To Explore the Optimal Dose of Alfentanil for Skull Pin Fixation in Intracranial Surgery

To Explore the Optimal Dose of Alfentanil for Skull Pin Fixation Under Surgical Pleth Index Monitor in Intracranial Surgery

Forty patients were enrolled, and all patients used total intravenous anesthesia (alfentanil-propofol based TIVA) as anesthesia induction and maintenance. According to our experience, patients who underwent intracranial surgery for skull pin fixation used alfentanil 100 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 EEG, maintaining a value of 40-60), first start with alfentanil 100 ng/ml, and use the up and down method as adjust 25 ng/ml of concentration of alfentanil each time. An SPI higher than 80 and hyperdynamics (the increased HR and MBP up 20% of baseline or HR>100bpm and ABP>180/100mmHg) indicates insufficient analgesia, therefore increase it by 25 ng/ml at the next patient; an SPI lower than 80 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 25 ng/ml during skull pin fixation. If the analgesia is inadequate, increase alfentanil concentration will be prescribed. On the other hand, if analgesia is adequate, however hyperdynamics was noted, beta blocker or calcium channel blocker will be prescribed. If hypotension (ABP<90/50 mmHg) or bradycardia (HR<50 bpm) occur, we first stop alfentanil infusion and treated with ephedrine or atropine, respectively.

Data collection: HR, MBP, SPI, BIS, systolic pressure variation (SPV), pulse pressure variation (PPV) , concentrations of propofol and alfentanil before 2 mins, during, 5, and 15 mins of skull pin fixation were recorded and analyzed.

Study Overview

• Status: Not yet recruiting
• Conditions: Procedural Pain
• Intervention / Treatment: Drug: Alfentanil

• Study Type: Interventional
• Enrollment (Estimated): 40
• Phase: Phase 4

Contacts and Locations

Study Locations

• Taiwan
  • Kaohsiung, Taiwan
    • Kaohsiung Medical University Chung-Ho Memorial Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Must be at least 18 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 alfentanil or propofol drugs
• Emergency patients

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Participant Group; Neurosurgery with fixation

Drug: Alfentanil; We first start with alfentanil 100 ng/ml, and use the up and down method as adjust 25 ng/ml of concentration of alfentanil each time. An SPI higher than 80 and hyperdynamics (the increased HR and MBP up 20% of baseline or HR>100bpm and ABP>180/100mmHg) indicates insufficient analgesia, therefore increase it by 25 ng/ml at the next patient; an SPI lower than 80 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 25 ng/ml during skull pin fixation. If the analgesia is inadequate, increase alfentanil concentration will be prescribed. On the other hand, if analgesia is adequate, however hyperdynamics was noted, beta blocker or calcium channel blocker will be prescribed. If hypotension (ABP<90/50 mmHg) or bradycardia (HR<50 bpm) occur, we first stop alfentanil infusion and treated with ephedrine or atropine, respectively.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
50% effect concentration of alfentanil	50% effect concentration of alfentanil will be recorded at 2 mins before fixation, during fixation, 5 mins after fixation, and 15 mins after fixation.	peri-fixation period
95% effect concentration of alfentanil	95% effect concentration of alfentanil will be recorded at 2 mins before fixation, during fixation, 5 mins after fixation, and 15 mins after fixation.	peri-fixation period

Collaborators and Investigators

• Sponsor: Kaohsiung Medical University Chung-Ho Memorial Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): August 13, 2024
• Primary Completion (Estimated): December 31, 2024
• Study Completion (Estimated): December 31, 2024

Study Registration Dates

• First Submitted: August 18, 2024
• First Submitted That Met QC Criteria: August 19, 2024
• First Posted (Actual): August 20, 2024

Study Record Updates

• Last Update Posted (Actual): August 20, 2024
• Last Update Submitted That Met QC Criteria: August 19, 2024
• Last Verified: June 1, 2024

More Information

Terms related to this study

• Keywords: pain; alfentanil; surgical pleth index
• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Pain, Procedural; Physiological Effects of Drugs; Central Nervous System Depressants; Peripheral Nervous System Agents; Analgesics; Sensory System Agents; Anesthetics, Intravenous; Anesthetics, General; Anesthetics; Analgesics, Opioid; Narcotics; Alfentanil
• Other Study ID Numbers: KMUHIRB-F(II)-20240191

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No