人体通气状态对动脉血气波浪式幅度的影响*

目的: 本研究旨在发现不同通气模式下动脉血气的变化特点。方法: 选择心功能正常,需要连续监测动脉血流动力学变化的患者6 例,4男2女,年龄（59.00±16.64）岁,体质量（71.67±10.37）kg,左心射血分数（LVEF）（61.33±2.16）%。患者签署知情同意书后,分别于正常呼吸、憋气20 s以及高潮气量过度通气状态下连续15~16次心跳桡动脉、颈静脉逐搏取血,测定PO₂,用于分析三种呼吸状态下动、静脉血气的变化特点。分别比较患者相邻最高和最低值,以验证三种呼吸状态下动、静脉血气是否都存在周期性波浪式信号变化;此外,将患者动、静脉血气周期性波浪式信号的变化幅度进行统计学t检验分析,比较有无差异。结果: 共6例ICU 住院监护患者, 抽取动、静脉血液充满肝素化细长塑化管需要15~16次心跳,即取血需要15~16次心跳,全部覆盖超过2个呼吸周期。患者正常呼吸、憋气20 s以及高潮气量通气状态下动脉血气中PaO₂呈现波浪式变化,幅度分别是（9.96±5.18）mmHg,（5.33±1.55）mmHg和（13.13±7.55）mmHg,分别是各自均值的（8.09±2.43）%,（5.29±2.19）%,（10.40±2.68）%,高通气量呼吸模式波浪式变化幅度大于正常呼吸模式（P<0.05）,正常呼吸模式波浪式变化幅度大于憋气状态（P<0.05）。正常呼吸、憋气20 s以及高潮气量通气状态下静脉血气中PO₂未呈现波浪式变化,幅度分别是（1.63±0.41）mmHg,（1.13±0.41）mmHg和（1.31±0.67）mmHg,分别是各自均值的（3.91±1.22）%,（2.92±1.12）%,（3.33±1.81）%,都显著低于同状态下动脉血气,但组间差异不明显。结论: 分别于三种通气状态下采用连续逐搏动脉取血血气分析法证实,患者高通气状态呼吸时动脉血气的周期性波浪式变化信号增强,憋气时波浪式呼吸变化信号变弱,而静脉血氧分压波浪式变化幅度于三种呼吸状态下都不明显。说明肺通气导致肺换气是影响动脉血液波浪式信号幅度的直接决定性因素。

The effectiveness of different respiration models to the amplitude of waveform information in arterial blood gas

Objective: The objective is to find the characteristics of arterial blood sample waveform in different respiration models. Methods: Six post-operative patients with normal heart function and negative Allen test, were 4 male and 2 female, (59.00±16.64)year, (71.67±0.37)kg, left ventricular ejection fraction(LVEF) (61.33±2.16)%, had been placed the arterial catheterization and central venous catheterization for continuous collecting arterial in 3 different kinds of respiration models: normal breathing, no breathing and deep breathing. We selected two breaths cycles of waveform from each patient for data calculations of magnitudes and time interval. Compare the adjacent highest and lowest values of patients to verify whether there are periodic wave-like signal changes in arterial and venous blood gas in the three breathing states. In addition, statistical t-test analysis was performed on the change amplitude of the periodic wave-like signal of the patient's arterial and venous blood gas to compare whether there is a difference. Results: The heart beat numbers for drawing blood into pipe were 15-16, and all covered more than 2 breathing cycles. There were significant changes of arterial PaO₂ (i.e. the highest high values compare to the next lowest values, P<0.05) in three different breathing models(normal, no breathing and high breathing), the magnitudes of which were (9.96±5.18)mmHg, (5.33±1.55)mmHg and (13.13±7.55)mmHg, with (8.09±2.43)%, (5.29±2.19)% and (10.40±2.68)% from their mean respectively. PO₂ in venous blood gas did not show wavy changes under normal breathing, 20 s breath holding and high tidal volume ventilation. The amplitudes were (1.63 ± 0.41) mmHg, (1.13 ± 0.41) mmHg and (1.31 ± 0.67) mmHg, which were (3.91 ± 1.22)%, (2.92 ± 1.12)%, (3.33 ± 1.81)%, respectively, which were significantly lower than that of arterial blood gas under the same state, but there was no significant difference between groups. Conclusion: With continuous beat-by-beat arterial blood sampling and ABG analyzing method in three different breathing models, We obtain a clear evidence of the biggest periodic parameters ABG waveform in high breathing models, which followed by normal breathing models, no breathing was the smallest, and the wave variation amplitude of venous oxygen partial pressure was not obvious in the three respiratory states, which implies the oscillatory information of the arterial blood with comes from the gas exchanging in the lung.