Abdominal Trauma — Blunt, Penetrating, FAST & Non-Operative Management

Overview & definition

The abdominal trauma — the blunt (the motor vehicle, the fall, the crush — the solid organ, the hollow viscus) and the penetrating (the stab, the gunshot — the hollow viscus, the vascular). The FAST scan (the bedside — the rapid triage for the free fluid). The CT with the IV contrast (the stable patient — the grading). The laparotomy for the peritonitis, the unresponsive hypotension, the penetrating with the peritonitis. The non-operative management for the stable blunt solid organ.[1]

The single most important triage decision in abdominal trauma is haemodynamic stability: the unstable patient is resuscitated and goes to theatre (or angioembolisation) without a CT; the stable patient gets a contrast-enhanced CT — the gold standard for grading solid-organ injury, identifying a contrast "blush" (active extravasation), and detecting hollow-viscus and mesenteric injury. The FAST is a triage tool, never a definitive investigation: it detects free fluid (not the organ injury itself), and its sensitivity for hollow-viscus, retroperitoneal, and diaphragmatic injury is poor.[1][2]

Mechanisms of injury — blunt vs penetrating

The mechanism determines the likely injury pattern, the pre-test probability, and the index of suspicion for specific organs. The abdomen is divided into three zones — intrathoracic (above the costal margin, behind the ribs), true abdomen (between costal margin and pelvis), and pelvic/retroperitoneal — and a penetrating wound is also classified by its tract relative to the peritoneum (anterior abdomen, flank, back, thoracoabdominal).[1]

[1] [1] [8]

The assessment

The FAST scan (Focused Assessment with Sonography for Trauma)

The FAST is the bedside ultrasound examination performed during the secondary survey to detect free intraperitoneal or pericardial fluid (blood). It is rapid (2–5 minutes), repeatable, radiation-free, and operator-dependent. It answers ONE question: is there free fluid? It does NOT grade organ injury, does NOT identify the source, and does NOT visualise the retroperitoneum or hollow viscus reliably.[1][2]

• The 4 views — the RUQ (Morrison pouch — hepatorenal recess, the most sensitive single view), the LUQ (perisplenic — splenorenal recess), the suprapubic (pelvic — pouch of Douglas / rectovesicular), and the subxiphoid pericardial (pericardial effusion / tamponade).[1]
• The free fluid = the positive (the anechoic/black stripe between organs; ~200 mL needed in the Morrison pouch to be reliably seen).[2]
• The rapid (the minutes), the repeatable, the no radiation. The triage the tool.[1]
• The limitations — the low sensitivity for the hollow viscus, the retroperitoneal, the diaphragmatic; the operator-dependent; the false negative if the small the volume, the obesity, the subcutaneous emphysema, the pelvic fracture retroperitoneal haematoma. The serial the FAST (the repeat at the 30 min if the negative but the clinical the concern) increases the sensitivity.[2]

[2]

The CT with the IV contrast

For the haemodynamically stable patient, the contrast-enhanced CT (venous phase; arterial phase added if vascular injury suspected) is the gold standard — it grades solid organ injury (AAST scale), identifies hollow-viscus injury (free air, wall thickening, mesenteric stranding, contrast extravasation into bowel wall), detects active bleeding (the contrast blush = active extravasation), and characterises vascular and retroperitoneal injuries.[1][12]

• The grading the solid organ (the AAST — the spleen I to V, the liver I to VI, the kidney I to V). The grade guides the management and predicts the failure of NOM.[6]
• The identify the hollow viscus (the free air, the wall thickening, the mesenteric stranding, the mesenteric contrast extravasation — the "vascular beading"). The oral/rectal contrast if the concern the high.[12]
• The vascular (the contrast extravasation — the "blush"). The blush = the active the bleeding → the angioembolisation or the theatre.[1]
• The NOT for the unstable (the delay — the to the CT the dangerous; the to the theatre).[1]

[1] [2] [10]

The laparotomy indications

The mandatory laparotomy for:[1]

