Ventilator-associated pneumonia using a heated humidifier or a heat and moisture exchanger: a randomized controlled trial [ISRCTN88724583]

Abstract

Introduction Some guidelines to prevent ventilator-associated pneumonia (VAP) do not establish a recommendation for the preferential use of either heat and moisture exchangers (HMEs) or heated humidifiers (HHs), while other guidelines clearly advocate the use of HMEs. The aim of this study was to determine the incidence of VAP associated with HHs or HMEs.

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

“…Indeed, this strategy represented considerable economy of financial resources in the context of a 16-bed ICU. Although HME do not prevent VAP (29, 30), in this study it demonstrated to be cost-effective.…”

Effectiveness of heat and moisture exchangers in preventing ventilator-associated pneumonia in critically ill patients: a meta-analysis

“… HME may present higher resistance to airflow than the manufacturer’s specifications after use for 24 h. The use of HME reduces costs. 1C Lorente et al, 2006 [ 19 ] ICU Quantitative variables were compared using the Student t test. Five risk models proportional to Cox were constructed for VAP analysis.…”

“… 15.7 VAP cases per one thousand ventilated patients per day. p >0.05 28.8 25 > 0.05 Lacherade et al, 2005 [ 14 ] 186 patients under MV 184 patients under MV 27.4 VAP cases per one thousand ventilated patients per day 25.3 VAP cases per one thousand ventilated patients per day 0.76 32.4 34.2 > 0.05 Odds Ratio (0.58–1.57) p > 0,05 Boots et al, 2006 [ 15 ] 190 patients 2 HH groups 13% - Group with heating upon inspiration: 10% 0.61 15 - Group with heating upon inspiration: 14 > 0.05 - Group with heating upon inspiration: 94 - Group with heating upon inspiration and expiration: 97 - Group with heating upon inspiration and expiration: 10% - Group with heating upon inspiration and expiration: 22 Lorente et al, 2006 [ 19 ] 53 patients under MV 51 patients under MV 21 episodes (39%) 8 episodes (15%) Hazard Ratio 16.2 (4.54-58.04) Data not shown p < 0.05 HME: Heat and moisture exchangers; HH: Heated Humidifiers; MV: Mechanical Ventilation; VAP: Ventilator-Associated Pneumonia.

Figure 2 Synthesis of the results considering the VAP outcome in the ten clinical assays selected for this review.

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“…Other two randomized studies reported non-significantly different VAP rates for HH and HME [ 14 , 15 ]. A randomized study of 120 patients demonstrated smaller VAP incidence during the use of HH in patients under mechanical ventilation for periods longer than five days (15.69 vs 39.62%, P = 0.006) [ 19 ]. A meta-analysis published by Siempos et al (2007) [ 16 ] included 13 randomized clinical assays and 2,580 patients; it did not detect any differences between HME and HH with respect to VAP incidence, mortality in the ICU, length of stay in the ICU, period of mechanical ventilation, or airway obstruction.…”

“…On the other hand, Auxiliadora-Martins et al (2012) [ 17 ] investigated severely ill patients (mean APACHE II score > 25) with associated comorbidities, to find that the HH and HME group did not have different VAP incidence. The heterogeneous study populations, the distinct brands of HME employed in the aforementioned studies, the frequency with which the nursing staff changed the moisturizer, and the criteria used to diagnose VAP may have contributed to these contrasting results [ 19 ]. Nevertheless, HME did offer advantages over HH: it did not require that the staff opened the device circuit to remove the condensate accumulated in the ventilator extensions, which reduced the occupational risk and optimized the work of the nursing team.…”