[Evaluation of body fluid compartments and their relationship with water-electrolyte changes in obstructive jaundice]

The alteration of the mechanisms of water and sodium preservation may be an important factor in the development of acute postoperative renal failure in obstructive jaundice (OJ). Experimental OJ has been associated with a depletion of the extracellular volume and alteration of the mechanisms of regulation of hydrosaline metabolism. The aim of this study was to evaluate the distribution of the body volumes and the regulating hormones of hydrosaline metabolism in human OJ.

A prospective, clinical study evaluating 18 patients with OJ (9 females and 9 males) with a mean age of 69 +/- 8.9 years was performed. The plasma levels of antinatriuretic peptide (ANP), aldosterone and renin were determined. The body volumes were evaluated by tetrapolar bioimpedanciometry. The results of the patients with OJ were compared with a control group (CG) of 12 healthy subjects, matched for age and sex (6 females and 6 males with a mean age of 64.5 +/- 14 years).

High ANP values were observed in 87.5% of the patients. The results of the hormonal studies compared with the CG were: ANP (117.33 +/- 37.7 vs 41.31 +/- 16.8 pg/ml; p < 0.001), aldosterone (185.68 +/- 82.1 vs 44.3 +/- 21.6 pg/ml; p < 0.001) and renine (57.18 +/- 69.9 vs 16.08 +/- 9.7 microU/ml; p < 0.05). Depletion of extracellular volume was found in 75% of the patients.

Human obstructive jaundice is associated with an important alteration in the hormonal mechanisms of water and sodium regulation. This alteration is accompanied by a marked depletion of extracellular volume.