdominal contents.
A Foley catheter should be inserted after excluding urethral injury to assist in detecting genitourinary trauma and monitoring urine output. Tetanus prophylaxis should be administered when indicated.
Medications
Broad-spectrum intravenous antibiotics with gram-negative and anaerobic coverage are required due to the high risk of contamination. Acceptable regimens include second-generation cephalosporins, beta-lactam/beta-lactamase inhibitor combinations, or combination therapy with aminoglycosides and anaerobic agents. Tetanus toxoid and tetanus immunoglobulin should be given as appropriate.
Disposition and Follow-Up
Patients requiring operative intervention must be admitted. Those with negative diagnostic studies should be observed for at least 8 hours with serial abdominal examinations and repeated hematocrit measurements.
Patients with stab wounds that do not penetrate the fascia may be discharged after a period of observation in the emergency department.
Clinical Pearls and Pitfalls
Permissive hypotension is increasingly supported during resuscitation to limit bleeding. Overaggressive crystalloid administration should be avoided. Complete exposure of the patient is essential to avoid missed injuries. Routine spinal immobilization is unnecessary unless there is clear evidence of spinal cord injury.
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