Gastrointestinal & Hepatic · Topic 22 of 26
Abdominal Trauma
Gastrointestinal · abdominal trauma
Abdominal Trauma
Hemodynamics decide the path: unstable or peritonitic goes to laparotomy, stable gets CT with IV contrast, and most stable solid-organ injuries heal without surgery.
Key numbers
Serial exams for at least 48 hours≥ 48 h
IAP above 20 with organ dysfunction: decompressIAP > 20 mmHg
01 · DoUnstable or peritonitis: laparotomy, not CT
Hemodynamic instability from abdominal injury, peritonitis, evisceration and most gunshot wounds mandate immediate operative exploration; never delay intervention for CT in an unstable patient.
02 · DoStable patient: CT with IV contrast
CT with IV contrast (oral contrast not needed) is the standard test in hemodynamically stable blunt trauma: it detects free fluid and grades solid-organ injury, and it also images the spine and pelvis.
03 · DoNonoperative care for stable solid-organ injury
Hemodynamically stable spleen and liver injuries without another laparotomy indication are managed nonoperatively — ICU monitoring, serial abdominal exams and serial hemoglobin — even many high-grade injuries.
01
Presentation
What you'll seeSeat belt sign: CT for bowel injuryA seat belt sign carries about a 12% chance of bowel injury and is part of the seat belt syndrome with lumbar spine fracture; it should prompt CT, while its absence does not exclude injury.
Free fluid without solid-organ injury: think bowelOn CT, free fluid without a solid-organ injury is a sensitive sign of hollow-viscus injury; highly specific findings — extraluminal air, extraluminal oral contrast or a bowel-wall defect — warrant prompt laparotomy.
Small bowel perforation shows signs lateSmall bowel contents have near-neutral pH and a low bacterial load, so peritoneal signs develop over hours; pain from a small-bowel perforation is often minimal at first, then steadily worsens.
02
Diagnosis & monitoring
Work-upSerial exams for at least 48 hoursNonoperative management of possible bowel injury requires at least 48 hours of serial clinical examinations by consistent examiners, vital signs and inflammatory markers; peritonitis can take hours to appear.
03
Do right now
In this orderFirst moves
1
→FAST at the bedside for free fluid
2
→Damage control resuscitation with balanced blood
3
→Unstable or peritonitis: laparotomy, not CT
4
Stable patient: CT with IV contrast
Why each step
FAST at the bedside for free fluidFAST images the pericardium, right and left upper quadrants and pelvis for free fluid during the primary survey; a large amount of free fluid in a hypotensive patient means laparotomy (E-FAST adds views for pneumothorax).
Damage control resuscitation with balanced bloodResuscitate hemorrhagic shock with blood products in about a 1:1:1 plasma:platelet:red cell ratio and minimal crystalloid until bleeding is controlled; crystalloid worsens acidosis and coagulopathy.
Unstable or peritonitis: laparotomy, not CTHemodynamic instability from abdominal injury, peritonitis, evisceration and most gunshot wounds mandate immediate operative exploration; never delay intervention for CT in an unstable patient.
Stable patient: CT with IV contrastCT with IV contrast (oral contrast not needed) is the standard test in hemodynamically stable blunt trauma: it detects free fluid and grades solid-organ injury, and it also images the spine and pelvis.
04
Management
OrdersOngoing bleeding ends nonoperative managementWorsening hemodynamics, ongoing transfusion (for example more than 2–4 units in 12 hours) or a hematocrit fall of more than 10–12 points signal ongoing hemorrhage — move to angioembolization or laparotomy.
Angioembolize contrast blush in stable patientsAngiographic embolization suits stable patients with active contrast extravasation (blush), pseudoaneurysm or arteriovenous fistula, and lowers nonoperative failure in high-grade splenic injury; it is not for unstable patients.
