Biddle C, Epps L, Hassanein R
AANA J. 1989 Apr;57(2):131-6.
Fourteen patients with COPD underwent elective procedures below the umbilicus, all receiving a standard anesthetic. They were randomized to one of four groups differentiated by the presence or absence of sighing during mechanical ventilation. Patients who were sighed experienced both statistically and clinically significant improvement in their oxygenation efficiency as measured by the alveolar to arterial oxygen gradient.
14名慢性阻塞性肺疾病（COPD）患者接受了脐下择期手术，均接受标准麻醉。他们被随机分为四组，根据机械通气期间是否有叹息进行区分。有叹息的患者在通过肺泡-动脉氧梯度测量的氧合效率方面，在统计学和临床上均有显著改善。
