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 Overview abdominal trauma is trauma to the abdomen causing visceral damage and hemorrhage treatment depends on extent of trauma Epidemiology Incidence difficult to recognize clear symptoms early blunt abdominal trauma 2/3 of all intraabdominal injuries mortality rate of ~8.5% motor vehicle crash (MVC) is main mode of injury penetrating abdominal trauma 1/3 of all intraabdominal injuries mortality rate ~12% 95% of all penetrating trauma associated with gunshot and stab wounds higher risk of wound site infection and abscess formation Demographics 2/3 injuries occur in males peak incidence between ages 14 and 30 Location blunt spleen is most commonly injured ogan, liver is second penetrating liver is most commonly injured organ Risk factors substance use ownership or access to firearms motor vehicle operation ETIOLOGY Pathogenesis blunt abdominal trauma divided into three mechanisms 1st: rapid change in organ momentum and speed causes shearing forces to tear organs 2nd: crush injury due to organ compression against blunt object and rigid structures in body (i.e. bones) 3rd: external compression due to rise of pressure inside organ, especially hollow organs, leading to organ rupture penetrating abdominal trauma divided into two mechanisms 1st: direct damage via tissue penetration 2nd: pressure damage from speed of penetrating object causes fragmentation of organ Presentation History important to ascertain mechanism of injury from initial report to determine workup unprotected trauma pedestrian victims of MVC, motorcycle / bicycle crash, assaults with objects high-energy trauma login to view 9 more bullets Symptoms symptoms and signs of blood loss may not be evident Physical exam inspection tachycardia, tachypnea, oliguria, febrile, hypotension primary and secondary survey login to view 3 more bullets provocative tests tenderness with and without rebound, rigidity, and guarding digital rectal exam nasogastric tube for bowel decompression Foley catheter placement if patient cannot void spontaneously Imaging Radiograph indications free air under diaphragm, hernia, air-fluid levels, fractures limitations soft tissue not visualized FAST ultrasound indications presence or absence of free fluid in peritoneal, pleural, pericardial cavities rapidly (<5 minutes) NOT used to identify specific organ injuries limitations if patient has ascites, FAST will be a false positive Diagnostic peritoneal lavage (DPL) indications most sensitive test for intraperitoneal blood login to view 1 more bullet NOT for retroperitoneal bleed or diaphragmatic rupture limitations rarely used (takes 1 hour) CT scan indications most specific test for all of above limitations significant radiation exposure NOT used if patient is hemodynamically unstable Studies Serum labs complete blood count electrolytes coagulation type and cross creatine kinase lipase / amylase liver function tests arterial blood gas blood EtOH urine or serum β-hCG (pregnancy test) urinalysis toxicology screen Differential Cardiac trauma cardiogenic shock can include cardiac tamponade, contusion, laceration bleeding above diaphragm Pulmonary trauma impaired oxygenation and ventilation diaphragmatic injury can cause bleeding to spill into abdomen Management Medical 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 start with FAST ultrasound for blunt abdominal trauma Surgical blunt abdominal trauma if positive: login to view 4 more bullets if negative: login to view 3 more bullets if equivocal: login to view 2 more bullets solid organ injuries in blunt abdominal trauma login to view 5 more bullets hollow viscus injuries in blunt abdominal trauma login to view 2 more bullets penetrating abdominal trauma if gunshot or stab wound login to view 1 more bullet 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 login to view 1 more bullet retroperitoneal trauma classified and triaged by zones on imaging zone 1 (central) login to view 2 more bullets zone 2 (perirenal) if stable, next best step: continue to observe if HD unstable or penetrating trauma, first obtain contralateral renal function login to view 1 more bullet zone 3 (pelvic) first control bleeding with pelvic binder if stable and blunt trauma, no surgical exploration login to view 1 more bullet if unstable and penetrating trauma, surgical exploration may be necessary Complications Surgical wound infection manage with surgical debridement and broad-spectrum antibiotics Shock resuscitate with a massive transfusion protocol (do NOT just give crystalloids) positive pressure ventilation can worsen hypotension secondary to increased intrathoracic pressure