A 72-year-old woman with a 10-year history of untreated right femoral hernia presents with sudden onset right groin pain and vomiting. She reports the hernia has been irreducible for the past 3 days but was painless until today. On examination, she is afebrile (37.2°C), BP 128/82, HR 92/min, with a tender, tense right femoral swelling. Abdominal examination reveals mild distension and hyperactive bowel sounds. Plain abdominal X-ray shows a few dilated small bowel loops. Serum lactate is 1.8 mmol/L and WBC 11,200/μL. What is the most likely diagnosis?

Explanation

## Clinical Assessment **Key Point:** This patient has an **acutely strangulated femoral hernia requiring emergency surgery** — the clinical picture is consistent with bowel ischemia, not merely impending strangulation. ## Why This Is Strangulation, Not Just Incarceration | Feature | This Patient | Significance | |---------|-------------|--------------| | **Duration of irreducibility** | 3 days | Prolonged → high ischemia risk | | **Sudden acute pain** | Yes (today) | Classic sign of vascular compromise | | **Vomiting + distension** | Yes | Bowel obstruction established | | **Dilated small bowel loops** | Yes (X-ray) | Mechanical obstruction confirmed | | **Tender, tense swelling** | Yes | Perihernia inflammation/ischemia | | **WBC 11,200** | Mildly elevated | Early systemic response | | **Lactate 1.8 mmol/L** | Near-normal | Does NOT exclude early ischemia | **High-Yield:** A near-normal lactate does NOT rule out strangulation. Lactate rises late in ischemia — by the time it is markedly elevated, bowel necrosis is advanced. The **clinical picture** (3 days irreducible, sudden pain, obstruction on X-ray, tender tense swelling) mandates emergency surgery regardless of lactate. ## Pathophysiology of Femoral Hernia Strangulation Femoral hernias are the **most prone to strangulation** of all hernias because: - The femoral ring is rigid (bounded by inguinal ligament, lacunar ligament, femoral vein, and pectineal ligament) - The neck is narrow — even small amounts of bowel edema cause vascular compromise - Strangulation can occur within hours of incarceration **Clinical Pearl (Bailey & Love / Sabiston):** Any femoral hernia that becomes acutely painful after a period of irreducibility must be treated as strangulated until proven otherwise. The combination of obstruction signs (vomiting, distension, dilated loops) with a tender irreducible femoral swelling is the classic presentation of strangulation requiring **immediate emergency surgery**. ## Why Option B Is Wrong Option B states "proceed to elective surgery within 24 hours" — this is **dangerously incorrect** for this clinical scenario. Even the original explanation acknowledged "urgent surgery within 2–6 hours," which itself contradicts the 24-hour framing. More importantly, the full clinical picture (3-day irreducibility, acute pain onset, bowel obstruction on imaging, tender tense swelling) represents strangulation, not merely impending strangulation. A 24-hour delay risks bowel necrosis, perforation, and sepsis. ## Correct Management 1. **Immediate resuscitation:** IV fluids, NG tube, NPO, urinary catheter 2. **Broad-spectrum IV antibiotics:** Cover gram-negatives and anaerobes 3. **Emergency surgery:** Do not delay — explore the hernia sac, assess bowel viability 4. **Intraoperative assessment:** If bowel is ischemic/necrotic → resection and anastomosis; if viable after release → repair only 5. **Hernia repair:** Low approach (Lockwood) or high approach (McEvedy) depending on bowel viability needs [cite: Bailey & Love's Short Practice of Surgery 27e Ch 55; Sabiston Textbook of Surgery 21e Ch 43]