Neuronal Inertia in Propofol Anesthesia (INERTIA)

Universidad del Desarrollo

Status and phase: Completed; Phase 4

Conditions: Propofol Plasma Concentration; General Anesthesia; Loss of Consciousness and Recovery of Consciousness; Propofol Pharmacodynamics; Propofol Target Controlled Infusion

Treatments: Drug: propofol targel controlled infusion

Study type: Interventional

Funder types: Other

Identifiers

NCT01962285

INERTIA

Details and patient eligibility

About

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.

Full 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.

Enrollment: 14 patients

Sex: All

Ages: 18+ years old

Volunteers: Accepts Healthy Volunteers

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)

Trial design

Primary purpose: Basic Science

Allocation: N/A

Interventional model: Single Group Assignment

Masking: None (Open label)

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14 participants in 1 patient group

propofol slow infusion

Experimental group

Description:

(healthy volunteers, non invasive monitoring and O2 supply via nasal cannula) Target controlled infusion of propofol using Schnider´s pharmacokinetic parameters in a slow, stepped fashion. beginning at Cp 0.5 mcg/ml and increasing in 0.5 mcg/ml every 7 minutes until LOC occurred, then a prolonged step of 14 minutes (2 samples), increase 2 steps further and then decrease in 0.5 mcg/ml steps until ROC and a 7 minute registry after ROC. Blood sampling for propofol plasma level every 7 minutes (at the end of each step, allowing for pseudo-equilibrium condition. 32 channel-EEg and BIS continuous monitoring

Treatment:

Drug: propofol targel controlled infusion