Effective Dose of Alfentanil Combined With Propofol for Laryngeal Mask Airway Insertion in Children

Effective Dose of Alfentanil Combined With Propofol for Laryngeal Mask Airway Insertion in Children: A Prospective, Up-and-Down Sequential Allocation Study

This study uses a prospective, up-and-down sequential allocation method to determine the median effective dose (ED50) and 95% effective dose (ED95) of alfentanil combined with propofol for successful laryngeal mask airway (LMA) insertion in children aged 7-12 undergoing elective day surgery.

Study Overview

• Status: Not yet recruiting
• Conditions: Pediatric Anesthesia; Airway Management; General Anesthesia; LMA
• Intervention / Treatment: Drug: Alfentanil

Detailed Description

Laryngeal mask airway (LMA) insertion is a common practice in pediatric day surgery. While it is less invasive than endotracheal intubation, children exhibit high airway reactivity, requiring an optimal depth of anesthesia to suppress airway reflexes. Alfentanil is an opioid with a rapid onset and short duration of action, making it potentially ideal for LMA insertion. However, current dosage recommendations for alfentanil are often extrapolated from tracheal intubation studies, which may lead to overdosage, respiratory depression, or delayed recovery in children. This study aims to determine the precise effective dose (ED50 and ED95) of alfentanil when combined with a fixed dose of propofol for smooth LMA insertion in children.

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

Contacts and Locations

• Study Contact: Name: Rui Zhang, M.D.; Phone Number: +86 15802025520; Email: zhangr52@mail.sysu.edu.cn

Study Locations

• China
  • Guangdong
    • Guangzhou, Guangdong, China, 510000
      • Department of Anesthesiology, Zhongshan Ophthalmic Center, Sun Yat-sen University
      • Contact: Tairan Lin, M.D.; Phone Number: +86 15622130745; Email: talonlam@foxmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Aged 7 to 12 years
• Undergoing elective day surgery
• ASA physical status I-II
• Body Mass Index (BMI) between 14 and 24 kg/m²
• Accompanied by a fully capable guardian within 24 hours after discharge

Exclusion Criteria:

• Allergy to opioids
• Unresolved upper respiratory tract infection within the past 1 week
• Abnormal heart, lung, liver, or kidney function, or metabolic diseases
• Airway anatomical abnormalities (e.g., micrognathia, laryngomalacia, macroglossia) or OSAHS (Obstructive Sleep Apnea-Hypopnea Syndrome)
• Use of analgesics, sedatives, or other psychotropic drugs within the past 2 weeks
• Refusal to sign the informed consent form

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• 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: Alfentanil Sequential Dose Group	Drug: Alfentanil; All patients receive 2.5 mg/kg propofol injected over 30 seconds. Alfentanil is administered 1 minute prior to propofol. The dose is adjusted by steps of 2 µg/kg based on the previous patient's response (successful insertion = decrease dose; failed insertion = increase dose).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Success of LMA insertion	Assessed by the absence of body movement, coughing, breath-holding, severe hemodynamic changes, or insertion difficulty.	Intraoperative (During LMA insertion procedure)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time required for LMA insertion	The time (in seconds) from picking up the LMA to the first successful breath as confirmed by capnography.	Intraoperative (from LMA pick-up to successful placement).
Number of LMA insertion attempts	The total number of attempts required to successfully place the LMA. An attempt is defined as the introduction of the LMA into the patient's mouth.	Intraoperative (during the anesthesia induction phase).
Airway Responses	Incidence and severity of body movement, cough, breath-holding, and laryngospasm.	During and up to 1 minute post-insertion
Changes in Heart Rate (HR)	Evaluation of heart rate (beats per minute) to assess hemodynamic stability at four time points: T0 (baseline), T1 (post-induction), T2 (immediate post-insertion), and T3 (1 min post-insertion).	From baseline (pre-induction) up to 1 minute after LMA insertion.
Changes in Mean Arterial Pressure (MAP)	Evaluation of mean arterial pressure (mmHg) to assess hemodynamic stability at four time points: T0 (baseline), T1 (post-induction), T2 (immediate post-insertion), and T3 (1 min post-insertion).	From baseline (pre-induction) up to 1 minute after LMA insertion.
Awakening time	The interval from the discontinuation of anesthetic agents to the moment the patient follows simple commands or opens eyes.	From end of surgery up to 1 hour.
Post-Anesthesia Care Unit (PACU) discharge time	The duration (in minutes) from arrival in the PACU until the patient meets discharge criteria.	Up to PACU discharge(assessed up to 4 hours after surgery completion).
Postoperative Adverse Events	Incidence of PONV (postoperative nausea and vomiting), sore throat, and hoarseness.	At 6 hours and 24 hours post-operation

Collaborators and Investigators

• Sponsor: Zhongshan Ophthalmic Center, Sun Yat-sen University

Study record dates

Study Major Dates

• Study Start (Estimated): May 1, 2026
• Primary Completion (Estimated): August 30, 2026
• Study Completion (Estimated): March 30, 2027

Study Registration Dates

• First Submitted: April 22, 2026
• First Submitted That Met QC Criteria: May 5, 2026
• First Posted (Actual): May 12, 2026

Study Record Updates

• Last Update Posted (Actual): May 12, 2026
• Last Update Submitted That Met QC Criteria: May 5, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Propofol; Alfentanil; Pediatric Anesthesia; LMA; Effective dose; Dixon Method
• Additional Relevant MeSH Terms: Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Piperidines; Fentanyl; Alfentanil
• Other Study ID Numbers: IIT2026026

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