SEASONAL VARIATIONS IN HEMODYNAMIC AND TEMPERATURE VARIABLES IN HEMODIALYSIS (HD) PATIENTS

Abstract

Prevention of HD-induced hypotension and control of chronic hypertension are major issues in the care of HD patients. In the general population seasonal variations in blood pressure (BP) are clearly documented, but results in HD patients have been conflicting. In 160 ESRD patients receiving regular HD, we performed a retrospective analysis comparing thirty-five different hemodynamic and temperature (BTM, Fresenius, Bad Homburg, Germany) parameters from treatments during three winter months, with those in the same patients during three summer months. Data captured electronically by the FinesseTM system (iSYMED, GmbH, Butzbach, Germany) was used for the analysis. For each patient mean values for each variable over the three month winter period were matched with their mean values over the summer period. Paired t-tests of the 35 variables were then performed. Average, pre- and post-dialysis pulse, systolic, diastolic and mean arterial BP were significantly higher (p≤0.001) in winter than in summer (e.g. average systolic 137.75±19.66mmHg winter, 132.98±17.12mmHg summer). Ultrafiltration volume was not significantly different between time periods. Minimum and end core temperatures were significantly higher in winter than in summer (end core temperature 36.706±0.238°C winter, 36.624±0.248°C summer, p<0.001), as was average dialysate temperature (36.444±0.241°C winter, 36.367±0.341°C summer, p=0.003). These results are important because they may affect patient outcomes and management. In addition, such differences should be considered in the planning and analysis of longitudinal studies involving these patient variables.