Air‐oxygen
Air‐oxygen
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空气-氧气
DOI：
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发表时间：
1987
期刊：
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通讯作者：
D. White
中科院分区：
文献类型：
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作者：
D. White
仅评价其设计的封闭系统麻醉循环器。在我们的结论中，我们指出，它提供了独立的控制Vr，通气频率。1：E比率和PEEP，并且如果发生自主呼吸，它将与患者同步。据我们所知，我们研究的型号预期不用作CPAP器械或SIMV模式。詹姆斯博士的评论可能与制造商的声明有关，但它们并不反映我们论文的内容。我们认为，这台机器是一个有趣的新的dcvclopmcnt机械通气在封闭系统麻醉。在测量潮气量时考虑了新鲜气体流量（FGF）的贡献。IPPV时用F-G-F测定的气道压力反映了V_1的降低。当在气管导管中供应FGF时，在吸气阶段，波纹管的冲程体积必须比FGF的贡献减少更多，以保持相对恒定的Pac'oz。发表这种测量Vl的操作细节被认为是不必要的。这包括调节关闭FGF的风箱的峰值气道容积。这是必要的，不仅测量的V，但也潮气末CO，浓度。参照图3，在呼气相的最后一部分，如果没有肺泡气中的CO2混合，FGF也会发生变化。在1：2的1：E比的I2 brcathsiminutc下，预计该时间段约为1-1.5秒。包括气管导管在内的装置死腔约为80 ml，因此，在1秒的时间内，FGF为4。2升/分钟和1升/分钟分别只能冲洗大约67、33和17毫升。这是一个复杂的情况，FGF的有效贡献主要取决于呼气肺泡气体流的模式及其组成、装置的dcadspacc容量和FCiF速率。有一个基本的情况，即用新鲜气体清除气管导管死腔将提高通气效率，因此需要较小的V1。从来没有。我们的研究表明，在这些vcn！迭代频率，即12次/分钟。通过使系统复杂化而不是以制造商推荐的方式在机器处供应新鲜气体，
evaluation solely a5 a closed system anaesthetic vcntilator as which it was designed. In our conclusions we indicated that i t provided independcnt controls for Vr, ventilation frequency. 1 : E ratio arid PEEP and that i t would synchronise with the patient if spontaneous breathing occurred. The model we studied was, as far as we are aware, not intended for use as a CPAP device or in an SIMV mode. It is possible that Dr James' commcnts are rclcvant to claims by the manufacturers hut they do not reflect the content of our paper. Our view of this machine is that i t is an interesting new dcvclopmcnt for mechanical ventilation during closed system anaesthesia. The contribution of the frcsh gas flow (FGF) during thc measurement of tidal volume (V,) was taken into account. The airway pressures ivhich were measured with the F G F flowing during IPPV reflect the decrease in thc V , . Whcn the FGF was supplied in the tracheal tube the stroke volumc of the bellows had to be reduccd more than the contribution of the F G F during the inspiratory phase to maintain a relatively constant Pac'oz. I t was not considered csscntial to publish the details of this manoeuvre for the measurement of V l . This consisted of adjusting the peak airway volume of thc bellows whcn thc FGF was switched off. This was necessary for the measurement not only of the V, but also the end tidal CO, concentration. Refcrcnce to thc tlow pattern (Fig. 3 in our article) shows that the F G F would scavenge without C 0 2 mixing from alveolar gar during the Last part of the expiratory phase. At I2 brcathsiminutc with an 1 : E ratio of 1 :2, approximatcly 1-1.5 seconds would be expected for this period. The apparatus deadspace including the tracheal tube was approximatcly 80 ml; therefore, during periods of say I second, FGF at 4. 2 and 1 litres/minute can flush only approximately 67, 3 3 and 17 ml, respectively. It is a complex situation and thc cffcctivc contribution of F G F depends mainly on the pattern of the expiratory alveolar gas flow and its composition, thc apparatus dcadspacc volumc and the FCiF rate. There is a prirno .fizcie case that removal of thc tracheal tube deadspace by scavcnging with fresh gas will improve the efficiency of ventilation and hence require a smaller V , . Hou,ever. our study shows that at these vcn!ilation frcquencics, i.e. 12 brcaths/minutc. there is little advantage to be gained by complicating the system rather than supplying the fresh gas at the machine in a manner recommended by the manufacturers