Obesity
Conditions
Keywords
anaesthetics iv, propofol, pharmacokinetics, pharmacodynamic
Brief summary
The aim of this study is to characterize the Pharmacokinetic/Pharmacodynamic relationship of a single bolus dose of propofol in obese patients and to extract a time to peak effect (t-peak) from the estimated model parameters.
Detailed description
Target controlled infusion (TCI) is a technique to administer intravenous drugs that allows rapid achievement and maintenance of predetermined drug concentrations, either in plasma (Cp) or at the site of effect (Ce). To characterize the time profile of propofol effect an additional parameter, the equilibration half time between plasma and effect site (T1/2keo) needs to be incorporated in the pharmacokinetic (PK) model.
Interventions
DRUGPropofol
Propofol was administered by plasma TCI and a bolus dose was given by setting the initial plasma target between 12-16 μg/ml according to the anesthesiologist criteria. The protocol target range was selected based on previous experience using this model in the obese. After the patients reached this target, propofol infusion was stopped until the patients woke up (BIS\>75). No other drugs were given during this period. Facemask ventilation was assisted only if necessary to maintain SpO2 \> 90%. BIS data and propofol infusion data were automatically recorded every five seconds using the AnestFusor© program. Arterial blood samples of 4 ml for propofol assays were collected at 1, 2, 3, 5, 7 and 10 minutes after the initial bolus dose or until BIS \> 75. After the patient woke up the study was considered finished and propofol infusion was restarted according to the anesthesiologist plan.
Sponsors
Universidad del Desarrollo
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
SUPPORTIVE_CARE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
20 Years to 60 Years
Healthy volunteers
Yes
Inclusion criteria
* IMC \> 35 kg m-2 * Scheduled for laparoscopic bariatric surgery * ASA I-II patients * Between 20 and 60 yr of age.
Exclusion criteria
* Patients with allergy to study drugs * Uncontrolled hypertension * Heart block greater than first degree * Take any drug acting in the central nervous system
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Profile of Pharmacokinetic and Pharmacodynamic of an induction bolus dose of propofol in obese patients. | 1, 2, 3, 5, 7 and 10 minutes after the initial bolus dose or until BIS > 75 | Pharmacokinetic parameters (V1, V2, V3, CL, Q) Pharmacodynamic parameters (E0, Emax, C50, Gamma, t1/2Ke0, T peak ) |
Countries
Chile
Outcome results
None listed