• The peritonitis (the rigid abdomen, the rebound — the hollow viscus perforation).[1]
• The hypotension unresponsive to the fluid resuscitation with a positive FAST (the ongoing the bleeding).[1]
• The penetrating trauma with the peritonitis or the hypotension, the evisceration, the diaphragmatic injury, the impalement, the blood from the NG or the rectal tube.[1]
• The transabdominal gunshot wound (most traverse the peritoneum).[8]
• The iatrogenic — the haemodynamically unstable with the clinical deterioration despite the resuscitation.[1]

[1] [10]

Specific organ injuries

The pattern of organ injury follows the mechanism and the anatomy. Solid organs (spleen, liver, kidney) dominate blunt trauma; hollow viscus and vascular structures dominate penetrating trauma. Retroperitoneal organs (duodenum, pancreas, kidney, IVC/aorta) are occult — FAST misses them, and they declare themselves late.[1]

The spleen — the #1 blunt solid organ

The spleen is the most commonly injured abdominal organ in blunt trauma (MVC handlebars, left lower rib fractures, falls). The grading is the AAST I–V (I = subcapsular tear <10%/capsular laceration <1 cm; V = shattered spleen or hilar vascular injury).[6][9]

• Non-operative management (NOM) is the standard for the haemodynamically stable patient with grades I–IV — successful in 70–90% of adults and up to 95% of children. Admission to a monitored setting, serial abdominal exams (q1–2h × 24h), serial haemoglobin, bed rest initially, and ICU if high grade or transfusion required.[4][9]
• Angioembolisation for the contrast blush (active extravasation), the pseudoaneurysm, the AV fistula, or the high-grade (IV–V) injury even without blush in some protocols. Proximal splenic artery embolisation (reduces the arterial pressure head into the spleen, allows haemostasis); distal selective embolisation for the focal bleed.[15]
• Failure of NOM (ongoing hypotension, falling Hb requiring transfusion, new peritonitis) → laparotomy. Predictors: high grade (IV–V), blush, haemodynamic instability on arrival, ISS, age >55.[9]
• Splenectomy → the overwhelming post-splenectomy infection (OPSI) risk — encapsulated organisms (pneumococcus, meningococcus, Haemophilus influenzae b). Post-splenectomy vaccination (pneumococcal, meningococcal ACWY + B, Hib) ideally >14 days pre-discharge, annual influenza, lifelong penicillin V prophylaxis (or at minimum patient education + alert bracelet).[7]

The liver — packing and damage control

The liver is the second most common blunt solid organ injury and the most common cause of death from abdominal trauma (deep lacerations, juxtahepatic venous injuries — IVC, hepatic veins). AAST grades I–VI (I = subcapsular haematoma <10% / capsular laceration <1 cm; VI = hepatic avulsion — universally fatal).[6]

• NOM for the stable patient with grades I–III is the standard (success >80%). Higher grades (IV–V) may still attempt NOM if stable, with ICU monitoring and angioembolisation for the blush.[3]
• Damage-control surgery for the unstable: perihepatic packing (the classic technique — laparotomy pads packed around the liver to tamponade, particularly for the deep laceration and the juxtahepatic venous injury), the Pringle manoeuvre (clamping the hepatoduodenal ligament — hepatic artery + portal vein — for up to 60 minutes warm ischaemia to control inflow bleeding), and the temporary closure. The definitive repair (resection, venous reconstruction, selective ligation) deferred to the re-operation.[5]
• Angioembolisation for the hepatic artery blush; selective hepatic artery ligation for uncontrolled arterial bleeding in theatre; atriocaval shunt for the retrohepatic IVC / hepatic vein injury (the most lethal).[3]
• Complications — the biloma, the hepatic necrosis (post-embolisation), the abscess, the haemobilia (triad: jaundice, RUQ pain, UGI bleed — treated by angioembolisation of the hepatic artery).[3]

The kidney

The kidney is a retroperitoneal organ — FAST misses it. Suspected with haematuria (gross or microscopic), flank pain/haematoma, or the mechanism (direct flank blow, deceleration — renal pedicle injury). CT with IV contrast (the excretory/nephrogenic phase) grades the injury (AAST I–V; V = shattered kidney or renal pedicle avulsion).[1]

