Blunt abdominal trauma (BAT) is a leading cause of preventable morbidity and mortality, accounting for ~80% of abdominal trauma cases. The prevalence of intra-abdominal injury in ED patients with BAT is approximately 13%, with ~4.7% requiring therapeutic surgery or angioembolization. [1] Mortality increases by 1% for every 3 minutes spent in the ED, making rapid assessment critical. [2] The diagnostic challenge lies in the fact that patients may lack external signs of injury, and delayed diagnosis of occult injuries remains a major cause of preventable death. [1]
1. History
- Mechanism of injury — the single most important HPI element: MVC (speed, restraint use, airbag deployment, steering wheel deformity, ejection), fall (height), assault, bicycle handlebar, pedestrian vs. vehicle, crush injury [1][3]
- Seatbelt use and position in vehicle (driver vs. passenger); seatbelt sign carries a 12% risk of bowel or splenic injury (LR 5.6–9.9) [1-2]
- Timing of injury to presentation; symptom progression (worsening vs. improving pain)
- Location, quality, and radiation of abdominal pain; associated nausea/vomiting, dyspnea, shoulder pain (Kehr sign suggesting diaphragmatic irritation)
- Pre-hospital vitals and fluid administration; any loss of consciousness
- Important negatives: absence of abdominal tenderness does not rule out intra-abdominal injury (LR 0.61) [1]
2. Alarm Features
- Hemodynamic instability (SBP <90 mmHg) despite crystalloid resuscitation — LR 5.2 for intra-abdominal injury [1]
- Peritoneal signs: rebound tenderness (LR 6.5), involuntary guarding (LR 3.7), abdominal distention (LR 3.8) [1]
- Seat belt sign or handlebar mark [2-3]
- Positive FAST with hemodynamic instability → immediate surgical consultation [2][4]
- Altered mental status (GCS <14) — unreliable exam, higher injury prevalence [1]
- Signs of hemorrhagic shock: tachycardia, pallor, delayed capillary refill, altered mentation
- Evisceration, impalement, or obvious peritoneal violation
- Progressive abdominal distention suggesting ongoing hemorrhage
3. Medications
- Anticoagulants/antiplatelets: warfarin, DOACs, aspirin, clopidogrel — increase hemorrhage risk and may require reversal (4-factor PCC for warfarin, idarucizumab for dabigatran, andexanet alfa for factor Xa inhibitors)
- Resuscitation medications: tranexamic acid (TXA) — administer within 3 hours of injury in hemorrhagic shock per CRASH-2 protocol (1 g IV bolus then 1 g over 8 hours)
- Avoid excessive crystalloid — balanced resuscitation with blood products in a 1:1:1 ratio (pRBC:FFP:platelets) for massive transfusion
- Analgesics: IV opioids for pain control; avoid NSAIDs acutely (platelet dysfunction, renal risk in hypovolemia)
- Antibiotics: indicated if bowel perforation suspected or operative intervention planned
4. Diet
- NPO status is mandatory on arrival — anticipate potential operative intervention
- Failed enteral feeding in admitted patients is a red flag for missed bowel injury (associated with higher sepsis rates and ICU readmission) [3]
- Resume diet only after clinical stability confirmed, bowel function returns, and surgical clearance obtained
- Long-term: no specific dietary restrictions after recovery from isolated solid organ injury
5. Review of Systems
- GI: abdominal pain, nausea, vomiting, hematemesis, hematochezia/melena
- GU: hematuria (LR 3.7–4.1 for intra-abdominal injury), flank pain, difficulty voiding [1]
- Pulmonary: dyspnea, pleuritic chest pain (associated thoracic injury, diaphragmatic rupture)
- MSK: rib pain (lower rib fractures associated with hepatic/splenic injury), pelvic pain, back pain
- Neuro: headache, LOC, confusion, extremity weakness (concomitant head/spine injury)
- Cardiac: chest pain, palpitations (cardiac contusion in high-energy mechanisms)
6. Collateral History and Family History
- Collateral: EMS report (mechanism details, extrication time, vitals en route, GCS trend), bystander account, police report
- Intoxication status — alcohol and drug use impair exam reliability and mask symptoms [1]
- Pre-injury functional status and baseline vitals (especially in elderly)
- Family history: generally not relevant acutely; however, bleeding diatheses (hemophilia, von Willebrand disease) may affect hemorrhage risk and management
- Social context: domestic violence screening, non-accidental trauma patterns (especially pediatric)
7. Risk Factors
- High-energy mechanisms: MVC >64 km/h, pedestrian struck, fall >6 m, motorcycle crash [3]
- Unrestrained occupant or ejection from vehicle
- Alcohol/drug intoxication (impairs protective reflexes and exam reliability)
- Elderly patients (>65 years): lower physiologic reserve, higher injury rates from ground-level falls, blunted tachycardic response to hemorrhage [5]
- Anticoagulant/antiplatelet use
- Prior splenectomy or hepatomegaly (increased vulnerability)
- Chronic liver disease, splenomegaly, pregnancy
- Obesity (difficult exam, higher-energy transfer)
