Hemodynamic Changes and Propofol Pharmacokinetic Variation During Anesthesia Induction and Knee-chest Positioning

NCT ID: NCT03961958

Last Updated: 2019-05-23

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 20 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2009-07-31
• Study Completion Date: 2014-01-31

Brief Summary

Induction of anesthesia and the knee-chest position are associated with hemodynamic changes that may impact patient outcomes.

Changes from baseline in cardiac output and other hemodynamic variables following induction of anesthesia and knee-chest positioning were compared. Propofol plasma concentrations were also measured after induction of anesthesia and after the knee-chest position.

The aim of this study was to assess whether planned reductions in target-controlled infusion propofol concentrations attenuate the hemodynamic changes associated with anesthesia induction and knee-chest position.

The secondary aim was to quantify the variation in propofol measured plasma concentrations (Cm), both after induction and after KC positioning, and correlate them with predicted concentrations (Cp) by the Schnider Pk model.

Detailed Description

A total of 20 patients scheduled for elective lumbar spinal surgery in the knee-chest position were included. In addition to standard anesthesia monitoring, bispectral index and noninvasive cardiac output monitoring were undertaken. The study was carried out in 2 parts. In phase 1, target-controlled infusion propofol anesthesia was adjusted to maintain BIS 40 to 60. In phase 2, there were 2 planned reductions in propofol target concentration: (1) immediately after loss of consciousness: reduction calculated using a predefined formula, and (2) before positioning: reduction equal to the average percentage decrease in CO after knee-chest position in phase 1.

Conditions

Hemodynamic Instability; Anesthesia; Surgery

Study Design

• Allocation Method: NON_RANDOMIZED
• Intervention Model: SEQUENTIAL
• Primary Study Purpose: PREVENTION
• Blinding Strategy: NONE

Study Groups

No protocolled propofol reduction

In phase 1, target-controlled infusion propofol anesthesia was adjusted to maintain BIS 40 to 60.

Group Type: NO_INTERVENTION

No interventions assigned to this group

Two protocolled propofol reductions

In phase 2, there were 2 planned reductions in propofol target concentration: (1) immediately after loss of consciousness-reduction calculated using a predefined formula, and (2) before positioning-reduction equal to the average percentage decrease in CO after knee-chest position in phase

Group Type: EXPERIMENTAL

Propofol reduction

Intervention Type: DRUG

Reduction of propofol target concentration

Interventions

Propofol reduction

Reduction of propofol target concentration

Intervention Type: DRUG

Eligibility Criteria

Inclusion Criteria

• Lumbar spinal condition for surgical treatment in knee-chest position

Exclusion Criteria

• Severe ischemic heart disease
• Congestive heart failure
• Atrial fibrillation or flutter
• Body mass index > 35 kg/m2
• Glasgow Coma Scale < 15
• Dementia disease
• History of drug abuse or addiction
• Consumption of opioid medication
• Pre-operative administration of midazolam

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

Sponsors

Centro Hospitalar do Porto

OTHER

Sponsor Role: collaborator

University of Salamanca

OTHER

Sponsor Role: lead

Responsible Party

Daniela Chalo

Principal Investigator

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Consuelo S Sanchez, PhD

Role: STUDY_DIRECTOR

University of Salamanca, Faculty of Medicine

Locations

Centro Hospitalar do Porto

Porto, , Portugal

Countries

Portugal

Other Identifiers

USalamanca

Identifier Type: -

Identifier Source: org_study_id