Fulltext

Effects of helium-oxygen on respiratory mechanics, gas exchange, and ventilation-perfusion relationships in a porcine model of stable methacholine-induced bronchospasm

Watremez, Christine ; Liistro, Giuseppe ; deKock, Marc ; Roeseler, Jean ; Clerbaux, Thierry ; Detry, Bruno ; Reynaert, Marc ; Gianello, Pierre ; Jolliet, Philippe

In: Intensive Care Medicine, 2003, vol. 29, no. 9, p. 1560-1566

Ajouter à la liste personnelle
    Titre
    • Effects of helium-oxygen on respiratory mechanics, gas exchange, and ventilation-perfusion relationships in a porcine model of stable methacholine-induced bronchospasm
    Auteur
    • Watremez, Christine. Division of Anesthesiology, Clinique Universitaire St.-Luc, Brussels, Belgium
    • Liistro, Giuseppe. Division of Pneumology, Clinique Universitaire St.-Luc, Brussels, Belgium
    • deKock, Marc. Division of Anesthesiology, Clinique Universitaire St.-Luc, Brussels, Belgium
    • Roeseler, Jean. Department of Emergency and Intensive Care, Clinique Universitaire St.-Luc, Brussels, Belgium
    • Clerbaux, Thierry. Division of Pneumology, Clinique Universitaire St.-Luc, Brussels, Belgium
    • Detry, Bruno. Division of Pneumology, Clinique Universitaire St.-Luc, Brussels, Belgium
    • Reynaert, Marc. Department of Emergency and Intensive Care, Clinique Universitaire St.-Luc, Brussels, Belgium
    • Gianello, Pierre. Laboratory of Experimental Surgery, Clinique Universitaire St.-Luc, Brussels, Belgium
    • Jolliet, Philippe. Division des soins intensifs de Médecine, Hôpital Cantonal Universitaire, 1211, Geneva14, Switzerland
    Type de document
    • Postprint
    Identifiant OAI-PMH
    • oai:doc.rero.ch:316618
    Summary
    Objective: To explore the consequences of helium/oxygen (He/O2) inhalation on respiratory mechanics, gas exchange, and ventilation-perfusion (VA/Q) relationships in an animal model of severe induced bronchospasm during mechanical ventilation. Design: Prospective, interventional study. Setting: Experimental animal laboratory, university hospital. Interventions: Seven piglets were anesthetized, paralyzed, and mechanically ventilated, with all ventilator settings remaining constant throughout the protocol. Acute stable bronchospasm was obtained through continuous aerosolization of methacholine. Once steady-state was achieved, the animals successively breathed air/O2 and He/O2 (FIO2 0.3), or inversely, in random order. Measurements were taken at baseline, during bronchospasm, and after 30min of He/O2 inhalation. Results: Bronchospasm increased lung peak inspiratory pressure (49±6.9 vs 18±1cmH2O, P<0.001), lung resistance (22.7±1.5 vs 6.8±1.5cmH2O.l−1.s, P<0.001), dynamic elastance (76±11.2 vs 22.8±4.1cmH2O.l−1, P<0.001), and work of breathing (1.51±0.26 vs 0.47±0.08, P<0.001). Arterial pH decreased (7.47±0.06 vs 7.32±0.06, P<0.001), PaCO2 increased, and PaO2 decreased. Multiple inert gas elimination showed an absence of shunt, substantial increases in perfusion to low VA/Q regions, and dispersion of VA/Q distribution. He/O2 reduced lung resistance and work of breathing, and worsened hypercapnia and respiratory acidosis. Conclusions: In this model, while He/O2 improved respiratory mechanics and reduced work of breathing, hypercapnia and respiratory acidosis increased. Close attention should be paid to monitoring arterial blood gases when He/O2 is used in mechanically ventilated acute severe asthma