title: Out of the blue.
authors.affiliation: Renal Unit , Lancashire Teaching Hospitals NHS Foundation Trust , Preston, Lancashire , UK.
authors.forename: Ajay
authors.initials: A
authors.lastname: Dhaygude
authors.affiliation: Renal Unit , Lancashire Teaching Hospitals NHS Foundation Trust , Preston, Lancashire , UK.
authors.forename: Patrick
authors.initials: P
authors.lastname: MacDowall
authors.affiliation: Renal Unit , Lancashire Teaching Hospitals NHS Foundation Trust , Preston, Lancashire , UK.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Coward
authors.affiliation: Renal Unit , Lancashire Teaching Hospitals NHS Foundation Trust , Preston, Lancashire , UK.
authors.forename: Alexander
authors.initials: A
authors.lastname: Woywodt
keywords: haemodialysis; phosphodiesterase inhibitors; pulmonary hypertension; sildenafil; syncope