Ch20: Abdominal Injury（腹部损伤）

Preparatory Mindset

Abdominal injury = closed (blunt) & open (penetrating) trauma to the abdomen. The lecture (Dr. Pan, 13.4KB) covers the principles of first aid, early diagnosis, and treatment; the differential of liver, spleen, pancreas & bowel rupture; and the diagnostic steps for closed injury. This pairs with the Trauma chapter (Ch12) — the ATLS/FAST approach applies here specifically to the abdomen.

Exam mindset: solid organs (liver, spleen) → hemorrhage; hollow organs (bowel) → peritonitis; the FAST scan & unstable → laparotomy vs stable → CT decision; and the classic signs (Kehr's sign for spleen, peritonitis for bowel).

Core Concepts

1. Overview & classification (MUST KNOW)

- Open (penetrating) injury (开放性): stab, gunshot — wound present, easier to recognize; exploration needed (may be laparotomy) - Closed (blunt) injury (闭合性): no wound — harder to diagnose (hidden visceral injury); RTA, falls, assault - Iatrogenic injury: endoscopy, surgery

• Incidence: peacetime 0.4-1.8%; wartime ~50%; mortality ~10% — mostly from severe visceral injury (massive bleeding or severe abdominal infection)
• Key to survival: early correct diagnosis + timely treatment
• Classification:

2. Mechanisms of injury (MUST KNOW)

- Spleen (most commonly injured solid organ in blunt trauma) — hemorrhage - Liver (second) — hemorrhage, bile leak - Kidney — hematuria - Pancreas — delayed presentation (retroperitoneal) - Small bowel (hollow — most common hollow organ) — perforation → peritonitis - Colon, mesentery, diaphragm, bladder

• Blunt: direct compression, deceleration (shear at fixed points — liver/spleen/renal pedicle, bowel at Treitz), crush
• Penetrating: stab (low velocity, path-dependent) vs gunshot (high velocity, blast cavity — more tissue damage, mandatory exploration)
• Common organs injured:

3. Clinical manifestations (MUST KNOW)

- Spleen: left upper quadrant pain, Kehr's sign (left shoulder-tip pain — blood irritates the diaphragm, phrenic C3-5), hypotension, tachycardia, falling Hb; left lower rib fractures - Liver: right upper quadrant pain, referred right shoulder, hypotension; hemobilia rare - Kidney: flank pain, hematuria, flank bruising

- Bowel perforation: progressive abdominal pain, guarding, rigidity, rebound tenderness, absent bowel sounds, fever, tachycardia; free air (pneumoperitoneum) — later - Pancreas: epigastric pain radiating to the back (delayed, retroperitoneal — easily missed); ↑ amylase/lipase; periumbilical (Cullen) / flank (Grey-Turner) ecchymosis (late, also pancreatitis)

• Solid organ (bleeding) — hypovolemic shock picture:
• Hollow organ (peritonitis) — delayed peritonitis picture:
• General: abdominal pain, distension, tenderness, rigidity; signs of shock; rectal exam (blood, tenderness); auscultation (absent bowel sounds = peritonitis/ileus)

4. Diagnosis (MUST KNOW)

• History & mechanism; ABCDE assessment (ATLS)
• FAST (focused assessment with sonography in trauma): 4 views — right upper quadrant (hepatorenal/Morison's pouch), left upper quadrant (splenorenal), pelvis (rectovesical/pouch of Douglas), pericardium — detects free fluid (blood); quick, bedside; positive in unstable patient = go to laparotomy; negative doesn't exclude injury
• CT abdomen with IV contrast: the definitive imaging in stable patients — identifies organ injury & grade, retroperitoneal injury, active bleeding (extravasation)
• Diagnostic peritoneal lavage (DPL): historical (positive: >100,000 RBC, bile, bowel content) — largely replaced by FAST/CT
• Laboratory: CBC (falling Hb), amylase/lipase (pancreas), LFTs (liver), urine (hematuria), cross-match, lactate, ABG
• X-ray: free air under the diaphragm (hollow viscus), rib/pelvic fractures, bullet/foreign body
• Serial examination: repeated abdominal exams (developing peritonitis) — for the stable blunt patient

5. Treatment principles (MUST KNOW)

- Hemodynamic instability + positive FAST (or peritonitis) - Evisceration, impalement - Penetrating injury with peritonitis/shock (gunshot wounds usually explored) - Free intraperitoneal air - Deteriorating/ongoing bleeding despite resuscitation - Evidence of hollow viscus perforation (peritonitis, gas)

- Spleen: splenorrhaphy or splenectomy (unstable); vaccinate (encapsulated organisms: pneumococcus, meningococcus, Hib) & lifelong antibiotics/post-splenectomy sepsis awareness after splenectomy - Liver: packing & Pringle maneuver (control porta hepatis), hepatorrhaphy, angioembolization; segmental resection; major vascular control - Kidney: NOM for minor; nephrectomy for non-salvageable (check contralateral) - Bowel: repair (primary closure) or resection & anastomosis; consider stoma if peritonitis/severe contamination/hemodynamic instability - Pancreas: drain; distal pancreatectomy for body/tail injury; ERCP/stenting for duct injury - Bladder/ureter: repair + drainage

• Resuscitation first (ABC): IV fluids/blood, treat shock; two large-bore IVs; blood products early
• Indications for laparotomy (MUST KNOW):
• Stable patients: CT → selective non-operative management (NOM) for low-grade solid organ injuries (liver/spleen grades I-III) — observe, serial exams/Hb, angioembolization for active bleeding
• Surgical principles (damage control):
• Postoperative: ICU, monitor for missed injury (repeat laparotomy/second look), complications (bleeding, infection, abscess, fistula, compartment syndrome)
• Antibiotics: broad-spectrum for penetrating/contaminated; tetanus prophylaxis

High-Yield Points

• Spleen = most commonly injured solid organ; small bowel = most common hollow organ
• Solid organ → hemorrhage (shock); hollow organ → peritonitis (delayed)
• Kehr's sign = left shoulder pain (splenic injury/diaphragm irritation)
• FAST: RUQ (Morison), LUQ (splenorenal), pelvis, pericardium — positive + unstable = laparotomy
• CT = definitive imaging in stable patients; NOM for low-grade liver/spleen
• Laparotomy indications: unstable + positive FAST, peritonitis, evisceration, free air, penetrating with shock
• Gunshot = explore; stab = selective (serial exams, CT)
• Post-splenectomy: vaccinate (pneumococcus, meningococcus, Hib) — encapsulated organism sepsis risk
• Packing + Pringle maneuver for liver hemorrhage; damage control surgery
• Pancreatic injury: delayed, retroperitoneal — ↑ amylase, CT; drain/resect

Topic Summary

Abdominal injury: open (penetrating) & closed (blunt). Solid organs (spleen most common, liver, kidney, pancreas) bleed → hypovolemic shock; hollow organs (small bowel most common) perforate → delayed peritonitis. Classic signs: Kehr's (spleen), free air (hollow viscus), hematuria (kidney), Cullen/Grey-Turner (pancreas, late). Diagnosis: ABCDE + FAST (unstable + positive → laparotomy) + CT (stable → definitive imaging, NOM for low-grade liver/spleen) + serial exams. Treatment: resuscitate; laparotomy for instability/peritonitis/evisceration/free air; non-operative management with angioembolization for stable solid-organ injuries; surgical principles (splenectomy + vaccination, liver packing/Pringle, bowel resection, pancreatic drain/resection); damage control in the unstable; broad-spectrum antibiotics & tetanus prophylaxis.