Clinical trial NCT03961958: Hemodynamic Changes and Propofol Pharmacokinetic Variation During Anesthesia Induction and Knee-chest Positioning
Official title: Relationship Between Hemodynamic Changes and Propofol Pharmacokinetic Variation During Anesthesia Induction and Knee-chest Positioning in Propofol TCI Guided Anesthesia
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Hemodynamic Instability
Anesthesia
Surgery
Keywords: Hemodynamics
Knee-Chest Position
Propofol
Anesthesia, General
Anesthetics, Intravenous
pharmacokinetics
Lead sponsor: University of Salamanca
Sponsor class: OTHER
Collaborators: name: Centro Hospitalar do Porto
First posted: 2019-05-23
Enrollment: 20
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: NON_RANDOMIZED
Intervention model: SEQUENTIAL
Intervention model description: 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.
Primary purpose: PREVENTION

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.

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

Primary outcomes:
measure: Hemodynamic changes
timeFrame: Baseline (moment 0), 10 minutes after induction of anesthesia (moment 1), 10 minutes after knee-chest positioning (moment 2)
Secondary outcomes:
measure: Pharmacokinetic changes
timeFrame: Baseline (moment 0), 10 minutes after induction of anesthesia (moment 1), 10 minutes after knee-chest positioning (moment 2)
Other outcomes:
Locations:
city: Porto
country: Portugal
facility: Centro Hospitalar do Porto
Study officials:
affiliation: University of Salamanca, Faculty of Medicine
name: Consuelo S Sanchez, PhD
role: STUDY_DIRECTOR
References: