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Difficulty: Very hardPreoperative and Postoperative Care

A 65-year-old man with a history of severe chronic obstructive pulmonary disease, heart failure with reduced ejection fraction, and stage III chronic kidney disease is evaluated on postoperative day 3 following an open abdominal aortic aneurysm repair. Over the past 12 hours, his urine output has decreased to 15 mL/hr. He is increasingly lethargic and mildly confused.

Vital signs are temperature 38.4°C (101.1°F), heart rate 112/min, blood pressure 90/55 mm Hg, and respiratory rate 24/min. Pulse oximetry is 92% on a 3 L/min nasal cannula. Central venous pressure is 16 mm Hg (normal: 2-8 mm Hg).

Physical examination reveals jugular venous distension. Lung auscultation demonstrates bibasilar crackles and scattered expiratory wheezes. The abdomen is moderately distended, tense, and diffusely tender with decreased bowel sounds.

Laboratory studies show:
Blood urea nitrogen: 52 mg/dL
Serum creatinine: 2.6 mg/dL (baseline 1.5 mg/dL)
Serum lactate: 3.8 mmol/L
Fractional excretion of sodium (FENa): 2.5%

A bedside bladder pressure measurement is 26 mm Hg.

Based on these findings, which of the following are the most appropriate immediate steps in management? (Select all that apply)

  1. Prepare the patient for an emergent decompressive laparotomyAnswer
  2. Perform endotracheal intubation and initiate mechanical ventilationAnswer
  3. C
    Administer intravenous furosemide and non-invasive positive pressure ventilation
  4. D
    Transport the patient to the radiology department for a computed tomography scan of the abdomen
  5. E
    Obtain a duplex ultrasound of the lower extremities

Answer

The correct immediate steps are to prepare the patient for an emergent decompressive laparotomy and to perform endotracheal intubation.
This patient has developed abdominal compartment syndrome (ACS), defined as an intra-abdominal pressure (measured via bladder pressure) greater than 20 mm Hg combined with new organ dysfunction. In this case, the patient has acute kidney injury, shock, and respiratory failure. The severely elevated intra-abdominal pressure pushes the diaphragm cephalad, significantly increasing intrathoracic pressure. This physiological change decreases venous return while simultaneously causing a falsely elevated central venous pressure and jugular venous distension. The compression of the lung bases leads to atelectasis, causing hypoxia, crackles, and wheezing. The compression of the renal veins leads to severe acute kidney injury (progressing to acute tubular necrosis with FENa > 2% due to prolonged ischemia). Definitive management requires an emergent decompressive laparotomy to immediately relieve the pressure and restore organ perfusion. Concurrently, due to the patient's altered mental status, respiratory distress, and impending surgical intervention, endotracheal intubation and mechanical ventilation are necessary stabilizing steps.

Step-by-Step Solution

1
Analyze the bladder pressure and organ function to establish the primary diagnosis.
Bladder pressure is 26 mm Hg, and the patient has new oliguric acute kidney injury, shock, and respiratory compromise, confirming abdominal compartment syndrome (ACS).
ACS is defined as intra-abdominal pressure >20 mm Hg associated with new-onset organ dysfunction.
2
Differentiate the hemodynamic findings from primary cardiopulmonary exacerbations.
The high CVP, JVD, crackles, and wheezes are secondary to elevated intra-abdominal pressure pushing the diaphragm upward, increasing intrathoracic pressure, rather than intrinsic heart failure or COPD exacerbation.
Increased intrathoracic pressure compresses the vena cava and right heart (causing JVD/high CVP) and compresses lung bases (causing crackles), closely mimicking cardiogenic shock.
3
Determine the definitive treatment for the identified condition.
The definitive treatment for ACS is emergent surgical decompression.
Only opening the abdomen will rapidly reduce the intra-abdominal pressure and restore perfusion to the mesentery, renal veins, and inferior vena cava.
4
Identify necessary stabilizing interventions prior to or concurrent with surgery.
Endotracheal intubation is required.
The patient has altered mental status, severe respiratory compromise, and requires immediate surgery, necessitating airway protection and mechanical ventilation.

Key Concept

Abdominal compartment syndrome presents with intra-abdominal pressure >20 mm Hg and new organ failure. It can mimic cardiogenic shock due to increased intrathoracic pressure and requires emergent decompressive laparotomy along with airway stabilization.
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Topics

Preoperative and Postoperative Care

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