Overlap of Obstructive Sleep Apnea (OSA) and Hypoventilation Syndrome in the context of advanced kyphoscoliosis

Keywords

hypoventilation syndrome - kyphoscoliosis - non-invasive ventilation

Introduction: In patients with neuromuscular diseases and thoracic wall deformities, sleep-disordered breathing can manifest in various forms. Hypoventilation Syndrome occurs when alveolar ventilation is insufficient to adequately eliminate the CO2 produced, and this imbalance may result from dysfunction of the respiratory muscles, changes in the mechanics of the thoracic wall, or depression of central ventilatory control.

Objective: Discuss the efficacy of BiPAP (Bilevel Positive Airway Pressure) in the treatment of sleep-disordered breathing in patients with OSA and Hypoventilation Syndrome.

Methods: Male, 54 years old, under Neurology follow-up due to the diagnosis of OSA, undergoing home non-invasive ventilation (NIV) with CPAP (Continuous Positive Airway Pressure) for over 10 years, reporting persistent daytime fatigue. Given the presence of congenital kyphoscoliosis and grade III obesity, additional investigations were performed. Type 1 polysomnography with arterial blood gas analysis during sleep revealed an increase in PaCO2 > 10 mmHg compared to the awake examination. Additionally, spirometry showed signs of restrictive lung disorder. Due to findings consistent with the diagnosis of Hypoventilation Syndrome overlapping with OSA, a switch to BiPAP was recommended, resulting in symptom improvement.

Results: Kyphoscoliosis, a common thoracic wall deformity, is associated with a marked restrictive respiratory pattern. The stiffness of the thoracic wall caused by this condition reduces functional residual capacity (FRC) and impairs lung compliance. Two large cohort studies over 10 years revealed that the survival of patients with thoracic wall deformities treated with oxygen was nearly three times lower compared to those treated with NIV. Piesiak et al. (2015) evaluated, over one year, 12 patients with chronic respiratory failure due to advanced kyphoscoliosis treated with BiPAP with AVAPS (Average Volume Assured Pressure Support). A significant improvement in PaO2 and PaCO2, as well as in average oxygen saturation during sleep, was observed.

Conclusion: The coexistence of OSA with other comorbidities, such as advanced kyphoscoliosis, demonstrates the complexity involved in the treatment of sleep-disordered breathing. In this condition, ventilation with BiPAP stands out as the therapy of choice.

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Publikationsverlauf

Artikel online veröffentlicht:
16. September 2025