The effect of Metabolic Acidosis on Nutritional Status and Adequacy of Dialysis in Pediatrics patients on Regular Hemodialysis.

ABSTRACT
Background: Metabolic acidosis is a well known feature of end-stage renal disease (ESRD) leading to protein breakdown, decreased cardiac inotropism and increase severity of bone disease. Objectives: This work was designed to study the consequences of metabolic acidosis on nutritional status and adequacy of dialysis in pediatric regular haemodialysis (HD)patients. Methods: Arterial blood samples were drawn immediately before HD from 30 patients with ESRDon regular HD therapy to determine Ph, PaCO2, HCO3, serum albumin, serum creatinine, blood urea nitrogen (BUN), C-reactive Protein (CRP) and complete blood count (CBC), post-dialysis arterial blood samples were drawn 3 minutes after session from all patients, to determine Ph, PaCO2, HCO3, serum creatinine and BUN. The normalized protein catabolic rate (Npcr) was calculated and correlation with serum albumin, bicarbonate level and CRP. Kt/V and urea reduction ratio (URR)were calculated and correlation with degree of biocarbonate correction. Results: Children with ESRD on regular HD therapy had elevated pre-dialysis BUN and serum creatinine levels in comparison with post-dialysis results. Pre-dialysis serum albumin was 3.43 ± 0.56 g/dl. Dietary protein intake was 1.32 ± 0.53 g/kg/day, PNA was 42.28 ± 10.3 g/dl, Npna was 1.77 ± 0.53 g/kg/dl. All patients had metabolic acidosis in the pre-dialysis period which was corrected after dialysis. Ph was 7.31 ± 0.057 and 7.45 ± 0.04 respectively. Dialysis raised the level of HCO3 and PaCO2 with mean ± SD of HCO3 19.4 ± 2.53 and 26.7 ± 2.17 mmol/L and PaCO2 was 35.9 ± 3.36 and 41.76 ± 1.83 Hg respectively. The patients were adequately dialysis as the mean ± SD of Kt/V and URR were 1.25 ± 0.25 and 64.13 ± 7.29 respectively. 80% of patients had –ve CRP and 20% of them had elevated CRP. The quantity of dialysis measured by Kt/V and URR showed no statistically significant correlation with either the pre-or the post-dialysis HCO3, (P > 0.05). There was no correlation between pre-dialysis HCO3 and Npna, pre-dialysis creatinine and albumin. There was –ve correlation between pre-dialysis HCO3 and protein intake (p < 0.05). CRP correlation negatively with both serum creatinine and pre-dialysis serum albumin (p < 0.05) but no correlation with both Npna and protein intake (p > 0.05) could be found. Conclusions: Pre-dialysis metabolic acidosis is still a common finding in HD patients, but it can be corrected by increasing the quantity of dialysis. Metabolic acidosis has a significantly deleterious effect on nutritional status of patients with CRF. Both serum albumin and creatinine concentrations are influenced by inflammation. Npna does not reflect the real dietary intake of the protein.