心衰患者动脉血气波浪式变化及其幅度降低的初步实验证据

Evidence of waveform information in arterial blood gas by beat-by-beat sampling method in patients with heart failure

目的:心力衰竭患者呼吸调控异常的机制众说纷纭,特别是动脉血气周期性波浪式变化信号的改变及其与心功能的关系尚缺乏直接的试验证据。本文依据心力衰竭患者动脉血气周期性波浪式变化信号的降低幅度,探讨心力衰竭导致呼吸调控异常的机制。方法:选择5名心力衰竭患者,连续桡动脉逐搏取血,测定PaO2,Pa CO2,p Ha和SaO2。选取2个典型呼吸周期,用于分析动脉血气的波浪式变化。比较患者相邻最高和最低值,以验证是否存在周期性波浪式信号变化。此外,将心力衰竭患者与心功能正常患者动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:心力衰竭患者包括2例外科手术和3例ICU住院监护患者,4男1女,年龄(69±7)岁,身高(169±10)cm,体质量(75±19)kg,左心射血分数(LVEF)=(38±3)%。动脉血液充满肝素化细长塑化管需要17±2次心跳,即取血需要17±2次心跳,覆盖超过2个呼吸周期。心力衰竭患者PaO2,Pa CO2,[H+]a和SaO2均呈现明显的波浪式变化(P<0.05),幅度分别是(7.94±2.02)mm Hg,(1.18±0.56)mm Hg,(0.54±0.17)nmol/L和(0.21±0.07)%,分别是各自均值的(6.1±1.5)%,(3.2±1.5)%,(1.5±0.5)%和(0.2±0.1)%。与心功能正常患者比较,动脉血气波浪式变化幅度呈现明显降低趋势,但仅PaO2和[H+]a有明显统计学差异(P<0.05)。结论:采用连续逐搏动脉取血血气分析法证实,心力衰竭患者自主呼吸时动脉血气也有周期性波浪式变化信号,但其变化幅度较心功能正常患者明显降低。

Objective： We investigate the magnitudes of waveform changes of arterial blood gas （ABG） in patients with heart failure. Methods： Five patients with heart failure were selected, continuous collecting radial artery blood and measured PaO2, PaCO2, pHa and SaO2. We selected two typical breaths cycles of waveform changes of ABG from each patient for data analysis. Comparison of the adjacent highest and lowest values to verify the presence of a periodic waveform changes of ABG, and in addition, we used t test to analysis the range of waveform changes of ABG in patients with heart failure and patients with normal cardiac function and compared whether the difference between them. Results： The 5 patients （2 surgical and 3 ICU） with heart failure, were 4 male and 1 female, （69±7）year, （169±10） cm, （75±19）kg, LVEF=（38＋3）%. The heart beat numbers for full blood into the blood sampling pipe were 17±2, and all covered more than 2 breath cycles. There were significant changes of PaO2, PaCO2, [H＋]a and SaOE（P〈0.05）. The magnitudes of changing PaO2, PaCO2, [H＋]a and SaO2 were （7.94_＋2.02）mmHg, （1.18_＋0.56）mmHg, （0.54_＋0.17）nmol/ L and （0.21±0.07）%, and they were （6.1±1.5）%, （3.2±1.5）%, （1.5±0.5）% and （0.2±0.1）% from their mean respectively. Even these magnitudes fo all ABG parameters were trendily lower than those of patients with normal cardiac function, but only PaO2 and [H＋]a were significant （P〈0.05）. Conclusion： Using this simple continuous beat-by-beat arterial blood sampling method, we obtained a clear evidence of periodic waveform of ABG parameters following by breath cycle in patients with heart failure, but the magnitude trendily be decreased.