[Nitrous oxide in anesthesia--present status of the use of nitrous oxide, risks for patients and personnel and treatment of side effects].

Mechanisms of some effects of nitrous oxide have recently been elucidated. Its antinociceptive action depends partly on the involvement of the endorphinergic system. Although vitamin B 12 becomes biologically inactive in the presence of nitrous oxide, this certainly is of no clinical consequence in exposures lasting less than eight hours. Should exposures last over 8 hours, effects of vitamin B 12 inactivation can be compensated for by administration of folinic acid. In contrast, professional exposure to trace levels of nitrous oxide seems not to interfere with human health. Furthermore, closed circle apparatus should be used and operating room air be well scavenged when nitrous oxide is used.