Serum sodium variation is a major determinant of peridialytic blood pressure trends in hemodialysis outpatients

Intradialytic hypotension (IDH) and peridialytic blood pressure (BP) in hemodialysis (HD) patients are associated with morbidity and mortality. Many individual factors have been reported to cause SBP changes during HD, but their respective contributions and potential role in determining the SBP phase have not been found. DavidA. Jaques and colleagues conducted a study with the title “Serum sodium variation is a major determinant of peridialytic blood pressure trends in hemodialysis outpatients” published in the Nature Journal. The summary of this research can be studied below:

Objective:

To identify the impact of small solutes and volume status variation on peridialytic systolic BP (SBP) trends in HD patients.

Method:

This retrospective study analyzed 647 outpatients. During the mid-week session, the relative peridialytic SBP decrease was identified with corresponding pre- and post-HD bioelectrical impedance analysis.

Findings:

Study reports indicate that intradialytic serum Na variation during HD has important clinical implications as it determines SBP trends independently of other important factors such as session duration, pre-HD volume status, Kt/V, dialysate temperature, UFR, and administration of IV fluid during treatment. Additionally, hypotensive patients were found to have higher pre-HD urea and greater urea decrease compared to stable and hypertensive patients. Mean arterial pressure (MAP) is wholly identified by SBP and DBP. Na variation did not influence peridialytic DBP trends in this study and hence it had a significant but weaker impact on peridialytic MAP trends. Findings also suggest that serum Na variation could affect preload, and thus stroke volume, while systemic vascular resistance remains unaffected.

The study found that younger, as well as older patients, managed to maintain their BP throughout the treatment period, while middle-aged and overweight individuals were subjected to peridialytic BP decline. Investigators suggest that SBP decrease was less evident in patients introduced to antihypertensive drugs. The study found an association of elevated serum albumin and lower dialysate calcium concentration with peridialytic SBP decline.

Limitation:

The authors highlight that intradialytic BP measurements were not available in this study. The study considered dialytic SBP regulation as a continuous phenomenon while not focusing on an arbitrary definition of IDH. Interdialytic BP measurements and post-HD glucose were not considered in this study.

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