临床麻醉过程中如果发生缺O_2,问题就非常严重,尤其当前广泛应用异氟醚-N_2O-O_2麻醉、芬太尼-O_2麻醉及肌松药等,O_2的监测就显得更重要,因为急性缺O_2往往导致循环骤停,造成神经系统的后遗症,甚至死亡。近年来由于对“氧阶梯”(Oxygen Cascade)认识的深化和O_2监测手段的逐步完善,使麻醉者在术中能够对不同氧阶梯(如麻醉机,呼吸道或病人)进行针对性强的监 In the process of clinical anesthesia, the lack of O_2, the problem is very serious, especially the widespread use of isoflurane-N_2O-O_2 anesthesia, fentanyl-O_2 anesthesia and muscle relaxants, O_2 monitoring is even more important because of acute shortage O_2 often leads to circulatory arrest, resulting in nervous system sequelae and even death. In recent years, due to the deepening of understanding of “Oxygen Cascade” and the gradual improvement of O_2 monitoring methods, anesthesiologists are able to perform targeted intraoperative monitoring of different oxygen ladders (such as anesthesia machines, respiratory tracts or patients)