Central sleep apnea

Abstract

Central apnea syndrome is a disorder with protean manifestations and concomitant conditions. It can occur as a distinct clinical entity or as part of another clinical syndrome. The pathogenesis of central sleep apnea (CSA) varies depending on the clinical condition. Sleep-related withdrawal of the ventilatory drive to breathe is the common denominator among all cases of central apnea, whereas hypocapnia is the final common pathway leading to apnea in the majority of central apnea. Medical conditions most closely associated with CSA include heart failure, stroke, spinal cord injury, and opioid use, among others. Nocturnal polysomnography is the standard diagnostic method, including measurement of sleep and respiration. The latter includes detection of flow, measurement of oxyhemoglobin saturation and detection of respiratory effort. Management strategy incorporates clinical presentation, associated conditions, and the polysomnographic findings in an individualized manner. The pathophysiologic heterogeneity may explain the protean clinical manifestations and the lack of a single effective therapy for all patients. While research has enhanced our understanding of the pathogenesis of central apnea, treatment options are extrapolated from treatment of obstructive sleep apnea. Co-morbid conditions and concomitant obstructive sleep apnea influence therapeutic approach significantly. Therapeutic options include positive pressure therapy, pharmacologic therapy, and supplemental Oxygen. Continuous positive airway pressure (CPAP) is the initial standard of care, although the utility of other modes of positive pressure therapy, as well as pharmacotherapy and device-based therapies, are currently being investigated.

Keywords: Apneic threshold; CPAP; Central sleep apnea; Cheyne–Stokes respiration; Hypocapnia; Sleep-disordered breathing.