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

Universidad del Desarrollo

Status: Completed

Conditions: Anesthesia; Functional

Treatments: Diagnostic Test: FOUR coma scale and frontal espectrograpy evaluation

Study type: Interventional

Funder types: Other

Identifiers

NCT03140982

Centro Bioetica 2016-05

Details and patient eligibility

About

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.

Full 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.

Enrollment: 16 patients

Sex: All

Ages: 18 to 65 years old

Volunteers: No Healthy Volunteers

Inclusion and exclusion criteria

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

Trial design

Primary purpose: Diagnostic

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Triple Blind

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16 participants in 2 patient groups

GR fast induction

Active Comparator group

Description:

propofol 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.

Treatment:

Diagnostic Test: FOUR coma scale and frontal espectrograpy evaluation

GL slow induction

Active Comparator group

Description:

propofol 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.

Treatment:

Diagnostic Test: FOUR coma scale and frontal espectrograpy evaluation