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

BACKGROUND: Moisturizing, heating and filtering gases inspired via the mechanical ventilation (MV) circuits help to reduce the adverse effects of MV. However, there is still no consensus regarding whether these measures improve patient prognosis, shorten MV duration, decrease airway secretion and lower the incidence of ventilator associated pneumonia (VAP) and other complications. OBJECTIVES: The aim of this study was to study the incremental cost-effectiveness ratio associated with the use of heat and moisture exchangers (HME) filter to prevent VAP compared with the heated humidifiers (HH) presently adopted by intensive care unit (ICU) services within the Brazilian Healthcare Unified System. PATIENTS AND METHODS: This study was a cost-effectiveness analysis (CEA) comparing HME and HH in preventing VAP (outcome) in mechanically ventilated adult patients admitted to an ICU of a public university hospital. RESULTS: The analysis considered a period of 12 months; MV duration of 11 and 12 days for patients in HH and HME groups, respectively and a daily cost of R$ 16.46 and R$ 13.42 for HH and HME, respectively. HME was more attractive; costs ranged from R$ 21,000.00 to R$ 22,000.00 and effectiveness was close to 0.71, compared with a cost of R$ 30,000.00 and effectiveness between 0.69 and 0.70 for HH. HME and HH differed significantly for incremental effectiveness. Even after an effectiveness gain of 1.5% in favor of HH, and despite the wide variation in the VAP rate, the HME effectiveness remained stable. The mean HME cost-effectiveness was lower than the mean HH cost-effectiveness, being the HME value close to R$ 44,000.00. CONCLUSIONS: Our findings revealed that HH and HME differ very little regarding effectiveness, which makes interpretation of the results in the context of clinical practice difficult. Nonetheless, there is no doubt that HME is advantageous. This technology incurs lower direct cost.