Neuropsychological symptoms and occupational exposure to anaesthetics

To analyse the relation between symptoms regularly reported by hospital personnel and exposure to anaesthetics.

Personnel of 18 hospitals in Paris from 1987 to 1989.

An exposed group that included all operating theatre members except for doctors, and which was divided into three subgroups depending on the degree of exposure--exposure was measured by the frequency of the use of the scavenging system--and a control group that included other hospital personnel matched by hospital, sex, occupation, age, and duration of service.

557 exposed workers and 566 unexposed workers.

The groups were compared according to the crude rates of regular symptoms. Adjusted odds ratios were calculated to estimate the risks associated with exposure to anaesthetic gas. Liver transaminase activities (alanine aminotransferase, aspartate aminotransferase (s-ASAT, and gamma-glutamyl transpeptidase) were measured and compared between groups of exposure.

After controlling for working conditions and matching factors, neuropsychological symptoms and tiredness were reported more by workers in less often scavenged theatres than by controls. No difference was found between workers of the well scavenged theatres and controls. Among the exposed workers, the members of paediatric surgical staffs reported a higher rate of neurological complaints (tingling, numbness, cramps) and tiredness than the members of the other surgical staffs. They had a high value of s-ASAT more frequently than the other exposed workers.

These results strengthen the hypothesis of a causal relation between exposure to anaesthetics and neuropsychological symptoms, and show a dose-response effect. They suggest that the use of ventilating systems in operating rooms is an effective means of prevention.