Neuronal Inertia in Propofol Anesthesia

Condition(s) targeted: General Anesthesia; Propofol Pharmacodynamics; Propofol Target Controlled Infusion; Loss of Consciousness and Recovery of Consciousness; Propofol Plasma Concentration

Intervention: propofol targel controlled infusion (Drug)

Phase: Phase 4

Status: Completed

Sponsored by: Universidad del Desarrollo

Official(s) and/or principal investigator(s):
pablo sepulveda, anesthesiologist, Principal Investigator, Affiliation: Universidad del Desarrollo

Loss and recovery of consciousness during propofol anesthesia seem to be mediated by different mechanisms beyond the actual effect-site concentration of anesthetic drug. This eventual difference between dose response curves for loss of consciousness (LOC) and for recovery of consciousness (ROC) beyond hysteresis has received the name of neuronal inertia. We performed a volunteer-study comparing LOC and ROC curves during a slow, steady-sate, stepped target controlled infusion of Propofol. Our hypothesis is that, at steady-state conditions between plasma an effect-site concentration, there is still going to exist a difference between LOC and ROC, demonstrating the existence of neuronal inertia.

Official title: Neuronal Inertia´s Effect on Pharmacological Behavior Representation of Propofol

Study design: Endpoint Classification: Pharmacokinetics/Dynamics Study, Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Basic Science

Primary outcome: plasma-equilibrated effect site concentration of propofol at LOC and ROC (mcg/ml)

Secondary outcome:

Bispectral Index (BIS) al LOC and ROC

Pharmacodynamic curve for propofol.

PROPOFOL effect site concentration during infusion

Detailed description: Loss and recovery of consciousness during propofol anesthesia seem to be mediated by different mechanisms beyond the actual effect-site concentration of anesthetic drug. This eventual difference between dose response curves for loss of consciousness (LOC) and for recovery of consciousness (ROC) beyond hysteresis has received the name of neuronal inertia. We performed a volunteer-study comparing LOC and ROC curves, during a slow, steady-sate, stepped target controlled infusion of Propofol using Schnider's pharmacologic model. Our hypothesis is that, at steady-state conditions between plasma an effect-site concentration, there is still going to exist a difference between LOC and ROC, demonstrating the existence of neuronal inertia.

Minimum age: 18 Years. Maximum age: N/A. Gender(s): Both.

Criteria:

Inclusion Criteria:

- american society of anesthesiologists status I or II age >18 years fasted at least 8

hours BMI<30 Exclusion Criteria:

- any known adverse reaction to propofol administration soy or egg-protein allergy

psychotropic use (illegal of medically indicated)

Clinica Alemana de Santiago, Santiago, Region Metropolitana, Chile

Starting date: August 2013
Last updated: October 11, 2013