This review concluded that antiseptic/antibiotic topical decontamination of the respiratory/digestive tract was effective in reducing ventilation-associated pneumonia in intensive care units (ICUs). Topical antibiotics may also reduce all ICU-acquired infections. The effects of either agent on mortality were uncertain. These conclusions were likely to be reliable, but relevant studies not in English may have been excluded.

To investigate the effect of topical digestive or respiratory tract antiseptics or antibiotics in the prevention of ventilator-associated pneumonia, mortality and all intensive care unit (ICU)-acquired infections in mechanically ventilated ICU patients.

MEDLINE, EMBASE and The Cochrane Library were searched to June 2010 and search terms were reported. The bibliographies of retrieved articles, systematic reviews and meta-analyses were screened for additional studies. Only studies in English were included.

Eligible randomised controlled trials (RCTs) assessed prophylactic use of one or more topical treatments for the reduction of ventilator-associated pneumonia and/or mortality and/or all ICU-acquired infections in mechanical ventilated ICU patients. Treatments included: oropharyngeal decontamination using antiseptics or antibiotics; gastrointestinal tract decontamination using antibiotics; oropharyngeal plus gastrointestinal tract decontamination using antibiotics; or respiratory tract decontamination using antibiotics. Studies were required to report sufficient data to estimate the odds ratio (OR) or risk ratio and their variance.

Study settings varied and included both medical and surgical ICUs, multidisciplinary ICUs and specialist settings such as cardiothoracic and neurosurgical ICUs. Antibiotic interventions varied (details reported in the article). Most antiseptic studies used chlorhexidine gluconate preparations. Control groups were standard care or inert placebo.

The authors did not state how many reviewers assessed studies for inclusion.

The methodological quality of included studies was assessed using the Jadad score (0-5), plus an additional score of 0-1 for data analysis and presentation.

Two reviewers independently assessed study quality and any disagreements were resolved by discussion.

Data were extracted on the numbers of participants and incidence of ventilator-associated pneumonia, all ICU infections and mortality (ICU and/or in-hospital), for treatment and control groups. Risk ratios with 95% confidence intervals (CIs) were calculated for each study and outcome.

Two reviewers independently extracted data and disagreements were resolved by consensus.

The risk ratios, with 95% confidence intervals, were calculated for each outcome measure using the Mantel-Haenszel fixed-effect model, or the DerSimonian and Laird random-effects model if there was evidence of between-study heterogeneity (defined as Ι² 50% or greater).

Statistical heterogeneity was assessed using the Cochran Q and Ι². Publication bias was assessed using by Egger’s test and Begg’s rank correlation test.

Subgroup analyses for patient population (medical, surgical, trauma, mixed) and site of decontamination (respiratory or digestive tract) were used to explore between-study heterogeneity. Sensitivity analyses were undertaken which included only those studies with Jadad scores above the median.

Twenty-eight studies were included in the review. Eleven studies of decontamination by antiseptics (3,258 patients) and 15 studies of antibiotic decontamination (2,463 patients) were included in the meta-analyses. Quality scores for data analysis and presentation ranged from 0.13 to 0.88 (mean 0.58). The mean Jadad score was 3.39 (median 4) and most trials (74%) adequately addressed withdrawals or drop-outs after randomisation and 63% were classified as double blinded. Only eight trials scored 5 on the Jadad scale.

Ventilator-associated pneumonia: Decontamination with antibiotics or antiseptics was associated with a reduced risk of ventilator-associated pneumonia compared with control. The pooled risk ratio for decontamination with antiseptics versus control (11 studies) was 0.73 (95% CI 0.63 to 0.84), Ι²=27.4%. The pooled risk ratio for decontamination with antibiotics versus control (15 studies) was 0.64 (95% CI 0.49 to 0.82), Ι²=70.3%. Sensitivity analyses showed similar results for both higher and lower quality studies. Subgroup analyses were also reported.

All ICU infections: Antiseptic decontamination had no significant effect on all ICU infections (four studies); if the analysis was restricted to higher quality studies (three studies) or surgical ICU (two studies), a significant treatment effect was observed (risk ratio not reported). Decontamination with antibiotics was associated with a reduced risk of ICU infection compared with control. The pooled risk ratio for antibiotic decontamination versus control (nine studies) was 0.71 (95% CI 0.59 to 0.86). Sensitivity analyses indicated that results were significant only in higher quality studies. Subgroup analyses were also reported.

There was no evidence of publication bias.

Mortality: There were no significant effects of decontamination on mortality in any of the analyses.

Topical decontamination of the respiratory or digestive tract using antiseptics or antibiotics agents was effective in reducing the incidence of ventilation-associated pneumonia in ICUs. The use of topical antibiotics, but not antiseptics, appeared to be effective reducing all ICU-acquired infections. The effects of either type of agent on mortality required further investigation.

The review stated a clear research question and defined appropriate inclusion criteria. A number of sources were searched for relevant studies but the restriction to studies in English raised the possibility of publication bias so relevant studies may have been omitted. The data extraction and quality assessment processes included measures to minimise error and/or bias, but it was not clear whether similar measures were applied to study selection.

The results of individual studies were reported and the meta-analytic methods used were broadly appropriate. The authors' conclusions reflected the data presented and were likely to be reliable, but some relevant studies may have been excluded.

Practice: The authors did not specify any recommendations for clinical practice.

Research: The authors stated that further research was needed to assess the effects of topical decontamination, using antiseptics or antibiotics, on mortality. Future studies should also compare different prophylactic decontamination protocols in ICU patients and assess the cost-effectiveness of preventive interventions.

Not stated.

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.