Breslau´s report on the two stillbirths induced by illuminating gas poisoning made many investigators explore the hazards of carbon monoxide(CO) poisoning to pregnancy. The pregnant woman, her fetus, and the newborn infant have been identified to be particiuIarly vulnerable to CO even in low concentration. Several factors, such as placental barrier, m0-ibrane resistance of maternal and fetal red blood cells etc., were considered to be related to the !;delayed elimination of CO from fetus. Slower elimination of CO from fetus than from mother was confirmed in several in vivo studies. But there are few studies which have confirmed the difference of carboxyhemoglobin (HbCO) dissociation in adult and fetal bloods.
Author investigated the effects of hemoglobin itself on the elimination of CO from mother and fetus. By observing the difference of CO dissociation from adult and fetal hemoglobin at the various partial pressures of oxygen, the author tries to suggest the base of the proper´; treatment measure for the CO poisoning of pregnant woman and_ newborn infant. The results ,verp as follows:
1 The total hemoglobin amounts of adults and fetal bloods were 16.1_.0.50gm% and 15.7 0. 32gms´0, respectively. The fetal hemoglobin proportions in adult and fetal bloods were 1. 2-´-0. 15% and 72.7_h3.01o, respectively.
2. Adult and fetal bloods saturated by CO to 1000 HbCO were exposed to ambient air(2150 02), ? 000 02, and 3 ATA02. After 30 minutes exposure, the IlbCO saturations of adult blood were 96.7%, 70. 9,,0, and 52.8%, respectively, and those of fetal blood were 98.5%, 76.10, and 62.250, respectively. HbCO dissociation was proportional to the partial pressure. of oxygen and the most marked dissociation was shown under 3 ATA 02, HbCO dissociation of fetal blood was slower than that of adult blood in all conditions.
According to the above results, it is possible that CO poisoning make, more serious damage to the fetus and newborn infant than to the adult due to the delayed dissopii4tion of HbCO. Thus in the treatment of CO poisoning of pregnant woman and newborn infant, byperbaric oxygen therapy seems to be the most effective treatment measure, but the duration of, 1hyperbaric oxygenation should be lengthened accordingly.
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