RESUMEN
During haemodialysis in the patient at high risk for bleeding, heparin cannot be safely used to prevent clotting in the dialysis assembly. Among numerous procedures proposed to reduce the risk for bleeding, Pinnick et al. (N Engl J Med, 308: 258, 1983) proposed the use of citrate as the sole anticoagulant. Citrate toxicity and efficiency were studied during 44 haemodialyses carried out in thirteen patients with a high risk for bleeding or with active bleeding. Three patients had hepatic failure. Two types of citrate solution were used, the trisodium form of citrate (102 mmol.l-1 citrate) or the monosodium form (306 mmol.l-1 citrate). The solutions were infused with a calibrated, pressure insensitive pump, before the dialysis unit at a flow rate of 600 ml.h-1 and 200 ml.h-1 respectively. Sufficient citrate was infused to maintain a clotting time of the blood line and dialyser of more than 18 min. Standard 10% calcium chloride was infused at a constant rate of 7 mg.min-1 into the blood being returned to the patient. The patients were dialysed for 4 h for each haemodialysis with a single-pass system. The dialyses were uncomplicated; no active bleeding was noted. The patient's clotting time was significantly reduced during haemodialysis (18.1 +/- 8.9 min to 14.5 +/- 6.3 min; p less than 0.001). Two-hundred and twenty serum citrate levels were measured. Only nine were above the toxic value of 2 mmol.l-1. No clinical evidence of a decrease in ionized calcium was found: there was no change in the corrected QT intervals and blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)