Maxwell Lyndal J, Ellis Elizabeth R
University of Sydney, Lidcombe, NSW, 2141, Australia.
Aust J Physiother. 2004;50(1):47-9. doi: 10.1016/s0004-9514(14)60248-8.
Operator performance during the expiratory phase of manual hyperinflation appears to vary between physiotherapists for Mapleson-B or C circuits. Some physiotherapists release the valve but maintain compression of the bag, whereas others release both the valve and the bag. The effect of this difference on peak expiratory flow rate (PEFR) has not been reported. The aim of this study was to document the effect of maintaining bag compression during expiration on PEFR and inspiratory to expiratory flow rate ratio (I:E). Six physiotherapists with experience using manual hyperinflation participated. A within-subjects repeated measures design was used. Subjects performed manual hyperinflation using a Mapleson-C circuit with 'rapid release', releasing the valve only, or releasing both the bag and the valve, during expiration in a test lung model. Inspiratory time was controlled using a metronome and flows were measured with a heated pneumotachometer. Maintaining bag compression significantly reduced PEFR (1.54 (0.08) vs 2.00 (0.07) l/sec, p = 0.008) and increased I:E flow rate ratio (0.65 (0.04) vs 0.50 (0.02), p = 0.02) for the Mapleson-C circuit at a 1.4 litre target volume. There were no significant differences for these measures between techniques when subjects emptied the bag. The effect needs to be confirmed in the clinical setting.
对于Mapleson - B或C回路，在手动过度通气呼气阶段，不同物理治疗师的操作表现似乎存在差异。一些物理治疗师松开阀门但保持对储气袋的挤压，而另一些则同时松开阀门和储气袋。这种差异对呼气峰值流速（PEFR）的影响尚未见报道。本研究的目的是记录呼气时保持储气袋挤压对PEFR和吸气与呼气流量比（I:E）的影响。六名有手动过度通气经验的物理治疗师参与了研究。采用受试者内重复测量设计。受试者在测试肺模型中使用Mapleson - C回路进行手动过度通气，在呼气时采用“快速释放”，即仅松开阀门，或同时松开储气袋和阀门。吸气时间用节拍器控制，流量用热式呼吸流速计测量。在目标容积为1.4升时，对于Mapleson - C回路，保持储气袋挤压显著降低了PEFR（1.54（0.08）对2.00（0.07）升/秒，p = 0.008）并增加了I:E流量比（0.65（0.04）对0.50（0.02），p = 0.02）。当受试者排空储气袋时，这些测量指标在不同技术之间没有显著差异。该效应需要在临床环境中得到证实。
