Medical Journal of the Islamic Republic Of Iran

en Effect of Controlled versus Spontaneous Ventilation on Postoperative Emergence Agitation in 2–4-Year-Old Children Undergoing Adenotonsillectomy: A Double-Blind Randomized Clinical Trial Anesthesia Anesthesia Original Research Original Research Background: Emergence agitation (EA), characterized by restlessness and inconsolable behavior, is a common postoperative complication in children after sevoflurane anesthesia, potentially causing secondary injuries and prolonged PACU stays. While its etiology is multifactorial, the mode of ventilation during anesthesia may be a contributing yet under-investigated factor. This study aimed to compare the effects of controlled mechanical ventilation (CMV) versus spontaneous ventilation (SV) on EA, pain, recovery time, and related outcomes in children aged 2–4 years undergoing adenotonsillectomy.    Methods: This randomized double-blind trial enrolled 79 children (2–4 years, ASA I) undergoing adenotonsillectomy. Patients were randomized to controlled mechanical ventilation (CMV) or spontaneous ventilation (SV) during emergence. Anesthesia was standardized with sevoflurane and reversal with neostigmine/atropine. The primary outcome was emergence agitation assessed via the Richmond Agitation-Sedation Scale (RASS). Statistical analysis involved Analysis of covariance (ANCOVA), independent t-tests, and Chi-square or Fisher’s exact tests. The P<0.05 was considered a statistically significant level.    Results: The mean age was significantly higher in the controlled ventilation group compared to the spontaneous breathing group (40.75 ± 4.73 vs. 37.31 ± 5.80 months, P=0.005). EA incidence and agitation scores were significantly lower in the CMV group (0.60 ± 0.63 vs. 1.21 ± 0.61, P=0.001). Postoperative pain was reduced (VAS 2.80 ± 1.18 vs. 5.15 ± 1.69, P=0.001), recovery duration was shorter (38.98 ± 6.96 min vs. 44.72 ± 6.57 min, P=0.001), and EtCO₂ levels were lower (34.43 ± 2.52 mmHg vs. 36.82 ± 1.83 mmHg, P=0.001) in the CMV group. Oxygen saturation, neuromuscular monitoring, and postoperative nausea were comparable between groups. No delirium cases were observed.    Conclusion: CMV significantly reduces EA, postoperative pain, and PACU stay duration compared with SV in children undergoing adenotonsillectomy, likely by preventing hypercapnia and stabilizing physiological parameters. CMV is recommended as the preferred ventilation strategy in this population, while the absence of delirium confirms the low inherent neurological risk in children less than 5 years.   Adenotonsillectomy, Emergence agitation, Controlled ventilation, Spontaneous ventilation, Pediatrics 328 334 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-9931-1&slc_lang=en&sid=1 Taymaz Amiraslani amiraslani.ta@iums.ac.ir 200319475328460097392 200319475328460097392 No Department of Anesthesiology and Pain Medicine, School of Medicine, Iran University of Medical Sciences, Tehran, Iran Salumeh Sehat Kashani Salume.sehat@gmail.com 200319475328460097393 200319475328460097393 Yes Department of Anesthesiology and Pain Medicine, School of Medicine, Iran University of Medical Sciences, Tehran, Iran Mohammad Ghaemi Mohamgh1986@gmail.com 200319475328460097394 200319475328460097394 No Department of Anesthesiology and Pain Medicine, School of Medicine, Iran University of Medical Sciences, Tehran, Iran Tahereh Sorbi drtaherehsorbi@yahoo.com 200319475328460097395 200319475328460097395 No Department of Anesthesiology and Pain Medicine, School of Medicine, Iran University of Medical Sciences, Tehran, Iran Mahya Sabouri mahya.sabourii@gmail.com 200319475328460097396 200319475328460097396 No Department of Anesthesiology and Pain Medicine, School of Medicine, Iran University of Medical Sciences, Tehran, Iran