Snapshot A 30-year-old male victim of an automotive hit-and-run incident presents to the ED. Initial primary survey reveals no airway obstruction and good ventilation. Two large bore IV's are inserted and blood pressure is 95/60 mmHg, pulse is 95/min, respirations are 18/min, and SaO2 is 95% on room air. One liter of Lactated Ringer's is started. Secondary survey reveals no obvious source of blood loss. Despite this and fluid resuscitation, the patient's blood pressure drops to 85/55 mmHg. A FAST ultrasound exam reveals fluid surrounding the spleen and in Morrison's pouch. The patient is rushed to the OR for an exploratory laparotomy. Introduction Mechanisms of abdominal trauma include blunt and penetrating blunt trauma accounts for 2/3 of all intraabdominal injuries motor vehicle crash (MVC) is main mode of injury usually causes solid organ injury, but hollow viscus is also usually damaged spleen is most common, liver is second penetrating trauma accounts for 1/3 firearms, knives, and other impalers are main modes usually causes hollow organ injury if solid, liver is most common Presentation Mechanism of injury can create wide spectrum of presentations symptoms and signs of blood loss may not be evident therefore, mechanism of injury can solely determine need for further imaging workup unprotected trauma pedestrian victims of MVC, motorcycle / bicycle crash, assaults with objects high-energy trauma MVC with no restraints, known high speeds, death at scene, substantial vehicular damage falls greater than 15 feet minor trauma in patients with limited reserve to tolerate injury elderly, patients with chronic debilitating disease, immunosuppressed e.g., seatbelt-associated injuries are widespread retroperitoneal duodenal trauma intraperitoneal bowel transection mesenteric injury lumbar spine injury penetrating trauma carries high risk of GI perforation and sepsis Evaluation Primary and secondary survey physical exam is often unreliable, necessitating serial exams abdomen inspect for contusions, abrasions, seatbelt sign, distention auscultate for bruits, bowel sounds palpate for tenderness, rebound, rigidity, guarding referred pain to shoulder DRE: rectal tone, blood, bone fragments, prostate location placement of NG tube and Foley catheter NG tube for decompression of stomach and proximal small bowel contraindicated in patients with facial / basal skull fracture Foley catheter for voiding in unconscious patient or patient with multiple injuries who cannot void spontaneously contraindicated if blood at meatus, scrotum is ecchymotic, or prostate is high-riding on DRE remember to assess other systems Imaging FAST ultrasound identifies presence or absence of free fluid in peritoneal, pleural, pericardial cavities rapidly (< 5 minutes) NOT used to identify specific organ injuries if patient has ascites, FAST will be a false positive diagnostic peritoneal lavage (DPL) rarely used (takes 1 hour) most sensitive test for intraperitoneal blood if > 10 ml gross blood, WBC > 500, amylase > 175, and/or bile/bacterial/foreign material found, DPL is considered positive NOT for retroperitoneal bleed or diaphragmatic rupture CT scan most specific test significant radiation exposure NOT used if patient is hemodynamically unstable Radiograph can detect free air under diaphragm, hernia, air-fluid levels, fractures Management When to obtain imaging in blunt abdominal trauma equivocal abdominal physical exam multiple trauma patient with altered mental status 2/2 head trauma or drugs/alcohol patient with suspected spinal cord injury causing abdominal anesthesia unexplained shock/hypotension fractures of lower ribs, pelvis, spine What imaging to obtain in blunt abdominal trauma start with FAST if positive: hemodynamically (HD) unstable: start IV fluids go to OR for laparotomy HD stable: get CT (sometimes CT may be a better initial step depending on the context) if negative: HD unstable: repeat FAST or get DPL but mechanism of injury is significant: get CT if no risk factors: observe with repeat serial physical exams if equivocal: HD unstable: get DPL HD stable: get CT Solid organ injuries in blunt abdominal trauma treat based on hemodynamic stability, not specific injury if unstable, go to OR for laparotomy if stable, spleen/liver/kidney lacerations and hematomas can be graded higher grade portends increased risk of bleeding consider angiography with embolization Hollow viscus injuries in blunt abdominal trauma evidence of perforation (free air in peritoneal cavity) next best step: go to OR for laparotomy Penetrating abdominal trauma if gunshot wound next best step: go to OR for laparotomy any gunshot wound below the nipple line is considered to be abdominal if shock, peritonitis, evisceration, free air in abdomen, or blood in NG/Foley/DRE nest best step: go to OR for laparotomy Retroperitoneal trauma classified and triaged by zones on imaging zone 1 (central) high risk of bleeding from major vessels, pancreas, and duodenum next best step: go to OR for laparotomy zone 2 (perirenal) if stable, next best step: continue to observe if HD unstable or penetrating trauma, first obtain contralateral renal function next best step: go to OR for exploration based on renal function zone 3 (pelvic) first control bleeding with pelvic binder if stable and blunt trauma, no surgical exploration next best step: consider angiography and embolization if unstable and penetrating trauma, surgical exploration may be necessary Complications Surgical wound infection manage with surgical debridement and broad-spectrum antibiotics References