There appears to be no association between mortality and ventilator-associated pneumonia (VAP) among patients with trauma or acute respiratory distress syndrome (ARDS), a study claims.

It is believed that VAP increases mortality in intensive-care unit patients owing to its occurrence in the presence of nosocomial infections; however results of studies investigating this association have hitherto been "contradictory", researchers claim.

The latest study therefore determined the mortality attributable to VAP by systematically identifying and quantitatively combining all of the available observational studies, which included those comparing patients with VAP against control patients, all patients mechanically ventilated and mortality rates.

Out of 2,267 individual citations retrieved, 52 studies with a total of 17,347 patients satisfied the inclusion criteria.

Analysis of the pooled studies showed a significant relative risk (RR) for an association of VAP with increased mortality.

However lead investigator Dr Marianne Melsen noted that a "great amount of heterogeneity was found".

On pooling the data from the nine studies that included only patients with trauma, or the four studies containing only patients with ARDS, researchers found almost no heterogeneity and no association between mortality and VAP.

"Although there is variation among the results, there is probably an attributable mortality of VAP. However, it differs among the patient subgroups," Dr Melsen said.

While there is evidence of significantly increased RR of mortality in specific subgroups of patients with VAP, this is not seen for patients with trauma and ARDS.

Findings were presented at the European Congress of Clinical Microbiology and Infectious Disease and reported by DGDispatch.

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