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Is Anesthetic Loss of Consciousness a Top Down or Bottom up Phenomenon. What Does the Neurologic Examination Say?.

Not Applicable
Completed
Conditions
Anesthesia; Functional
Interventions
Diagnostic Test: FOUR coma scale and frontal espectrograpy evaluation
Registration Number
NCT03140982
Lead Sponsor
Universidad del Desarrollo
Brief Summary

Using very slow or fast propofol intravenous injection, monitored using standard American Society of Anesthesiology (ASA) standard and SEDLine EEG (Med Tech), the patient was evaluate by a neurologist every 30 sec using the FOUR coma scale.

Detailed Description

Clinical experimental randomized study, approved by the Ethic Committee, with informed consent, included ASA I- II adults, without neurological illness and normal physical exam.

The patient randomized in two groups, rapid induction (GR) with propofol in target controlled infusion (TCI) effect site mode using the phamacokinetic (PK) model from Marsh ke0 1,21 min-1 using a calculated target of 5.4 ug/ml (loss of counsciousness EC95) and slow induction (GL) 10 mg/kg/h with calculated effect site concentrations (CeCALC) same PK model.

The same neurologist, blind to the correspondent group, evaluated all the patients every 30 sec using the coma FOUR scale until loss of counsciousness (LOC), defined as a FOUR (E0 no eyes opening response and /or M0 no motor response). At LOC the existance of brainstem reflex was evaluated (B no pupil and corneal reflex), respiratory pattern (R apnoea), CeCALC and patient state index (PSI) SEDline™ was recorded during all the examination.

After LOC in both groups we maintain in GR the initial target (5.3 ug/ml) and the LOC CeCALC during 10 min without intervention, except respiratory support if it was required.

Frontal EEG 4 channel and spectrogram from SEDline monitor was extracted for each case and posterior analysis.

Fisher exact test was used to describe primary outcome and difference between B and R for each group. The difference in time to reach LOC LOC, Ce and PSI was analysed with T- Student.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
16
Inclusion Criteria

ASA 1-2 patients programmed for elective surgery, normal neurologic examination -

Exclusion Criteria

neurologic illness, receiving drugs that affect Central Nervous System during the last 48 hours

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
GL slow inductionFOUR coma scale and frontal espectrograpy evaluationpropofol infused at 10 mg/kg/h with CeCALC PK Marsh model ke0 1,21 min-1 same PK model After LOC we maintain the CeCALC observed al LOC during 10 min without intervention, except respiratory support if it was required.
GR fast inductionFOUR coma scale and frontal espectrograpy evaluationpropofol TCI effect site mode infusion using the PK Marsh model ke0 1,21 min-1 target 5.4 ug/ml (LOC EC95) util loss of consciousness (LOC) After LOC we maintain initial target during 10 min without intervention, except respiratory support if required.
Primary Outcome Measures
NameTimeMethod
loss of consciousness a cortical or brainsteam phenomenon1 year

with fast and slow induction we use the FOUR coma scale ( Ann Neurol. 2005;58(4): 585-93) to identify lost of brain stem activities.

Secondary Outcome Measures
NameTimeMethod
evaluation of the alfa band behavior after fast and slow inductions1 year

the investigators analyze the time delay in stabilizing the frontal alfa band after fast and slow anesthesia inductions

Trial Locations

Locations (1)

Clinica Alemana de Santiago

🇨🇱

Santiago, Region Metropolitana, Chile

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