Allen Scott G, Brewer Lara, Gillis Erik S, Pace Nathan L, Sakata Derek J, Orr Joseph A
Department of Anesthesiology, University of Utah, Salt Lake City, Utah.
Physician Assistant School at Duke University, Durham, North Carolina.
Respir Care. 2017 Sep;62(9):1166-1170. doi: 10.4187/respcare.05368. Epub 2017 Aug 14.
Research has shown that increased breathing frequency during cardiopulmonary resuscitation is inversely correlated with systolic blood pressure. Rescuers often hyperventilate during cardiopulmonary resuscitation (CPR). Current American Heart Association advanced cardiac life support recommends a ventilation rate of 8-10 breaths/min. We hypothesized that a small, turbine-driven ventilator would allow rescuers to adhere more closely to advanced cardiac life support (ACLS) guidelines.
Twenty-four ACLS-certified health-care professionals were paired into groups of 2. Each team performed 4 randomized rounds of 2-min cycles of CPR on an intubated mannikin, with individuals altering between compressions and breaths. Two rounds of CPR were performed with a self-inflating bag, and 2 rounds were with the ventilator. The ventilator was set to deliver 8 breaths/min, pressure limit 22 cm HO. Frequency, tidal volume (V), peak inspiratory pressure, and compression interruptions (hands-off time) were recorded. Data were analyzed with a linear mixed model and Welch 2-sample test.
The median (interquartile range [IQR]) frequency with the ventilator was 7.98 (7.98-7.99) breaths/min. Median (IQR) frequency with the self-inflating bag was 9.5 (8.2-10.7) breaths/min. Median (IQR) ventilator V was 0.5 (0.5-0.5) L. Median (IQR) self-inflating bag V was 0.6 (0.5-0.7) L. Median (IQR) ventilator peak inspiratory pressure was 22 (22-22) cm HO. Median (IQR) self-inflating bag peak inspiratory pressure was 30 (27-35) cm HO. Mean ± SD hands-off times for ventilator and self-inflating bag were 5.25 ± 2.11 and 6.41 ± 1.45 s, respectively.
When compared with a ventilator, volunteers ventilated with a self-inflating bag within ACLS guidelines. However, volunteers ventilated with increased variation, at higher V levels, and at higher peak pressures with the self-inflating bag. Hands-off time was also significantly lower with the ventilator. (ClinicalTrials.gov registration NCT02743299.).
研究表明，心肺复苏期间呼吸频率增加与收缩压呈负相关。救援人员在心肺复苏（CPR）过程中经常过度通气。美国心脏协会目前的高级心血管生命支持建议通气频率为8 - 10次/分钟。我们假设，一种小型涡轮驱动呼吸机将使救援人员更严格地遵守高级心血管生命支持（ACLS）指南。
24名获得ACLS认证的医护专业人员两两配对。每个团队在一个插管人体模型上进行4轮随机的2分钟CPR周期，人员在按压和呼吸之间交替。两轮CPR使用自动充气式复苏气囊进行，另外两轮使用呼吸机。呼吸机设置为每分钟送气8次，压力限制为22厘米水柱。记录频率、潮气量（V）、吸气峰压和按压中断时间（松开时间）。数据采用线性混合模型和韦尔奇两样本检验进行分析。
使用呼吸机时的频率中位数（四分位间距[IQR]）为7.98（7.98 - 7.99）次/分钟。使用自动充气式复苏气囊时的频率中位数（IQR）为9.5（8.2 - 10.7）次/分钟。呼吸机的潮气量中位数（IQR）为0.5（0.5 - 0.5）升。自动充气式复苏气囊的潮气量中位数（IQR）为0.6（0.5 - 0.7）升。呼吸机的吸气峰压中位数（IQR）为22（22 - 22）厘米水柱。自动充气式复苏气囊的吸气峰压中位数（IQR）为30（27 - 35）厘米水柱。呼吸机和自动充气式复苏气囊的平均±标准差松开时间分别为5.25±2.11秒和6.41±1.45秒。
与呼吸机相比，志愿者使用自动充气式复苏气囊时通气符合ACLS指南。然而，志愿者使用自动充气式复苏气囊时通气的变异性更大、潮气量更高、吸气峰压更高。使用呼吸机时的松开时间也显著更短。（ClinicalTrials.gov注册号NCT02743299。）
