National High Blood Pressure Education Program.

Alterations have been found to occur in every component of immune response during anaesthesia and surgery. These alterations represent the body's general physiological responses and are mainly dependent on the extent of surgery, as well as other factors such as the patient's age and health status, medication and blood transfusion. Anaesthetic and operative complications have profound effects on these responses. Basically, the immune response to anaesthesia and surgery is a beneficial reaction, needed in local host defences and wound healing and in preventing the body from making autoantibodies against its own tissues. The responses may, however, contribute to the development of postoperative infections and spread of malignant disease. During uncomplicated conventional surgery, the immune response usually passes clinically unnoticed without any harmful effects. Absent responses and excessively high responses, on the other hand, harm the patient. Our understanding of immunological phenomena and our possibilities of controlling mediator activation are now lagging behind the technical advances made in operative treatment. If we want to decrease operative morbidity and mortality to below their present levels, more attention should be directed to immune responses to major surgery, injuries and operative complications with massive mediator release which place the surgical patient at risk. Experimental evidence suggests that results of treatment in injured and operated patients can in the future be improved by controlling immune responses and their mediator systems. Our current level of knowledge of immune responses is already helping us to avoid many immune-mediated complications. However, routine interference with these responses is not indicated.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1399-6576.1992.tb03452.x

Effects of anaesthesia and surgery on the immune response.

BACKGROUND Fertility is reduced in female rats exposed to levels of nitrous oxide similar to those found in some dental offices. Epidemiologic studies have suggested an association between exposure to mixed anesthetic gases and impaired fertility. We investigated the effects of occupational exposure to nitrous oxide on the fertility of female dental assistants. METHODS Screening questionnaires were mailed to 7000 female dental assistants, ages 18 to 39, registered by the California Department of Consumer Affairs. Sixty-nine percent responded. Four hundred fifty-nine women were determined to be eligible, having become pregnant during the previous four years for reasons unrelated to the failure of birth control, and 91 percent of these women completed telephone interviews. Detailed information was collected on exposure to nitrous oxide and fertility (measured by the number of menstrual cycles without contraception that the women required to become pregnant). RESULTS After controlling for covariates, we found that women exposed to high levels of nitrous oxide were significantly less fertile than women who were unexposed or exposed to lower levels of nitrous oxide. The effect was evident only in the 19 women with five or more hours of exposure per week. These women were only 41 percent (95 percent confidence interval, 23 to 74 percent; P less than 0.003) as likely as unexposed women to conceive during each menstrual cycle. CONCLUSIONS Occupational exposure to high levels of nitrous oxide may adversely affect women's ability to become pregnant.

https://www.nejm.org/doi/pdf/10.1056/NEJM199210013271405

Reduced fertility among women employed as dental assistants exposed to high levels of nitrous oxide.

Results from a survey of 30,650 dentists and 30,547 chairside assistants suggest that long-term exposure to trace anesthetics in the dental operatory can be associated with increased general health problems and reproductive difficulties. Incidences of spontaneous abortion, congenital abnormalities in offspring, cancer, liver disease, and kidney disease were compared among exposed, nonexposed, and indirectly exposed persons.

Occupational Disease in Dentistry and Chronic Exposure to Trace Anesthetic Gases

Nurses working in selected departments of general hospitals in Finland were collected from a central register on health personnel in Finland. Using the Hospital Discharge Register and the Register of Congenital Malformations, case nurses were selected who had had a spontaneous abortion (N = 217) or a malformed child (N = 46) between the years 1973 and 1979. Controls consisted of three nurses who had had a normal birth; the control nurses were matched for age and hospital of employment. Information on exposure in the first trimester of pregnancy was sought through the head nurses of the hospitals. No significant increase in risk of spontaneous abortion or of malformation was observed after exposure to anaesthetic gases (odds ratio for spontaneous abortion 1.2), sterilising gases and soaps, or x-rays. Handling of cytostatic drugs did not affect the frequency of spontaneous abortion but was associated with malformations in the offspring. The odds ratio, based on eight cases, was 4.7 (p = 0.02) when the logistic model was adopted. The results suggest that the exposures investigated, other than cytostatic drugs, do not cause a strong reproductive risk. Further studies are needed, particularly on cytostatic drugs.

