Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we will assume that you are happy to receive all cookies and you will not see this message again. Click 'Find out more' for information on how to change your cookie settings.

To investigate the effects of enflurane on the control of breathing we have studied the ventilatory responses to isocapnic hypoxia in 12 adults with and without sedation with enflurane. Design 1 consisted of three steps into hypoxia (PE' O2 = 6.7 kPa), each lasting 3 min, separated by periods of euoxia lasting 5 min (PE' O2 = 13.3 kPa). Design 1 was repeated four times in each subject on the same day in random order: with carrier gas (control) and with 0.04 MAC, 0.07 MAC and 0.13 MAC of end-tidal enflurane concentrations. Design 2 consisted of 20-min exposures to hypoxia with and without 0.07 MAC of enflurane. Each exposure was preceded and followed by 5 min of euoxia. End-tidal PCO2 was held constant at 0.13-0.27 kPa greater than the resting level throughout both designs. Mean (SEM) ventilatory responses to hypoxia for design 1 were: 8.2 (1.3) litre min-1 (control), 6.6 (1.4) litre min-1 (0.04 MAC), 5.7 (1.1) litre min-1 (0.07 MAC) and 3.7 (0.5) litre min-1 (0.13 MAC) (P < 0.001). For design 2, enflurane produced a 15% reduction in resting ventilation (P < 0.01), a 40% decrease in the acute ventilatory response to hypoxia (P < 0.01) and a 32% reduction in ventilatory decline (ns) which occurred during sustained hypoxia.

Type

Journal article

Journal

Br J Anaesth

Publication Date

05/1994

Volume

72

Pages

509 - 514

Keywords

Adult, Carbon Dioxide, Depression, Chemical, Enflurane, Female, Humans, Male, Oxygen, Partial Pressure, Respiration, Tidal Volume, Time Factors