Interrelationship between cardiac output and vascular resistance as determinants of effective arterial blood volume in cirrhotic patients

Interrelationship between cardiac output and vascular resistance as determinants of effective arterial blood volume in cirrhotic patients. The effect of head-out water immersion (HWI) in decompensated cirrhotic patients to correct sodium and water excretion has been found to be incomplete and variable. The explanation may be that the efficacy of HWI in correcting a decreased effective arterial blood volume (EABV) in decompensated cirrhotic patients is limited by an accompanying decrease in systemic vascular resistance (SVR) and thus a relative increase in arterial vascular holding capacity. The present studies were undertaken to examine this possibility by maintaining SVR (dynes · sec · cm −5 ) nearly constant during HWI with an exogenous infusion of norepinephrine (HWI + NE). In six decompensated cirrhotic patients, neither HWI nor NE infusion alone significantly increased sodium excretion (U Na V, 13 vs. 19 and 13 µEq/min, respectively), but each maneuver increased the excretion of a 20 ml/kg water load (28 to 60 and 61%, respectively, both P Na V to 70 µEq/min (P 2 , P −5 , P 2 , P −5 , P