The purpose of this study is to assess the feasibility of supplemental oxygen delivery during hemodialysis in people with pulmonary hypertension and intradialytic hypoxemia.

Inclusion Criteria:

• Adults ≥18 years
• Receiving Monday-Wednesday-Friday or Tuesday-Thursday-Saturday hemodialysis
• Screened positive for pulmonary hypertension (defined by tricuspid regurgitant velocity [TRV] >2.5 m/s on echocardiography) and intradialytic hypoxemia (defined by spending ≥1/3 treatment with O2 saturation <90%) or hypoxemia for ≥10% of the treatment if associated with a desaturation event (≥4% decline in O2 saturation to <88% for ≥10 seconds) during enrollment in the PH-ESKD study (Pro00108710).

Exclusion Criteria:

• Daily supplemental oxygen use
• Inability to provide informed consent