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Difficulty: HardPreoperative and Postoperative Care

A 62-year-old man is evaluated in the surgical intensive care unit for a new-onset fever. He was admitted 12 days ago after sustaining severe blunt abdominal trauma in a motor vehicle collision. He underwent an emergency exploratory laparotomy with splenectomy and repair of multiple small bowel lacerations. His postoperative course has been complicated by acute respiratory distress syndrome requiring prolonged mechanical ventilation, and he has been receiving total parenteral nutrition via a right internal jugular central venous catheter for the past 10 days.

Today, his temperature has spiked to 39.4°C (102.9°F). Blood pressure is 100/65 mm Hg, pulse is 118/min, and respirations are 22/min on the ventilator. He is sedated but grimaces when the right upper quadrant of his abdomen is palpated. The laparotomy incision is clean and intact. The central venous catheter site shows no erythema, induration, or purulent exudate.

Laboratory studies:
ParameterResult
Leukocyte count24,000/mm³ (85% segmented neutrophils, 10% bands)
Total bilirubin3.8 mg/dL
Direct bilirubin2.9 mg/dL
Alkaline phosphatase410 U/L
Aspartate aminotransferase (AST)95 U/L
Alanine aminotransferase (ALT)102 U/L

Blood and urine cultures are drawn, and empiric broad-spectrum intravenous antibiotics are initiated.

Which of the following is the most appropriate next step in diagnosis?

  1. Bedside right upper quadrant ultrasonographyAnswer
  2. B
    Computed tomography of the abdomen and pelvis
  3. C
    Removal and tip culture of the central venous catheter
  4. D
    Endoscopic retrograde cholangiopancreatography
  5. E
    Hepatobiliary iminodiacetic acid (HIDA) scanning

Answer

The correct answer is bedside right upper quadrant ultrasonography.
The correct answer is bedside right upper quadrant ultrasonography. This patient's clinical picture is highly characteristic of acute acalculous cholecystitis. Risk factors include critical illness (severe trauma, ARDS, mechanical ventilation), prolonged fasting, and total parenteral nutrition (TPN). These factors lead to gallbladder stasis and ischemia, resulting in inflammation without the presence of gallstones. The patient's new-onset fever, leukocytosis, right upper quadrant tenderness (evidenced by grimacing on palpation), and classic cholestatic liver enzyme pattern (disproportionately elevated direct bilirubin and alkaline phosphatase) point directly to a hepatobiliary source. Bedside right upper quadrant ultrasonography is the diagnostic test of choice because it is fast, highly specific for gallbladder pathology (showing a thickened gallbladder wall and pericholecystic fluid), and can be performed without transporting an unstable, mechanically ventilated patient.

Step-by-Step Solution

1
Analyze the patient's risk factors and timeline.
The patient is critically ill, mechanically ventilated, and receiving total parenteral nutrition on postoperative day 12. This places him at extremely high risk for biliary stasis and gallbladder ischemia.
Identifying the systemic risk factors helps narrow the differential diagnosis for late postoperative fever in the intensive care unit.
2
Evaluate the physical examination and laboratory data.
The patient exhibits localized right upper quadrant tenderness (grimacing) along with a prominent cholestatic pattern on liver function tests (elevated direct bilirubin and alkaline phosphatase).
These findings localize the infectious source to the hepatobiliary system, differentiating it from generalized abdominal abscesses or catheter-related infections.
3
Select the optimal initial diagnostic modality.
Bedside right upper quadrant ultrasonography is selected as the first-line test.
Ultrasound is the most appropriate initial step because it is highly sensitive for gallbladder wall thickening and pericholecystic fluid, and it avoids the significant risks associated with transporting a critically ill, mechanically ventilated patient to the radiology suite.

Key Concept

Acute acalculous cholecystitis should be suspected in critically ill patients (e.g., trauma, burns, prolonged total parenteral nutrition) who develop unexplained fever, leukocytosis, and cholestatic liver enzymes. Bedside right upper quadrant ultrasound is the initial diagnostic test of choice.
Estimated Time:1m 30s
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Topics

Preoperative and Postoperative Care

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