Individual effect-site concentrations of propofol at return of consciousness are related to the concentrations at loss of consciousness and age in neurosurgical patients.
OBJECTIVE
To investigate whether a patient's propofol effect-site concentration at return to consciousness (ROC) was related to the propofol effect-site concentration at loss of consciousness (LOC) and to patients' individual demographic parameters.


METHODS
Prospective study.


METHODS
Operating room.


METHODS
31 ASA physical status I and II neurosurgical patients with Glasgow Coma Score > 15, and scheduled to receive total intravenous anesthesia with effect-site target controlled infusion (TCI) of propofol and remifentanil.


METHODS
A constant propofol infusion was administered until LOC. At LOC, remifentanil started with a plasma concentration target of 2.5 ng mL(-1).


RESULTS
Propofol concentration at LOC was 4.9 +/- 1 microg mL(-1). At ROC, propofol and remifentanil concentrations were 1.16 +/- 0.3 microg mL(-1) and 3.41 +/- 1.5 ng mL(-1). Significant correlation was observed between propofol concentrations at ROC and LOC, between propofol concentration at ROC and patient age (48.7 +/- 15 yrs), and between propofol concentrations at ROC and LOC, divided by patient's age.


CONCLUSIONS
The correlation between propofol concentrations at ROC and LOC was improved by inclusion of patient age data.
Nunes
Catarina S
CS
Division of Engineering, King's College London, London WC2R 2LS, UK. catarina.nunes@kcl.ac.uk
Ferreira
David A
DA
Antunes
Luís
L
Lobo
Francisco
F
Santos
Isabel A
IA
Amorim
Pedro
P
D000328:Adult; D000367:Age Factors; D000368:Aged; D000762:Anesthesia Recovery Period; D018686:Anesthetics, Intravenous / Q000493:pharmacokinetics* / Q000627:therapeutic use; D003243:Consciousness / Q000187:drug effects; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000379:methods*; D010880:Piperidines / Q000493:pharmacokinetics / Q000627:therapeutic use; D015742:Propofol / Q000493:pharmacokinetics* / Q000627:therapeutic use; D011446:Prospective Studies; D000077208:Remifentanil; D055815:Young Adult
D018686:Anesthetics, Intravenous; D010880:Piperidines; D000077208:Remifentanil; D015742:Propofol