Department of Woman and Child Health, Medical School, University of Padua, Azienda Ospedaliera Padova, Via Giustiniani, 3, 35128 Padua, Italy.
Pediatrics. 2013 Apr;131(4):e1144-9. doi: 10.1542/peds.2012-3116. Epub 2013 Mar 25.
We evaluated the effect of oxygen (O₂) flow rate on the corresponding delivered fraction of oxygen (FiO₂) during positive pressure ventilation (PPV) when using a neonatal self-inflating bag (SIB).
Fifteen health care professionals administered PPV at a respiratory rate of 40 to 60 breaths per minute and at peak inspiratory pressures of 25 and 35 cm H₂O to a manikin by using a SIB with reservoir connected to an O₂ source equipped with a flowmeter (flow rates: 0-10 L/min). The FiO₂ corresponding to each flow rate was measured at the inflow to the facial mask for 60 seconds.
In total, 2520 FiO₂ data points were collected. At every O₂ flow rate, the FiO₂ gradually increased from time 0 seconds to time 60 seconds, both at 25 cm H₂O and at 35 cm H₂O. After 1 minute of PPV at 25 cm H₂O, the delivered FiO₂ was 31.5% ± 2.1% and 43.1% ± 3.1% at O₂ flow rates of 0.1 and 0.5 L/min, respectively. After 1 minute of PPV at 35 cm H₂O, the delivered FiO₂ was 29.4% ± 2.0% and 42.1% ± 4.6% at O₂ flow rates of 0.1 and 0.5 L/min, respectively. At all O₂ flow rates >5 L/min, the delivered FiO₂ was >85% and >95%, after 1 minute of PPV at 25 and 35 cm H₂O, respectively.
Delivered FiO₂ during PPV depends on 3 factors: oxygen flow rate, peak inspiratory pressures, and time elapsed. These data can be used to develop a scheme correlating the oxygen flow rate and the corresponding delivered FiO₂ when using a neonatal SIB.
我们评估了在使用带有贮气袋的新生儿复苏气囊（SIB）进行正压通气（PPV）时，不同氧流量对相应吸入氧分数（FiO₂）的影响。
15 名医护人员以 40 至 60 次/分钟的呼吸频率，对复苏气囊连接到一个带有流量计（流速：0-10 L/min）的氧气源的模型，在峰压 25 和 35 cmH₂O 时进行 PPV。在面罩入口处测量每个流量下 60 秒的 FiO₂。
共收集到 2520 个 FiO₂数据点。在每个 O₂流量下，FiO₂在 0 秒至 60 秒的时间内逐渐增加，在 25 cmH₂O 和 35 cmH₂O 时均如此。在峰压 25 cmH₂O 时行 1 分钟的 PPV 后，O₂流速为 0.1 和 0.5 L/min 时，输送的 FiO₂分别为 31.5%±2.1%和 43.1%±3.1%。在峰压 35 cmH₂O 时行 1 分钟的 PPV 后，O₂流速为 0.1 和 0.5 L/min 时，输送的 FiO₂分别为 29.4%±2.0%和 42.1%±4.6%。在所有 O₂流速＞5 L/min 时，在峰压 25 和 35 cmH₂O 时行 1 分钟的 PPV 后，输送的 FiO₂分别＞85%和＞95%。
PPV 时输送的 FiO₂取决于 3 个因素：氧流量、峰压和经过的时间。这些数据可用于制定一个方案，当使用新生儿 SIB 时，该方案可关联氧气流量和相应的输送 FiO₂。
