Upper airway obstruction during midazolam/nitrous oxide sedation in children with enlarged tonsils

Dan Boboia 4/2/10 Lit. Review

Title: Upper airway obstruction during midazolam/nitrous oxide sedation in children with enlarged tonsils

Author: Litman et al

Main Purpose: To examine the incidence and severity of upper airway obstruction in children with enlarged tonsils during the inhalation of 50% N2O after premed. with oral versed.

Methods:
25 children presenting for tonsillectomy were used as the study population and 25 children presenting for other types of elective surgery were used as control. Following premed with Versed (0.5mg/kg) measurements were collected during a 3-minute control period followed by 3 min. of breathing 50% N2O with 50% O2. An anesthesiologist held a mask over the child’s mouth and nose without supporting the head and neck or attempting to maintain airway patency. Every 20 seconds the airway patency was graded as none, partial, or complete based on clinical signs and capnography. Clinical signs included chest rise, stridor, and feeling movement of the ventilation bag.

Results:
During 50% N2O inhalation 14 children in the tonsillectomy group and four in the control group demonstrated upper airway obstruction (UAO). One child in the tonsillectomy group developed hypoxemia (SpO2 = 72%). One child in the tonsil group developed complete UAO (50%).

Conclusion:
Children who receive sedation with oral Versed and 50% N2O may exhibit significant UAO, especially in the presence of enlarged tonsils. Presedation physical exams should evaluate the presence of tonsil size during examination of the mouth and airway.