Kinouchi K, Tanigami H, Tashiro C, Nishimura M, Fukumitsu K, Takauchi Y
Department of Anesthesiology, Osaka Medical Center, Japan.
Anesthesiology. 1992 Dec;77(6):1105-7. doi: 10.1097/00000542-199212000-00010.
Sixty-one patients ASA physical status 1-2 aged 1 month to 12 years undergoing elective surgery were included in the study. Anesthesia was induced via a mask with sevoflurane up to 5% and 66% nitrous oxide in oxygen. After paralysis with vecuronium (0.12 mg/kg iv), the trachea was intubated and the lungs were ventilated manually with 3% sevoflurane in oxygen until the end-tidal nitrous oxide decreased to less than 5%. Apnea was started by disconnecting the breathing circuit from the endotracheal tube. The time from the start of apnea to Spo2 of 95% was measured. Manual ventilation was reinstituted when Spo2 decreased to 95% and another set of vital signs was recorded. Twenty of 61 patients had symptoms of upper respiratory infection. The time to Spo2 of 95% correlated well with height, age, and body weight both by linear and non-linear regression analyses. The patients with symptomatic upper respiratory infection required less time for Spo2 to decrease to 95% compared to the asymptomatic children. We conclude that younger children require less time for Spo2 to decrease to 95%. The presence of upper respiratory infection is an additional factor increasing the susceptibility of small children to hypoxemia.
61例年龄在1个月至12岁、ASA身体状况为1-2级的择期手术患儿纳入本研究。通过面罩给予七氟醚（浓度高达5%）和66%氧化亚氮与氧气的混合气体诱导麻醉。静脉注射维库溴铵（0.12mg/kg）使患儿肌肉松弛后，进行气管插管，然后用3%七氟醚与氧气的混合气体手动通气，直至呼气末氧化亚氮浓度降至5%以下。通过将呼吸回路与气管导管断开开始呼吸暂停。测量从呼吸暂停开始到血氧饱和度（Spo2）降至95%的时间。当Spo2降至95%时重新进行手动通气，并记录另一组生命体征。61例患儿中有20例有上呼吸道感染症状。通过线性和非线性回归分析，Spo2降至95%的时间与身高、年龄和体重均有良好的相关性。与无症状儿童相比，有上呼吸道感染症状的患儿Spo2降至95%所需时间更短。我们得出结论，年幼儿童Spo2降至95%所需时间更短。上呼吸道感染的存在是增加小儿低氧血症易感性的另一个因素。
