A 29-year-old man arrives on a backboard in a stiff, blood-speckled shirt, one hand clamped over a small stab wound just below the left costal margin. He’s pale but talking, every breath shallow, the monitor tracing a fast narrow pulse while a paramedic peels off a gauze pad that’s already dark red. In the corner of the bay, a nurse notices his abdomen tightening with each wince, but the wound itself looks deceptively small. The question is whether this is a superficial cut or a hole that has already reached something that matters.

— What’s your move? Read on.

Before you read
  • What bedside findings are reliable enough to override a “looks stable” patient?
  • When should FAST, CT, or a local wound exploration actually change management?

When to Think of It

Any stab, gunshot, or impalement to the torso below the nipples and above the groins, especially with peritonitis, evisceration, hemodynamic instability, or an unreliable exam. Think of it when the trajectory could cross the diaphragm, retroperitoneum, mesentery, or solid organs.

Sick or Not Sick

The fork is unstable/peritonitic vs. stable and examinable. If the patient is hypotensive, has diffuse peritonitis, or is too unreliable to examine, assume operative injury until proven otherwise.

The First Fifteen Minutes

  • Massive hemorrhage or shock → balanced blood product resuscitation with PRBC:plasma:platelets in roughly 1:1:1 ratio; if profound shock, give TXA 1 g IV over 10 min, then 1 g IV over 8 hr within 3 hours of injury, because it slows fibrinolysis.
  • Hypotension after penetrating trauma → permissive hypotension is not for obvious TBI; otherwise keep perfusion just adequate while activating the trauma team, because crashing patients need source control, not liters of crystalloid.
  • Open abdominal evisceration or obvious bowel contamination → cover exposed viscera with sterile saline-moistened gauze and an occlusive dressing, because it limits desiccation and contamination.
  • Pain/anxiety with stable airway and pressure → fentanyl 25–50 mcg IV q5–10 min titrated (or hydromorphone 0.5–1 mg IV), because analgesia improves exam and reduces catecholamine stress.
  • Suspected bowel injury/open wound with contamination risk → cefazolin 2 g IV now; if gross hollow viscus contamination is likely, add metronidazole 500 mg IV, because early antibiotics reduce infectious complications.
  • Unclear tetanus status with dirty penetrating wound → Tdap 0.5 mL IM now (plus TIG if indicated by immunization history), because tetanus prophylaxis prevents toxin-mediated disease.

Definitive Care & Disposition

Unstable patients, those with peritonitis, free air, evisceration with concerning exam, or a positive FAST with shock go to the OR for exploratory laparotomy. Stable patients usually get contrast CT of chest/abdomen/pelvis to define trajectory and injury pattern; some require serial abdominal exams or local wound exploration if the wound is superficial and the patient is reliable. Admit all true penetrating abdominal injuries; floor vs ICU depends on hemodynamics, transfusion requirement, associated injuries, and operative findings.

How This One Kills

The fatal miss is assuming a small wound means a minor injury and sending home a patient with a delayed hollow viscus perforation or mesenteric bleed that declares itself hours later with sepsis or exsanguination.
The Differential — What Else Looks Like This
  • Abdominal wall stab only — no fascial violation on local exploration; confusing it with true penetration leads to unnecessary laparotomy.
  • Blunt abdominal trauma — lacks a penetrating tract; missing the distinction delays targeted evaluation for bowel/vascular injury.
  • Lower thoracic injury with diaphragmatic violation — trajectory crosses the diaphragm; confusing it with isolated abdominal injury misses a repairable but dangerous thoracoabdominal injury.
  • Flank/back soft tissue wound — retroperitoneal injuries can be occult; confusing it with superficial trauma misses duodenal, pancreatic, renal, or vascular injury.

The Second-Day Story

Older adults, intoxicated patients, and those with distracting injuries may look “okay” while bleeding internally. The abdomen may be soft, the wound tiny, and the vitals only mildly abnormal—yet a mesenteric tear or hollow viscus injury can smolder until the patient suddenly becomes febrile, tachycardic, and peritoneal hours later. Treat any unreliable exam with a lower threshold for CT, observation, or operative consultation.
Back to Our Patient
Back to our 29-year-old with the small left upper quadrant stab wound and worsening tachycardia: this is a penetrating abdominal trauma patient with possible transdiaphragmatic or splenic/colonic injury. He is recognized as high risk because the exam is concerning and the wound location is dangerous; if he becomes hypotensive or peritonitic, he goes straight to the OR, and if he remains stable he needs urgent trauma evaluation and contrast CT after initial resuscitation. His wound is covered, blood is prepared if needed, tetanus and antibiotics are addressed, and he is admitted under trauma surgery rather than watched casually.
Patient Presentation to Attending
How you’d present this patient on the floor — tight, pertinent positives and negatives, no rambling
“29-year-old man with a stab wound to the left upper abdomen just below the costal margin, here after assault. He’s tachycardic with abdominal pain and guarding around the wound but no respiratory distress; blood pressure has been borderline but currently holding. I’m concerned for penetrating abdominal injury with possible diaphragmatic, splenic, or hollow viscus involvement. FAST is pending and I’ve activated trauma surgery; we’ve covered the wound, given analgesia, started blood preparation, updated tetanus, and are deciding between immediate OR if he worsens versus CT if he remains stable.”

Study Directive

  • Sketch the decision tree for penetrating abdominal trauma from memory: unstable/peritonitic → OR; stable → CT/serial exams/LWE as appropriate.
  • Make a one-page list of injuries by anatomic zone: anterior abdomen, flank/back, thoracoabdominal, and groin.
  • Practice a 30-second oral sign-out that includes mechanism, hemodynamics, abdominal exam, FAST status, and disposition.
  • Review your institution’s trauma antibiotic and tetanus prophylaxis pathway for penetrating wounds.

Recent Literature