Park Y K, Hidaka A
Department of Obstetrics and Gynecology, Osaka City University School of Medicine.
Nihon Sanka Fujinka Gakkai Zasshi. 1991 Jun;43(6):647-54.
In order to prove the usefulness of the left-lateral position (l-lat.) in preventing the cardiovascular complications associated with ritodrine, twenty-nine patients having preterm labor were employed as the subjects of this study. Before and during the administration of ritodrine, the cardiac function was recorded by impedance cardiography. (1) When ritodrine was administered in the supine position, SV and CO first increased but eventually tended to decrease. When the position was changed to the l-lat. after SV and CO had almost returned to the preadministration level, HR decreased and SV and CO increased in 70% (10/14) of the patients. However, in patients showing no change in HR in the supine position, the cardiac function did not change either. (2) The magnitude of the changes in cardiac function accompanying the postural change during ritodrine administration was compared with that observed before administration. The decrease in HR and the increase in SV due to the postural change to the l-lat. were larger during ritodrine administration than before administration. The l-lat. position is recommended as a means for preventing the side effects accompanying ritodrine administration. This study also indicated the possibility that the inferior vena cava may be more strongly compressed in the supine position by the relaxed gravid uterus.
为了证明左侧卧位（l-lat.）在预防与利托君相关的心血管并发症方面的有效性，本研究以29例早产患者为研究对象。在使用利托君之前和期间，通过阻抗心动图记录心功能。（1）当在仰卧位使用利托君时，每搏输出量（SV）和心输出量（CO）首先增加，但最终趋于下降。当SV和CO几乎恢复到用药前水平后将体位改为左侧卧位时，70%（10/14）的患者心率下降，SV和CO增加。然而，在仰卧位时心率无变化的患者中，心功能也没有改变。（2）将使用利托君期间体位改变时伴随的心功能变化幅度与用药前观察到的变化幅度进行比较。在使用利托君期间，由于体位改为左侧卧位导致的心率下降和SV增加比用药前更大。推荐左侧卧位作为预防利托君用药副作用的一种方法。本研究还表明，在仰卧位时，松弛的妊娠子宫可能会更强烈地压迫下腔静脉。
