Effects of different posture on hemodynamics and plasma atrial natriuretic polypeptide during laparoscopic surgery

Abstract

Objective To observe the effects of different posture on hemodynamics and plasma atrial natriuretic polypeptide(ANP) during laparoscopic surgery. Methods Forty patients who scheduled for elective laparoscopic surgery under general anesthesia were allocated into two groups according to their posture during laparoscopic surgery,20 cases for each group. In group A, the patients were arranged in a head-down tilt position, in group B, the patients were arranged in a head-up tilt position systolic blood pressure (SBP),diastolic blood pressure (DBP),central venous pressure (CVP) and electro cardio gram (ECC) were monitored continuously. Blood samples were taken from central venous at four time points of prepneumoperitoneum(T1), 10 minutes after that(T2) and 20 mintues(T3) when the patients were arranged at the different operation-needed position with a stable pneumoperitoneum pressure of 14 mm Hg (1 mm Hg = 0.133 kPa),and at 5 minutes (T4) after deflation of pneumoperitoneum when the patients returned to supine position. The plasma ANP was assessed by radioimmunoassay. Results In group A,the CVP at T2 and T3 [(14.45 ±2.72),(14.20 ±2.46) mm Hg] was significantly higher than that at T1 [(6.05 ±1.76) mm Hg] (P<0.01), in group B,the CVP at T2 and T3 [(8.90±1.27),(9.02 ±0.47) mm Hg] was significantly higher than that at T1[(6.30 ±1.34) mm Hg](P< 0.01) ,with a higher level in group A than those in group B at the same time point during pneumoperitoneum(P< 0.01). The ANP level in group A was higher at T2 than that at T1, and there was significantly higher at T3 than that at T1 (P < 0.05). But the ANP level was significantly higher in group A than that in group B at the same time points of T2 and T3 (P < 0.05). Conclusion The posture may have obvious effect on CVP and plasma ANP level during laparoscopic surgery. Key words: Anaesthesia,general; Pneumoperitoneum,artificial; Posture; Central Venous pressure; Atrial natriuretic factor