Clinical Characteristics of Patients with Intradialytic Hypertension

Introduction: Intradialytic hypertension with a prevalence of 15% among hemodialysis patients is with unknown pathophysiology, demographic, laboratoiy and clinical characteristic of patients, and it’s influence on longtenn clinical effects (cardiovascular morbidity and mortality, rate of hospitali­zation). The aim of the study is to present the clinical, laboratoiy and demographic characteristics of patients with intradialytic hypertension in our dialysis center.

Materials and methods: Out of 110 hemodialysis patients, 17 patients (15,45%) had intradialytic hy­pertension - started at a systolic pressure greater than 140 nun Hg or had an increase in systolic pres­sure more than 10 mm Hg during the session, and 17 patients were nonnotensive or had a drop in blood pressure dining the dialysis. HD were performed 3 times per week with a duration of 4-5 hours, on machines with controlled ultrafiltration and high flux syntetic membrane (polyetersulfon) sterilized with gamma rays. A dialysate with standard electrolytes content was used (Na⁺ 138 mmol/L, K⁺ 2,0 mmol/L, Ca⁺⁺ 1,5 mmol/L, Mg ⁺1,0 mmol/L, CH₃COO^- 3,0 mmol/L, Cl ^-110 mmol/1, HCO₃^- 35 mmol/L). We analysed the following demographic and clinical characteristics: gender, age, BMI, dialysis vintage, vascular acces, cardiovascular comorbidity (cardiomyopathy, ischemic cardiac disease, peripheral artery disease, heart valve disease), number and type of antihypertensive drugs, weekly dose of erythropoesis - stimulating agent, standard monthly, three and six months laboratoiy analyzes, and sp Kt/V and PCR. Statistical analysis was performed using the statistical software SPSS 17.0.

Results: hi both groups men were predominant (IDH group 88.23%, control group 64.07%). The IDH group was older (59.00 ± 7.64 versus 49.00 ± 13.91, p = 0.314) and with lower BMI (p = 0.246) compared to the control group. The DDH patients had significantly lower serum sodium and higher sodium gradient (135.75 ± 2.03 versus 137.33 ± 1.97, p = 0.042; 2.25 ± 1.98 versus 0.66 ± 1.44, p = 0.0267, respestively). All other laboratoiy findings showed no statistically significant differences between the two groups. The IDH group had significantly higher interdialysis weight gain and less effective ultrafiltration individually at each dialysis session compared to the control group (2.23 ± 0.866 versus 2.37 ± 0.69, p = 0.011; 3.87 ± 1,26 versus 3.56 ± 1.18, p = 0.025, respectively). The systolic and mean arterial pressure after the HD were statistically higher in the IDH group.

Conclusion: Older age, lower BMI, borderline hyponatremia, higher sodium gradient and smaller ultrafiltration rate are the clinical characteristics of patients with intradialytic hypertension.