Selective Performance Effects of Nitrous Oxide

Twenty-one U.S. Navy divers were given several standard visual tests, the Purdue Peg-board, the Bennett Hand Tool Dexterity Test, and the Wechsler Memory Scale while breathing air or 30% nitrous oxide. The results showed that visual function, fine and gross motor performance, and long-term memory were normal under nitrous oxide, while learning and short-term memory were significantly impaired. The subjective effects of breathing nitrous oxide were similar to those experienced during compressed air narcosis. The selective impairment of short-term memory suggests that divers might be able to perform useful work at depths deeper than those currently authorized, provided the tasks were well learned and practiced.