Infectious Diseases in Critical Care Medicine

treatment is oral vancomycin 500 mg four times daily and/or metronidazole 500 to 750 mg
intravenously every eight hours. If the patient has complete ileus, the treatment recommen-
dation includes intravenous metronidazole and rectal installation of vancomycin (IDSA, 2007).
Colectomy should be performed before serum lactate>5. Anecdotal reports have studied the
use of intravenous IgG (IVIG) in severe CDI but the efficacy is unproven (55).
Response to treatment is generally rapid, with decreased fever within one day and
improvement of diarrhea in four to five days. Patients who fail to respond may have alternate
diagnoses, lack of compliance, or the inability of drug to reach the colon such as with ileus or
megacolon (26). Yet, all studies have shown failures with both metronidazole and vancomycin
(*15% failure rates in the randomized controlled trials).
Standard duration of treatment is 10 to 14 days, regardless of antibiotic used. Patients
requiring prolonged courses of other antibiotics should continue CDI treatment throughout the
antibiotic course and for an additional week postcompletion. It is not recommended to check
stoolC. difficiletoxin assays after the first positive since a positive result can remain for up to
eight weeks.

Surgery
Overall, a minority of patients (0.39–3.6%) withC. difficilecolitis require surgery (54). Surgery is
indicated for patients with peritoneal signs, systemic toxicity, toxic megacolon, perforation,
multiorgan failure, or progression of symptoms despite appropriate antimicrobial therapy and

Table 3 Treatment of CDI as per IDSA Draft Guidelines from 2007

Clinical definition Recommended treatment

General measures
l Stop implicated antibiotic or switch to lower-risk drug
l Fluid and electrolytes as needed
l Avoid antimotility drugs
l Consider surgery if severe colitis and rising lactate (before lactate¼5)
Initial episode Mild to moderate disease (leukocytosis
<15,000 and creatinine<1.5 times
premorbid level)

Metronidazole 500 mg three times daily

for 10–14 days

Severe (leukocytosis>15,000 or

creatinine>1.5 times premorbid

level)

Oral vancomycin 125 mg four times a

day for 10–14 days

Fulminant (severe disease complicated

by hypotension or shock, megacolon,

perforation, severe colitis on CT

scan)

Absence of complete ileus

Oral vancomycin 500 mg four times a

day administered orally or via

nasogastric tube

and

Intravenous metronidazole 500–750 mg

every 8 hours

Complete ileus

Intravenous metronidazole 500–750 mg

every 8 hours

and if feasible

Rectal installation of vancomycin

First recurrencea Same as for initial episode x 14 days

Second recurrencea Oral vancomycin, tapered/pulsed
125 mg 4 times daily x 10–14 days
125 mg twice daily x 7 days
125 mg daily x 7 days
125 mg every 2–3 days for 2–8 weeks
A 3-week course of probiotics may be
used, first week overlapping with last
week of vancomycin

aNo rigorous trials available—class B recommendations.

Abbreviation: BM, bowel movement.

282 Hjalmarson and Gorbach