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NCT Number: NCT03961958

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

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.

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Key information

Conditions

Hemodynamic Instability Anesthesia Surgery

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Centro Hospitalar do Porto

Porto, Portugal

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Propofol reduction

Drug

Reduction of propofol target concentration

Primary outcomes

  1. Hemodynamic changes

    Time frame: Baseline (moment 0), 10 minutes after induction of anesthesia (moment 1), 10 minutes after knee-chest positioning (moment 2)

    Changes from baseline in cardiac output and comparison of the changes between both groups.

Secondary outcomes

  1. Pharmacokinetic changes

    Time frame: Baseline (moment 0), 10 minutes after induction of anesthesia (moment 1), 10 minutes after knee-chest positioning (moment 2)

    Correlation between propofol measured plasma concentrations and predicted plasma concentrations (Cp) by the Schnider Pk model.

Sponsors and collaborators

Lead sponsor

University of Salamanca

Other

Collaborators

  • Centro Hospitalar do Porto

Registry information

Official study title

Relationship Between Hemodynamic Changes and Propofol Pharmacokinetic Variation During Anesthesia Induction and Knee-chest Positioning in Propofol TCI Guided Anesthesia

Important dates

Study start
2009
Primary completion
2014
Study completion
2014
First posted
May 23, 2019
Registry last updated
May 23, 2019

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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