Optimal Remifentanil Concentration and Thyroidectomy

Study Overview
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Brief Summary
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The study is aimed at determining the remifentanil effect site concentration suppressing the cough at extubation after surgical thyroidectomy, performed under remifentanil/desflurane based general anesthesia, expressed as median and 95th percentile effective dose. Possible hemodynamic instability, respiratory depression or prolongation of awakening time are also sought.

Official Title
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Optimal Effect Site Remifentanil Concentration for Smooth Extubation After Thyroid Surgery

Conditions
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Anesthesia

Intervention / Treatment
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* Other: Remifentanil Effect site concentration


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 18<age<67 6 hrs fasting American society of anesthesiology (ASA) Physical Status I o II Informed consent Exclusion Criteria: Absence of inclusion criteria Use of cough suppressors, angiotensin converting enzyme-inhibitors, sedatives 4 weeks before surgery Arhythmia, pacemaker or unstable cardiovascular disease Hepatic or renal failure Anticipated difficulty in airways management Chronic obstructive pulmonary disease (COPD), Asthma, increased risk for inhalation, airway infection in the previous 4 weeks; Smoker Obesity (BMI >35) Pregnancy Hypersensitivity to drugs administered for the study

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 67 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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Design Details

Primary Purpose: Other
Intervention Model: Single Group Assignment
Interventional Model Description: Prospective observational study. Decreasing/increasing remifentanil effect site concentrations (Dixon's up and down model) to obtain cough-free extubation after thyroidectomy
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: remifentanil<br>After skin suture, a predetermined Effect site remifentanil concentration will be achieved. Starting from 1.5 ng/ml in the first patient and increased or decreased by 0.2 ng/ml intervals based on the previous patient response: up if cough present, down otherwise (Dixon's up and down method). | Other: Remifentanil Effect site concentration<br>* After skin suture, a predetermined Effect site remifentanil concentration will be achieved. Starting from 1.5 ng/ml in the first patient and increased or decreased by 0.2 ng/ml intervals based on the previous patient response: up if cough present, down otherwise (Dixon's up and down method).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cough | Any episode of sudden and violent abdominal contraction interrupting normal quite spontaneous or assisted ventilation would be accounted as cough and defines non-smooth extubation | 15 minutes after surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Hemodynamics 1 | Heart Rate (bpm) | 15 minutes after surgery | 
| Hemodynamics 2 | Blood pressure (mmHg) | 15 minutes after surgery | 
| Respiratory outcome 1 | Tidal Volume (ml) | 15 minutes after surgery | 
| Respiratory outcome 2 | End Tidal Carbon Dioxide (mmHg) | 15 minutes after surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Thyroidectomy, Remifentanil, Extubation, Cough, Target controlled infusion