Pregnancy Decreases the Requirement for Inhaled Anesthetic Agents

Isoflurane potency and cardiovascular effects during short exposures in the foetal lamb

“…The close proximity of these two values supports the validity of the formula used to convert blood concentrations to a gaseous phase. Palahniuk et al 9 determined MAC in pregnant ewes for isoflurane to be 1.01 vol%, higher than our value. The reason for this difference is not known.…”

“…Palahniuk et al 9 desmonstrated that MAC was lower in pregnant, as opposed to non-pregnant, ewes and suggested that progesterone may be responsible for decreasing MAC. Elevated progesterone levels and endorphin levels have been suggested as possible reasons for a decreased MAC in the foetus.…”

O sevofluorano em cadelas gestantes

“…A concentração de anestésico inalatório requerido para as cadelas gestantes foi o mesmo para o grupo não-gestante, entre 2,5 e 3% de sevofluorano, durante todo o procedimento anestésico, discordando de estudos prévios realizados por PALAHNIUK et al (1974), os quais relataram diminuição do requerimento anestésico do halotano, isofluorano e metoxifluorano em ovelhas no terço-final de gestação. Essa redução seria explicada pelos efeitos sedativos da progesterona e das endorfinas que se encontram elevadas na gestação.…”

Management of Urological Problems During Pregnancy: A Rationale and Strategy

“…Gestation is associated with a decrease in drug requirements for both general and regional anesthesia. Palahniuk and associates [ 35 ] have reported a 25-40% reduction in minimal alveolar concentrations by using halothane and iso fl urane during ovine pregnancy. This is most likely because of the sedative effects of progesterone and the increased levels of endogenous opiates [ 36,37 ] .…”