Correspondence
Correction
The Prevention of Ventilator-Associated Pneumonia
N Engl J Med 1999; 341:293-294July 22, 1999
- Article
To the Editor:
In stating that selective decontamination of the digestive tract has no effect on mortality, Dr. Kollef (Feb. 25 issue)1 ignores two recent meta-analyses,2,3 both of which showed a significant reduction in mortality. The magnitude of the survival benefit from this method is impressive. Mortality is reduced by 20 percent in a mixed population of medical and surgical patients and by 30 percent in surgical patients who are critically ill. The number needed to treat to prevent one death is 23 patients.2 One meta-analysis2 summarized 33 randomized trials, which involved 5725 patients and were conducted over a period of more than 10 years (1987 to 1997). In none of the trials was the emergence of resistant microorganisms, subsequent superinfections, or epidemics of multiresistant microorganisms reported. This observation is in line with the results of three studies in which resistance during selective decontamination of the digestive tract was the end point.4-6
Because of the proven clinical benefits in the clear absence of toxicity, we fail to understand why this method has not gained acceptance in the United States, a country known to prefer practicing medicine based on evidence rather than expert opinion.
6 ReferencesH.K.F. van Saene, M.D., Ph.D.
Paul B. Baines, M.R.C.P.
Royal Liverpool Children's Hospital, Liverpool L12 2AP, United Kingdom1
Kollef MH . The prevention of ventilator-associated pneumonia. N Engl J Med 1999;340:627-634
Full Text | Web of Science | Medline2
D'Amico R ,Pifferi S ,Leonetti C ,Torri V ,Tinazzi A ,Liberati A . Effectiveness of antibiotic prophylaxis in critically ill adult patients: systematic review of randomised controlled trials. BMJ 1998;316:1275-1285
CrossRef | Web of Science | Medline3
Nathens AB ,Marshall JC . Selective decontamination of the digestive tract in surgical patients: a systematic review of the evidence. Arch Surg 1999;134:170-176
CrossRef | Web of Science | Medline4
Hammond JM ,Potgieter PD . Long-term effects of selective decontamination on antimicrobial resistance. Crit Care Med 1995;23:637-645
CrossRef | Web of Science | Medline5
Stoutenbeek CP ,van Saene HK ,Zandstra DF . The effect of non-absorbable antibiotics on the emergence of resistant bacteria in patients in an intensive care unit. J Antimicrob Chemother 1987;19:513-520
CrossRef | Web of Science | Medline6
Tetteroo GW ,Wagenvoort JH ,Bruining HA . Bacteriology of selective decontamination: efficacy and rebound colonization. J Antimicrob Chemother 1994;34:139-148
CrossRef | Web of Science | Medline
Author/Editor Response
Dr. Kollef replies:
To the Editor: Drs. van Saene and Baines suggest that selective decontamination of the digestive tract reduces mortality and should therefore gain clinical acceptance for the prevention of ventilator-associated pneumonia in the United States. Their recommendation is based on the results of two recent meta-analyses.1,2 Unfortunately, it is not clear from these meta-analyses whether the use of this method was responsible for the reported reductions in mortality.
D'Amico and colleagues1 observed a reduction in mortality only when the use of topical and systemic antibiotic prophylaxis was compared with no use of prophylaxis (16 studies). There were no differences in mortality when topical and systemic antibiotic prophylaxis was compared with systemic antibiotic prophylaxis alone (7 studies) and when topical antibiotic prophylaxis was compared with no antibiotic prophylaxis (11 studies). These findings would suggest that systemic antibiotic prophylaxis — not the topical administration of antibiotics — is responsible for the reduction in mortality. Interestingly, the majority of patients in the meta-analysis who had a survival advantage were surgical and trauma patients (>70 percent), groups for which systemic antibiotic prophylaxis has already been shown to be advantageous.3
Nathens and Marshall2 had similar findings in their meta-analysis. Antibiotic prophylaxis was not found to influence survival in the 10 studies with no more than 25 percent postoperative and trauma patients. A survival advantage was found in the 11 studies with more than 75 percent postoperative and trauma patients. This meta-analysis also showed that the survival advantage was greatest in studies in which both topical and systemic antibiotic prophylaxis was used. These two meta-analyses add support for the use of parenteral antibiotic prophylaxis in surgical and trauma patients, which is common practice in the United States.
The emergence of antibiotic-resistant bacterial infections has become a pivotal issue in the care of critically ill patients. There are increasing calls to limit rather than increase the use of antibiotics in order to restrain such emerging resistance.4 The use of selective decontamination of the digestive tract has been associated with antibiotic-resistant infections. In fact, one of the journal articles cited by Drs. van Saene and Baines showed a statistically significant increase in infections due to acinetobacter species after the use of this method.5 Other experiences with selective decontamination of the digestive tract have also shown greater rates of subsequent infection due to antibiotic-resistant gram-positive bacteria. For these reasons, practitioners in the United States have resisted the routine application of topical antibiotic prophylaxis.
Finally, in my review I mistakenly referred to histamine H2-receptor antagonists and antacids as gastric pH–lowering drugs; in fact, they increase gastric pH.
5 ReferencesMarin H. Kollef, M.D.
Washington University School of Medicine, St. Louis, MO 63110-10931
D'Amico R ,Pifferi S ,Leonetti C ,Torri V ,Tinazzi A ,Liberati A . Effectiveness of antibiotic prophylaxis in critically ill adult patients: systematic review of randomised controlled trials. BMJ 1998;316:1275-1285
CrossRef | Web of Science | Medline2
Nathens AB ,Marshall JC . Selective decontamination of the digestive tract in surgical patients: a systematic review of the evidence. Arch Surg 1999;134:170-176
CrossRef | Web of Science | Medline3
Dellinger EP . Antibiotic prophylaxis in trauma: penetrating abdominal injuries and open fractures. Rev Infect Dis 1991;13:Suppl 10:S847-S857
CrossRef | Medline4
Goldmann DA ,Weinstein RA ,Wenzel RP , et al. Strategies to prevent and control the emergence and spread of antimicrobial-resistant microorganisms in hospitals: a challenge to hospital leadership. JAMA 1996;275:234-240
CrossRef | Web of Science | Medline5
Hammond JM ,Potgieter PD . Long-term effects of selective decontamination on antimicrobial resistance. Crit Care Med 1995;23:637-645
CrossRef | Web of Science | Medline
- Citing Articles (2)
Citing Articles
1
Josep-Maria Sirvent, Antoni Torres. (2003) Antibiotic prophylaxis strategies in the prevention of ventilator-associated pneumonia. Expert Opinion on Pharmacotherapy 4:8, 1345-1354
CrossRef2
Santiago Ewig, Antoni Torres. (2002) Prevention and management of ventilator-associated pneumonia. Current Opinion in Critical Care 8:1, 58-69
CrossRef
