Morley Colin J, Dawson Jennifer A, Stewart Michael J, Hussain Farhat, Davis Peter G
Neonatal Research, The Royal Women's Hospital, Melbourne, Australia.
J Paediatr Child Health. 2010 Jan;46(1-2):51-6. doi: 10.1111/j.1440-1754.2009.01617.x. Epub 2009 Nov 23.
Self-inflating bags are used to provide ventilation during neonatal resuscitation. However, they cannot provide positive end expiratory pressure (PEEP) unless a PEEP valve is attached. The ability of Laerdal neonatal self-inflating bags fitted with PEEP valves to reliably deliver PEEP is unclear. The aim of this study was to measure the delivered PEEP at different set PEEP levels and inflation rates.
We connected disposable and non-disposable 240 mL Laerdal self-inflating resuscitation bags fitted with PEEP valves to a leak-free test lung. We measured PEEP delivered with the valve set at 5, 7 and 10 cm H(2)O whilst inflating the test lung at rates of 20, 40 and 60 min. Studies were done with 8 L/min of gas flow and with no gas flow.
The PEEP delivered was close to the set level immediately after inflation but declined rapidly between inflations. The mean PEEP was higher with faster ventilation rates. When PEEP was set at 7 cm H(2)O, using a non-disposable bag, and an inflation rate of 60/min the mean (SD) PEEP was 5.4 (0.19) cm H(2)O. The PEEP delivered was unrelated to the gas flow into the device.
The 240 mL Laerdal self-inflating bag with a PEEP valve delivers PEEP that loses pressure quickly. The level of PEEP delivered is less than that set, particularly at rates below 40/min.
自充气式气囊用于新生儿复苏时提供通气。然而,除非连接呼气末正压(PEEP)阀,否则它们无法提供呼气末正压。配备PEEP阀的Laerdal新生儿自充气式气囊能否可靠地提供PEEP尚不清楚。本研究的目的是测量在不同设定的PEEP水平和充气速率下输送的PEEP。
我们将配备PEEP阀的一次性和非一次性240 mL Laerdal自充气式复苏气囊连接到无泄漏测试肺上。我们在将测试肺以20、40和60次/分钟的速率充气时,测量将阀门设定在5、7和10 cmH₂O时输送的PEEP。在气体流速为8 L/分钟和无气体流速的情况下进行研究。
充气后立即输送的PEEP接近设定水平,但在两次充气之间迅速下降。通气速率越快,平均PEEP越高。当将PEEP设定为7 cmH₂O时,使用非一次性气囊,充气速率为60次/分钟,平均(标准差)PEEP为5.4(0.19)cmH₂O。输送的PEEP与进入设备的气体流速无关。
带有PEEP阀的240 mL Laerdal自充气式气囊输送的PEEP压力迅速下降。输送的PEEP水平低于设定水平,尤其是在速率低于40次/分钟时。