RESUMO
A previous report suggested that airway compromise without self-correction may occur in pediatric dental patients sedated with chloral hydrate (CH) and nitrous oxide (N2O) and may be interpreted as "deep" sedation. The purpose of this institutionally approved study was to determine 1) the association between the size of the tonsils and 2) the degree of expired carbon dioxide (CO2) and oxygen saturation (SaO2) changes to simulated airway obstruction using the Moore head-tilt maneuver for 30 sec or less. Thirty healthy children (ASA I), aged 22-40 months, were evaluated for tonsil size and sedated with CH (50 mg/kg) and hydroxyzine (2 mg/kg) and supplemented with N2O. Pulse oximetry and capnography were used to monitor the child. During the restorative phase when the patient appeared asleep, the head was rolled forward with the chin touching the chest for a period of 30 sec. Changes in SaO2 and CO2 waveform were observed during this period. The results indicated that seven children who had enlarged tonsils had blocked airways (as determined by capnography) lasting approximately 15 sec. The remaining children did not have enlarged tonsils and continued to exchange air appropriately. O2 levels did not change during this period. The results suggest that the likelihood of airway blockage increases with enlarged tonsils. In children without airway blockage, ventilation occurs unimpeded, and attempts to readjust the head may not occur. The association between airway blockage and patient responsiveness is discussed in relation to sedation levels.