- Pediatric patients: proportionally larger solid organs, less protective musculature
8. Differential Diagnosis
The key diagnostic challenge is identifying which intra-abdominal structure is injured:
- Splenic injury — most commonly injured organ in blunt trauma; LUQ pain, Kehr sign; spleen is the most common organ requiring operative intervention [6]
- Liver injury — most common injured abdominal solid organ overall; RUQ pain, elevated transaminases [7]
- Bowel/mesenteric injury — delayed presentation is common; peritoneal signs may take hours to develop; 20% missed on initial CT [3]
- Renal injury — flank pain, hematuria; usually managed nonoperatively
- Pancreatic injury — epigastric pain, elevated lipase; notoriously understaged on CT [6]
- Diaphragmatic rupture — dyspnea, bowel sounds in chest; easily missed on initial imaging
- Bladder/urethral injury — pelvic fracture association, gross hematuria
- Retroperitoneal hemorrhage — may present with back pain, hemodynamic instability without peritoneal signs
- Abdominal wall injury (rectus sheath hematoma, muscle disruption) — can mimic intra-abdominal pathology
- Cannot-miss mimics: ruptured AAA, ectopic pregnancy (in reproductive-age females), acute MI presenting as epigastric pain
9. Past Medical History
- Prior abdominal surgeries (adhesions alter injury patterns and complicate operative approach)
- Splenectomy, hepatic disease, cirrhosis, portal hypertension
- Bleeding disorders or anticoagulant use
- Chronic kidney disease (contrast considerations for CT)
- Pregnancy status — mandatory uCG in reproductive-age females
- Prior trauma history, especially prior splenic or hepatic injury
- Immunosuppression (may blunt inflammatory response)
10. Physical Exam
- Vitals: serial BP, HR, RR, SpO2, temperature — tachycardia may precede hypotension; elderly may not mount tachycardia
- Inspection: abdominal contusions, abrasions, seat belt sign, distention, asymmetry, flank ecchymosis (Grey Turner sign), periumbilical ecchymosis (Cullen sign) [1][3]
- Palpation: tenderness (diffuse vs. focal), involuntary guarding, rebound tenderness, pelvic stability (AP and lateral compression)
- Auscultation: absent bowel sounds (ileus, peritonitis); bowel sounds in chest (diaphragmatic rupture)
- Rectal exam: high-riding prostate (urethral injury), gross blood
- GU exam: blood at urethral meatus, scrotal/labial hematoma
- Back/flank: log-roll for posterior tenderness, step-offs, ecchymosis
- Pearl: Serial abdominal exams increase diagnostic accuracy significantly — a single normal exam does not exclude injury [2-3]
11. Lab Studies
12. Imaging
- E-FAST (Extended Focused Assessment with Sonography for Trauma): first-line bedside imaging in all trauma patients; detects free intraperitoneal fluid (requires ~400–620 mL to be positive), hemopericardium, hemothorax, pneumothorax. Positive FAST with hemodynamic instability → OR. A negative FAST does not rule out injury (adjusted LR 0.26). [1][4][11]
- CT abdomen/pelvis with IV contrast: gold standard for hemodynamically stable patients; sensitivity 97–98%, specificity 97–99%. Delayed-phase CT helps differentiate active bleeding from contained vascular injury. However, <20% of CT scans in blunt trauma are positive, and <3% identify injuries requiring intervention. [1][12]
- Repeat CT at 6 hours: indicated for equivocal initial CT findings, high-risk mechanisms with non-specific findings, or clinical deterioration [3]
- Chest and pelvis radiographs: useful triage tools, especially in geriatric patients; abnormal CXR (LR 2.5–3.8 for intra-abdominal injury) [1][5]
- CT is contraindicated in hemodynamically unstable patients who cannot be stabilized — these patients should not leave the resuscitation bay for the CT suite [4]
13. Special Tests
- Diagnostic Peritoneal Lavage (DPL): largely replaced by FAST but still useful when FAST is negative in an unstable patient with high clinical suspicion; lower positive predictive value than FAST [2][4]
- Diagnostic laparoscopy: useful in hemodynamically stable patients with suspected hollow viscus injury; can be both diagnostic and therapeutic [10]
- AAST Organ Injury Scale (OIS): grades I–V for solid organ injuries; the 2018 revision incorporates vascular injury findings (pseudoaneurysm, AV fistula) and better correlates with need for surgery [13-14]
- Bowel Injury Prediction Score (BIPS): combines radiologic, biochemical, and clinical signs to guide management in equivocal cases [3]
- Clinical prediction rule for low-risk patients (ACEP): absence of all 6 variables (hematuria ≥25 RBC/HPF, SBP <90, abdominal tenderness, GCS <14, costal margin tenderness, Hct <30%) has 100% sensitivity and NPV for excluding injury requiring acute intervention [8]
- PedSRC Rule: for pediatric patients <16 years with blunt abdominal trauma to identify very low-risk patients who may not need CT
14. ECG
- Indicated in high-energy mechanisms (especially direct sternal/precordial impact) to evaluate for myocardial contusion
