Increased ventilation requirements during obstetric general anaesthesia
Rampton, A.J.; Mallaiah, S.; Garrett, C.P.
British Journal of Anaesthesia 61(6): 730-737
1988
ISSN/ISBN: 0007-0912 PMID: 3145001 Document Number: 315718
The inspiratory fresh gas flow rate (FGF) required to produce an end-tidal carbon dioxide tension (PE'CO2) of 4 kPa during general anaesthesia, neuromuscular blockade and artificial ventilation, was compared in a group of 46 obstetric patients and a matched group of 50 nonpregnant female patients. The nonpregnant patients required a mean (SD) inspiratory FGF of 77 (10.6) ml kg-1 min-1, where the pregnant patients required a mean FGF of 121 (24.6) ml kg-1 min-1 before delivery (in those who reached a stable state), and 109 (19.3) ml kg-1 min-1 after delivery. These represent significant (P < 0.0001) increases of 57% and 42%, respectively, over the nonpregnant state.