Kemps Hareld M C, Thijssen Eric J M, Schep Goof, Sleutjes Boudewijn T H M, De Vries Wouter R, Hoogeveen Adwin R, Wijn Pieter F F, Doevendans Pieter A F M
Dept. of Sports Medicine, Máxima Medical Centre, P.O. Box 7777, 5500 MB Veldhoven, The Netherlands.
J Appl Physiol (1985). 2008 Dec;105(6):1822-9. doi: 10.1152/japplphysiol.90430.2008. Epub 2008 Oct 23.
The purpose of this study was to evaluate the accuracy of two techniques for the continuous assessment of cardiac output in patients with chronic heart failure (CHF): a radial artery pulse contour analysis method that uses an indicator dilution method for calibration (LiDCO) and an impedance cardiography technique (Physioflow), using the Fick method as a reference. Ten male CHF patients (New York Heart Association class II-III) were included. At rest, cardiac output values obtained by LiDCO and Physioflow were compared with those of the direct Fick method. During exercise, the continuous Fick method was used as a reference. Exercise, performed on a cycle ergometer in upright position, consisted of two constant-load tests at 30% and 80% of the ventilatory threshold and a symptom-limited maximal test. Both at rest and during exercise LiDCO showed good agreement with reference values [bias +/- limits of agreement (LOA), -1% +/- 28% and 2% +/- 28%, respectively]. In contrast, Physioflow overestimated reference values both at rest and during exercise (bias +/- LOA, 48% +/- 60% and 48% +/- 52%, respectively). Exercise-related within-patient changes of cardiac output, expressed as a percent change, showed for both techniques clinically acceptable agreement with reference values (bias +/- LOA: 2% +/- 26% for LiDCO, and -2% +/- 36% for Physioflow, respectively). In conclusion, although the limits of agreement with the Fick method are pretty broad, LiDCO provides accurate measurements of cardiac output during rest and exercise in CHF patients. Although Physioflow overestimates cardiac output, this method may still be useful to estimate relative changes during exercise.
本研究的目的是评估两种用于持续评估慢性心力衰竭（CHF）患者心输出量的技术的准确性：一种采用指示剂稀释法进行校准的桡动脉脉搏轮廓分析方法（LiDCO）和一种阻抗心动图技术（Physioflow），以Fick法作为参考。纳入了10名男性CHF患者（纽约心脏协会II-III级）。在静息状态下，将LiDCO和Physioflow获得的心输出量值与直接Fick法的值进行比较。在运动期间，采用连续Fick法作为参考。在直立位的自行车测力计上进行的运动包括两次分别为通气阈值30%和80%的恒负荷试验以及一次症状限制最大试验。在静息和运动期间，LiDCO与参考值均显示出良好的一致性[偏差±一致性界限（LOA），分别为-1%±28%和2%±28%]。相比之下，Physioflow在静息和运动期间均高估了参考值（偏差±LOA，分别为48%±60%和48%±52%）。以百分比变化表示的与运动相关的患者心输出量变化，两种技术与参考值在临床上均显示出可接受的一致性（偏差±LOA：LiDCO为2%±26%，Physioflow为-2%±36%）。总之，尽管与Fick法的一致性界限相当宽，但LiDCO可准确测量CHF患者静息和运动期间的心输出量。虽然Physioflow高估了心输出量，但该方法仍可能有助于估计运动期间的相对变化。
