Tolerance to Sevoflurane in Children Undergoing Repeated Drug Exposure

Study Overview
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Brief Summary
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Deep sedation or general anesthesia is frequently required for infant that need radiotherapy to treat malignancies. As radiation therapy usually consist of several sessions, these patients are exposure to several consecutive anesthetic exposures (e.g. for some central nervous system tumors 30 sessions of radiotherapy are required). In our center, this 30-min anesthetic exposure are with sevoflurane. Considering that repeated daily exposure to such potent drugs, as general anesthetics, may induce tolerance, it is reasonable to explore whether this phenomenon is occurring in this population. The aim of this observational study was to determine if a repeated exposure to sevoflurane is associated with the development of clinical and electroencephalographic tolerance. We will enroll 16 pediatric patients, and we will measure the time needed to appropriately place the laryngeal mask (clinical effect) and we also will compare the electroencephalographic signal under anesthesia across the different sessions (electroencephalographic effect).

Detailed Description
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The purpose of this study is to evaluate the development of tolerance to sevoflurane in children undergoing repeated drug exposure. We will evaluate the development of tolerance in two ways: Clinical: as the time needed to perform the inhalation induction, with a standardized protocol. Electroencephalographic: we will record every 3 sessions the electroencephalographic activity of the patients. We will perform classical spectral analysis, and coherence analysis as well. This observational study will be mainly exploratory since there are no other previous report in this topic

Official Title
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Evaluation of the Development of Tolerance to Sevoflurane in Children Undergoing Repeated Anesthesia Exposure

Conditions
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Anesthesia, Tolerance

Intervention / Treatment
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* Drug: Sevoflurane


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients undergoing radiotherapy Requiring general anesthesia Exclusion Criteria: Previous Radiotherapy Malignant Hyperthermia history

Ages Eligible for Study
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Minimum Age: 10 Months
Maximum Age: 12 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Pediatric patients undergoing radiotherapy<br>Pediatric patients undergoing general anesthesia for radiotherapy treatment. General anesthesia will be accomplished exclusively by the administration of sevoflurane. The inhalatory induction will be performed with sevofluorane at 8% with O2 4Lt/min. The maintenance will be with sevofluorane at an end tidal of 2.5% with 1Lt/min of O2. The EEG will be obtain with SedLine monitor | Drug: Sevoflurane<br>* Describe how a reiterative anesthesia exposure could induce tolerance to the anesthetic.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Theta power in the EEG spectrum under anesthesia | Theta power obtained from the EEG signal, with the patient under general anesthesia | Last session of radiotherapy (compare to first session) - Up to 6 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time to Laryngeal Mask insertion | The time in seconds between the induction beginning and the correct laryngeal mask placement | Last session of radiotherapy (compare to first session) - Up to 6 weeks | 
| Alpha power in the EEG spectrum under anesthesia | Alpha power obtained from the EEG signal, with the patient under general | Last session of radiotherapy (compare to first session) - Up to 6 weeks | 
| Coherence | Coherence between frontal electrodes in bands of the spectrum | Last session of radiotherapy (compare to first session) - Up to 6 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Anesthesia, Electroencephalogram, Spectral analysis