Children's development effecting blood oxygen desaturation following apnea.

One hundred and fifty-six children aged from 4 months to 12 years undergoing elective plastic surgery were included in this study. All children were ASA physical status I, under normal development, ranging from 64 to 140 cm in body height and from 6.0 to 41.0 kg in body weight. Following 2-minute preoxygenation, the time when SpO2 dropped to 95% and 90% in apneic period had a close correlation with age, weight and height of children by means of linear and non-linear regression analysis. The smaller the children's weight, the higher the incidence of severe arterial desaturation after reinstitution of manual ventilation with 100% oxygen at SpO2 of 90%. It is suggested that younger children are more susceptible to hypoxemia than older ones during apnea and provided no problem existing other than oxygen delivery, an SpO2 of 95% might be the safe limitation of apnea in pediatric anesthesia induction.