0805 Halo-Traction induced Obstructive sleep apnea
Authors: Nayak Vignesh , Bliton Kyle , Maddox Mary 
Published: May 2022

Abstract

Introduction
Obstructive sleep apnea (OSA) is the most common sleep-related breathing disorder. It is a multi-factorial disease with a variety of identified causes including age, male gender, obesity, craniofacial and upper airway abnormalities. We would like to describe a patient who had severe OSA following application of Halo traction, which significantly improved following the removal of the device.
Report of Cases: 14-year-old male with medical history of spina bifida, chiari malformation s/p decompression, shunted hydrocephalus and severe scoliosis, was admitted to the hospital for anterior spinal discectomy L2-S1 and Halo application with traction for scoliosis. He previously had nocturnal polysomnogram (NPSG) in 2017 that demonstrated very mild mixed apnea with an apnea hypopnea index (AHI) of 5.5. Because central apneas were very brief and clustered in REM, family elected to repeat a study rather than treat. In 2019, he had a follow up study with
complaints of snoring and thirst, and this demonstrated an AHI of 21 with 29 brief central
apneas and 72 hypopneas, 1 obstructive apnea. He had a T&A and turbinate ablation and due
to the global pandemic did not undergo repeat sleep study.
During admission for his anterior spinal discectomy and Halo, he demonstrated persistent night
time hypoxia. A split night sleep study showed evidence of severe OSA with pretreatment AHI
of 94.4, oxygen nadir 86%. Continuous positive airway pressure (CPAP) was initiated at 5 cm
of water and titrated to 11 cm of water. On CPAP of +11 severe obstructive events continued
with an AHI of 40.6, oxygen nadir 92%. A bilevel positive airway pressure (BIPAP) titration
study the subsequent night started at pressures of 12/6 and titrated to 21/9 with respiratory
rate of 12 yet demonstrated AHI of 51, oxygen nadir 89%. Study transitioned to average
volume assisted pressure support (AVAPS) with IPAP max of 26, IPAP minimum of 12 EPAP of 9, tidal volume of 175ml, rate of 12 with inadequate control of his obstructive events with an
AHI of 24.8, minimum oxygen saturations of 91. While hospitalized, he remained on AVAPS
with normal capillary blood gases. Halo traction was removed 2 weeks following his surgery
with plan was to send him home on AVAPS and repeat NPSG in 6 weeks. However, as a result
of COVID pandemic/Philips recall, CPAP was the only device available for home use, so CPAP
therapy at +8 cm was trialed overnight, demonstrating oxygen nadir of 92% and a normal
capillary blood gas in the morning. Patient was then discharged home on CPAP of +8 cm of
water. He returned back to sleep center for a BIPAP titration study to re-establish BIPAP/AVAPS settings, as his inpatient sleep study had shown severe OSA. During the sleep study, he was started on BIPAP 12/6 and he remained on it throughout the night with 0 central and 0 obstructive events. As he did well, he was advised to continue CPAP +8 with plans to repeat the sleep study off CPAP. In clinic follow up, he reported mild skin breakdown and occasionally waking unrefreshed.

Conclusion
As our patient did significantly better following the removal of Halo traction device, it is likely that Halo traction device caused fixed over flexion of the cervical spine that resulted in decrease in his airway diameter, which further worsened during his sleep, and caused severe OSA.

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