Haemo-dialysis/-filtration using sodium bicarbonate depresses cardiac function in critically ill patients with acute...

The effect of sodium bicarbonate haemodialysis or haemofiltration on cardiac function was prospectively studied in 8 patients with acute renal failure. All of the patients exhibited consciousness disturbance and seven patients were on mechanical ventilation. All but one of the patients demonstrated moderate hyperlactataemia and seven patients were receiving vasoactive amine support. Arterial and mixed venous gas analysis and haemodynamic measurements were performed before and after haemodialysis/-filtration treatment. The buffer was changed in a randomised order between bicarbonate and acetate and 11 crossover studies were completed. After treatment with bicarbonate, the cardiac index and stroke index decreased significantly (4.0 +/- 0.3 to 3.4 +/- 0.4 L/ min/m2, p < 0.05 and 39.6 +/- 2.5 to 32.9 +/- 1.8 L/m2, p < 0.05), whereas no significant changes were observed in cardiac index or stroke index after treatment with acetate. Therefore, the post-dialytic percent changes of cardiac index, stroke index and left ventricular stroke work index were significantly decreased after bicarbonate sessions, as compared to after acetate sessions. Haemo-dialysis/-filtration using sodium bicarbonate can depress cardiac function in critically ill patients on mechanical ventilation with disturbed consciousness, and in those who are receiving vasoactive amine support due to uncompromised haemodynamics associated with hyperlactataemia.