A 59-year-old woman is evaluated on postoperative day 7 following an open hysterectomy and… — USMLE Step 2 CK

A 59-year-old woman is evaluated on postoperative day 7 following an open hysterectomy and lysis of adhesions. She had been tolerating a liquid diet and passing flatus until 24 hours ago, when she developed progressive, crampy abdominal pain and obstipation. Over the past 4 hours, the pain has become severe and constant. Her temperature is $39.1^\circ\text{C}$ ( $102.4^\circ\text{F}$ ), pulse is $126/\text{min}$ , respirations are $26/\text{min}$ , and blood pressure is $86/52\text{ mmHg}$ . Physical examination reveals a markedly distended abdomen with diffuse rigidity, rebound tenderness, and involuntary guarding. Laboratory studies show a leukocyte count of $21,000/\text{mm}^3$ and a serum lactate level of $5.1\text{ mmol/L}$ . An abdominal radiograph demonstrates multiple dilated loops of small bowel with air-fluid levels and a lack of gas in the colon. Which of the following are the most appropriate next steps in this patient's management? (Select two)

Initiate aggressive resuscitation with intravenous crystalloidsAnswer
Proceed directly to the operating room for exploratory laparotomyAnswer
C
Insert a nasogastric tube and observe for clinical improvement over 24 hours
D
Transport the patient to radiology for a computed tomography scan of the abdomen
E
Obtain blood and urine cultures to direct antimicrobial therapy for the postoperative fever

Answer

The correct next steps in management are to initiate aggressive resuscitation with intravenous crystalloids and to proceed directly to the operating room for exploratory laparotomy.

This patient presents with a small bowel obstruction (SBO) that has progressed from simple to complicated (strangulated). The transition from crampy pain to severe, constant pain, combined with peritonitis (rigidity, rebound), fever, marked leukocytosis, and elevated serum lactate, strongly indicates bowel ischemia. In this setting, the bowel is undergoing necrosis, which leads to systemic toxicity and septic shock (evidenced by hypotension and tachycardia). The only definitive treatment for a strangulated SBO is immediate surgical exploration (exploratory laparotomy) to resect ischemic tissue and relieve the obstruction. Concurrently, the patient requires aggressive intravenous fluid resuscitation to stabilize her hemodynamics and correct the severe dehydration caused by third-spacing and vomiting.

Step-by-Step Solution

Analyze the clinical presentation and radiographic findings.

The patient has a history of prior abdominal surgery, obstipation, crampy pain, and radiographs showing dilated small bowel with air-fluid levels, confirming a small bowel obstruction (SBO).

Establishing the baseline diagnosis is the first step in evaluating postoperative abdominal pain.

Evaluate the patient for signs of complications (ischemia, necrosis, or perforation).

The patient exhibits fever (

39.1^\circ\text{C}

), tachycardia (

126/\text{min}

), hypotension (

86/52\text{ mmHg}

), a rigid abdomen with rebound tenderness, leukocytosis, and an elevated lactate (

5.1\text{ mmol/L}

Differentiating between a simple and a complicated (strangulated) SBO dictates whether management will be medical or surgical.

Determine the appropriate management for a complicated SBO.

Immediate intravenous fluid resuscitation and emergency exploratory laparotomy are selected.

Strangulated SBO is a surgical emergency. Delaying for imaging or attempting conservative observation results in bowel necrosis, sepsis, and high mortality.

Key Concept

Patients with a small bowel obstruction who develop signs of clinical deterioration, hemodynamic instability, or peritonitis require immediate surgical exploration alongside aggressive fluid resuscitation, rather than conservative management or further diagnostic imaging.

Estimated Time:1m 30s

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