Abstract:
Background: Intradialytic hypertension (IDH) increases morbidity and mortality. The prevalence in South Africa is unknown.
The pathogenesis is unclear, but it has been suggested that IDH may be due to subclinical fluid overload. The objective of this
study was to determine the prevalence of IDH and to evaluate its association with fluid overload using bioimpedance
spectroscopy (BIS).
Methods: A cross-sectional study involving 190 chronic haemodialysis patients in the Western Cape province of South Africa
was conducted between January 2013 and May 2014. IDH was defined as a >10 mmHg increase in systolic blood pressure in at
least four of six prior consecutive haemodialysis sessions.
Results: The prevalence of IDH was 28.4% (n = 54). Therewas a trend towards pre-dialysis overhydration in the IDH group when
compared with controls {2.6 L [95% confidence interval (CI) 1.7–3.4] versus 1.8 L [95% CI 1.4–2.1], respectively; P = 0.06} as
measured by BIS, but no difference in mean ultrafiltration (UF) volume (2.4 versus 2.6 L; P = 0.30). A trend towards greater use of
antihypertensive drugs was noted in the IDH group [2.5 drugs (95% CI 2.15–2.87) versus 2.1 (95% CI 1.82–2.30); P = 0.05]. More
participants in the IDH group received calcium channel blockers (54 versus 36; P = 0.03).
Conclusions: The prevalence of IDH in our treatment centres is much higher than previously reported. Subclinical fluid
overload may be a major contributing factor to the mechanism of this condition. The use of BIS identifies patients who may
benefit from additional UF.
