Ventilatory support and pharmacological treatment of patients with central apnoea or hypoventilation during sleep

The concept of central sleep apnoea or hypoventilation encompasses hypercapnic central hypoventilation, such as obesity hypoventilation syndrome and eucapnic or hypocapnic central sleep apnoea. Among subjects with eucapnic or hypocapnic central sleep apnoea, several therapeutic options are available for those with Cheyne–Stokes respiration (CSR). CSR is frequent in patients with New York Heart Association stage III and IV chronic heart failure, and in various neurological disorders. In these patients, treatment modalities include optimising cardiac condition and drugs, such as theophylline, acetazolamide and/or oxygen. Ventilatory support, such as nasal continuous positive airway pressure (CPAP), bi-level pressure support, or adaptive servoventilation (ASV), has been shown to improve CSR in patients with cardiac failure; however, convincing evidence that nasal CPAP improves life expectancy in these patients is lacking. Nevertheless, the treatment of associated obstructive sleep-disordered breathing is indicated per se, as it may improve cardiac function. There is currently no proof that bi-level ventilation is superior to nasal CPAP. The few available studies that have focused on ASV have shown satisfactory control of CSR in cardiac failure patients. While ASV is not a first-line treatment choice, it appears to be superior to oxygen, CPAP and bi-level pressure ventilation in controlling the apnoea/hypopnea index and probably sleep fragmentation. As yet there are no data on mortality and, as such, firm conclusions cannot be drawn as to the role of ASV in the management of cardiac failure patients suffering from CSR. Obesity-related hypoventilation has increased dramatically over recent decades due to the epidemic increase in obesity in the developed countries. Obesity hypoventilation syndrome predisposes to the development of pulmonary hypertension and cor pulmonale. Noninvasive home ventilation is increasingly applied in obese patients with hypercapnic respiratory failure, however, initial mechanical ventilatory support can be reduced to nasal continuous positive airway pressure in only a subset of these individuals.