Louvaris Zafeiris, Spetsioti Stavroula, Andrianopoulos Vasileios, Chynkiamis Nikolaos, Habazettl Helmut, Wagner Harrieth, Zakynthinos Spyros, Wagner Peter D, Vogiatzis Ioannis
Faculty of Movement and Rehabilitation Sciences, Division of Respiratory Rehabilitation, Department Rehabilitation Sciences KU Leuven, University Hospitals Leuven, Leuven, Belgium.
1st Department of Critical Care Medicine and Pulmonary Services, GP Livanos and M Simou Laboratories, Medical School of Athens University, Evangelismos Hospital, Athens, Greece.
Clin Respir J. 2019 Apr;13(4):222-231. doi: 10.1111/crj.13002. Epub 2019 Feb 28.
Impedance cardiography (IC) derived from morphological analysis of the thoracic impedance signal is now commonly used for noninvasive assessment of cardiac output (CO) at rest and during exercise. However, in Chronic Obstructive Pulmonary Disease (COPD), conflicting findings put its accuracy into question.
We therefore compared concurrent CO measurements captured by IC (PhysioFlow: CO ) and by the indocyanine green dye dilution method (CO ) in patients with COPD.
Fifty paired CO measurements were concurrently obtained using the two methods from 10 patients (FEV : 50.5 ± 17.5% predicted) at rest and during cycling at 25%, 50%, 75% and 100% peak work rate.
From rest to peak exercise CO and CO were strongly correlated (r = 0.986, P < 0.001). The mean absolute and percentage differences between CO and CO were 1.08 L/min (limits of agreement (LoA): 0.05-2.11 L/min) and 18 ± 2%, respectively, with IC yielding systematically higher values. Bland-Altman analysis indicated that during exercise only 7 of the 50 paired measurements differed by more than 20%. When data were expressed as changes from rest, correlations and agreement between the two methods remained strong over the entire exercise range (r = 0.974, P < 0.001, with no significant difference: 0.19 L/min; LoA: -0.76 to 1.15 L/min). Oxygen uptake (VO ) and CO were linearly related: r = 0.893 (P < 0.001), CO = 5.94 × VO + 2.27 L/min. Similar results were obtained for VO and CO (r = 0.885, P < 0.001, CO = 6.00 × VO + 3.30 L/min).
These findings suggest that IC provides an acceptable CO measurement from rest to peak cycling exercise in patients with COPD.
通过对胸部阻抗信号进行形态学分析得出的阻抗心动图（IC），目前常用于静息和运动期间心输出量（CO）的无创评估。然而，在慢性阻塞性肺疾病（COPD）中，相互矛盾的研究结果对其准确性提出了质疑。
因此，我们比较了IC（PhysioFlow：CO）和吲哚菁绿染料稀释法（CO）在COPD患者中同时测量的CO值。
使用这两种方法，从10名患者（FEV：预测值的50.5 ± 17.5%）中同时获取了50对静息状态以及在25%、50%、75%和100%峰值工作率下骑行期间的CO测量值。
从静息到运动峰值，CO和CO高度相关（r = 0.986，P < 0.001）。CO和CO之间的平均绝对差值和百分比差值分别为1.08 L/分钟（一致性界限（LoA）：0.05 - 2.11 L/分钟）和18 ± 2%，IC得出的值系统性更高。Bland-Altman分析表明，运动期间50对测量值中只有7对的差值超过20%。当数据表示为相对于静息状态的变化时，两种方法在整个运动范围内的相关性和一致性仍然很强（r = 0.974，P < 0.001，无显著差异：0.19 L/分钟；LoA： - 0.76至1.15 L/分钟）。摄氧量（VO）与CO呈线性相关：r = 0.893（P < 0.001），CO = 5.94 × VO + 2.27 L/分钟。VO和CO也得到了类似的结果（r = 0.885，P < 0.001，CO = 6.00 × VO + 3.30 L/分钟）。
这些发现表明，IC在COPD患者从静息到骑行运动峰值期间能够提供可接受的心输出量测量值。
