A 54-year-old male construction worker is urgently evaluated in the emergency department a… — USMLE Step 2 CK

A $54$ -year-old male construction worker is urgently evaluated in the emergency department after leaving work due to the abrupt onset of excruciating, unremitting mid-abdominal pain. He reports vomiting greenish fluid twice since the pain began $6$ hours ago. His surgical history is notable for a complex open appendectomy performed for a ruptured appendix $10$ years ago. Current vital signs include a temperature of $38.6^\circ\text{C}$ ( $101.5^\circ\text{F}$ ), blood pressure of $92/58\text{ mm Hg}$ , pulse of $122\text{/min}$ , and respirations of $22\text{/min}$ . On physical examination, the patient is diaphoretic and avoids any movement. His abdomen is mildly distended and exhibits board-like rigidity, diffuse severe tenderness to light palpation, and absent bowel sounds.

Laboratory investigations reveal:
- Leukocyte count: $19,000\text{/mm}^3$
- Serum bicarbonate: $15\text{ mEq/L}$
- Blood urea nitrogen: $34\text{ mg/dL}$
- Serum creatinine: $1.6\text{ mg/dL}$
- Lactic acid: $5.4\text{ mmol/L}$

An initial upright chest and abdominal radiograph series demonstrates a nonspecific bowel gas pattern with no pneumoperitoneum and no distinct air-fluid levels. Aggressive intravenous crystalloid resuscitation is initiated. Which of the following is the most appropriate next step in the management of this patient?

Immediate open exploratory laparotomyCevap
B
Computed tomography of the abdomen and pelvis with intravenous contrast
C
Nasogastric tube decompression and serial clinical assessments
D
Administration of oral water-soluble radiopaque contrast medium
E
Admission to the intensive care unit for broad-spectrum intravenous antibiotic therapy

Cevap

Immediate open exploratory laparotomy

The correct answer is immediate open exploratory laparotomy. This patient presents with an acute surgical abdomen, characterized by systemic toxicity (fever, tachycardia, hypotension), lactic acidosis, and hard signs of peritonitis (board-like rigidity, lying completely still). Given his history of a prior complex open appendectomy, he is at high risk for adhesive small bowel obstruction (SBO). The abrupt onset of excruciating, unremitting pain combined with these physical findings is highly suspicious for a strangulated closed-loop obstruction, where a segment of bowel is obstructed at two points, rapidly leading to vascular compromise, ischemia, and necrosis. Importantly, a closed-loop obstruction often presents with a paucity of gas and no classic air-fluid levels on plain radiographs because the isolated loop is filled with fluid rather than air. When a patient exhibits unequivocal signs of generalized peritonitis and bowel ischemia (elevated lactate, metabolic acidosis), emergent laparotomy is indicated regardless of non-diagnostic imaging findings.

Adım Adım Çözüm

Identify the patient's primary syndrome based on history and physical examination.

The patient has an acute surgical abdomen with signs of generalized peritonitis (rigidity, absent bowel sounds, severe tenderness to light palpation) and systemic toxicity (fever, tachycardia, hypotension).

Recognizing peritonitis is the critical first step in triaging abdominal pain.

Analyze the laboratory data for evidence of tissue ischemia or sepsis.

The elevated leukocyte count (

19,000\text{/mm}^3

) and significant lactic acidosis (

5.4\text{ mmol/L}

) with a low bicarbonate (

15\text{ mEq/L}

) strongly indicate necrotic or ischemic tissue.

Lactic acidosis in the setting of a rigid abdomen is highly specific for bowel infarction.

Integrate the past surgical history with the current findings to determine the most likely etiology.

A history of complex appendectomy places the patient at high risk for adhesive small bowel obstruction. The abrupt, unremitting pain suggests a strangulated closed-loop obstruction.

Closed-loop obstructions rapidly progress to ischemia because the bowel is trapped at two points, cutting off mesenteric blood supply.

Determine the appropriate management prioritizing definitive treatment over further diagnostics.

Immediate exploratory laparotomy is chosen over advanced imaging (like CT) or conservative measures.

When hard signs of peritonitis and bowel ischemia are present, further imaging dangerously delays life-saving surgical resection of the necrotic bowel.

Anahtar Kavram

Surgical triage and management of strangulated small bowel obstruction.

Soru

Cevap

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