Jellema W T, Wesseling K H, Groeneveld A B, Stoutenbeek C P, Thijs L G, van Lieshout J J
Department of Internal Medicine, Academic Medical Center, University of Amsterdam, The Netherlands.
Anesthesiology. 1999 May;90(5):1317-28. doi: 10.1097/00000542-199905000-00016.
To compare continuous cardiac output obtained by simulation of an aortic input impedance model to bolus injection thermodilution (TDCO) in critically ill patients with septic shock.
In an open study, mechanically ventilated patients with septic shock were monitored for 1 (32 patients), 2 (15 patients), or 3 (5 patients) days. The hemodynamic state was altered by varying the dosages of dopamine, norepinephrine, or dobutamine. TDCO was estimated 189 times as the series average of four automated phase-controlled injections of iced 5% glucose, spread equally over the ventilatory cycle. Continuous model-simulated cardiac output (MCO) was computed from radial or femoral artery pressure. On each day, the first TDCO value was used to calibrate the model.
TDCO ranged from 4.1 to 18.2 l/min. The bias (mean difference between MCO and TDCO) on the first day before calibration was -1.92 +/- 2.3 l/min (mean +/- SD; n = 32; 95% limits of agreement, -6.5 to 2.6 l/min). The bias increased at higher levels of cardiac output (P < 0.05). In 15 patients studied on two consecutive days, the precalibration ratio TDCO:MCO on day 1 was 1.39 +/- 0.28 (mean +/- SD) and did not change on day 2 (1.39 +/- 0.34). After calibration, the bias was -0.1 +/- 0.8 l/min with 82% of the comparisons (n = 112) < 1 l/min and 58% (n = 79) < 0.5 l/min, and independent of the level of cardiac output.
In mechanically ventilated patients with septic shock, changes in bolus TDCO are reflected by calibrated MCO over a range of cardiac output values. A single calibration of the model appears sufficient to monitor continuous cardiac output over a 2-day period with a bias of -0.1 +/- 0.8 l/min.
比较通过模拟主动脉输入阻抗模型获得的连续心输出量与脓毒性休克重症患者的团注热稀释法（TDCO）测量的心输出量。
在一项开放性研究中，对机械通气的脓毒性休克患者进行了1天（32例患者）、2天（15例患者）或3天（5例患者）的监测。通过改变多巴胺、去甲肾上腺素或多巴酚丁胺的剂量来改变血流动力学状态。TDCO通过对4次自动相位控制的5%冰葡萄糖注射进行系列平均估算得出，这些注射在呼吸周期中均匀分布，共估算了189次。连续的模型模拟心输出量（MCO）由桡动脉或股动脉压力计算得出。每天，第一个TDCO值用于校准模型。
TDCO范围为4.1至18.2升/分钟。校准前第一天的偏差（MCO与TDCO之间的平均差异）为-1.92±2.3升/分钟（平均值±标准差；n = 32；95%一致性界限，-6.5至2.6升/分钟）。在心输出量较高水平时偏差增加（P < 0.05）。在连续两天研究的15例患者中，第1天校准前TDCO:MCO比值为1.39±0.28（平均值±标准差），第2天未改变（1.39±0.34）。校准后，偏差为-0.1±0.8升/分钟，82%的比较结果（n = 112）<1升/分钟，58%（n = 79）<0.5升/分钟，且与心输出量水平无关。
在机械通气的脓毒性休克患者中，校准后的MCO在一定的心输出量值范围内反映了团注TDCO的变化。对模型进行一次校准似乎足以在2天内监测连续心输出量，偏差为-0.1±0.8升/分钟。
