Hypotension during haemodialysis as a cardiovascular risk factor

Intradialytic hypotension is associated with increased morbidity and mortality. Furthermore, there is a link between intradialytic hypotension and ‘myocardial stunning’ as well as cerebral ischaemia. This, in turn, leads to increased cerebral damage, gastrointestinal ischaemia and thrombosis of arteriovenous shunts. A comprehensive understanding of the pathophysiological processes that influence or even trigger intradialytic hypotension can therefore have a significant impact on both mortality and morbidity in dialysis patients.

The development of intradialytic hypotension

Intradialytic hypotension occurs in 20% of dialysis sessions and is defined as a reduction in systolic blood pressure of ≥20 mmHg or a reduction in mean arterial pressure of ≥10 mmHg. Furthermore, the term ‘intradialytic hypotension’ is also used when clinical symptoms such as nausea, headache, dizziness and cramps occur during dialysis treatment.

Other risk factors for the development of intradialytic hypotension include aging, diabetes mellitus, female gender, arterial hypertension, cardiovascular disease, high interdialytic weight gain, food intake during the dialysis session, and the pre-dialytic use of antihypertensive medication.

Prevention of intradialytic hypotension

Measures to prevent intradialytic hypotension primarily include limiting interdialytic weight gain, fluid and salt restriction, increasing the duration of dialysis, or increasing the number of treatments. Sequential haemodialysis is also recommended as a further preventive strategy. This involves isolated ultrafiltration followed by conventional haemodialysis and is used to increase haemodynamic stability, particularly at high ultrafiltration volumes.

Research into new therapeutic approaches

At the Division of Nephrology at the Medical University of Graz, researchers are currently attempting to characterise the haemodynamics of dialysis patients using non-invasive bioimpedance measurements. This allows different forms of dialysis to be compared in terms of haemodynamic stability, enabling preventive measures and strategies to be developed more precisely.

Profile: Alexander Kirsch

Alexander Kirsch heads the Advanced CKD and Haemodialysis Research Group. The aim of the research group is to address questions in the field of clinical nephrology, with a particular focus on advanced chronic kidney disease and haemodialysis. Clinically, he serves as Deputy Head of the Clinical Division of Nephrology at the Medical University of Graz.

Text contribution written by Bence Szemes as part of the postgraduate programme in “Medical Research”.