Videira R L, Neto P P, do Amaral R V, Freeman J A
Division of Anaesthesia, Hospital das Clinicas Sao Paulo University School of Medicine, Brazil.
Acta Anaesthesiol Scand. 1992 Feb;36(2):109-11. doi: 10.1111/j.1399-6576.1992.tb03433.x.
Although preoxygenation has been extensively studied, to our knowledge this is the first study addressing its optimal length in children, who form a high risk group for developing hypoxaemia during induction of anaesthesia. Recommended preoxygenation times in children range between 1 and 4 min, but whether one of these times maintains arterial oxygen saturation (Sao2) at an adequate level for a longer time period is unknown. This study was performed on 11 healthy children, randomly distributed into either Group 1 (1 min of preoxygenation, n = 6) or Group 2 (3 min of preoxygenation, n = 5). Sao2 was measured by pulse oximetry. While the patients were breathing room air, Sao2 was similar in both groups (97%) and rose to 100% after preoxygenation in all patients. After intravenous induction of anaesthesia and muscle relaxation, all patients became apnoeic. The time taken for the Sao2 to decrease to 90% was measured. In Group 1 this occurred in 91 s, whereas Group 2 required 144 s. Thus, a 3-min rather than a 1-min period of preoxygenation would appear to maintain Sao2 at a safe level for a longer time in children.
尽管预给氧已得到广泛研究，但据我们所知，这是第一项针对儿童预给氧最佳时长的研究，儿童是麻醉诱导期间发生低氧血症的高危人群。儿童推荐的预给氧时间在1至4分钟之间，但这些时间中的某一个是否能在更长时间段内将动脉血氧饱和度（Sao2）维持在适当水平尚不清楚。本研究对11名健康儿童进行，随机分为第1组（预给氧1分钟，n = 6）或第2组（预给氧3分钟，n = 5）。通过脉搏血氧饱和度仪测量Sao2。在患者呼吸室内空气时，两组的Sao2相似（97%），且所有患者预给氧后均升至100%。静脉注射麻醉药和肌肉松弛剂后，所有患者均出现呼吸暂停。测量Sao2降至90%所需的时间。第1组在91秒时出现这种情况，而第2组需要144秒。因此，对于儿童而言，3分钟而非1分钟的预给氧时间似乎能在更长时间内将Sao2维持在安全水平。
