Jackson M, King M A, Shneerson J M
Assisted Ventilation Unit, Papworth Hospital, Cambridge, UK.
Eur Respir J. 1992 May;5(5):587-91.
Two studies were performed to investigate the differences in pressure stability performance of the continuous positive airway pressure (CPAP) machines used by our patients. The variations of mask pressures during each respiratory cycle were measured during overnight studies of two groups of patients with obstructive sleep apnoea, who were using either a Sleep-Easy III CPAP machine or a Si-Plan CPAP unit. The patients were well-matched for age, weight and neck circumference. The group using the Si-Plan unit had more constant mask pressures and were using lower CPAP pressures (mean 10.6 cmH2O) than those using the Sleep-Easy III machine (mean 13.8 cmH2O) (p less than 0.02). The pressure stability performance of five CPAP machines used by our patients was also compared using standardized simulated patient breaths produced by a negative pressure cuirass pump. There were large differences between the machines in ability to maintain a constant pressure. Using a tidal volume of 0.5 l and peak flow rates of between 20-40 l.min-1 the pressure variation ranged from 0-67% of the minimum inspiratory pressure. The maintenance of a constant pressure during inspiration and expiration lowers the mean pressure required to eliminate obstructive sleep apnoeas and reduces the likelihood of pressure related side-effects.
开展了两项研究，以调查我们的患者所使用的持续气道正压通气（CPAP）机器在压力稳定性性能方面的差异。在两组阻塞性睡眠呼吸暂停患者的夜间研究期间，测量了每个呼吸周期中面罩压力的变化，这两组患者分别使用Sleep-Easy III CPAP机器或Si-Plan CPAP设备。患者在年龄、体重和颈围方面匹配良好。使用Si-Plan设备的组面罩压力更稳定，且与使用Sleep-Easy III机器的组相比，他们使用的CPAP压力更低（平均10.6 cmH2O）（使用Sleep-Easy III机器的组平均为13.8 cmH2O）（p<0.02）。还使用负压胸甲泵产生的标准化模拟患者呼吸，比较了我们的患者使用的五台CPAP机器的压力稳定性性能。各机器在维持恒定压力的能力方面存在很大差异。使用0.5升的潮气量和20 - 40升·分钟-1的峰值流速时，压力变化范围为最低吸气压力的0 - 67%。在吸气和呼气期间维持恒定压力可降低消除阻塞性睡眠呼吸暂停所需的平均压力，并降低与压力相关的副作用的可能性。
