Subjective Thirst in Relation to Interdialytic Weight Gain: A Systematic Review of Observational Studies

Introduction: Hemodialysis (HD) patients are often prescribed salt and fluid-restricted diets to reduce their interdialytic weight gain (IDWG) and prevent chronic volume overload and hypertension. However, adherence to fluid restrictions is poor, which may be due to HD patients' excessive thirst. The purpose of the review is to explore the association between HD patients' subjective thirst and IDWG, which may inform strategies to manage chronic volume overload. Methods: We conducted the literature search in Web of Science, Cumulative Index to Nursing and Allied Health Literature, PubMed, and the Cochrane Library, until February 25, 2019. Studies performing statistical tests to assess the association between patients' subjective thirst and IDWG were included. Results: A total of eighteen studies were included in the systematic review, which measured the relationship between patients' subjective thirst and IDWG. Among them, 14 studies found that different domains of thirst and different units of IDWG are positively associated. Therefore, there is a positive association between the patients' subjective thirst and IDWG. However, the findings should be interpreted cautiously as there was variability in thirst and IDWG measurement techniques, which might influence the estimated relationship in these studies. Discussion/Conclusion: These data suggest that strategies are needed to reduce thirst to control IDWG in HD patients.