Spontaneous bacterial peritonitis Quiz: Ace Your Exams

A 59-year-old woman is brought to the emergency department for fever and confusion. Her partner states that she has been “acting differently” over the past 24 hours. The patient has not had nausea, vomiting, constipation or diarrhea. Medical history is significant for cirrhosis due to chronic alcohol use. Medications include spironolactone and furosemide. The patient also has an umbilical hernia that has not been repaired. Temperature is 38.0 ℃ (100.4 ℉), pulse is 102/min, respiratory rate is 14/min, blood pressure is 102/70 mmHg, and oxygen saturation is 99% on room air. The patient is unable to perform a timed connect-the-numbers test. Bowel sounds are decreased. Abdominal examination shows moderate ascites with diffuse tenderness to palpation. There is no rigidity or rebound tenderness. A bulge in the umbilicus is mildly tender and reducible without overlying skin changes. Creatinine is 1.1 mg/dL (reference range: 0.6-½ mg/dL; patient’s baseline is 1.0 mg/dL). Urinalysis shows no hematuria and a bland urine sediment. Abdominal radiograph shows dilated loops of small and large bowels with air in the colon. Which of the following is the most likely underlying cause of this patient’s current condition?