Use of a Heat and Moisture Exchanger during Long-term Mechanical Ventilation

Abstract

To the Editor: I read with interest the data reported by Misset et al1Misset B Escudier B Rivara D Leclercq B Nitenberg G Heat and moisture exchanger vs heated humidifier during long-term mechanical ventilation: a prospective randomized study.Chest. 1991; 100: 160-163Abstract Full Text Full Text PDF PubMed Scopus (70) Google Scholar in the July 1991 issue of Chest, concerning the use of a heat and moisture exchanger (HME) during long-term mechanical ventilation. This work raises interesting questions about the adequate humidification of respiratory gases. As reported by the authors, the choice of the Fall Ultipore Breathing Filter BB2215 (PUBF) is probably not optimal; more efficient hygroscopic HMEs are now available. Recently, a study was interrupted after the death of a patient in a PUBF group because of total obstruction of the tracheal tube.2Martin C Perrin G Gevaudan MJ Saux P Gouin F Heat and moisture exchangers and vaporizing humidifiers in the intensive care unit.Chest. 1990; 97: 144-149Abstract Full Text Full Text PDF PubMed Scopus (148) Google Scholar In an unpublished study, we found that the PUBF was significantly less effective than two other HMEs (Hygrobac [DAR] and Humid-Vent [Gibeck Respiration]) in terms of physiologic performance and clinical tolerance. Like Martin et al,2Martin C Perrin G Gevaudan MJ Saux P Gouin F Heat and moisture exchangers and vaporizing humidifiers in the intensive care unit.Chest. 1990; 97: 144-149Abstract Full Text Full Text PDF PubMed Scopus (148) Google Scholar we suspended evaluation of the PUBF during prolonged ventilation following several dramatic instances of tracheal tube occlusion. Tracheal tube occlusion is not completely prevented by tracheal instillations.2Martin C Perrin G Gevaudan MJ Saux P Gouin F Heat and moisture exchangers and vaporizing humidifiers in the intensive care unit.Chest. 1990; 97: 144-149Abstract Full Text Full Text PDF PubMed Scopus (148) Google Scholar, 3Perch SA Realey AM Effectiveness of the Servo SH 150 “Artificial Nose” humidifier: a case report.Respir Care. 1984; 29: 1009-1012Google Scholar In spite of the very high efficiency of the PUBF as a bacterial filter, we decided that its use as a passive humidifier should definitely be avoided and that it should be replaced by a more effective device. Furthermore, an HME should be used no longer than 48 h; increase in thickness of bronchial secretions can be relatively occult (unproductive tracheal aspiration), developing in several hours or days and suddenly leading to acute respiratory failure requiring extraction of a bronchial cast.3Perch SA Realey AM Effectiveness of the Servo SH 150 “Artificial Nose” humidifier: a case report.Respir Care. 1984; 29: 1009-1012Google Scholar Subjective evaluation of tracheal secretions is not always reliable. Measurement of biorheologic properties of sputum (spinnability, viscosity) requires specific expensive devices, and the current data are not conclusive for application in clinical practice.4Sottiaux T Goffart A Van Der Linden P Roeseier J Van Melsem A Reynaert M Variations of spinability and protein content of bronchial mucus during controlled ventilation.Acta Anaesth Ital. 1990; 41: 33-36Google Scholar, 5Conti G, Spunticchia G, Rocco M, Nicoli P, Cogliati A. Mesure de la viscosité des secrétions trachéo-bronchiques chez les patients sous ventilation mécanique avec filtre-humidificateur chauffant (HME) ou humidificateur réchauffé. Presented at the 18th Congrès de la Société de Réanimation de Langue Française, Paris, November 23-26, 1989Google Scholar Daily bronchoscopic evaluation could be an alternative but is not defensible in clinical practice. Use of a Heat and Moisture Exchanger during Long-term Mechanical VentilationCHESTVol. 102Issue 3PreviewTo the Editor: Full-Text PDF