Effect of Opioid-Free vs Opioid-Based Anesthesia on Postoperative Pain and Emergence Agitation in Children Undergoing Cleft Surgery

Orofacial clefts are among the most common congenital malformations, affecting approximately 1 in 700-1500 live births worldwide. They are associated not only with aesthetic concerns but also with functional impairments in feeding, speech, hearing, and dentition, and may be accompanied by other systemic malformations, often requiring multiple surgical procedures and long-term multidisciplinary care. Although cognitive development is preserved, the psychosocial impact on both children and families can be significant.

Anesthesia in children with clefts presents specific challenges. Airway management is often more difficult due to anatomical variations, particularly in syndromic patients and those under 1 year of age. Immature organ systems affect drug metabolism, requiring careful dose adjustment. Preoperative anxiety and stress responses are common and may contribute to complications such as laryngospasm and bronchospasm. In the postoperative period, emergence agitation (EA) and emergence delirium (ED) are frequent, with reported incidence up to 80%. These conditions are characterized by restlessness, inconsolability, and disorientation, and may result in self-injury or disruption of surgical repairs.

Differentiating agitation from pain is challenging in young children due to limited communication abilities. Validated observational tools such as CHIPPS, PAEDS, and Cravero scales are used for routine clinical assessment of pain and EA/ED, although their subjective nature may limit accuracy. Therefore, evaluation of the perioperative serum cortisol, alpha-amylase, and neuropeptide Y levels will be used. These biomarkers reflect activation of the physiological stress response and indirectly indicate the presence and intensity of pain.

Pain management requires a multimodal approach. While opioids remain standard, their use is associated with adverse effects such as respiratory depression, nausea, vomiting, and delayed recovery. Consequently, opioid-free (OF) strategies using different anesthetics, including ketamine and dexmedetomidine have gained attention.

This prospective randomized clinical trial will compare opioid-based anesthesia with an opioid-free protocol in children undergoing cleft surgery. A total of 90 patients age of 3 months-7 years will be randomized in a 1:1 ratio. The opioid group will receive fentanyl, while the OF group will receive ketamine and dexmedetomidine; both groups will receive propofol, vecuronium, sevoflurane, and nitrous oxide.

Primary outcomes are postoperative pain (CHIPPS) and emergence agitation (PAEDS, Cravero). Pain will be assessed at 5 min, 15 min, 1, 2, 12, and 24 h after extubation, whereas emergence agitation will be evaluated at 5 min, 15 min, 1 h, and 2 h post-extubation. While these scales are routinely used in clinical practice, their subjective nature necessitates additional objective assessment. Therefore, secondary outcomes include evaluation of perioperative stress markers (cortisol, alpha-amylase, neuropeptide Y) and adverse events (nausea, vomiting, pruritus, constipation, respiratory depression, altered consciousness) within 24 h. Procedures will be standardized, with morning surgeries to minimize circadian variations of the biomarkers, performed by the same team. Blood samples will be collected before and after intravenous induction.

Postoperative analgesia will include paracetamol and NSAIDs, with fentanyl as rescue therapy.

The study hypothesis is that opioid-free anesthesia will provide comparable or superior analgesia, reduce the incidence of emergence agitation, attenuate the stress response, and decrease opioid-related adverse effects, thereby improving overall perioperative safety and recovery in pediatric patients undergoing cleft surgery.

The particular value of this study lies in the subgroup of children who will undergo at least two surgical procedures within the observation period. In these patients, each child will be exposed to both anesthetic protocols in separate procedures-once according to the randomly assigned regimen and the second time according to the alternative protocol. In this way, each patient serves as their own control, allowing for a more precise comparison of outcomes with a substantial reduction in inter-individual variability. This approach largely eliminates individual differences such as age, body weight, baseline hemodynamic status, individual sensitivity to anesthetics and analgesics, as well as variability in stress response and pain perception. Such a design enhances the internal validity of the study and enables a more reliable interpretation of the results.