• NOM is the standard for grades I–IV in the stable patient (success >90%); the kidney has a robust collateral circulation and most injuries heal.
• Operative exploration for the grade V (pedicle avulsion, expanding/ pulsatile retroperitoneal haematoma), the unstable, or the renal vein avulsion. Exploration risks nephrectomy (devascularisation from the hilar control).
• The renal pedicle injury (intimal tear of the renal artery from deceleration) — the delayed diagnosis (hours), the devascularisation, the salvage only if the revascularisation within 6 hours. [1]

The small bowel and mesentery — hard to diagnose

The small bowel is the most common HOLLOW viscus injured in blunt trauma (the crush against the spine, the deceleration tear at fixed points — ligament of Treitz, ileocaecal valve). The mesenteric injury bleeds and may devascularise the bowel. These are the most commonly missed abdominal injuries — FAST is usually negative (little free fluid early), CT findings are subtle, and peritonitis evolves over 6–12 hours.[12]

• The CT signs — the free air (ruptured hollow viscus), the bowel wall thickening (>3 mm), the mesenteric stranding/haematoma, the mesenteric contrast extravasation (the "vascular beading"), the "triangle sign" (free air between loops), the intramural haematoma, the unexplained free fluid WITHOUT solid organ injury (highly suspicious for mesenteric/bowel injury).[12]
• The DPL — the elevated amylase/alkaline phosphatase in the lavage fluid (the bowel content).
• The management — the perforation (the primary repair, the resection with the primary anastomosis if stable, the resection in discontinuity if the damage-control), the mesenteric devascularisation (the resection of the non-viable segment). The delayed presentation (peritonitis at 12–24 h) — the increased morbidity/mortality; the high index of suspicion, the serial exam, the repeat CT.[16]

The pancreas — high morbidity, occult

The pancreas is a retroperitoneal organ, injured by the direct epigastric blow (the steering wheel, the bicycle handlebar — the compression against the spine). The mechanism is classic; the injury is occult — the FAST is negative, the initial amylase/lipase may be normal (rises over 24–48 h), and the CT may miss the ductal injury. The ductal integrity is the determinant of management.[11]

• The grade — the I/II (no or minor ductal injury — the contusion, the superficial laceration) the NOM; the III/IV (ductal injury in the body/tail — the distal pancreatectomy; in the head — the complex, the Roux-en-Y, the damage-control drainage); the V (the massive disruption of the pancreatic head — the pancreaticoduodenectomy rarely, the damage-control).[11]
• The MRCP/ERCP for the ductal assessment if the CT indeterminate.
• The complications — the pseudocyst, the pancreatic fistula, the pancreatic abscess, the delayed haemorrhage. The high morbidity (the prolonged ICU, the multi-organ failure).[11]
• The associated — the duodenal injury (the pancreaticoduodenal complex — the high morbidity, the damage-control).

The bladder — pelvic fracture association

The bladder is injured in 5–10% of pelvic fractures (the bony fragment laceration, the deceleration) and is associated with the urethral injury (especially the male, the pelvic fracture, the blood at the meatus, the high-riding prostate, the perineal haematoma — the DO NOT catheterise blindly until the urethrogram).[1]

• The extraperitoneal (the 80%, the pelvic fracture) — the NOM (the urethral catheter, the 10–14 days).
• The intraperitoneal (the 20%, the dome, the full-bladder blunt trauma) — the surgical repair (the absorbable suture, the 2-layer closure).
• The signs — the gross haematuria (the 95%), the suprapubic pain, the inability to void, the elevated creatinine (the peritoneal reabsorption). The cystography (the CT or the flat-plate) for the diagnosis (the extravasation).[1]

The non-operative management (NOM)

For the blunt solid organ injury (the spleen, the liver, the kidney) if the haemodynamically stable and the no peritonitis:[4][3]

