Barends Clemens R M, Yavuz Pembegul, Molenbuur Bouwe, Absalom Anthony R
Department of Anesthesiology, University of Groningen and University Medical Center Groningen, Groningen, The Netherland.
Paediatr Anaesth. 2018 Dec;28(12):1142-1147. doi: 10.1111/pan.13515. Epub 2018 Oct 29.
Providing supplemental oxygen with a blow-by method is used to provide additional oxygen to patients who will not tolerate an oxygen delivery device in direct contact with their face. Blow-by methods are often improvised from parts of standard equipment. The performance is very dependent on the distance to the face and the direction of the gas flow. Blow-by methods are used by anesthetists during transport but their performance in delivering supplemental oxygen has only been tested in static situations. The aim of this nonclinical study was to determine the performance of different blow-by methods in the delivery of additional oxygen to pediatric patients during transport.
A manikin of a child with a facemask of appropriate size was transported along a 60 m corridor from the operating theater to the PACU. Oxygen delivery to the face of the manikin was measured during transport. Six blow-by methods were tested with oxygen flows of 3, 6, and 10 L/min and with the facemask at 0 cm from the face and at 5 cm from the face. The outcome parameter was: blow-by method reaching and maintaining an FiO >50% during transport from the pediatric operating theater to the PACU.
At 0 cm from the face, five out of six blow-by methods maintained a FiO >50% with all three flow rates. At 5 cm only two of the blow-by methods were able to maintain an FiO >50% and this only at flow rates of 10 L/min. All other blow-by methods provided lower FiO s; in three, the FiO decreased to values only marginally above 21%. The decrease in FiO typically started within 6-12 m from the start of the transport.
It is concluded that the ability of blow-by methods to deliver a FiO >50% depends on the method used and distance from the face.
采用吹氧法提供补充氧气，用于给无法耐受与面部直接接触的输氧设备的患者额外供氧。吹氧法通常是用标准设备的部件临时拼凑而成。其性能非常依赖于与面部的距离和气流方向。麻醉师在转运过程中会使用吹氧法，但在输送补充氧气方面的性能仅在静态情况下进行过测试。这项非临床研究的目的是确定不同吹氧法在转运过程中给儿科患者输送额外氧气的性能。
一个佩戴合适尺寸面罩的儿童人体模型沿着一条60米长的走廊从手术室转运至麻醉后监护室。在转运过程中测量输送至人体模型面部的氧气量。测试了六种吹氧法，氧气流量分别为3升/分钟、6升/分钟和10升/分钟，面罩与面部的距离分别为0厘米和5厘米。结果参数为：在从儿科手术室转运至麻醉后监护室的过程中，吹氧法达到并维持FiO>50%。
在面罩与面部距离为0厘米时，六种吹氧法中有五种在所有三种流量下都能维持FiO>50%。在距离为5厘米时，只有两种吹氧法能够维持FiO>50%，且仅在流量为10升/分钟时。所有其他吹氧法提供的FiO较低；其中三种方法的FiO降至仅略高于21%的值。FiO的下降通常在转运开始后的6至12米内开始。
得出的结论是，吹氧法输送FiO>50%的能力取决于所使用的方法和与面部的距离。
