ABSTRACT
INTRODUCTION: The purpose of positioning is to allow the procedure to be performed as simply as possible and to achieve the best possible results free of complications. In a normal person, many investigators have researched the hemodynamic changes during positional adjustments. But the delicate qualitative hemodynamic changes in various positions has not been recorded very much. So we studied the qualitative hemodynamic changes in various positions with a noninvasive bioimpedance method. METHOD: Healthy adult males were studied (n=25). The protocol was that the position changed from supine to head-up, head-down, lithotomy, sitting, right-lateral, prone and Jackknife (J-K) position. Each position was sustained for three minutes. The mean arterial pressure (MAP), heart rates (HR), left cardiac work index (LCWI), systemic vascular resistance index (SVRI), cardiac index (CI), stroke index (SI) and end diastolic index (EDI) were measured with the bioimpedance method and an automated blood pressure device. Result: The contractility of heart expressed by LCWI, CI and SI decreased in head-down, sitting, right-lateral, prone and J-K positions. The preload expressed by EDI decreased in right-lateral and J-K positions. The afterload expressed by SVRI increased in sitting, prone and J-K positions, and decreased in right-lateral position. CONCLUSIONS: These results may be used as reference for anesthesiologist managing many patients of various physical status.