Reply: Sleep Outcomes in Neonates with Pierre Robin Sequence Undergoing External Mandibular Distraction: A Longitudinal Analysis

We appreciate the authors’ interest in and thoughtful review of our article describing sleep and respiratory outcomes in neonates with Robin sequence undergoing mandibular distraction.1 Our primary goal was to report full polysomnography data before and after surgery. Our findings indicate that obstructive sleep apnea improves postoperatively, although it may not be completely resolved. The indication to perform distraction was multifactorial and based on the decision made by a multidisciplinary team. Although the major component of the decision-making process was the severity of obstructive sleep apnea, the definitive decision for surgery was also dependent on other aspects of the clinical scenario (e.g., findings from microlaryngoscopy and bronchoscopy, facial computed tomography scan, neurologic status of the neonate, feeding, and other comorbidities). In the absence of standardized care guidelines, it was difficult to use an a priori obstructive apnea-hypopnea index cutoff for surgical decision-making. However, all infants in our cohort undergoing surgery had severe obstructive sleep apnea (obstructive apnea-hypopnea index >10) preoperatively. In response to issues related to body position, polysomnographic study was performed in all sleep positions (supine, side-lying, and prone) in accordance with practice parameters set forth by the American Academy of Sleep Medicine. Because our retrospective study included infants over a long period of 14 years, the data on body position and the apnea-hypopnea index in prone and supine positions were not consistently available in the medical records. Therefore, body position during polysomnogram recording was not reported. While we agree with the authors that the prone versus supine obstructive apnea-hypopnea index may differ in this subset, it is not our institutional practice to recommend prone positioning in this cohort with significant obstructive sleep apnea. However, Logjes et al. raise an important point: we do not have consensus on diagnostic thresholds for obstructive sleep apnea in neonates. There is very limited literature regarding polysomnography data in normal healthy infants, especially in young neonates. This lack of data makes it challenging to interpret and quantify abnormal polysomnography results. Currently, our standard of clinical care is to extrapolate abnormal cutoffs from published literature in older children. However, this is less than ideal, as we know that infants have different sleep and respiratory physiology and pathology from children. While we used an obstructive apnea-hypopnea index cutoff of 1 to define obstructive sleep apnea (current “standard” for pediatric obstructive sleep apnea), we felt a more meaningful threshold of 10 may be more appropriate to describe persistent obstructive sleep apnea, given the findings from a recent normative data study by Daftary et al.2 In addition, a recent survey of sleep physicians by the lead author suggests that variable cutoffs are used for obstructive sleep apnea diagnosis and there is little consensus for cutoffs in this age group.3 For obstructive apnea-hypopnea index greater than 40 and less than 40, we aimed to assess the outcomes of surgery by comparing between patients with very severe obstructive sleep apnea (obstructive apnea-hypopnea index >40) and severe obstructive sleep apnea (obstructive apnea-hypopnea index <40). The obstructive apnea-hypopnea index of 40 was an arbitrary cut-off based on our institutional practice. We agree that prospective, large-scale studies are needed to better understand sleep parameters in neonates and young infants, so that more informed clinical decisions can be made. ACKNOWLEDGMENT This study was funded by the Cincinnati Children’s Hospital Research Fund. DISCLOSURE None of the authors has a financial interest to declare in relation to the content of this communication. Zarmina Ehsan, M.D.Division of Pulmonary and Sleep MedicineChildren’s Mercy–Kansas CityKansas City, Mo. K. Nicole Weaver, M.D.Division of Human Genetics Brian S. Pan, M.D.Division of Plastic Surgery Guixia Huang, M.S.Md. M. Hossain, Ph.D.Division of Biostatistics and Epidemiology Narong Simakajornboon, M.D.Division of Pulmonary and Sleep MedicineCincinnati Children’s Hospital Medical CenterCincinnati, Ohio