In this study the investigators will submit patients with treatment resistant depression to deep anesthesia with isoflurane to get 15 minutes of cortical burst suppression on electroencephalogram, once a week for six weeks. The follow up will be for 6 months. The aim is to evaluate the change in depression severity during the entire period.
This study protocol will measure the efficacy of deep anesthesia, until burst suppression rate of 80% or more measured with Bi-spectral Index (BIS), with the volatile anesthetic Isoflurane. The investigators will select 30 subjects. The participants will be separated into 2 arms of 15 individuals. One arm called ISOAD will keep the oral treatment with antidepressants. The second arm, called ISO, will do a washout of any oral medications for depression. Both groups will go under six sessions, once per week, of deep anesthesia and will be followed up for 6 months to evaluate the survival of the antidepressant effect, if any effect happens. Before the anesthesia occurs, blood samples will be drawn to measure Brain-derived neurotrophic factor and investigators will apply depression rating scales such as MADRS and Hamilton - 17 , Young mania Scale, UKU scale for side effects, electroencephalogram will be recorder to be compared with the data shown on BIS. All the anesthesia procedure will be done with induction with propofol, fentanyl and muscular relaxant, to facilitate the tracheal intubation and compliance with the mechanical ventilator,based on body weight in standard dosages. Isoflurane will be set to 2,4% ( 2 cam) until Burst suppression rate \>80% is achieve. Then the anesthesia will be maintained for 15 minutes, then the flow of anesthetic gas will be ended and the patient will be allowed to awake and discharged home when the anesthesiologist decide based on Aldrete Kroulik scale. After the 6th session the participant will return in one week to final evaluation. All the patients that shows improvement in depression scores will enter the phase 2 with one visit every 15 days for 2 months and then once a month until the 6th month. The non responders of the ISO group will start oral antidepressant sertraline to evaluate any potentialization effect of the intervention and be allocated in ISOPOT group. Those from ISOAD group (Isoflurane plus oral antidepressants) that did not respond to the intervention will be discontinued from the study and their data used in the study as non-responders. Those from ISOPOT group that did not improve their depression scores after 4 weeks will be discontinued from the study and the data computed as non-responders.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
30
Deep anesthesia with isoflurane to achieve burst suppression pattern for more than 80% of the time for 15 minutes measured in electroencephalogram and Bi-Spectral Index
Patients that did not respond to Isoflurane treatment, will star on sertraline to evaluate any enhancement in antidepressant efficacy after pre-treatment with isoflurane
Insitute of Psychiatry of the University of São Paulo
São Paulo, Brazil
Reduction in Depression severity - MADRS
Any reduction in Montgomery Asperger Depression Rating Scale ( 0 to 60 , lower score means less depression severity)
Time frame: Six days after the last session
Reduction in Depression - HDRS 17
Any reduction in Hamilton Depression rating scale 17 ( 0 to 49, lower score means less depression severity
Time frame: Six days after the last session
Udvalg for Kliniske Undersøgelser - side effects rating scale
Development and tolerability of collateral effects using the Udvalg for Kliniske Undersøgelser - side effects rating scale ( 0 to 43 - lower score means less side effects)
Time frame: From 6th day after the first intervention up to week 24th
Change in Depression severity MADRS
Any change in Montgomery Asperger depression ratings scale ( 0 to 60 , lower score means less depression severity)
Time frame: From 6th day after the intervention up to week 24th
Change in Depression severity HDRS17
Any change in Hamilton depression ratings scale 17 ( 0 to 49, lower score means less depression severity)
Time frame: From 6th day after the intervention up to week 24th
Magnitude MADRS
The amount of the reduction, if any, in Montgomery Asperger Depression Rating Scale ( 0 to 60 , lower score means less depression severity)
Time frame: From 6th day after the intervention up to week 24th
Magnitude HDRS 17
The amount of the reduction, if any, in Hamilton Depression rating scale 17 ( 0 to 49, lower score means less depression severity)
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Time frame: From 6th day after the intervention up to week 24th
Survival of the effect - HDRS 17
For how long the Hamilton Depression rating scale 17 remains below the initial value (lower value means less depression) in each participant that had variation in this scale
Time frame: After the 6th session through 24th week
Survival of the effect - MADRS
For how long the Montgomery Asperger Depression Rating Scale remains below the initial value (lower value means less depression) in each participant that had variation in this scale
Time frame: After the 6th session through 24th week
Enhance HDRS 17
The magnitude, if any, of the change in Hamilton Depression rating scale 17 measured in patients that did not achieve any primary outcome in the first phase of the study after started sertraline as oral antidepressant.
Time frame: After the 10th visit through the 24th week
Enhance MADRS
The magnitude, if any, of the change in Montgomery Asperger Depression Rating Scale measured in patients that did not achieve any primary outcome in the first phase of the study after started sertraline as oral antidepressant.
Time frame: After the 10th visit through the 24th week