A 72-year-old man in the ICU is intubated, mechanically ventilated, and receiving continuous vasopressor support via a central line for acute respiratory failure. Over the past 48 hours he has developed progressive abdominal distention. On exam his abdomen is distended and tympanitic with absent bowel sounds. Abdominal radiograph demonstrates marked colonic dilation with a cecal diameter of 12 cm. He has remained NPO with nasogastric decompression and positional changes for 30 hours, but his distention has worsened. Which of the following is the most appropriate pharmacologic intervention at this time?

A 65-year-old man is in the ICU on postoperative day 3 after emergency laparotomy for perforated diverticulitis. He remains sedated on assist-control ventilation and is receiving norepinephrine at 6 mcg/min via a central line. His vital signs are temperature 37.8 °C, heart rate 105 bpm, blood pressure 90/60 mmHg (on norepinephrine), respiratory rate 16 (ventilator-controlled), and SpO₂ 95% on FiO₂ 40%. Over the past 48 hours he has not passed flatus or stool. His abdomen is progressively distended, tympanitic to percussion, diffusely tender, and bowel sounds are absent. A plain abdominal radiograph shows marked colonic dilation with a cecal diameter of 12 cm and air throughout all colonic segments; no transition point or mechanical obstruction is identified. Based on these clinical and radiographic findings, which of the following is the most appropriate interpretation of this patient’s condition?

A 68-year-old man is in the ICU 3 days after abdominal surgery for a perforated diverticulum. He is on assist-control ventilation with a continuous propofol infusion and is receiving fentanyl for pain control via a central line. His vital signs are temperature 37.1 °C, heart rate 84 beats/min, blood pressure 122/78 mm Hg, and respiratory rate 14 breaths/min. During morning rounds, the team notes significant abdominal distension, hypoactive bowel sounds, and no passage of flatus or stool since surgery. His abdomen is soft and non-tender on palpation, and electrolytes are within normal limits. An abdominal X-ray shows diffuse gaseous distension of both small and large bowel loops without air-fluid levels or a transition point. This patient’s presentation is most consistent with which of the following conditions?

A 68-year-old man is admitted to the critical care unit following a complicated abdominal aortic aneurysm repair. He is on assist-control ventilation and a continuous norepinephrine infusion through a central line. On postoperative day 3, he develops significant abdominal distension, diffuse abdominal pain, and absent bowel sounds. His last bowel movement was 4 days ago. Abdominal X-rays show diffuse colonic dilation without evidence of mechanical obstruction or free air. Electrolytes are within normal limits. He has been kept NPO with nasogastric decompression and received bowel rest and electrolyte correction for 48 hours without improvement. He remains hemodynamically stable. Which of the following is the most appropriate initial pharmacologic intervention?

A 68-year-old man is admitted to the ICU for severe sepsis. He is on assist-control ventilation, receiving a continuous norepinephrine infusion via a central line, and has been on a continuous fentanyl infusion for pain control over the past 5 days. Over the last 24 hours, he has developed progressive abdominal distension, absent bowel sounds, and has not passed flatus. An abdominal CT scan shows no mechanical obstruction. His most recent ECG shows a QTc of 510 ms; all other labs are within normal limits. Which of the following is the most appropriate next step in management?

A 68-year-old man (weight 75 kg) is in the medical intensive care unit for septic shock. He is managed with assist-control ventilation, a continuous norepinephrine infusion at 0.1 mcg/kg/min via a right internal jugular central line, and is on continuous cardiac monitoring. Over the past 48 hours, he has developed progressive abdominal distension, absent bowel sounds, and has not passed flatus or stool. A CT scan of the abdomen and pelvis showed massive colonic dilation without evidence of mechanical obstruction. His current medications include a fentanyl infusion at 50 mcg/hr, a midazolam infusion at 2 mg/hr, and pantoprazole. Laboratory results are notable for a creatinine of 2.8 mg/dL (baseline 0.9 mg/dL). Despite holding the fentanyl infusion for 12 hours and encouraging ambulation, his abdominal distension has worsened, and he remains anuric. Given this patient’s presentation, which of the following is the MOST appropriate pharmacotherapeutic intervention for his refractory colonic pseudo-obstruction?

A 68-year-old man with acute colonic pseudo-obstruction (Ogilvie’s syndrome) received intravenous neostigmine 2 mg over 5 minutes after conservative measures failed. Three minutes into the infusion, his heart rate drops from 75 bpm to 38 bpm and his mean arterial pressure falls from 85 mmHg to 55 mmHg. Which of the following is the most appropriate immediate pharmacologic intervention?

A 72-year-old man with severe sepsis and multi-organ dysfunction is on assist-control ventilation and a continuous norepinephrine infusion at 0.1 mcg/kg/min via a central line. Over the past 48 hours he has developed progressive abdominal distention, nausea, and absent bowel sounds. An abdominal X-ray shows marked colonic dilation with a cecal diameter of 12 cm and air throughout all colonic segments without mechanical obstruction. Conservative measures—including bowel rest and nasogastric suction—have been in place for 30 hours without improvement. His vital signs are HR 88 bpm, BP 105/60 mmHg, RR 16 (ventilator-controlled), and SpO₂ 96%. Which of the following is the most appropriate initial intervention?

A 68-year-old man in the ICU is on assist-control ventilation with a norepinephrine infusion for septic shock. An abdominal radiograph shows a cecal diameter of 12 cm, confirming acute colonic pseudo-obstruction (Ogilvie’s syndrome). After 48 hours of bowel rest and IV fluids, colonic distention persists. A single 2.0 mg dose of IV neostigmine is administered over 5 minutes. Which parameter requires the most immediate and vigilant monitoring following neostigmine administration?

A 72-year-old man in the intensive care unit for severe pneumonia is mechanically ventilated and receiving a continuous vasopressor infusion via a central line. Over the past 24 hours, he has developed significant abdominal distention. Despite bowel rest and correction of electrolytes, his abdominal girth has continued to increase. An abdominal radiograph reveals massive colonic dilation with a cecal diameter of 12 cm. He has not passed flatus or stool. Which of the following is the most appropriate initial pharmacologic intervention?