Monitoring pediatric dental patients with nasal mask capnography.

Purpose: The purpose of this study was to evaluate the potential of using capnography to analyze respiratory samples taken from a scavenging nitrous oxide nasal hood during routine pediatric dental procedures.

Methods: Twenty-two subjects, aged 60-116 months, were administered alternately either 40% nitrous oxide/60% oxygen or 100% oxygen during two sequential restorative appointments. All subjects were monitored continuously for end-tidal carbon dioxide and respiratory rate using a capnograph whose sampling line was attached directly to the nitrous oxide nasal hood. The subject's breath sound, displayed behavior, type of dental procedure being performed, and presence of rubber dam isolation were recorded every minute throughout the two appointments.

Results: Values for end-tidal carbon dioxide and respiratory rate were displayed on the capnograph when administering either oxygen or a combination of nitrous oxide/oxygen inhalation through the nasal hood. These respiratory values were lowered significantly when comparing 40% nitrous oxygen-60% oxygen to 100% oxygen inhalation. They were not significantly altered by the type of breath sound, patient behavior, dental procedure, or presence of rubber dam isolation, with the exception of some dental procedures which significantly lowered end-tidal carbon dioxide. The apnea alarm on the capnograph occurred during 5% of the total treatment time, but its occurrence represented a 97% false positive rate. The occurrence of the apnea alarm was significantly associated with the type for breath sound, patient behavior, and dental procedure. When used in this manner, the capnograph was effective in alerting the practitioner to potential apneic events, but likely has limited value in monitoring valid end-tidal carbon dioxide levels due to limitations in the sampling technique.

Conclusions: This study demonstrated the potential of the capnograph as a respiratory monitor for pediatric dental patients when the sampling line was attached to a scavenging nitrous oxide nasal hood.