Table 2.

Ce of remifentanil for preventing emergence cough following extubation

	Male group (n=23)	Female group (n=22)
Dixon’s method (ng/mL)
EC50 of remifentanil Ce	2.56±0.37*	1.56±0.26
Isotonic regression method (ng/mL)
EC50 of remifentanil Ce	2.60 (2.29–2.91)#	1.67 (1.55–1.83)
EC95 of remifentanil Ce	3.41 (3.27–3.58)#	2.30 (2.02–2.62)

Notes: Values are expressed as mean ± standard deviation determined by Dixon’s method and the EC₅₀ (83% CI) and EC₉₅ (95% CI) determined by the isotonic regression method.

^*P<0.001 vs females (independent t-test).

^#Significantly higher vs females (nonoverlapping CI method).

Abbreviations: Ce, effect-site concentration; CI, confidence interval.