significance of tubular and glomerular proteinuria in critically ill patients with severe acute kidney injury

ABSTRACT

Critically ill patients with acute kidney injury [AKI] frequently need acute renal replacement therapy [aRRT]. We evaluated an inexpensive, rapid quantitative and qualitative analysis of proteinuria on the course of AKI patients requiring aRRT in intensive care. This was a prospective, observational study of critically ill patients with severe established AKI or Acute on Chronic Kidney Injury [AoCKI] requiring aRRT. Urine samples were analyzed using Sodium-Dodecyl-Sulphate-Polyacryamide Gel Electrophoresis [SDS-PAGE]. A total of 30 critically ill patients were studied. Those who died have higher APACHE II [29 +/- 6 vs. 20 +/- 5, p<0.001], multi-organ failure [0.7 +/- 0.5 vs. 0.2 +/- 0.4, p < 0.02] and Tubular/Glomerular ratio [114 +/- 60 vs. 75 +/- 37, p < 0.05]. The renal non-recoverers have higher baseline creatinine [415 +/- 328 vs. 125 +/- 19 umol/l, p < 0.01], urinary Dipstick value [1.8 +/- 0.8 vs. 0.5 +/- 0, p <0.05] and Glomerular score [3.0 +/- 1.8 vs. 0.6 +/- 0.2, p < 0.02]. Heavy tubular proteinuria also predicts a longer duration of interim dialysis support and mortality whereas glomerular proteinuria correlates with development of chronicity and End Stage Renal Disease [ESRD]. The dominant presence of tubular proteinuria is associated with poor survival in patients who have high APACHE II score and multi-organ failure. It also correlates with a longer duration of dialysis support in survivals. Renal Non-recoverers had heavy dominant presence of glomerular proteinuria. SDS-PAGE proteinuria analysis offers a reliable and inexpensive method to prognosticate proteinuria in this group of critically ill patients