Abstract

PATTERN OF BICARBONATE IN PATIENTS ON MAINTENANCE HEMODIALYSIS

Anchana Raj* and E. Sam Jeevakumar

Abstract

Chronic metabolic acidosis is common in dialysis patients. Acid base balance in chronic kidney disease patients with metabolic acidosis can the corrected by supplementing bicarbonate via the dialysate. Serum bicarbonate level in dialysis patients is determined by several factors that includes dietary protein intake, nutritional status and dialysis prescription etc… Metabolic acidosis occurs when there is accumulation of plasma anions in excess of cations reduces plasma pH concentration. Replacement of sodium bicarbonate to patients can be done when sodium bicarbonate loss due to diarrhea or renal proximal tubular acidosis. Serum bicarbonate level in individuals with normal renal function is 24-28mEq/l and the acid base values with pH of 7.38– 7.42 and pCO2 is 38–42 mmHg. In patients on maintenance hemodialysis (MHD), the bicarbonate level is highest for post dialysis and lowest for predialysis. The average predialysis serum bicarbonate ranges from 20 to 24 mEq/l at the beginning of the week with the dialysate bicarbonate set at 35 mEq/L. The current kidney dialysis outcomes quality initiative guidelines recommend predialysis serum bicarbonate >22mEq/l. Normally functioning kidneys maintain acid base homeostasis by excreting hydrogen ions (as ammonium) and regenerating bicarbonate. In End stage renal disease (ESRD), alkali supplementation through dialysis helps to prevent accumulation of acid and maintain the pH in the physiological range. Metabolic acidosis is a common consequence for the progressive loss of kidney function. The progressive chronic kidney disease (CKD) and poor survival of these patients is because of low serum bicarbonate level.

Keywords: Dalysate bicarbonate, Hemodialysis, Metabolic acidosis.