Nitrous oxide sedation and bispectral index.

OBJECTIVES

To determine whether bispectral analysis (BIS) changes during nitrous oxide (N(2)O) sedation in anxious children undergoing extraction of primary teeth.

METHODS

In this prospective study 45, ASA physical status I children, aged between 7 to 12 years and scheduled for primary teeth extraction under N(2)O/O(2) sedation are included. At baseline (T0) and during the sedation procedure (T1-6); BIS levels, Ramsay Sedation Scores (RSS), oxygen saturation (Sp0(2)), and heart rate (HR) were recorded at one-minute intervals. Forty percent N(2)O in O(2) was given by a nasal hood, and N(2)O concentration was enhanced to 60% in a two-minute period. Paired measurements of BIS levels with Observer's Assessment of Alertness and Sedation (OAA/S) scores were obtained during sedation procedure.

RESULTS

Since 5 patients refused application of the nasal hood, a total 40 of the original 45 subjects completed the study. Mean age and weight of the children were 9.5 +/- 1.4 years and 23.7 +/- 9.7 kg, respectively. Nitrous oxide inhalation produced no changes in BIS levels despite a sedation level in OAA/S scores were observed at 40-60% N(2)O concentrations.

CONCLUSIONS

BIS values do not change during N(2)O/O(2) sedation and the BIS monitor is not appropriate to evaluate the depth of sedation provided by N(2)O/O(2) during primary teeth extraction in children.