Thomas H. Corbett

Birth defects among children of nurse-anesthetists.

A survey of 621 female nurse-anesthetists in Michigan was performed to determine the incidence of birth defects among the offspring of this group. Two separate mailings and telephone interviews resulted in a response rate of 84.5 per cent. Of children whose mothers worked during pregnancy, 16.4 per cent had birth defects, while only 5.7 per cent of children whose mothers did not work during pregnancy had birth defects. This difference was significant (P < 0.005). Three neoplasms were reported in two children whose mothers worked during pregnancy. One neoplasm was reported among the offspring of mothers not working during pregnancy.

Incidence of Cancer among Michigan Nurse-anesthetists

A survey of the 621 female nurse-anesthetists in Michigan was performed to determine the incidence of malignancy in this group. Two separate mailings and telephone interviews resulted in a response rate of 84.5 per cent. A total of 33 malignancies in 31 nurse-anesthetists was reported. Several unusual types were noted. Ten malignancies, including three skin cancers, were diagnosed during 1971. Excluding skin cancers, the expected incidence adjusted for age distribution, based on statistics from the Connecticut Tumor Registry, is 402.8/100,000. The adjusted incidence in Michigan nurse-anesthetists is 1,333.3/ 100,000. This difference is significant at the 3.1 per cent level.

Effects of Low Concentrations of Nitrous Oxide on Rat Pregnancy

Pregnant rats were exposed to concentrations of nitrous oxide similar to those present in the operating room during routine occupational exposure for various periods during pregnancy. Those exposed to 15,000 ppm and 1,000 ppm for 24 hours/day had fetal death rates and pregnancies/rat ratios which were significantly different from the controls. Two groups exposed to 1,000 ppm for 8 hours/day also had fetal death rates significantly different from the controls. Exposure for 8 hours/day did not significantly alter the pregnancies/rat ratios. Differences in the fetal death rates between groups exposed from 6 AM to 2 PM and from 2 PM to 10 PM suggest a diurnal variation in the embryotoxic effect of nitrous oxide in the rat.

Pharmacology and Toxicology of Halogenated Anesthetics

Publisher Summary This chapter discusses the pharmacology and toxicology of halogenated anesthetics. Trichloroethylene is relatively soluble in blood, and induction of anesthesia is slow, as is recovery. In clinical practice, the slow induction time if offset partially by the high anesthetic potency of the drug. The minimum alveolar concentration (MAC) necessary to maintain the first plane of surgical anesthesia is 0.17%. Trichloroethylene was the first of the inhalation anesthetics demonstrated to be biotransformed. Halothane is relatively insoluble in blood, and induction of anesthesia is relatively rapid. The minimum alveolar concentration necessary to maintain the first plane of surgical anesthesia is 0.7%. Halothane is extremely soluble in fat, allowing the body to absorb large amounts of the anesthetic. Many halogenated hydrocarbons are known to be hepatotoxic, and at least in certain individuals, halothane is no exception. The usual clinical picture of halothane hepatitis presents with fever, leukocytosis, and with eosinophilia, followed by jaundice within 5– 21 days after anesthesia. Liver dysfunction is confirmed by finding high alkaline phosphatase, serum glutamic oxaloacetic transaminase (SGOT), and serum glutamic pyruvic transaminase (SGPT) levels.

Inhalation Anesthesia: An Occupational Hazard

An excess incidence of certain cancers, spontaneous abortions, and birth defects in their offspring has been documented among anesthesia personnel, giving rise to concern about the effects of chronic exposure to anesthetic gases. Yet it is possible, with scavenging equipment and properly designed ventilating systems, to reduce operating room concentrations of these gases by 98%. Why, then, are such measures not yet routine?