Upper airway morphology in Down Syndrome patients under dexmedetomidine sedation / Morfologia das vias aéreas superiores em pacientes com síndrome de Down sob sedação com dexmedetomidina

Abstract Background and objectives: Children with Down Syndrome are vulnerable to significant upper airway obstruction due to relative macroglossia and dynamic airway collapse. The objective of this study was to compare the upper airway dimensions of children with Down Syndrome and obstructive sleep apnea with normal airway under dexmedetomidine sedation. Methods: IRB approval was obtained. In this retrospective study, clinically indicated dynamic sagittal midline magnetic resonance images of the upper airway were obtained under low (1 mcg/kg/h) and high (3 mcg/kg/h) dose dexmedetomidine. Airway anteroposterior diameters and sectional areas were measured as minimum and maximum dimensions by two independent observers at soft palate (nasopharyngeal airway) and at base of the tongue (retroglossal airway). Results and conclusions: Minimum anteroposterior diameter and minimum sectional area at nasopharynx and retroglossal airway were significantly reduced in Down Syndrome compared to normal airway at both low and high dose dexmedetomidine. However, there were no significant differences between low and high dose dexmedetomidine in both Down Syndrome and normal airway. The mean apnea hypopnea index in Down Syndrome was 16 ± 11. Under dexmedetomidine sedation, children with Down Syndrome and obstructive sleep apnea when compared to normal airway children show significant reductions in airway dimensions most pronounced at the narrowest points in the nasopharyngeal and retroglossal airways.

Resumo Justificativa e objetivos: As crianças com síndrome de Down (SD) são vulneráveis à obstrução significativa das vias aéreas superiores devido à macroglossia relativa e ao colapso dinâmico das vias aéreas. O objetivo deste estudo foi comparar as dimensões das vias aéreas superiores de crianças com SD e apneia obstrutiva do sono (AOS) com vias aéreas normais (VAN) sob sedação com dexmedetomidina (DEX). Métodos: Aprovação IRB foi obtida. Neste estudo retrospectivo, imagens clinicamente indicadas de ressonância magnética da dinâmica das vias aéreas superiores em plano sagital na linha média foram obtidas sob dose baixa (1 mcg/kg/h) e dose alta (3 mcg/kg/h) de DEX. Os diâmetros anteroposteriores das vias aéreas e as áreas seccionais foram medidas como dimensões mínimas e máximas por dois observadores independentes, no palato mole (região nasofaríngea) e na base da língua (região retroglossal). Resultados e conclusões: O diâmetro mínimo anteroposterior e a área seccional mínima das regiões nasofaríngea e retroglossal estavam significativamente reduzidos na SD em comparação com VAN, tanto com a dose baixa quanto com a dose alta de DEX. Contudo, não houve diferenças significativas entre as doses baixa e alta de DEX em SD e VAN. A média do índice de apneia e hipopneia na SD foi de 16 ± 11. Sob sedação com DEX, as crianças com SD e AOS, quando comparadas com as crianças com VAN, apresentaram reduções significativas nas dimensões das vias aéreas, mais pronunciadas nos pontos mais estreitos das regiões nasofaríngea e retroglossal.

Upper airway morphology in Down Syndrome patients under dexmedetomidine sedation.

BACKGROUND AND OBJECTIVES: Children with Down Syndrome are vulnerable to significant upper airway obstruction due to relative macroglossia and dynamic airway collapse. The objective of this study was to compare the upper airway dimensions of children with Down Syndrome and obstructive sleep apnea with normal airway under dexmedetomidine sedation. METHODS: IRB approval was obtained. In this retrospective study, clinically indicated dynamic sagittal midline magnetic resonance images of the upper airway were obtained under low (1mcg/kg/h) and high (3mcg/kg/h) dose dexmedetomidine. Airway anteroposterior diameters and sectional areas were measured as minimum and maximum dimensions by two independent observers at soft palate (nasopharyngeal airway) and at base of the tongue (retroglossal airway). RESULTS AND CONCLUSIONS: Minimum anteroposterior diameter and minimum sectional area at nasopharynx and retroglossal airway were significantly reduced in Down Syndrome compared to normal airway at both low and high dose dexmedetomidine. However, there were no significant differences between low and high dose dexmedetomidine in both Down Syndrome and normal airway. The mean apnea hypopnea index in Down Syndrome was 16±11. Under dexmedetomidine sedation, children with Down Syndrome and obstructive sleep apnea when compared to normal airway children show significant reductions in airway dimensions most pronounced at the narrowest points in the nasopharyngeal and retroglossal airways.

