Oxygen Therapy in Sleep Disordered Breathing.
Sleep disordered breathing (SDB) is highly prevalent in adults and leads to significant cardiovascular and neurological sequelae. Intermittent hypoxia during sleep is a direct consequence of SDB. Nocturnal supplemental oxygen (NSO) administration has been used as a therapeutic alternative to positive airway pressure (PAP) in SDB.This review critically evaluates the current evidence regarding the use of NSO in patients with SDB, and whether it is an effective therapy in comparison to PAP or no therapy.NSO significantly improves oxygen saturation in obstructive sleep apnea (OSA) but is inferior to PAP in terms of reducing apnea severity and may prolong the duration of obstructive apneas. The effect of NSO on daytime sleepiness remains unclear, but NSO may improve physical function-related quality of life in OSA. Its effects on blood pressure reduction remains inconclusive. The effects of NSO vs. PAP in OSA with comorbid COPD (Overlap Syndrome, OVS) are unknown. NSO is effective in reducing central sleep apnea (CSA) related to congestive heart failure, however, its impact on mortality and cardiovascular clinical outcomes are being investigated by an ongoing clinical trial.Studies are inconclusive or limited regarding clinical outcomes with oxygen therapy compared with sham or PAP therapy in patients with OSA and OVS. Oxygen does mitigate central sleep apnea. This review examines the crucial knowledge gaps and suggests future research priorities to clarify the effects of optimal dose and duration of NSO, alone or in combination with PAP, on cardiovascular, sleep and cognitive outcomes.
Authors: Salam Zeineddine, James A Rowley, Susmita Chowdhuri