Efficacy of Oxygen Therapy for the Relief of Dyspnea in Palliative Care: A Systematic Review.

IntroductionDyspnea is a prevalent, debilitating, and distressing symptom in palliative care. This systematic review evaluated the efficacy of oxygen therapy and oxygen delivery modalities compared with room air, medical air (FiO2 21%), pharmacological therapy, or other respiratory support modalities for relieving dyspnea in patients with advanced, progressive, and incurable diseases.MethodsA systematic search of PubMed and Scopus was conducted for studies published up to February 15, 2026, evaluating oxygen therapy or oxygen delivery modalities for dyspnea in palliative care. Risk of bias was assessed using the Cochrane RoB 2 tool and the Newcastle-Ottawa Scale. Data synthesis was performed narratively.ResultsNine studies encompassing 879 participants were included. Among seven clinical trials, only one presented a low overall risk of bias. In non-hypoxemic patients, oxygen therapy was not consistently superior to medical air. In hypoxemic patients, limited evidence suggested benefit from conventional oxygen compared with room air, while high-flow nasal cannula was associated with greater short-term dyspnea relief than conventional oxygen therapy in one emergency department trial. Opioid therapy was associated with greater dyspnea reduction than oxygen alone in one prospective study.ConclusionOxygen therapy should not be prescribed routinely for dyspnea in non-hypoxemic palliative care patients. Its use should be guided by baseline oxygenation status, delivery modality, expected symptomatic benefit, patient goals, and treatment burden. The certainty of evidence remains limited by small samples, heterogeneity, and risk of bias.