A 72-year-old man is admitted to the intensive care unit with septic shock requiring norepinephrine at 0.2 mcg/kg/min to maintain a mean arterial pressure of 65 mm Hg. Over the past 24 hours, he has developed profuse watery diarrhea (8–10 episodes/day). Stool assays are positive for Clostridioides difficile toxin. Laboratory studies show a white blood cell count of 28,500 cells/mm³ (baseline 8,000), serum creatinine 2.8 mg/dL (baseline 0.9), and albumin 2.1 g/dL. On examination, his abdomen is distended and bowel sounds are absent. Which of the following is the MOST appropriate initial pharmacotherapy regimen for his C. difficile infection?

A 65-year-old male is admitted to the critical care unit, currently on a norepinephrine infusion at 0.1 mcg/kg/min via a central line for refractory hypotension, and intubated on assist-control ventilation due to altered mental status. He was recently diagnosed with Clostridioides difficile infection (CDI) with initial labs showing a white blood cell count of 22,000 cells/mL and serum creatinine 2.1 mg/dL (baseline 0.9 mg/dL). Over the past 12 hours, he has developed increasing abdominal distension, absent bowel sounds, and persistent hypotension despite fluid resuscitation. His current blood pressure is 80/50 mmHg, and heart rate is 125 bpm. In addition to antimicrobial therapy, which of the following supportive care measures is the highest priority for this patient?

“A 62-year-old man is admitted to the ICU on assist-control ventilation with a continuous propofol infusion and receiving total parenteral nutrition via a central line. Over the past 24 hours, he has developed profuse watery diarrhea, with nursing staff documenting 8–10 stools. A Clostridioides difficile toxin PCR test returns positive. His white blood cell count is 18,500/mm³, and his serum creatinine is stable at baseline. He has a nasogastric (NG) tube in place. Based on current guidelines, which of the following is the most appropriate initial treatment for this patient’s severe, non-fulminant C. difficile infection?”

A 65-year-old man recovering from severe pneumonia–associated sepsis developed new-onset diarrhea. Stool toxin assay is positive for Clostridioides difficile. His white blood cell count is 18,500 cells/µL and serum creatinine is 1.2 mg/dL (baseline 0.8 mg/dL). He has no hypotension, ileus, or megacolon. Which of the following is the most appropriate oral antimicrobial regimen for this patient’s current condition?

A 68-year-old man on assist-control ventilation and a norepinephrine infusion for septic shock develops a new fever (39.2°C), increased purulent tracheal secretions, and new bilateral infiltrates on chest X-ray 48 hours ago. His white blood cell count is 18,500/mm³. He was admitted 10 days ago for aspiration pneumonia, treated initially with ceftriaxone and azithromycin, and completed a 7-day course of piperacillin–tazobactam 5 days ago for a suspected intra-abdominal infection. The local antibiogram shows high rates of multidrug-resistant Pseudomonas aeruginosa and MRSA in ventilator-associated pneumonia. Which empiric antibiotic regimen is most appropriate for this patient?

A 72-year-old man presents with an initial, non-severe episode of Clostridioides difficile infection, defined by ≥3 unformed stools per day without hypotension, ileus, or megacolon. He has risk factors for recurrence including advanced age and recent broad-spectrum antibiotic use. Which of the following oral antibiotic regimens is most appropriate to minimize the risk of future CDI episodes?

A 62-year-old man is admitted to the hospital for community-acquired pneumonia and is receiving intravenous ceftriaxone and azithromycin. On hospital day 4, he develops profuse, watery diarrhea (8 stools/day) over the past 24 hours. A Clostridioides difficile toxin assay returns positive. His white blood cell count is 22,000/mm³, and serum creatinine has acutely risen from a baseline of 0.9 mg/dL to 2.1 mg/dL. His abdomen is soft, non-tender, and non-distended, with no signs of ileus or toxic megacolon. Given his severe CDI and ongoing antibiotic exposure (which increases recurrence risk), which of the following is the MOST appropriate initial pharmacotherapy to optimize both clinical cure and minimize recurrence?

A 70-year-old woman in the intensive care unit was diagnosed 3 days ago with fulminant Clostridioides difficile infection, presenting with hypotension (MAP 55 mmHg) and ileus. She was started on oral vancomycin 500 mg every 6 hours via nasogastric tube plus intravenous metronidazole 500 mg every 8 hours. Today, she is hemodynamically stable (MAP 75 mmHg) off vasopressors, has passed flatus, and her ileus has resolved. Her white blood cell count has decreased from 25,000 to 12,000 cells/mm³, and serum creatinine from 2.0 to 1.1 mg/dL. Which of the following is the most appropriate modification to her Clostridioides difficile infection regimen?

A 72-year-old man with end-stage renal disease on hemodialysis and chronic heart failure (HFrEF) was recently hospitalized for sepsis and is now in the intensive care unit. He is hemodynamically stable off vasopressors and extubated. Over the past 24 hours, he has developed profuse watery diarrhea (8–10 stools/day) and moderate abdominal pain. A Clostridioides difficile toxin assay is positive. His white blood cell count is 28,000 cells/mm³, serum creatinine is 3.5 mg/dL (baseline 2.8 mg/dL), and serum albumin is 2.1 g/dL. Which of the following is the MOST appropriate next step in management?

A 62-year-old man is admitted to the medical intensive care unit for severe sepsis secondary to pneumonia. He is intubated, mechanically ventilated on pressure support, and is receiving enteral nutrition via a nasogastric tube. He is on a continuous norepinephrine infusion through a right internal jugular central line. On hospital day 5, he develops profuse watery diarrhea (8–10 stools/day) and tests positive for Clostridioides difficile toxin. His white blood cell count is 12,000/mm³ and creatinine is stable at 0.9 mg/dL. He has no signs of ileus or toxic megacolon and remains NPO except for medications and tube feeds. Considering this patient’s nonsevere C. difficile infection and his enteral access, which of the following is the MOST appropriate initial pharmacotherapy plan, including route and delivery device?