Ban Koji, Kochi Kazuhiro, Imai Katsuhiko, Okada Kenji, Orihashi Kazumasa, Sueda Taijiro
Department of Surgery, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan.
Circ J. 2005 Jun;69(6):688-94. doi: 10.1253/circj.69.688.
To explore an alternative to the systemic vascular resistance index (SVRI) for monitoring peripheral circulation in patients in the intensive care unit (ICU), the resistive index (RI) in the upper extremity arteries was measured by using surface Doppler ultrasound.
The correlation between RI and vascular resistance was assessed in vitro using a vessel phantom in a Donovan-type mock circulation system. In addition, 15 ICU patients who had undergone open-heart surgery were studied. Mean arterial pressure, central venous pressure and cardiac output were measured 30 times at 10 min intervals after patients returned to the ICU following surgery, and the SVRI was calculated from these parameters. At the same time points, 3 parts of the upper extremity arteries (brachial artery in the cubital fossa (BA), radial artery at the wrist (RA), and radial artery at the anatomical snuffbox (SB)) were scanned by Doppler ultrasound, and the resistance index (RI) for each artery region was calculated. In vitro, RI increased with higher vascular resistance, exhibiting a significant correlation (r = 0.982, p < 0.0001). In vivo, the average incidence angles at the BA and RA were larger than 60 degrees , while that at the SB was only 11.5+/-10.8 degrees. The overall correlation between SVRI and RI for all patients was not significant for the BA or RA, but was significant for the SB (p < 0.0001). In individual patients, the correlation of SVRI with RI at the BA or RA was significant in 3 patients only, whereas significant correlation for the SB was observed in all patients. Doppler waveform analysis at the SB revealed diastolic flow reversal with increased SVRI.
Measurement at the SB provides an ideal ultrasound incidence angle for the measurement of blood flow velocity. Hence, RI measured in this way may serve as an indicator of peripheral vascular resistance, and may be effective for the evaluation of peripheral circulatory disturbance.
为探索一种替代全身血管阻力指数（SVRI）来监测重症监护病房（ICU）患者外周循环的方法，采用表面多普勒超声测量上肢动脉的阻力指数（RI）。
在多诺万型模拟循环系统中使用血管模型在体外评估RI与血管阻力之间的相关性。此外，对15例接受心脏直视手术的ICU患者进行了研究。患者术后返回ICU后，每隔10分钟测量平均动脉压、中心静脉压和心输出量30次，并根据这些参数计算SVRI。在同一时间点，用多普勒超声扫描上肢动脉的3个部位（肘窝肱动脉（BA）、腕部桡动脉（RA）和解剖鼻烟窝桡动脉（SB）），并计算每个动脉区域的阻力指数（RI）。在体外，RI随血管阻力升高而增加，呈现显著相关性（r = 0.982，p < 0.0001）。在体内，BA和RA处的平均入射角大于60度，而SB处仅为11.5±10.8度。所有患者中，BA或RA处的SVRI与RI之间的总体相关性不显著，但SB处显著（p < 0.0001）。在个体患者中，仅3例患者BA或RA处的SVRI与RI具有显著相关性，而所有患者SB处均观察到显著相关性。SB处的多普勒波形分析显示，随着SVRI增加出现舒张期血流逆转。
在SB处测量可为血流速度测量提供理想的超声入射角。因此，以这种方式测量的RI可作为外周血管阻力的指标，可能对评估外周循环障碍有效。
