Effect of scavenging on the psychomotor and cognitive function of subjects sedated with nitrous oxide and oxygen inhalation.

Maximizing scavenger effectiveness using a 45 L/min evacuation rate as recommended by the National Institute of Occupational Safety and Health (NIOSH) may alter the sedation level of the dental patient. The purpose of this pilot study was to determine if scavenging at the recommended NIOSH evacuation rate reduced psychomotor and cognitive impairment as a result of inhaling nitrous oxide. Computer-administered neurobehavioral tests of human psychomotor and cognitive function previously established in controlled trials to be sensitive to nitrous oxide inhalation were employed in this blind, randomized, crossover study of 30 healthy adult subjects. The results indicated that scavenging produced statistically significant improvement in finger-tapping speed, symbol/digit coding speed, and recall accuracy. Hand/eye coordination was not improved significantly by scavenging. Enhancement of psychomotor skills and cognitive functioning was interpreted as an undesirable side effect of scavenging that could potentially influence dental patient anxiety management when using nitrous oxide inhalation. The results of this pilot study suggested that scavenger operation under the conditions tested could reduce the level of psychosedation achieved with nitrous oxide inhalation.