Patients with cirrhosis have a hyperdynamic circulation and an abnormal blood volume distribution with central hypovolemia, an activated sympathetic nervous s ystem (SNS) as well as the renin-angiotensin-aldosterone s...Patients with cirrhosis have a hyperdynamic circulation and an abnormal blood volume distribution with central hypovolemia, an activated sympathetic nervous s ystem (SNS) as well as the renin-angiotensin-aldosterone system (RAAS). As the hyperdynamic circulation in cirrhosis may be present only in the supine patient , we studied the humoral and central hemodynamic responses to changes with postu re. Twenty-three patients with alcoholic cirrhosis (Child-Turcotte-Pugh class es A/B/C: 2/13/8) and 14 healthy controls were entered. Measurements of central hemodynamics and activation of SNS and RAAS were taken in the supine position, a fter 30°head-down tilting, and after 60°passive head-up tilting for a maximu m of 20 minutes. After the head-up tilting, the central blood volume (CBV) decr eased in both groups, but the decrease was significantly smaller in patients tha n in controls (-19%vs. -36%, P < .01). Central circulation time increased on ly in the patients (+30%vs. -1%, P < .01). The absolute increases in circula ting norepinephrine and renin after head-up tilting were significantly higher i n the patients than in the controls (P < .05 and P < .01, respectively). In pati ents with cirrhosis, changes in SNS and RAAS were related to changes in arterial blood pressure, systemic vascular resistance, heart rate, non-CBV, plasma volu me, and arterial compliance. In conclusion, cardiovascular and humoral responses to changes in posture are clearly abnormal in patients with cirrhosis. Head-up tilting decreases the CBV less in patients with cirrhosis, and the results sugg est a differential regulation of central hemodynamics in patients with cirrhosis .展开更多
文摘Patients with cirrhosis have a hyperdynamic circulation and an abnormal blood volume distribution with central hypovolemia, an activated sympathetic nervous s ystem (SNS) as well as the renin-angiotensin-aldosterone system (RAAS). As the hyperdynamic circulation in cirrhosis may be present only in the supine patient , we studied the humoral and central hemodynamic responses to changes with postu re. Twenty-three patients with alcoholic cirrhosis (Child-Turcotte-Pugh class es A/B/C: 2/13/8) and 14 healthy controls were entered. Measurements of central hemodynamics and activation of SNS and RAAS were taken in the supine position, a fter 30°head-down tilting, and after 60°passive head-up tilting for a maximu m of 20 minutes. After the head-up tilting, the central blood volume (CBV) decr eased in both groups, but the decrease was significantly smaller in patients tha n in controls (-19%vs. -36%, P < .01). Central circulation time increased on ly in the patients (+30%vs. -1%, P < .01). The absolute increases in circula ting norepinephrine and renin after head-up tilting were significantly higher i n the patients than in the controls (P < .05 and P < .01, respectively). In pati ents with cirrhosis, changes in SNS and RAAS were related to changes in arterial blood pressure, systemic vascular resistance, heart rate, non-CBV, plasma volu me, and arterial compliance. In conclusion, cardiovascular and humoral responses to changes in posture are clearly abnormal in patients with cirrhosis. Head-up tilting decreases the CBV less in patients with cirrhosis, and the results sugg est a differential regulation of central hemodynamics in patients with cirrhosis .
