Blood concentrations of nitrous oxide in theatre personnel
Blood concentrations of nitrous oxide were measured in anaesthetists, surgeons and theatre nursus. Comparison of anaesthetists and surgeons working in the same theatre showed that in ENT surgeons concentrations were greater (p≪0.01), while in general surgeons they were smaller (P≪0.003). Blood concentrations of nitrous oxide in the "circulating" nurses were low; with scavenging they were unmeasurable. Atmogpheric concentrations in the breathing zones were usually greater than the correspondmg blood concentrations, but this was not always true. However, a positive correlation between blood and atmospheric concentrations was obrained (r = 0.82). Meticulous use of scavenging devices produced a mean reduction in blood nitrous oxide concentranons of 86% for all groups. The mean blood concentration of nitrous oxide in anaesthetists when scavenging was used was 45 p.p.m. (1.9 μmol litre-1).This figure should be taken into account in establishing maximum permitted exposure to nitrous oxide. © 1980 Macmillan Publishers Ltd.