An 86-year-old multiparous woman is brought to the emergency department due to a 3-day his… — USMLE Step 2 CK

An 86-year-old multiparous woman is brought to the emergency department due to a 3-day history of progressive abdominal distension, intractable vomiting, and failure to pass flatus or stool. She resides in an assisted living facility and has a history of severe chronic obstructive pulmonary disease and profound, unintentional weight loss over the past 6 months. She also complains of pain radiating down the medial aspect of her right thigh, which is exacerbated by extending and internally rotating the right hip. Her temperature is $38.4^{\circ}\text{C}$ ( $101.1^{\circ}\text{F}$ ), pulse is $122/\text{min}$ , respirations are $24/\text{min}$ , and blood pressure is $88/55\text{ mm Hg}$ . Physical examination reveals a tympanic, distended abdomen with marked right lower quadrant tenderness and involuntary guarding. Bowel sounds are high-pitched and tinkling. Laboratory studies show a leukocyte count of $18,500/\text{mm}^3$ with $15\%$ bands and a serum lactate level of $4.6\text{ mmol/L}$ . An upright abdominal radiograph demonstrates multiple dilated loops of small bowel with prominent air-fluid levels, but no pneumoperitoneum. Which of the following is the most appropriate next step in management?

A
Insertion of a nasogastric tube and aggressive intravenous fluid resuscitation
B
Computed tomography scan of the abdomen and pelvis with intravenous contrast
Immediate exploratory laparotomyAnswer
D
Administration of broad-spectrum antibiotics and surgical observation
E
Right hip and pelvic radiography with orthopedic evaluation

Answer

Immediate exploratory laparotomy

The correct answer is immediate exploratory laparotomy. This patient presents with a small bowel obstruction (SBO) secondary to a strangulated obturator hernia. She exhibits the classic Howship-Romberg sign (pain radiating to the medial thigh, exacerbated by hip extension and internal rotation), which occurs when the herniated bowel compresses the obturator nerve within the obturator canal. Obturator hernias typically occur in elderly, multiparous women with significant recent weight loss, which causes the loss of the protective preperitoneal fat pad in the obturator canal. Most importantly, this patient has 'hard signs' of bowel ischemia and strangulation: fever, tachycardia, hypotension, peritonitis (involuntary guarding), marked leukocytosis, and lactic acidosis. Any patient with SBO who develops hemodynamic instability, peritonitis, or signs of ischemia must undergo immediate surgical exploration to prevent bowel perforation, overwhelming sepsis, and death.

Step-by-Step Solution

Identify the primary clinical syndrome from the patient's presentation.

The patient has a mechanical small bowel obstruction (SBO) complicated by strangulation and ischemia, evidenced by fever, hypotension, peritonitis, leukocytosis, and lactic acidosis.

Recognizing the severity of the SBO dictates the urgency of intervention.

Determine the specific etiology of the obstruction.

The patient has an obturator hernia.

The triad of an elderly, multiparous woman with profound weight loss presenting with SBO and the Howship-Romberg sign (medial thigh pain exacerbated by hip extension and internal rotation) is pathognomonic for an obturator hernia compressing the obturator nerve.

Select the most appropriate next step in management based on the patient's stability.

Immediate exploratory laparotomy.

Because the patient is hemodynamically unstable and has hard signs of bowel necrosis, diagnostic imaging (like CT) and conservative measures must be bypassed in favor of emergent surgical exploration.

Key Concept

Patients with mechanical small bowel obstruction who exhibit signs of strangulation (fever, tachycardia, leukocytosis, lactic acidosis) or peritonitis require immediate exploratory laparotomy, overriding the need for further diagnostic imaging.

Question

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Topics

More questions from this topic