[Which propofol target concentration for ASA III elderly patients for conscious sedation combined with regional anaesthesia?].
OBJECTIVE
To determine the optimal propofol target concentration between 0.9-1.1 and 1.3 mg l(-1), for conscious sedation and amnesia using Diprifusor in ASA III patients over 60 years.


METHODS
Prospective study.


METHODS
In ASA III patients over 60 years presented for elective vascular procedures under regional anaesthesia, sedation was induced with propofol TCI by increasing target concentrations from 0.9 to 1.3 mg l(-1) by 0.2 mg l(-1) steps up to a sedation score corresponding to light level (patient awakable with tactile stimulation). At baseline and each step, specific pictures were shown to the patient and clinical parameters and unwanted side effects occurrence were recorded. In PACU, memorisation of pictures and events was looked for.


RESULTS
Conscious sedation was obtained in 100% of the patients at 0.9 mg l(-1), 94% at 1.1 and 78% at 1.3 mg l(-1). Amnesia was concentration-dependent and for each concentration was always more important for pictures than for events. Haemodynamic parameters did not change significantly. Incidents occurred in 12% of cases at 1.1 and 39.4% at 1.3 mg l(-1).


CONCLUSIONS
None of those three concentrations was satisfying in 100% of cases for the three criterias (sedation < S2, amnesia and none side effects). These results suggest that propofol target concentration 0.9 microg ml(-1) could be used safely for sedation in elderly ASA III patients. Moreover, we have shown that amnesia for events requires higher propofol concentrations than amnesia for pictures during conscious sedation.
Département d'anesthésie-réanimation, CHR, hôpital de La Source, 45000 Orléans, France. isabellevilleret@wanadoo.fr
I
I
Villeret
M
M
Laffon
M
M
Ferrandière
D
D
Delerue
J
J
Fusciardi
D000368:Aged; D000369:Aged, 80 and over; D000765:Anesthesia, Conduction; D018686:Anesthetics, Intravenous / Q000008:administration & dosage / Q000009:adverse effects / Q000493:pharmacokinetics; D016292:Procedural Sedation; D017558:Elective Surgical Procedures; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D008297:Male; D011939:Mental Recall / Q000187:drug effects; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D015742:Propofol / Q000008:administration & dosage / Q000009:adverse effects / Q000493:pharmacokinetics; D014656:Vascular Surgical Procedures
D018686:Anesthetics, Intravenous; D015742:Propofol