A RANDOMIZED CLINICAL-TRIAL COMPARING AN EXTENDED-USE HYGROSCOPIC CONDENSER HUMIDIFIER WITH HEATED-WATER HUMIDIFICATION IN MECHANICALLY VENTILATED PATIENTS

Study objective: To determine the safety and cost-effectiveness of mec hanical ventilation with an extended-use hygroscopic condenser humidif ier (Duration; Nellcor Puritan-Bennett; Eden Prairie, Minn) compared w ith mechanical ventilation with heated-water humidification. Design: P rospective randomized clinical trial. Setting: Medical and surgical IC Us of Barnes-Jewish Hospital, St. Louis, a university-affiliated teach ing hospital. Patients: Three hundred ten consecutive qualified patien ts undergoing mechanical ventilation. Interventions: Patients requirin g mechanical ventilation were randomly assigned to receive humidificat ion with either an extended-use hygroscopic condenser humidifier (for up to the first 7 days of mechanical ventilation) or heated-water humi dification. Measurements: Occurrence of ventilator-associated pneumoni a, endotracheal tube occlusion, duration of mechanical ventilation, le ngths of intensive care and hospitalization, acquired multiorgan dysfu nction, and hospital mortality. Results: One hundred sixty-three patie nts were randomly assigned to receive humidification with an extended- use hygroscopic condenser humidifier, and 147 patients were randomly a ssigned to receive heated-water humidification. The two groups were si milar at the time of randomization with regard to demographic characte ristics, ICU admission diagnosis, and severity of illness. Risk factor s for the development of ventilator-associated pneumonia were also sim ilar during the study period for both treatment groups. Ventilator-ass ociated pneumonia was seen in 15 (9.2%) patients receiving humidificat ion with an extended-use hygroscopic condenser humidifier and in 15 (1 0.2%) patients receiving heated-water humidification (relative risk, 0 .90; 95% confidence interval = 0.46 to 1.78; p = 0.766). No statistica lly significant differences for hospital mortality, duration of mechan ical ventilation, lengths of stay in the hospital or ICU, or acquired organ system derangements were found between the two treatment groups. No episode of endotracheal tube occlusion occurred during the study p eriod in either treatment group. The total cost of providing humidific ation was $2,605 for patients receiving a hygroscopic condenser humidi fier compared with $5,625 for patients receiving heated-water humidifi cation. Conclusion: Our findings suggest that the initial application of an extended-use hygroscopic condenser humidifier is a safe and more cost-effective method of providing humidification to patients requiri ng mechanical ventilation compared with heated-water humidification.