经双腔鼻导管吸氧时吸入氧浓度波形的变化

目的 研究实际吸入氧浓度的波形及吸气流速、呼吸频率对其影响。方法 选择健康受试者16例,经双腔鼻导管吸氧,随机平静呼吸或模拟快呼吸、慢呼吸,同步测量氧浓度。结果 吸气开始时氧浓度陡升,吸气中期下降,呼气前观察到第二个上升波,常常形成M形吸入氧浓度波形,呼气期刚开始时氧浓度下降速度较快,后渐减慢,呼气后期氧浓度波形为一平台。不同呼吸形式时氧浓度曲线变异较大。结论 经双腔鼻导管吸氧时,常常形成M形吸入氧浓度波形。吸气流速越大,呼吸频率越快,FOI2越小。

Objective To evaluate the waveform of the inspired oxygen concentration（FIO2） and the effect of inspiration flow rate and respiratory frequency on it. Methods 16 normal subjects were enrolled. The subjects were asked to respire quietly or mimic slow respiration or fast respiration randomly. Oxygen concentration was measured in real time. Results The oxygen concentration ascended sharply at the onset of inspiration, and then decreased in the mid-inspiration, and a second upward wave could be observed, and that formed a M-shape waveform of the oxygen concentration of inspiration. The oxygen concentration declined swiftly when expiration started, and then slower gradually, finally a platform could be observed at the later period of expiration. The waveform of the oxygen concentration changed greatly in different respiratory mode. Conclusion A M-shape waveform of the oxygen concentration of inspiration could be observed when the subjects were received oxygen therapy via nasal cannulas simply. The faster the inspiration flow rate and the respiratory frequency, the lower the inspired oxygen concentration.