Summary
Maternal and foetal cardiovascular, blood gas and acid-base changes were studied during 90 minutes of methoxyflurane anaesthesia. At 1.0 and 1.5 MAC anaesthesia, despite slight to moderate falls in maternal blood pressure, cardiac output and uterine blood flow, no serious foetal deterioration was seen. 2.0 MAC methoxyflurane was associated with marked falls in maternal blood pressure, cardiac output and uterine blood flow. Foetal hypoxaemia and a mixed respiratory and metabolic acidosis developed. Little foetal cardiovascular depression was seen with any level of anaesthesia. There was no direct effect of methoxyflurane on the uterine vasculature.
Résumé
Cette étude a porté sur les changements cardiovasculaircs et acidobasiques survenant chez les brebis enceintes et leur foetus durant 90 min d’anesthésie au methoxyflurane. A une profondeur d’anesthésie correspondant à 1.0 et 1.5 MAC, on n’a observé aucune détérioration de l’état du foetus malgré une chute de pression modérée chez la mère ainsi qu’une diminution de son débit cardiaque et du flot utérin.
A une profondeur équivalent à 2 MAC, on observe une chute de la pression artérielle accentuée de même qu’une diminution du débit cardiaque et du débit utérin, au point d’entraîner une hypoxémie foetale avec acidose respiratoire et métabolique épargnant cependant le système cardiovasculaire qui est peu touché. Aucun effet direct du méthoxyflurane sur la circulation utérine n’a pu être observé.
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Palahniuk, R. Inhalation anesthesia and analgesia in obstetrics, in The Anesthesiologist, Mother and Newborn. S.M. Shnider & F. Moya, Eds. Williams & Wilkins Co., Baltimore, pp. 56–63 (1974).
Shnider, S.M., Steffenson, J.L., &Margolis, A. Methoxyflurane analgesia in obstetrics. Obstet. Gynec.33: 594 (1969).
Latto, I.P., Rosen, M., &Molloy, M.J. Absence of accumulation of methoxyflurane during intermittent self-administration for pain relief in labor. Br. J. Anaesth.44: 39 (1972).
Clarke, R.B., Cooper, J.O., Brown, W.E., &Greifenstein, F.E. An evaluation of methoxyflurane analgesia and anesthesia for obstetrics. Southern Med. J.61: 687 (1968).
Smith, B.E. &Moya, F. Inhalation analgesia with methoxyflurane for vaginal delivery. Southern Med. J.61: 386 (1968).
Ivankovic, A.D., Elam, J.O., &Huffman, J. Methoxyflurane anesthesia for Caesarean section. J. Reprod. Med.6: 105 (1971).
Houle, G.L. &Gertel, M. Methoxyflurane: clinical and laboratory studies during Caesarean section. Anesth. Analg. (Cleveland)48: 1011 (1969).
Latto, I.P. &Wainwricht, A.C. Anaesthesia for Caesarean section. Analysis of blood concentration of methoxyflurane using 0.1 per cent methoxyflurane and 40 per cent oxygen. Br. J. Anaesth.44: 1050 (1972).
Moih, D.D. Anaesthesia for Caesarean section. An evaluation of method using low concentrations of halothane and 50 per cent oxygen. Br. J. Anaesth.42: 136 (1970).
Rorke, M.J., Davey, D.A., &Du Toit, H.J. Foetal oxygénation during Caesarean section. Anesthesia23: 585 (1968).
Marx, G.F. &Mateo, C.V. Effects of different oxygen concentrations during general anaesthesia for elective Caesarean section. Canad. Anaesth. Soc. J.18: 586 (1971).
Baraka, A. Correlation between maternal and foetal Po2 and PCo2 during Caesarean section. Br. J. Anaesth.42: 434 (1970).
Sevehinchaus, J.W. Blood gas calculator. J. Appl. Physiol.21: 1108 (1966).
Hellegers, A.E. &Schruefer, J.J.A. Nomograms and empirical equations relating oxygen tension, percentage saturation, and pH maternal and fetal blood. Am. J. Obstet. Gynecol.81: 337 (1961).
Palahniuk, R.J., Shnider, S.M., &Eger, E.I. Pregnancy decreases the requirements for inhaled anesthetic agents. Anesthesiology41: 82 (1974).
Palahniuk, R.J. &Shnider, S.M. Maternal and fetal cardiovascular and acid-base changes during halothane and isoflurane anesthesia in the pregnant ewe. Anesthesiology41: 462 (1974).
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This study was supported by the Medical Research Council of Canada. Presented in part at the Canadian Anaesthetists’ Society Meeting, St. John’s, Newfoundland, June, 1974.
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Smith, J.B., Manning, F.A. & Palahniuk, R.J. Maternal and foetal effects of methoxyflurane anaesthesia in the pregnant ewe. Canad. Anaesth. Soc. J. 22, 449–459 (1975). https://doi.org/10.1007/BF03004859
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DOI: https://doi.org/10.1007/BF03004859