Doering L, Dracup K
Cedar-Sinai Medical Center, Los Angeles.
Nurs Res. 1988 Mar-Apr;37(2):114-8.
Cardiac output was measured by thermodilution in 51 adult postcardiac surgical patients using three positions, supine, right lateral, and left lateral, each with 20 degrees backrest elevation. Measurements were taken 4 to 24 hours (M = 10.58) after surgery. Mean cardiac output was significantly different in the three positions, p = .03. This difference resulted from changes in stroke volume, p = .004, rather than changes in heart rate, p = .12. The largest variation occurred between cardiac outputs measured in the supine position and those measured in the left lateral position. Patients at greatest risk for variations in cardiac output with lateral postural change were those with a cardiac index less than 2.3 L/min/m2, those in whom the time elapsed since surgery was less than 12 hours, and those receiving either vasoactive drugs or mechanical ventilation. These results suggest that nurses need to measure cardiac output using a supine position to control for physiological changes that may occur with lateral postural change.
采用热稀释法，对51名心脏外科术后成年患者在三个体位（仰卧位、右侧卧位和左侧卧位，每个体位均将靠背抬高20度）下测量心输出量。测量在术后4至24小时（平均为10.58小时）进行。三个体位下心输出量均值存在显著差异，p = 0.03。这种差异是由每搏输出量的变化导致的，p = 0.004，而非心率变化，p = 0.12。仰卧位和左侧卧位测量的心输出量之间差异最大。心输出量随体位变化差异最大的患者是心脏指数低于2.3L/min/m²的患者、术后时间少于12小时的患者以及接受血管活性药物或机械通气的患者。这些结果表明，护士需要采用仰卧位测量心输出量，以控制因体位变化可能发生的生理改变。
