Is increased subjective thirst associated with greater interdialytic weight gains, extracellular fluid and dietary sodium intake?

BACKGROUND

Some previous studies have reported an effect of increasing subjective thirst and interdialytic weight gains (IDWG), and that this may be influenced by nonadherence to dietary sodium restrictions, whereas others reported no such association. As such we wished to review the effect of self-reported thirst on IDWGs and dietary sodium intake.

METHODS

Dialysis patients were asked to complete visual analogues thirst, distress thermometer (DT) scores and complete a sodium food frequency questionnaire (SFFQ). IDWG and pre and post dialysis volumes were measured with multifrequency bioelectrical impedance.

RESULTS

One hundred and eleven patients completed the questionnaires and had bioimpedance measurements: 63% male, mean age 63.8 ± 16.1 years, 33% diabetic with a median thirst score 3 (0-5) and SFFQ 52.0 ± 18, and IDWG 2.1 ± 1.3%. Thirst was associated with DT (r = 0.28, p = 0.004) and negatively with age (r = -0.31, p < 0.001), but not SFFQ, IDWG, extracellular water, or dialysate sodium, or dialysate to plasma gradient. Patients with higher thirst scores were younger (58.0 ± 15.2 vs. 69.4 ± 15.0 years, p < 0.001) with higher DT scores (5 [2-7] vs. 2 [0-5], p < 0.001). On multivariate logistic analysis, only age was associated with self-reported thirst (odds ratio 0.95, 95% confidence limits 0.92-0.98, p < 0.001).

CONCLUSION

We found that subjective thirst was greater for younger patients and those who reported higher levels of distress, but no association with IDWGs, dietary sodium intake, or dialysate sodium. However, most of our patients followed the dietary advice, as evidenced by the low SFFQ scores and % IDWGs. Whether thirst increases distress or distress increases subjective thirst remains to be determined.

Effects of Standard and Individualized Dialysate Sodium in Chronic Hemodialysis Patients Upon Echocardiography Parameters

Aims: This study assessed the effects of individualized dialysis sodium prescription on changes of echo-cardiography in hemodialysis (HD) patients. Methods: 77 chronic hemodialysis patients were analysed. In the first phase all patients underwent dialysis with standard dialysate sodium of 138 mmol/L followed by the second phase where dialysis was performed with individualized dialysate sodium concentration according to average pre HD serum sodium concentration. After the first phase, the subjects were divided into 3 groups: normotensive, hypertensive and hypotensive based on the average pre-HD systolic BP during the first phase. In all patients echocardiography was performed at the end of the first and second phase. Results: Patients had no statistical significant change in blood pressure compared with standard dialysate sodium, only statistical significant change in interdialytic weight gain (IDWG). By dividing the patients, sodium individualization resulted in significantly lower blood pressure and IDWG (p=0.018) in hyper-tensive patients, whereas normotensive patients showed only significant decrease in IDWG (p=0,004). Hypertensive patients had significant highest sodium gradient compared to other patients (p<0.05), followed by significant increase of 0,6% IDWG confirmed with univariate regression analysis. In all patients, echocardiography analysis showed an increase of 2.04 mm of LVDD by increasing the sodium gradient for 1 mmol/L and significantly increased LVM of 35.69 gr by 1 kg increase in IDWG. Conclusions: A reduction of the dialysate sodium concentration based on the pre HD serum sodium level of the patient, reduced the SBP, DBP and IDWG and decreased the volume overload upon the heart and consequently heart hypertrophy assessed by echocardiography.

Determinants of thirst distress in patients on hemodialysis

PURPOSE

Thirst sensation can induce nonadherence with fluid restriction in patients on hemodialysis (HD) and may lead to large interdialytic weight gain (IWG). This study aimed to evaluate thirst distress and its determinants and to explore fluid management strategies used by patients on HD.

METHODS

A cross-sectional study was conducted in a sample of 203 patients who were followed in three HD centers in Turkey, from January 2015 to June 2015. Data were collected by a personal information form, the Thirst Distress Scale (TDS) and the Visual Analogue Scale (VAS) for thirst and xerostomia. Data analysis was performed using descriptive statistics, Student's t test, the one-way analysis of variance, Pearson's correlation coefficients, and linear regression analysis.

RESULTS

The mean TDS score was 20.71 ± 8.34, which is a higher than moderate level of thirst distress. The significant determinants of thirst distress of the patients were the VAS thirst score (unstandardized β = 1.73, p < 0.001), the VAS xerostomia score (unstandardized β = 0.42, p < 0.001), and the IWG values (unstandardized β = 1.20, p = 0.003), after controlling for specific variables. The most common strategies used to reduce fluid intake or relieve thirst were avoiding salty foods (70.9 %), limiting salt on food (70.9 %), and spacing liquids over the entire day (57.6 %).

CONCLUSIONS

Patients with higher levels of thirst and xerostomia and those with a high IWG were more likely to have higher thirst distress. A greater understanding of thirst distress and its related factors could contribute to more effective interventions that improve health and well-being in patients on HD.