Effect of heat and moisture exchangers on the prevention of ventilator-associated pneumonia in critically ill patients

Abstract

Ventilator-associated pneumonia (VAP) remains one of the major causes of infection in the intensive care unit (ICU) and is associated with the length of hospital stay, duration of mechanical ventilation, and use of broad-spectrum antibiotics. We compared the frequency of VAP 10 months prior to (pre-intervention group) and 13 months after (post-intervention group) initiation of the use of a heat and moisture exchanger (HME) filter. This is a study with prospective before-and-after design performed in the ICU in a tertiary university hospital. Three hundred and fourteen patients were admitted to the ICU under mechanical ventilation, 168 of whom were included in group HH (heated humidifier) and 146 in group HME. The frequency of VAP per 1000 ventilator-days was similar for both the HH and HME groups (18.7 vs 17.4, respectively; P = 0.97). Duration of mechanical ventilation (11 vs 12 days, respectively; P = 0.48) and length of ICU stay (11 vs 12 days, respectively; P = 0.39) did not differ between the HH and HME groups. The chance of developing VAP was higher in patients with a longer ICU stay and longer duration of mechanical ventilation. This finding was similar when adjusted for the use of HME. The use of HME in intensive care did not reduce the incidence of VAP, the duration of mechanical ventilation, or the length of stay in the ICU in the study population.

Cost-Effectiveness Analysis of Heat and Moisture Exchangers in Mechanically Ventilated Critically Ill Patients

“…The study by Auxiliadora-Martins et al (12) was conducted in ICU of the hospital complex where the present investigation was performed; the study included patients under MV for over 48 hours, subdivided into HH group (168 patients, 53%) and the HME group (146 patients, 47%). Based on the aforementioned study, HH and HME patients presented similar clinical and sociodemographic characteristics; the compared variables did not differ significantly.…”

“…In 2011, 29438 patients (1.033% of the inhabitants) were admitted to the wards of the hospital complex; 910 of these patients (that is, 3.09% of patients admitted to the wards) were admitted to the ICU. Therefore, the target population was selected based on (i) the demand measured in 2011, (ii) a recently published clinical trial (12) and (iii) meta-analysis (13) comparing the effectiveness of HH and HME in preventing VAP.…”

“…The CEA was initially conducted based on (i) a pre-post clinical trial reported by Auxiliadora-Martins et al (12) and (ii) the results of a meta-analysis published by Niel-Weise et al (13). The study by Auxiliadora-Martins et al (12) involved 314 patients admitted to the ICU (nine beds) of the hospital complex studied herein; 146 and 168 patients used HME and HH, respectively.…”

“…The study by Auxiliadora-Martins et al (12) involved 314 patients admitted to the ICU (nine beds) of the hospital complex studied herein; 146 and 168 patients used HME and HH, respectively. The study by Niel-Weise et al (13) compared HME and HH for VAP incidence, which were 13.6% and 14.7%, respectively (effectiveness of 86.3% and 85.2%, respectively; P > 0.05).…”

“…Some studies demonstrated that changing HME every 24 hours leads to lower daily cost per ventilated patient (12, 16, 17). …”