- Findings: sinus tachycardia (most common), new arrhythmias (PVCs, atrial fibrillation, bundle branch blocks), ST changes
- Dangerous patterns: new RBBB (most common ECG finding in cardiac contusion), ventricular tachycardia, high-degree AV block
- ECG also useful to evaluate for tension pneumothorax (low voltage, electrical alternans) and pericardial tamponade
- Normal ECG with normal troponin effectively excludes significant blunt cardiac injury
15. Assessment
Severity stratification is driven by hemodynamic status, not injury grade alone: [15]
- Hemodynamically unstable / non-responder → immediate operative intervention (WSES Class IV) [12]
- Transient responder → requires close monitoring; may proceed to CT if briefly stabilized under supervision of trauma team; consider angioembolization [12]
- Hemodynamically stable → CT-guided management; majority managed nonoperatively
Key clinical pearls:
- The liver is the most commonly injured organ overall; the spleen is the most common to require operative intervention [6-7]
- 85–90% of blunt liver injuries and >90% of appropriately selected splenic injuries can be managed nonoperatively [7][15]
- Bowel injury is the most commonly missed injury on initial CT (~20% miss rate); peritoneal signs may be delayed for hours [3]
- Pancreatic injuries are notoriously understaged on CT [6]
16. Treatment Plan
Initial stabilization (all patients)
- ATLS primary survey: ABCDE approach
- Two large-bore IVs; initiate balanced crystalloid resuscitation
- Activate massive transfusion protocol (1:1:1 pRBC:FFP:platelets) for hemorrhagic shock
- TXA 1 g IV bolus within 3 hours of injury if hemorrhagic shock suspected
- E-FAST at bedside during primary survey [4]
Hemodynamically unstable + positive FAST
- Immediate exploratory laparotomy [3-4]
- If FAST negative but clinical suspicion high → DPL or proceed to OR [4]
- REBOA may be used as a bridge to definitive hemorrhage control in select cases [12]
Hemodynamically stable
- CT abdomen/pelvis with IV contrast [1][3]
- Nonoperative management (NOM) is standard for hemodynamically stable solid organ injuries regardless of grade, provided: continuous monitoring (ICU for AAST grade III–V), serial exams, serial labs, surgical team immediately available [12][15]
- Angioembolization for arterial blush on CT in stable patients (first-line for splenic and hepatic arterial bleeding) [12][16]
- Operative indications: hemodynamic instability despite resuscitation, peritonitis, extraluminal air/contrast on CT (bowel perforation), failed NOM [3][12]
NOM monitoring protocol
- Serial abdominal exams q2–4h
- Serial hemoglobin (significant drop on day 1 is the most common reason for NOM failure) [6]
- Repeat CT at 6 hours if equivocal initial findings [3]
- Serial procalcitonin/CRP for bowel injury surveillance [2-3]
17. Disposition
- Admit (ICU): AAST grade III–V solid organ injuries, transient responders, patients requiring angioembolization, polytrauma, unreliable exam (intoxication, TBI) [10][12]
- Admit (floor/observation): low-grade solid organ injuries (AAST I–II), high-risk mechanism with non-specific CT findings, seatbelt sign with equivocal imaging [3]
- Observation minimum 24 hours: recommended for all patients with confirmed blunt abdominal trauma, as no single investigation reliably excludes all injuries [10]
- Discharge considerations: truly isolated minor mechanism, completely normal exam, normal labs, negative FAST, and negative CT (if obtained); reliable patient with ability to return
- Surgical consultation triggers: positive FAST, any solid organ injury on CT, free fluid without solid organ injury, hemodynamic instability, peritoneal signs, suspected bowel injury [2][4]
18. Follow Up / Return Precautions
- Follow-up timing: solid organ injuries managed nonoperatively typically require surgical follow-up at 1–2 weeks; repeat imaging at 48–72 hours for high-grade injuries or if clinically indicated [17]
- Activity restriction: varies by organ and grade; splenic injuries typically require 3–6 months of activity restriction; liver injuries 2–3 months
- Return precautions — instruct patients to return immediately for:
- Increasing or new abdominal pain
- Lightheadedness, dizziness, or syncope
- Fever >38.3°C (concern for abscess, missed bowel injury, post-embolization necrosis)
- Nausea/vomiting, inability to tolerate oral intake
- Blood in urine or stool
- Shoulder pain (referred diaphragmatic irritation)
- Expected recovery: most low-grade solid organ injuries heal within 6–8 weeks; delayed splenic rupture can occur up to 2 weeks post-injury
- Counseling: avoid contact sports and heavy lifting during recovery; avoid anticoagulants/NSAIDs until cleared; ensure understanding of delayed presentation risk
Images
References
1. Does This Adult Patient Have a Blunt Intra-abdominal Injury?. — Nishijima DK, Simel DL, Wisner DH, Holmes JF. The Journal of the American Medical Association. 2012.
