Humidification in the long-term ventilated patient; a systematic review.

This review aims to identify which method of humidification is most effective in Intensive Care patients intubated and ventilated for longer than 48hours with regard to the prevention of tracheal tube occlusion and the incidence of ventilator associated pneumonia (VAP). The Cochrane Library, Medline, CINAHL and Embase databases were searched for randomised controlled trials (RCTs) that compared any type of heated water humidifier with any type of heat moisture exchange (HME) filter. Two prospective RCTs met the inclusion criteria and were available to include in the main body of the review. These studies showed no difference in the rate of tracheal tube occlusion between devices but a significantly higher level of VAP with the heated humidifier. However, many potential studies were excluded from the review due to insufficient data within the published articles, and both included studies were undertaken in USA and excluded high risk patients. This limits the wide applicability of findings.