THE USE OF PROPOFOL FOR SEDATION OF CRITICALLY ILL PATIENTS UNDERGOING HEMODIAFILTRATION

Objective: To assess the requirement for propofol to provide sedation in critically ill patients in established renal failure during the commencement of haemodiafiltration. Design: Prospective clinical study. Setting: ICU, University Hospital. Patients: 10 adult patients. All were mechanically ventilated, had acute oliguric renal failure which necessitated continuous veno-venous haemodiafiltration and were receiving a continuous intravenous infusion of propofol for sedation. Sedation was assessed using a scoring system. Intervention: Veno-venous haemodiafiltration. Measurements and results: Connection of the extracorporeal circuit produced a reduction in plasma propofol concentration in 7 out of 9 patients (one sample misplaced) with subsequent awakening in 3 of these 7 patients. The commencement of haemodiafiltration itself did not significantly influence the requirement for propofol (8 out of 10 patients). Conclusion: Haemodiafiltration does not substantially influence the requirement for propofol but the initial introduction of the extracorporeal circuit will reduce plasma concentrations in the majority of patients. This may be due to haemodilution alone or absorption of plasma albumin (with propofol) onto the membrane.