[Upper airway morphology in Down Syndrome patients under dexmedetomidine sedation]. / Morfologia das vias aéreas superiores em pacientes com síndrome de Down sob sedação com dexmedetomidina.

BACKGROUND AND OBJECTIVES: Children with Down Syndrome are vulnerable to significant upper airway obstruction due to relative macroglossia and dynamic airway collapse. The objective of this study was to compare the upper airway dimensions of children with Down Syndrome and obstructive sleep apnea with normal airway under dexmedetomidine sedation. METHODS: IRB approval was obtained. In this retrospective study, clinically indicated dynamic sagittal midline magnetic resonance images of the upper airway were obtained under low (1mcg/kg/h) and high (3mcg/kg/h) dose dexmedetomidine. Airway anteroposterior diameters and sectional areas were measured as minimum and maximum dimensions by two independent observers at soft palate (nasopharyngeal airway) and at base of the tongue (retroglossal airway). RESULTS AND CONCLUSIONS: Minimum anteroposterior diameter and minimum sectional area at nasopharynx and retroglossal airway were significantly reduced in Down Syndrome compared to normal airway at both low and high dose dexmedetomidine. However, there were no significant differences between low and high dose dexmedetomidine in both Down Syndrome and normal airway. The mean apnea hypopnea index in Down Syndrome was 16±11. Under dexmedetomidine sedation, children with Down Syndrome and obstructive sleep apnea when compared to normal airway children show significant reductions in airway dimensions most pronounced at the narrowest points in the nasopharyngeal and retroglossal airways.

Effect of increasing depth of dexmedetomidine and propofol anesthesia on upper airway morphology in children and adolescents with obstructive sleep apnea.

STUDY OBJECTIVE: To examine the dose-response effects of dexmedetomidine (DEX) and propofol (PROP) on airway morphology in children and adolescents with a history of obstructive sleep apnea (OSA). DESIGN: Prospective, single-blinded, controlled comparative study. SETTING: University-affiliated teaching hospital. PATIENTS: 60 patients with a history of OSA who presented for a magnetic resonance imaging (MRI) sleep study. INTERVENTIONS: Patients were randomized to two equal groups (DEX or PROP). Magnetic resonance images of the airway were obtained during low (1 µg/kg/hr) and high (3 µg/kg/hr) doses of DEX, or low (100 µg/kg/m) and high (200 µg/kg/m) doses of PROP, based on group assignment. MEASUREMENTS: The airway anteroposterior (AP) diameter, transverse diameter, and sectional areas were measured at the level of the nasopharyngeal airway and retroglossal airway. The influence of the two drugs and OSA severity, as determined by polysomnography, on airway dimensions was examined using mixed-effects analysis of covariance models. MAIN RESULTS: Upper airway morphology was completed in 45 patients. Most airway measurements showed statistically nonsignificant associations with increasing doses of PROP and DEX. As the dosage increased, average airway dimensions were typically unchanged or slightly increased with DEX compared with airway dimensions that were unchanged or slightly decreased with PROP. An airway intervention was required in three children (11%) in the DEX group and 7 children (23%) in the PROP group (P = NS). CONCLUSIONS: Both agents provided an acceptable level of anesthesia for MRI sleep studies in patients with OSA, with statistically nonsignificant changes in airway dimensions.