2. Bowel Injury in Trauma: Guidelines for Diagnosis and Treatment From the World Society of Emergency Surgery. — Mentler E, Vietor R, Maddox J. American Family Physician. 2023.
3. WSES Guidelines on Blunt and Penetrating Bowel Injury: Diagnosis, Investigations, and Treatment. — Smyth L, Bendinelli C, Lee N, et al. World Journal of Emergency Surgery : WJES. 2022.
4. Initial Care of the Severely Injured Patient. — King DR. The New England Journal of Medicine. 2019.
5. ACR Appropriateness Criteria® Minor Blunt Trauma. — Expert Panel on Polytrauma Imaging, Hoff CN, Hajibonabi F, et al. Journal of the American College of Radiology : JACR. 2026.
6. Evaluation of Management of CT Scan Proved Solid Organ Injury in Blunt Injury Abdomen-a Prospective Study. — Mukharjee S, B V D, S V B. European Journal of Trauma and Emergency Surgery : Official Publication of the European Trauma Society. 2024.
7. Liver Injury: What You Need to Know. — Reed CR, Brown JB, Peitzman AB. The Journal of Trauma and Acute Care Surgery. 2025.
8. Clinical Policy: Critical Issues in the Evaluation of Adult Patients Presenting to the Emergency Department With Acute Blunt Abdominal Trauma. — Diercks DB, Mehrotra A, Nazarian DJ, et al. Annals of Emergency Medicine. 2011.
9. Predictive Parameters for Early Detection of Clinically Relevant Abdominal Trauma in Multiple-Injury or Polytraumatised Patients: A Retrospective Analysis. — Fabig S, Weigert N, Migliorini F, et al. European Journal of Medical Research. 2024.
10. Diagnostic Options for Blunt Abdominal Trauma. — Achatz G, Schwabe K, Brill S, et al. European Journal of Trauma and Emergency Surgery : Official Publication of the European Trauma Society. 2022.
11. Appropriateness of Initial Course of Action in the Management of Blunt Trauma Based on a Diagnostic Workup Including an Extended Ultrasonography Scan. — Planquart F, Marcaggi E, Blondonnet R, et al. JAMA Network Open. 2022.
12. Liver Trauma: WSES 2020 Guidelines. — Coccolini F, Coimbra R, Ordonez C, et al. World Journal of Emergency Surgery : WJES. 2020.
13. Validation of the Revised 2018 AAST-OIS Classification and the CT Severity Index for Prediction of Operative Management and Survival in Patients With Blunt Spleen and Liver Injuries. — Morell-Hofert D, Primavesi F, Fodor M, et al. European Radiology. 2020.
14. Grading Abdominal Trauma: Changes in and Implications of the Revised 2018 AAST-OIS for the Spleen, Liver, and Kidney. — Dixe de Oliveira Santo I, Sailer A, Solomon N, et al. Radiographics : A Review Publication of the Radiological Society of North America, Inc. 2023.
15. Dr. Joseph Sakran, MD, MPH, MPA. — Director of Emergency General Surgery, Johns Hopkins Hospital, Associate Professor of Surgery and Nursing, Johns Hopkins Hospital, Associate Chief of the Division of Acute Care Surgery, Johns Hopkins Hospital, Vice Chair of Clinical Operations, Johns Hopkins Hospital, Executive Vice Chair of Surgery, Johns Hopkins Hospital, and Director of Clinical Operations for Surgery, Johns Hopkins Hospital 2026.
16. Outcomes of Isolated Severe Blunt Splenic Injury. — Huang W, Braschi C, Jin F, Lewis M, Demetriades D. JAMA Network Open. 2025.
17. Blunt Abdominal Trauma: Watch and Wait. — Cioffi SP, Cimbanassi S, Chiara O. Current Opinion in Critical Care. 2023.