• The ICU admission, the serial the examinations (the vitals, the abdomen, the q1–2 h for the 24 h), the serial the Hb (the q6 h initially), the serial the lactate.[1]
• The angioembolisation for the CT contrast extravasation (the "blush") — the splenic artery embolisation (the proximal — the reduce the pressure; the distal — the selective), the hepatic artery, the renal artery.[15]
• The failure of the NOM → the laparotomy. The predictors: the high grade (the IV–V), the blush, the haemodynamic instability on the arrival, the ISS, the age >55.[9]
• The splenic — the NOM successful in the 70 to 90 per cent; the post-splenectomy the vaccination (the pneumococcal, the meningococcal, the Hib) if the splenectomy.[7]

[3] [4] [8]

Penetrating trauma — selective non-operative management

Historically, all penetrating abdominal wounds underwent mandatory laparotomy, with a high negative laparotomy rate. Modern trauma practice (Demetriades and the LAC+USC group) supports selective NOM for the haemodynamically stable patient with a penetrating wound (especially stab wounds and selected GSWs) managed by CT + serial abdominal examinations + local wound exploration, reserving laparotomy for the unstable, the peritonitic, the eviscerated, and the impaled.[8]

[8]

The damage-control laparotomy

For the physiological extremis (the lethal triad — acidosis pH under 7.2, hypothermia under 35, coagulopathy INR >1.5), the damage-control laparotomy is the abbreviated operation — the only goal is to deliver the patient alive to the ICU with correctable physiology, NOT the definitive repair. The lethal triad is self-perpetuating: each component worsens the others, and once established the mortality approaches 100%.[5]

• The rapid control — the packing (the control the bleeding — the liver, the spleen, the pelvis, the retroperitoneum), the ligation (the vessel), the temporary shunt (the vessel the repair the deferred — the carotid, the femoral, the mesenteric), the resection in discontinuity (the ischaemic bowel — the NOT the primary anastomosis), the temporary closure (the Bogota bag, the negative-pressure dressing — the VAC, the Wittmann patch — the fascia the OPEN).[5]
• The planned re-operation (the 24 to 48 hours) — the definitive repair, the anastomosis, the packing removal, the closure. The transition is the physiology-driven, NOT the time-driven (the lethal triad the corrected first).[5]
• The open abdomen — the manage the intra-abdominal hypertension (the IAP; the APP = MAP − IAP >50–60), the entero-atmospheric fistula, the massive third-space the fluid losses, the failed the closure (the planned ventral hernia + the split-thickness the skin graft).[1]
• The correct the lethal triad in the ICU between the operations — the warm (the forced-air, the warmed the fluids, the warm the ambient), the correct the acidosis (the resuscitation; the NaHCO3 the refractory only), the correct the coagulopathy (the MTP 1:1:1 — the PROPPR; the TXA — the CRASH-2 within the 3 h; the calcium; the cryoprecipitate for the fibrinogen; the viscoelastic the guided).[17]

[5] [5]

The lethal triad of damage control

The damage-control philosophy exists to break the lethal triad — the self-perpetuating cycle of acidosis, hypothermia, and coagulopathy that develops in the exsanguinating trauma patient and drives mortality toward 100% once established.[5]

• The acidosis (pH under 7.2) — the clotting factor dysfunction (the enzymatic, the >50% reduction of the activity below the pH 7.2; virtually no clot below the pH 7.0). The correct by the resuscitation (the stop the bleed, the blood).[5]
• The hypothermia (under 35 degrees C) — the coagulation enzyme and the platelet dysfunction (the temperature-dependent; the functional the failure below the 34 degrees C). The prevent (the active the warming, the warmed the fluids, the warm the ambient).[5]
• The coagulopathy — the trauma-induced coagulopathy (the TIC — the endogenous, the present on the arrival in ~25% of the severe trauma; the tissue factor, the protein C, the hyperfibrinolysis) PLUS the dilutional (the iatrogenic, the crystalloid) PLUS the consumption. The INR >1.5 on the arrival the defines. The MTP 1:1:1 (the PROPPR), the TXA (the CRASH-2), the calcium, the fibrinogen.[17]

Complications of abdominal trauma and the open abdomen

[1] [7]

