Case 4 occurred in an 80-year-old female who was admitted due to increasing fatigue and copious diarrhea consistent with community onset CDI. Her risk factors for CDI included advanced age and recent antibiotic use (vancomycin, levofloxacin, and piperacillin–tazobactam). This patient’s initial severity of illness was mild (WBC 9,100/μL, serum creatinine 116% of the premorbid level) and she was treated with oral metronidazole 500 mg three times daily beginning on hospital day 1. After 3 days of metronidazole treatment, her abdominal pain had improved, but the diarrhea persisted and her WBC began trending upward (16,500/μL). On hospital day 4, the patient developed septic shock secondary to CDI. As her CDI had progressed to a severe complicated case, intravenous tigecycline and vancomycin 250 mg four times daily were added. Tigecycline was given as a 100-mg loading dose followed by 50 mg twice daily. The patient was treated successfully with 6 days of triple therapy with tigecycline, vancomycin, and metronidazole. Due to the high risk of CDI recurrence in this patient, a vancomycin taper was completed. The patient was discharged to home and had no CDI recurrence within 28 days of follow-up.
Case 2 occurred in a 46-year-old male who was admitted to the ICU with severe diarrhea and septic shock requiring 13 L fluid resuscitation and vasopressors. The patient presented with severe leukocytosis (WBC 35,400/μL) and renal impairment (serum creatinine increased 166% of the premorbid level). This patient had a number of risk factors for CDI, including admission from a long-term care facility and multiple prior antibiotic use (see Table for full listing). He was treated initially with oral metronidazole 500 mg three times daily. Oral metronidazole was switched to intravenous and oral vancomycin 125 mg four times daily was added on hospital day 2 upon detection of toxigenic C. difficile. At this point, the patient was intubated due to decreasing respiratory function and pulmonary edema. He also had other symptoms of severe complicated CDI, included nausea and vomiting, abdominal pain, colonic wall thickening, and ascites. Oral vancomycin was changed to rectal vancomycin 500 mg four times daily on hospital day 3 due to the development of paralytic ileus. This regimen continued through hospital day 7, with fever, ileus, and abdominal pain resolving. On hospital day 8, the patient again developed diarrhea with abdominal pain and persisting leukocytosis (WBC 24,300/μL). Due to these non-resolving symptoms and the severity of the patient’s condition, intravenous tigecycline was added on hospital day 8 as a 100-mg loading dose followed by 50 mg twice daily. Clinical cure was achieved after 8 days of treatment with tigecycline, rectal vancomycin, and intravenous metronidazole. Due to the high risk of recurrence, the patient completed a vancomycin taper upon discharge to a long-term care facility. There was no documented recurrence of CDI on record.