Removal of branched‐chain amino acids andα‐ketoisocaproate by haemofiltration and haemodiafiltration

Abstract

Venovenous haemofiltration (VVHF) and haemodiafiltration (VVHDF) were performed with a neonatal haemo(dia)filter (Miniflow 10, Hospal) on 8 anaesthetized rabbits infused with branched-chain amino acids (leucine, isoleucine and valine) and alpha-ketoisocaproate. The branched-chain amino acids (BCAA) and alpha-ketoisocaproate blood levels were close to those previously observed in neonates with maple syrup urine disease when extracorporeal blood purification was required. VVHF and VVHDF performances were assessed with two different blood flows (Qb = 8.3 and 16.6 ml/min). VVHDF was performed with four dialysate flow rates (Qd = 0.5, 1.0, 2.0 and 3.0 L/h). Within each period, clearances of the three BCAA were strictly similar. BCAA clearances obtained by VVHF were similar to ultrafiltration rates (respectively, 0.78 +/- 0.14 and 1.79 +/- 0.28 ml/min at high and low Qb; p < 0.05). The alpha-ketoisocaproate clearances obtained by VVHF were 0.39 +/- 0.17 and 0.92 +/- 0.43 ml/min at low and high Qb (not significantly different). Whatever the Qd value, the VVHDF procedures always allowed higher BCAA and alpha-ketoisocaproate clearances as compared with the corresponding VVHF period with similar Qb. BCAA clearances obtained by VVHDF with a 0.5 L/h dialysate flow were 4.1 +/- 0.5 and 5.4 +/- 0.5 mL/min at low and high Qb, respectively. The concurrent alpha-ketoisocaproate clearances were 2.5 +/- 0.8 and 2.9 +/- 1.0 ml/min.

Amino acid clearance during acute metabolic decompensation in maple syrup urine disease treated with continuous venovenous hemodialysis with filtration

“…The decreased clearances of the acidic AA, heterocyclic AA, and tryptophan can be attributed to the negative charge of the AN69 membrane used in this filter, which limits the clearance of anions. The similarity of AA clearances to creatinine clearance and the total filtrate flow rates is otherwise consistent with previous studies (8) and suggests that at this blood flow rate, clearance is dependent primarily on filtrate flow rates.…”

Metabolic crisis in maple syrup urine disease: an unusual complication of a rare disease: a case report

“…As BCAAs are low molecular weight molecules, use of CVVHDF in this scenario can be beneficial. [3][4][5][6][7][8] A major confounding factor in instituting and titrating the effect of treatment was a discrepancy in the daily leucine level compared with the clinical manifestations observed. It was noted that despite the leucine levels decreasing exponentially, her clinical signs did not show any significant improvement that should have occurred for the levels measured as per the guidelines and evidence known to us.…”

“…As the cerebral oedema is due to the neurotoxicity associated with accumulation of the ketoacids and leucine, CVVHDF was commenced on day 3 to assist with clearance of these metabolites. [3][4][5][6][7][8] Nutritional management. The patient's baseline weight (53 kg) and height (1.51 m) were in the normal range (body mass index 23 kg/m 2 ).…”

“…As the cerebral oedema is due to the neurotoxicity associated with accumulation of the ketoacids and leucine, CVVHDF was commenced on day 3 to assist with clearance of these metabolites. 3 –8…”