Comparison of markers of circulating blood volume in hemodialysis patients

Pulse dye-densitometry (PDD) is a newly developed technique for monitoring the arterial concentration of indocyanine green (ICG). By using this method, the circulating blood volume (CBV) can be measured as accurately as by established dilution methods using (131)I-labeled human serum albumin in healthy subjects. In the present study, we estimated the CBV in hemodialysis (HD) patients, using PDD, and compared the utility of this method with that of other markers of the CBV.

We measured the CBV in seven HD patients and eight healthy volunteers, using PDD, and evaluated the correlation between the CBV measured by PDD (CBV-PDD) and the calculated CBV (CBV-Cal), using a prediction formula (CBV (l) = 2.68 x BSA, where BSA is body surface area (m(2))). We also investigated the correlation between CBV-PDD and the maximal inferior vena cava diameters in quiet expiration (IVCe), and the plasma levels of atrial and brain natriuretic peptides (ANP and BNP, respectively) in the HD patients.

CBV-Cal was closely correlated with CBV-PDD in the healthy volunteers, but there was no such correlation in the HD patients. On the other hand, IVCe was significantly correlated with the CBV-PDD in the healthy volunteers as well as in HD patients. ANP and BNP were not correlated with the CBV-PDD in the HD patients.

We concluded that CBV-PDD and IVCe were useful parameters in evaluating the CBV in HD patients, while CBV-Cal was not a useful parameter. Also, as a marker of changes in the CBV in HD patients, IVCe was considered to be more sensitive than either ANP or BNP.