https://jech.bmj.com/content/jech/39/2/141.full.pdf

Spontaneous abortions and malformations in the offspring of nurses exposed to anaesthetic gases, cytostatic drugs, and other potential hazards in hospitals, based on registered information of outcome.

Twenty males, paid volunteer medical or dental students were exposed on two occasions to four hours of inhalation of either air or 500 ppm nitrous oxide and 15 ppm halothane in air. Immediately following this, a battery of tests of perceptual cognitive and motor skills were administered to them. Evaluating their responses compared to their control conditions when they breathed only air, there was a significant decrement in performance following anesthetic exposure on a task of divided attention between auditory and visual signals, a visual tachistoscopic test, and memory tests involving digit span and recall of word pairs. These findings may indicate a subtle but significant negative effect on the ability of anesthesiologists to provide vigilant care for their patients. Further investigation of possible long-term effects upon the effective function and accident record of the anesthetist is indicated.

Trace Anesthetic Effects on Perceptual, Cognitive, and Motor Skills

During the years 1947–1966, there were 441 deaths among junior, active and retired members of the American Society of Anesthesiologists living in the United States or Canada. A cause of death was found for each member and death rates calculated for this group. Comparisons of these rates with those for U. S. males and with male policyholders of the Metropolitan Life Insurance Company were made. Anesthesiologists appear to have a low incidence of lung cancer, a somewhat lower than average incidence of coronary artery disease in recent years, and a high death rate from suicide and malignancies of the lymphoid and reticuloendothelial tissues. These data only suggest trends and point to the need for a prospective study of this subject.

Causes of death among anesthesiologists: a 20-year survey.

All male members of the American Society of Oral Surgeons and a sample of the American Dental Association membership were surveyed for exposure to anesthetic gases and the incidences of certain health problems. Concentrations of waste inhalation anesthetic gases in the dental surgery are several times those found in hospital operating rooms. This study establishes a relationship between exposure to waste gases and the incidence of health problems including spontaneous abortion in spouses, congenital abnormalities in offspring, and cancer and liver disease. Measurable concentrations of waste anesthetic gases have been found in hospital dental operating rooms. A mail survey of 4,797 general dental practitioners and 2,642 oral surgeons indicated that 20.2% of the general practitioners and 74.8% of the oral surgeons had anesthetic exposures exceeding three hours per week. In the comparison of the health of individuals exposed or unexposed to inhalation anesthetics, there was a significant increase (78%) of spontaneous abortion in the spouses of exposed dentists and a significant increase (156%) in liver disease for exposed dentists. The implication of these findings and possible solutions are discussed.

A survey of anesthetic health hazards among dentists

Thirty human subjects were exposed for four hours to 500 ppm N-2O and 15 ppm enflurane in air and then, within five minutes, given a 35-minute battery of psychological tests. Performance of a divided-attention audiovisual task and a digit-span memory test were significantly decreased compared with control data following exposure to air. A tachistoscopic task, four tests from the Wechsler memory scale, and five others from the Wechsler Adult Intelligence Scale were unaffected. Thirty subjects exposed to 500 ppm N-2-O in air only scored significantly lower on the digit-span test only. Language: en

David L. Bruce

Papers

Trace Anesthetic Effects on Perceptual, Cognitive, and Motor Skills

Causes of death among anesthesiologists: a 20-year survey.

A survey of anesthetic health hazards among dentists

Psychological studies of human performance as affected by traces of enflurane and nitrous oxide.

Occupational Exposure of Anesthetists to Halothane, Nitrous Oxide and Radiationz