TY - JOUR
T1 - The effect of a bellows leak in an Ohmeda 7810 ventilator on room contamination, inspired oxygen, airway pressure, and tidal volume
AU - Lampotang, Samsun
AU - Sanchez, Justin C.
AU - Chen, Baixi
AU - Gravenstein, Nikolaus
PY - 2005/7
Y1 - 2005/7
N2 - We investigated the effect of a small bellows leak (bellows full at end-expiration) on inspired oxygen fraction (FIO2), exhaled tidal volume (VT), airway pressure, and room contamination in an oxygen-driven anesthesia ventilator (Ohmeda 7810, Madison, WI). CO2 concentration at the ventilator exhalation valve, FIO2, VT, and airway pressure were measured (n = 3) while ventilating a CO2-producing test lung at 8 breaths/min and an inspiratory/expiratory ratio of 1:2, with and without a bellows leak (4-mm-long tear). Set VT was 400, 600, 800, and 1000 mL. Fresh gas flow (FGF) was 0.3 L/min O2 and (a) 5.0 L/min air, (b) 2.0 L/min air, and (c) 0.2 L/min nitrogen. There was no clinical difference in FIO 2, VT, PIP (peak inspiratory pressure) and PEEP (positive end-expiratory pressure), with and without a 4-mm bellows tear, at all FGFs and VT settings. CO2 at the ventilator exhalation valve was always nonzero with a bellows leak, indicating that CO2-laden circuit gas was contaminating the drive gas via the bellows leak. A 4-mm bellows tear in an Ohmeda 7810 ventilator allows anesthetic gases to contaminate ambient air but does not cause clinically significant changes in FIO2, exhaled VT, PIP, or PEEP.
AB - We investigated the effect of a small bellows leak (bellows full at end-expiration) on inspired oxygen fraction (FIO2), exhaled tidal volume (VT), airway pressure, and room contamination in an oxygen-driven anesthesia ventilator (Ohmeda 7810, Madison, WI). CO2 concentration at the ventilator exhalation valve, FIO2, VT, and airway pressure were measured (n = 3) while ventilating a CO2-producing test lung at 8 breaths/min and an inspiratory/expiratory ratio of 1:2, with and without a bellows leak (4-mm-long tear). Set VT was 400, 600, 800, and 1000 mL. Fresh gas flow (FGF) was 0.3 L/min O2 and (a) 5.0 L/min air, (b) 2.0 L/min air, and (c) 0.2 L/min nitrogen. There was no clinical difference in FIO 2, VT, PIP (peak inspiratory pressure) and PEEP (positive end-expiratory pressure), with and without a 4-mm bellows tear, at all FGFs and VT settings. CO2 at the ventilator exhalation valve was always nonzero with a bellows leak, indicating that CO2-laden circuit gas was contaminating the drive gas via the bellows leak. A 4-mm bellows tear in an Ohmeda 7810 ventilator allows anesthetic gases to contaminate ambient air but does not cause clinically significant changes in FIO2, exhaled VT, PIP, or PEEP.
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U2 - 10.1097/00000539-200507000-00028
DO - 10.1097/00000539-200507000-00028
M3 - Article
C2 - 15976223
AN - SCOPUS:20744437748
VL - 101
SP - 151
EP - 154
JO - Anesthesia and Analgesia
JF - Anesthesia and Analgesia
SN - 0003-2999
IS - 1
ER -