Ventilator-associated pneumonia (VAP) poses a significant patient safety threat for intensive care unit (ICU) patients and has an attributable mortality rate that may exceed 50%.  In the November issue of Lancet Infectious Diseases, Sonia Labeau, MD, and colleagues from Ghent University, Belgium, conducted a systematic review and meta-analysis to determine whether oral care with chlorhexidine or povidone-iodine (experimental; antiseptic group) reduced the occurrence of VAP compared with absence of oral care, or oral care with other products (control). 

A comprehensive search strategy was employed with inclusion criteria that only accepted randomized controlled trials in mechanically ventilated adult patients receiving oral care with either chlorhexidine or povidone.  Articles were screened four-fold, quality assessments were performed, and a random-effects model was utilized for the meta-analysis.  

Fourteen studies met inclusion criteria.  The studies were moderately heterogeneous (I2=38%), and 36.8% of all included patients came from two reports conducted in cardiac surgery ICUs. Overall, patients treated with chlorhexidine had a statistically significantly lower risk of VAP compared to control subjects (RR 0.72; 95% CI, 0.55-0.94, p=0.02).  A subgroup analysis that included studies using 2% chlorhexidine found a 47% lower risk of VAP compared to controls (RR 0.53; 95% CI, 0.31-0.91, p=0.02). The use of antiseptics appeared to have the greatest benefit in cardiac surgery patients (RR 0.41; 95% CI, 0.17-0.98, p=0.05).

This study was methodologically sound, although over a quarter of the data came from cardiac surgery ICUs.  This might have introduced bias since cardiac surgery patients are often electively admitted and intubated under more controlled conditions than trauma or other types of ICU patients. Only two studies evaluated the use of povidone iodine, and different concentrations of chlorhexidine (0.12-2%) were used. Despite the limitations of this review, this meta-analysis provides strong evidence that the use of antiseptics may be beneficial for ICU patients in the prevention of VAP.  The effect appears to be most pronounced in cardiac surgery patients and with 2% chlorhexidine.

Concise Critical Appraisal is a regular feature authored by SCCM member Samuel M. Galvagno Jr., DO. Each installment highlights journal articles most relevant to the critical care practitioner.