The use of propofol for sedation of critically ill patients undergoing haemodiafiltration.

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.