Damage control laparotomy for the lethal triadIn the acidotic, coagulopathic, hypothermic patient, do an abbreviated laparotomy — control hemorrhage and contamination, temporarily close — then restore physiology in the ICU and return for definitive repair, typically within 24 hours.
Anterior stab wound: local wound explorationStable anterior abdominal stab wound without peritonitis: explore the wound locally — fascia intact, repair and discharge; fascia violated, admit for serial exams. Flank or back stab wounds need CT.
Vaccinate against encapsulated bacteria after splenectomyAfter splenectomy, vaccinate against pneumococcus, meningococcus and Haemophilus influenzae type b — starting no sooner than 14 days after surgery, or before discharge if the patient may be lost to follow-up.
05
Red flags & don'ts
Avoid harmIAP above 20 with organ dysfunction: decompress complicationAfter massive resuscitation, suspect abdominal compartment syndrome with oliguria, rising airway pressures or hypotension; intra-abdominal (bladder) pressure above 20 mmHg with new organ dysfunction requires surgical decompression.
Delayed splenic rupture: new pain plus tachycardia complicationSplenic (and less often hepatic) hematomas can rupture days or even months after injury, usually in the first few days; sudden worsening pain with tachycardia or hypotension needs imaging or operation.
06
FAST or CT?
Commonly confused| Patient | Any, including unstable — done during resuscitation |
|---|---|
| Main finding | Free intraperitoneal or pericardial fluid |
| Weak spot | Poor for solid-organ detail and hollow-viscus perforation |
| Radiation | None |
07
More detail
ReferenceShow 10 reference facts
In blunt abdominal trauma the spleen is injured most often, followed by the liver and then a hollow viscus (usually small bowel).
AAST scales grade spleen and liver injuries 1–5; splenic grade 4 is a segmental or hilar vessel laceration devascularizing over 25% of the spleen; grade 5 is a shattered or devascularized spleen.
Penetrating chest wounds below the fourth intercostal space (nipple line) must be evaluated as possible abdominal wounds, and the back, flank, buttocks and perineum must be inspected for entry wounds.
Diagnostic peritoneal lavage is positive with gross blood or more than 100,000 RBC/µL; it is sensitive but nonspecific, misses retroperitoneal injury and has largely been replaced by FAST and CT.
Nonoperative management succeeds in over 90% of grade 1–3 and about 80% of grade 4–5 liver injuries; complications include bile leak (ERCP with biliary decompression), biloma (percutaneous drainage) and abscess in about 5%.
Splenic injury without ongoing bleeding is not an absolute contraindication to LMWH thromboprophylaxis; start it as soon as safely possible in selected nonoperative patients, with mechanical prophylaxis for all.
Lipase and liver enzymes are not sensitive or specific enough to detect organ injury; lactate or base deficit helps find occult shock, and a chest radiograph looks for free air and diaphragm rupture.
FAST needs on average about 620 mL of intraperitoneal fluid to be positive (about 400 mL for expert operators), and free fluid on FAST is nonspecific for bowel injury.
Prophylactic antibiotics are not indicated for nonoperatively managed abdominal injuries; they are usually given before operative exploration.
FAST uses no radiation and detects larger fluid volumes but cannot grade organ injury and misses hollow-viscus perforation; CT with IV contrast grades solid-organ injury but adds radiation and can miss small-bowel perforation.
The scanner is no place for an unstable patient — FAST in the bay, then the operating room; CT is for the patient who is stable.
Sources · Merck Manual Professional — Overview of Abdominal Trauma · Merck Manual Professional — Splenic Injury · Merck Manual Professional — Hepatic Injury · Smyth L et al. WSES guidelines on blunt and penetrating bowel injury: diagnosis, investigations, and treatment. World J Emerg Surg 2022;17:13 · Coccolini F et al. Splenic trauma: WSES classification and guidelines for adult and pediatric patients. World J Emerg Surg 2017;12:40 · Starter sheet built from the verified AGACNP fact map (facts reviewed 2026-10-15).