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.

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.

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