[Early diagnosis of acute renal insufficiency in patients with peritonitis]

Changes in osmolarity, blood and urine levels of medium-size molecules (MSM), osmolarity and MSM index, free water clearance (FWC) and alterations in traditional clinical and biochemical parameters typical of acute renal failure (creatinine, urea nitrogen, K+, Na+, diuresis) have been compared in 27 patients with peritonitis complicated in 17 cases by acute renal failure (ARF). In patients with developing ARF disturbances in osmotic condition, osmotic clearance, FWC, MSM level precede an increase in creatinine and urea nitrogen level and diuresis decrease. Dynamic studies of FWC and MSM blood and urine levels allow of early ARF diagnosis in patients with peritonitis. Progressive growth of plasma osmolarity and FWC with a parallel decrease in MSM index below 1 is a criterion indicative of functional renal failure turning into organic one.