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.
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
Allocation
NA
Purpose
TREATMENT
Masking
NONE
Enrollment
40
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).
Department of Anesthesiology, Zhongshan Ophthalmic Center, Sun Yat-sen University
Guangzhou, Guangdong, China
Success of LMA insertion
Assessed by the absence of body movement, coughing, breath-holding, severe hemodynamic changes, or insertion difficulty.
Time frame: Intraoperative (During LMA insertion procedure)
Time required for LMA insertion
The time (in seconds) from picking up the LMA to the first successful breath as confirmed by capnography.
Time frame: 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.
Time frame: Intraoperative (during the anesthesia induction phase).
Airway Responses
Incidence and severity of body movement, cough, breath-holding, and laryngospasm.
Time frame: 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).
Time frame: 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).
Time frame: From baseline (pre-induction) up to 1 minute after LMA insertion.
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Awakening time
The interval from the discontinuation of anesthetic agents to the moment the patient follows simple commands or opens eyes.
Time frame: 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.
Time frame: 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.
Time frame: At 6 hours and 24 hours post-operation