Intradialysis hypertension, a diagnosis to be discovered

Abstract

Introduction: Intradialytic hypertension (IDH) is a poorly understood phenomenon with no consensus on its definition, etiology, or related factors, and there is limited evidence on its consequences.

Objective: To determine the prevalence of IDH according to different definitions in hemodialysis (HD) units, with different clinical practices and assessment of possible events after 18 months have passed.

Materials and methods: A cross-sectional observational study was conducted in 2 HD units, including all prevalent patients from March 2021 to September 2022. We established 3 definitions of IDH: IDH was considered present if the criterion was met in more than 50% of the 6 consecutive sessions (2 weeks) of follow-up. Personal history, medications, dialysis characteristics, and pre- and post-HD biochemical data were collected. Residual renal function (RRF) was considered as urine output >250 ml/24 h. At 18 months, the possible events of the group were analyzed.

Results: We included 169 patients (68% men) with a mean age of 67.9 (14.2) years and a median HD duration of 34.5 (IQR 17.5-67.5) months. Of these, 94 come from one unit and 75 from the other. The prevalence of IDH was 8.3% according to Def 1, 27.2% according to Def 2, and 29.6% according to Def 3. Def 2 showed an association with a history of previous hypertension, use of renin-angiotensin system inhibitors (RASIs), and furosemide, as well as with patients with RRF. Def 3 showed an association only with coronary artery disease. There was an association with different prescriptions of dialysis fluids. Catecholaminergic hormones and aldosterone did not increase in patients with hypertension during the HD session. They did not present a higher incidence of cardiovascular events or mortality at 18 months.

Conclusions: IDH has different prevalence rates depending on the definition used and the studied center. The future poses an important challenge: to determine which definition correlates with higher morbidity and mortality and the role of differences found in different HD units.

Keywords: Hemodialysis complications; Intradialytic hypertension.