Validation of a Pharmacokinetic Pharmacodynamic Model to Administer Propofol in Obese Patients

NCT ID: NCT01596387

Last Updated: 2012-05-11

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: PHASE4
• Total Enrollment: 20 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2012-03-31
• Study Completion Date: 2012-05-31

Brief Summary

The purpose of this study is to validate an integrated pharmacokinetic-pharmacodynamic model to administer propofol in obese patients.

Our hypothesis is that pharmacokinetic and pharmacodynamic changes occur with increasing weight and that mathematical models to administer drugs in obese patients can be developed to accurately predict dose schemes in this population.

Detailed Description

Propofol is the most frequently used IV anesthetic today. Propofol TCI is commonly used for induction and maintenance of general anaesthesia in obese and non obese patients. However, current propofol PK models, used in TCI devices, were derived from studies that did not include obese patients. A controversial issue for propofol dose adjustment in this population has been the selection of an adequate size descriptor to scale PK parameters, as drug administration based on total body weight can result in overdose, and conversely, administration based on ideal body weight can result in a sub-therapeutic dose. In a previous study from our group, we developed a PK model capable of characterizing the influence of obesity on propofol disposition. The purpose of this study is to validate this model to administer propofol in obese patients.

Conditions

Obesity

Study Design

• Allocation Method: NA
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: SUPPORTIVE_CARE
• Blinding Strategy: NONE

Study Groups

Propofol

20 obese patients(IMC\>35 kg m-2) scheduled for laparoscopic bariatric surgery.

Group Type: EXPERIMENTAL

Propofol

Intervention Type: DRUG

General anesthesia will be induced administering propofol by effect site TCI system using our previously derived model, the target plasma concentration initially will be set at 4 mcg/ml. After loss of consciousness, rocuronium 0.6mg/kg, and remifentanil 0.2mcg/kg/min will be given to facilitate tracheal intubation. After intubation propofol target will be decreased to 3 for 10 minutes and then adapted to the needs of each patient to maintain stable BIS values between 40 and 50. At the end of surgery propofol infusion will be stopped, and patients will be transferred to the recovery unit extubated. Samples of 2.5 ml of arterial blood will be taken at 2, 5 and 10 min after every new target is set. Thereafter samples will be taken at 2, 5, 10, 15, 30, 60, 120 min after stopping drug infusion. Blood samples will be immediately centrifuged and then stored until analysis.

Interventions

Propofol

General anesthesia will be induced administering propofol by effect site TCI system using our previously derived model, the target plasma concentration initially will be set at 4 mcg/ml. After loss of consciousness, rocuronium 0.6mg/kg, and remifentanil 0.2mcg/kg/min will be given to facilitate tracheal intubation. After intubation propofol target will be decreased to 3 for 10 minutes and then adapted to the needs of each patient to maintain stable BIS values between 40 and 50. At the end of surgery propofol infusion will be stopped, and patients will be transferred to the recovery unit extubated. Samples of 2.5 ml of arterial blood will be taken at 2, 5 and 10 min after every new target is set. Thereafter samples will be taken at 2, 5, 10, 15, 30, 60, 120 min after stopping drug infusion. Blood samples will be immediately centrifuged and then stored until analysis.

Intervention Type: DRUG

Eligibility Criteria

Inclusion Criteria

• IMC > 35 kg m-2
• Scheduled for laparoscopic bariatric surgery
• ASA I-II patients
• Between 18 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 within 24 hrs before surgery.

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 60 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Pontificia Universidad Catolica de Chile

OTHER

Sponsor Role: lead

Responsible Party

Ignacio Cortínez F.

Profesor Asociado, Departamento de Anestesiología

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Luis I Cortínez, MD

Role: PRINCIPAL_INVESTIGATOR

Departamento de Anestesiología, Hospital Clínico Pontificia Universidad Católica de Chile

Locations

Hospital Clinico Pontificia Universidad Catolica

Santiago, Santiago Metropolitan, Chile

Countries

Chile

References

Cortinez LI, De la Fuente N, Eleveld DJ, Oliveros A, Crovari F, Sepulveda P, Ibacache M, Solari S. Performance of propofol target-controlled infusion models in the obese: pharmacokinetic and pharmacodynamic analysis. Anesth Analg. 2014 Aug;119(2):302-310. doi: 10.1213/ANE.0000000000000317.

Reference Type: DERIVED

PMID: 24977639 (View on PubMed)

Other Identifiers

11-142-Fondecyt-UC-2012

Identifier Type: -

Identifier Source: org_study_id