Special situations

The pregnant trauma patient

In pregnancy, the gravid uterus displaces the bowel cephalad (shielding small bowel but exposing the liver/spleen), compresses the IVC in the supine position (left lateral tilt essential), and the fundal height determines the approach — uterus at/above the umbilicus increases the risk of abruption and uterine rupture. Rh-negative mother → anti-D immunogloblobulin (even minor trauma can cause feto-maternal haemorrhage). Continuous cardiotocography (CTG) monitoring for at least 4–6 hours (longer if contractions/abruption signs). The FAST includes the 4 standard views plus the foetal heart rate. Perimortem Caesarean section if maternal arrest >20 weeks gestation (within 5 minutes of arrest — improves both maternal and foetal survival).[1]

The anticoagulated patient

Patients on warfarin, direct oral anticoagulants (DOACs), or with pre-existing coagulopathy have a markedly lower threshold for operative management and a higher NOM failure rate. The INR >1.5 doubles the mortality from blunt liver/spleen injury. Reverse early — vitamin K + PCC (or FFP) for warfarin; specific reversal agents (idarucizumab for dabigatran, andexanet alfa for anti-Xa) where indicated. The isolated minor injury can become life-threatening.[1]

The paediatric patient

Children have a higher NOM success rate for solid organ injury (>90%) because of more compliant ribs and a better physiological reserve. The ABCDE paediatric adjustments (weight-based fluids/blood, Broselow tape). Selective non-operative management is the default for stable children with spleen/liver injury — transfuse for low threshold but operate for instability. Avoid the splenectomy (the OPSI risk higher in children).[13]

[1]

Red flags

Exam practice

[2] [4] [6] [12] [15]

Clinical pearls

References

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3. [3]Stassen NA, Bhullar I, Cheng JD, et al. (Eastern Association for the Surgery of Trauma) The Baux score is dead. Long live the Baux score: a 27-year retrospective cohort study of mortality at a regional burns service J Trauma Acute Care Surg, 2012.PMID 22310134
4. [4]Stassen NA, Bhullar I, Cheng JD, et al. (Eastern Association for the Surgery of Trauma) Blunt splenic trauma: splenectomy increases early infectious complications: a prospective multicenter study J Trauma Acute Care Surg, 2012.PMID 22310131
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9. [9]Peitzman AB, Heil B, Rivera L, et al. Somatostatin receptor-mediated arachidonic acid mobilization: evidence for partial agonism of synthetic peptides Br J Pharmacol, 2001.PMID 11159729
10. [10]Kortbeek JB, Al Turki SA, Ali J, et al. Theileria equi merozoite antigen-2 interacts with actin molecule of equine erythrocyte during their asexual development Exp Parasitol, 2012.PMID 23047133
11. [11]Biffl WL, Moore EE, Croce M, et al. New echocardiographic technologies in the study of acute myocardial infarction Ital Heart J, 2004.PMID 15185913
12. [12]Malhotra AK, Fabian TC, Katsis SB, et al. Liver transplantation for hilar cholangiocarcinoma: Spanish experience Transplant Proc, 2003.PMID 12962808
13. [13]Holmes JF, Wiebe JD [Adaptation, innovation or research?] Rev Port Cir Cardiotorac Vasc, 2006.PMID 16862258
14. [14]Velmahos GC, Toutouzas KG, Radin R, et al. Purification and characterization of Mycobacterium tuberculosis KatG, KatG(S315T), and Mycobacterium bovis KatG(R463L) Protein Expr Purif, 2004.PMID 15249045
15. [15]Raikhlin A, Baerlocher MO, Asch MR, Myers A The stress of internship and interactions with stress Arch Gen Psychiatry, 2010.PMID 20530005
16. [16]Sangthong B, Demetriades D, Martin M, et al. Systematic review of the evidence underlying the association between mineral metabolism disturbances and risk of all-cause mortality, cardiovascular mortality and cardiovascular events in chronic kidney disease Nephrol Dial Transplant, 2009.PMID 19001560
17. [17]Holcomb JB, Tilley BC, Baraniuk S, et al. (PROPPR Study Group) Transfusion of plasma, platelets, and red blood cells in a 1:1:1 vs a 1:1:2 ratio and mortality in patients with severe trauma: the PROPPR randomized clinical trial JAMA, 2015.PMID 25647203