Increased plasma levels of atrial natriuretic peptide and endocrine markers of volume depletion in patients with obstructive jaundice.

BACKGROUND

Hypovolaemia may cause renal dysfunction in obstructive jaundice. This study investigated whether, in patients with obstructive jaundice: (1) atrial natriuretic peptide (ANP) is increased; (2) fluid-regulating hormones are altered; and (3) biliary drainage improves fluid homoeostasis.

METHODS

Forty-three patients with obstructive jaundice were investigated. A renal profile was obtained and levels of ANP, renin, aldosterone and vasopressin were determined. In a subset of 18 patients, studies were repeated 3 days after endoscopic biliary drainage and changes in extracellular volume were measured.

RESULTS

Creatinine clearance was impaired in ten of 30 patients. Patients with obstructive jaundice had higher mean levels of ANP (118 versus 40 pg/ml, P = 0.0001) and aldosterone (156 versus 43 pg/ml, P = 0.0001) than matched controls. Increased renin levels were observed in ten of the 43 patients and were associated with impaired creatinine clearance. After biliary drainage ANP concentration decreased (110 versus 67 pg/ml, P = 0.004) as well as aldosterone level (182 versus 85 pg/ml, P = 0.0002) and the mean extracellular volume increased (20.5 versus 23.1 per cent of body-weight, P = 0.001).

CONCLUSION

Plasma ANP concentration is increased in obstructive jaundice. Endocrine markers of hypovolaemia are activated in obstructive jaundice. After biliary drainage there is an improvement of endocrine and fluid derangements.