ANI and Remifentanil in Skull Pin Fixation.

Study Overview
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Brief Summary
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Forty patients were enrolled, and all patients used total intravenous anesthesia (remifentanil-propofol based total intravenous analgesia) as anesthesia induction and maintenance. According to the preliminary data of this department, patients who underwent intracranial surgery for skull pin fixation used remifentanil 5.0-6.0 ng/ml, while the hemodynamics is relatively stable. Therefore, when this plan is implemented, the patient needs to be under the same depth of anesthesia (monitored by electroencephalography, maintaining a value of 40-60), first start with remifentanil 6.0 ng/ml, and use the up and down method as adjust 0.5 ng/ml of concentration of remifentanil each time. An Analgesia Nociception Index(ANI) lower than 30 and hyperdynamics (the increased heart rate(HR) and mean blood pressure(MBP) up 20% of baseline or HR>100bpm and arterial blood pressure(ABP)>180/100mmHg) indicates insufficient analgesia, therefore increase it by 0.5 ng/ml; an ANI higher than 30 and stable hemodynamics (the changes of HR and MBP within 20% of baseline or HR<50bpm and ABP<90/50mmHg) indicates that analgesia is acceptable, and the next patient will decrease it by 0.5 ng/ml during skull pin fixation. Data collection: Heart Rate, Measure blood pressure, Analgesia Nociception Index, Bispectral index, concentrations of propofol and remifentanil before 2 mins, during, 5, and 15 mins of skull pin fixation were recorded and analyzed.

Official Title
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To Explore the Optimal Dose of Remifentanil for Skull Pin Fixation in Intracranial Surgery.

Conditions
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Pain, Procedural

Intervention / Treatment
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* Drug: Remifentanil


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Must be at least 20 years old and less than 80 years old With anesthesia risk grade below grade three (including grade three) (ASA I III) Patients who are expected to undergo intracranial surgery for skull pin fixation Exclusion Criteria: Those with anesthesia risk classification ASA class IV or higher Those who are allergic to opioid analgesics or propofol drugs Emergency patients

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 80 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: Prevention
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: neurosurgery with fixation<br> | Drug: Remifentanil<br>* First start with remifentanil 6.0 ng/ml, and use the up and down method as adjust 0.5 ng/ml of concentration of remifentanil each time. An ANI lower than 30 and hyperdynamics (the increased heart rate and mean blood pressure up 20% of baseline or heart rate>100bpm and arterial blood pressure>180/100mmHg) indicates insufficient analgesia, therefore increase it by 0.5 ng/ml; an ANI higher than 30 and stable hemodynamics (the changes of HR and MBP within 20% of baseline or HR<50bpm and ABP<90/50mmHg) indicates that analgesia is acceptable, and the next patient will decrease it by 0.5 ng/ml during skull pin fixation.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 50% effect concentration of remifentanil | 50% effect concentration of remifentanil will be recorded at 2 mins before fixation, during fixation, 5mins after fixation, and 15 mins after fixation. | peri-fixation period | 
| 90% effect concentration of remifentanil | 90% effect concentration of remifentanil will be recorded at 2 mins before fixation, during fixation, 5mins after fixation, and 15 mins after fixation. | peri-fixation period | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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remifentanil, pain, analgesia nociception index