Efecto del helio sobre los parámetros de los respiradores en ventilación mecánica: estudio in vitro con el respirador Servoi
- Jesús López Herce Cid
- J. Urbano Villaescusa
- E. Cidoncha Escobar
- J. del Castillo Peral
- Mª J. Santiago Lozano
- José M. Bellón Cano
- S. Mencía Bartolomé
ISSN: 1695-4033, 1696-4608
Datum der Publikation: 2008
Ausgabe: 68
Nummer: 4
Seiten: 336-341
Art: Artikel
Andere Publikationen in: Anales de Pediatría: Publicación Oficial de la Asociación Española de Pediatría ( AEP )
Zusammenfassung
Objective To analyze the changes in respiratory parameters in a Servoi ventilator with heliox. Material and methods In vitro study with a Servoi (Maquet) ventilator in volume controlled (VC), pressure controlled (PC) and volume control regulated by pressure (VCPR) modes connected to an artificial lung. A heliox tank with a fixed concentration of helium 70 % and oxygen 30 % was connected to the air inlet of the ventilator. The ventilator was set in VC mode with tidal volumes of 30, 50, 100, 250 and 500 ml; in PC mode with pressure of 20 and 30 cmH2O and in VCPR mode with tidal volume of 150 ml. In each case FiO2 of 21, 30, 40, 50, 60, 70, 80, 90 and 100 % was used. The FiO2, inspired and expired tidal volume and inspiratory pressure measured by the ventilator and a pitot spirometer (Datex_S5) were compared. Results In VC and VCPR modes the increase in helium produced a progressive decrease in the pressure needed to administrate the set volume. Heliox also produced a decrease in the tidal volume measured by the spirometer and the tidal expired volume measured by the respirator. In PC mode, heliox produced a progressive increase in the inspired tidal volume, increasing the differences between inspired and expired tidal volumes. Conclusions Heliox used with Servoi ventilator produces a decrease in inspiratory pressures in VC and VCPR modes, and an increase in inspiratory tidal volume in PC mode. In all modes heliox reduced the expired tidal volume measured by the ventilator and the spirometer. These changes should be borne in mind if heliox is used with this ventilator.