Cleft lip and palate surgeries present unique anesthetic challenges due to shared airway access with the surgical field, frequent anatomical abnormalities, and a predominantly infant and toddler population. These factors substantially increase the risk of perioperative respiratory adverse events (PRAEs), including laryngospasm, bronchospasm, desaturation, post-extubation stridor, and unanticipated re-intubation.

This prospective single-center observational cohort study aims to determine the true incidence of PRAEs in pediatric patients undergoing elective cleft lip and/or palate repair under general anesthesia, and to identify independent predictive risk factors using standardized airway assessment tools including the Han Mask Ventilation Score and the Intubation Difficulty Score (IDS). No interventions beyond routine clinical practice will be applied. All airway management decisions will remain at the discretion of the attending anesthesiologist.

Cleft lip and palate are among the most common congenital craniofacial anomalies.

The surgical population predominantly consists of infants and young children who may present with associated syndromes, micrognathia, retrognathia, or obstructive sleep apnea - all of which contribute to difficult mask ventilation and difficult intubation. Sharing the airway with the surgical team and the use of the Dingman retractor further increase the risk of airway compromise during emergence and extubation. Published data on PRAE incidence in this population are largely retrospective and heterogeneous, and no adequately powered prospective study has systematically evaluated predictive risk factors using validated scoring systems.

Study Design:

Prospective, single-center, observational cohort study conducted at Marmara University Pendik Training and Research Hospital, Istanbul, Turkey. No interventions beyond established routine anesthesia protocols will be performed. Parental written informed consent will be obtained prior to enrollment.

Anesthetic Protocol:

All patients will undergo standard intraoperative monitoring (ECG, non-invasive blood pressure, pulse oximetry, end-tidal CO₂). Anesthesia will be induced with sevoflurane inhalation followed by intravenous induction after vascular access. Maintenance will be achieved with sevoflurane and remifentanil infusion. Analgesia and perioperative steroid administration will follow the department's routine protocol.

Data Collection:

Preoperative variables: age, weight, cleft type (unilateral/bilateral/isolated lip/isolated palate/combined), cleft width and depth, alveolar gap, micrognathia, retrognathia, cervical extension limitation, OSAS history, Pierre Robin sequence, and prior ICU admission.

Intraoperative variables: induction type and agents, neuromuscular blockade use, operator experience level, mask ventilation difficulty (Han Score), number of intubation attempts, laryngoscopy device used, Cormack-Lehane grade, VIDIAC score, IDS score, adjunct airway tools employed, minimum SpO₂ and bradycardia during intubation, Dingman retractor duration, and steroid use.

Primary outcome assessment: extubation-related minimum SpO₂, laryngospasm, bronchospasm, post-extubation stridor, coughing episodes, and need for unplanned re-intubation or ICU admission.

Vital signs (heart rate, SpO₂, blood pressure) will be recorded at intubation, 15, 30, 60, 90, 120 minutes intraoperatively, and postoperatively.

Statistical Analysis:

Descriptive statistics will be reported as mean ± SD or median (IQR) for continuous variables and as n (%) for categorical variables. Univariate comparisons between PRAE and non-PRAE groups will employ independent samples t-test, Mann-Whitney U test, chi-square, or Fisher's exact test as appropriate. Independent predictors of PRAE will be identified via binary logistic regression (backward stepwise method), reported as odds ratios (OR) with 95% confidence intervals. Statistical significance threshold: p<0.05.

Sample Size:

Based on a reported PRAE incidence of ~25% in comparable populations, a minimum of 120 patients is required (α=0.05, power=80%, G*Power 3.1). Accounting for anticipated dropout and exclusions, the target enrollment is 140-150 patients.

Inclusion Criteria:

• Age 0-3 years (infants and toddlers)
• Scheduled for elective cleft lip and/or palate repair surgery
• General anesthesia planned
• Written parental/guardian informed consent obtained

Exclusion Criteria:

• Pre-existing respiratory failure or active tracheostomy
• Emergency surgical procedures
• Inability to obtain parental/guardian consent

Infants and toddlers aged 0-3 years scheduled for elective cleft lip and/or palate repair under general anesthesia . No randomization is performed; all management follows routine institutional anesthesia practice.