Urinary diagnostic indices in the management of leptospirosis. Selection of patients for dialysis therapy.

Cases of leptospirosis admitted to the Queen Elizabeth Hospital (QEH), Barbados, were assessed for the presence of "pre-renal azotaemia" (NON-ARF) as opposed to "acute renal failure" (ARF). Distinction between the two diagnoses was made on the basis of clinical course. Peritoneal dialysis was inappropriately utilised in 26% of patients receiving such therapy. This study evaluates diagnostic tests for pre-renal azotaemia, and acute renal failure in leptospirosis, and indicates guidelines for the management of azotaemia in such patients. U/P urea and osmolar ratios show high sensitivity and specificity in diagnosing pre-renal azotaemia. While "early" dialysis is essential for patients with acute leptospiral renal failure, in those with plasma creatinines less than 600 mumol/litre on entry and indices indicating NON-ARF, decisions regarding dialysis can safely be delayed for 48-72 hours while the effect of rehydration is assessed.