Clinical and bacteriological comparison of effects of heated humidifier and HME - booster in mechanically ventilated patients

CLINICAL AND BACTERIOLOGICAL COMPARISON OF EFFECTS OF HEATEDHUMIDIFIER AND HME-BOOSTER IN MECHANICALLY VENTILATEDPATIENTSDr. Türkan Nadir ÖZ ŞVentilator associated pneumonia (VAP) is one of the most important nosocomialinfections in the intensive care unit. There are numerous devices to supply humidity toinspired gases during mechanical ventilation. The aim of this study is to compare the efficacyand safety of two different humidifiers, Heated humidifier (HH) and Booster combined with aheat and moisture exchanger (HME-Booster) in VAP.Intubated ICU patients were randomized to receive either HH with conventionalmicrobiological filter (CMF) (Group1) or HME-Booster (Group2). The primary end point washumidifier efficacy measured by daily secretion scores and need for endotracheal tube changedue to tube occlusion from secretions. The secondary end point was humidifier safetymicrobiologicaly [measured by ventilator associated pneumonia (VAP) rates] and its effectson blood gases measured by change in end tidal CO2(PETCO2) and partial arterialCO2(PaCO2) levels. PETCO2 and PaCO2 were measured with and without CMF in Group1and with and without HME-Booster in Group2.41 patients were included in the study. 20 patients were randomized in Group1 where21 were in Group2. Mean secretion scores were 2.7±0.7 and 3.2±0.7 in Groups1 and 2respectively (p=0.041). Tube occlusion rates were not different between the groups.VAP rates were similar between groups (40% and 43.9% in Groups1 and 2 respectively).PETCO2 decreased with the removal of CMF and HME-Booster in both groups. The decreasewas significantly higher in Group2 (p=0.016). PaCO2 decreased more with the removal ofdevices in Group2 than Group1, however the difference was not different between groups.Though these two different humidifiers are shown to be safe microbiologicaly, HHseems to be preferable in pulmonary ICU because of its effects on PETCO2 and secretionscore, which are very important in patients with pulmonary problems.