Hemodynamic and Body Weight Trajectories across Consecutive Hemodialysis Sessions in Patients with End-Stage Renal Disease

Abstract

Background: Hypertension represents one of the most pervasive and challenging clinical complications in patients with End-Stage Renal Disease (ESRD) undergoing maintenance hemodialysis, affecting 70% to 85% of this population globally. Unmanaged, persistent high blood pressure exponentially escalates the risk of catastrophic cardiovascular events, which remain the leading cause of mortality among dialysis patients. Re-evaluating diagnostic standards and management protocols is essential to mitigating cardiovascular risk and optimizing quality of care in this high-risk population. Objective: The primary aim was to evaluate short-term intra-individual fluctuations in body weight and blood pressure (BP) across five consecutive hemodialysis (HD) cycles. Materials and Methods: A prospective, single-center observational study was conducted over a one-month period. A non-probability convenience sampling technique was adopted to enroll adult participants under 75 years of age undergoing maintenance hemodialysis who completed five cycles. Patients presenting with acute hemodialysis indications, severe hemodynamic instability, active sepsis, or decompensated heart failure were excluded. Based on a monthly volume of 250 to 300 dialysis patients, a target sample size of N = 30 was determined following the application of eligibility criteria, in alignment with pilot study recommendations and the Central Limit Theorem. Results: Male participants constituted 63.3% (n = 19) of the cohort, while female participants accounted for 36.7% (n = 11). Pre-dialysis systolic blood pressure (SBP) demonstrated Grade 1 to Grade 2 hypertension across baseline cycles, peaking at Cycle 2 (156 ± 7.81mmHg) before settling at 147.10 ± 8.26 mmHg by Cycle 5. Pre-dialysis diastolic blood pressure (DBP) remained elevated above 87mmHg across all cycles, peaking at Cycle 3 (92.33 ± 4.49 mmHg). Pre-dialysis body weight remained highly stable prior to treatment sessions (55.42 to55.46 kg). Ultrafiltration led to uniform, steady fluid removal across all five cycles. Intradialytic weight loss widened progressively from 2.0 kg (95% CI:1.99 to 2.02) in Cycle 1 to 2.19 kg (95% CI 2.08 to 2.30) in Cycle 5 (t (29 ) = 41.092, p < 0.001). Post-hoc pairwise comparisons with Bonferroni correction revealed that pre-dialysis baseline SBP remained statistically stable across Cycles 1 through 4 (p < 0.05); however, baseline SBP in Cycle 5 dropped significantly compared to Cycle 1 (Mean difference = 8.13 mmHg, p < 0.005), Cycle 2 (Mean difference = 8.90  mmHg , p < 0.001), and Cycle 3 (Mean difference = 6.57mmHg , p < 0.003). Pre-dialysis baseline DBP decreased significantly by Cycle 5 relative to Cycle 2 (Mean difference = 4.33mmHg), p < 0.001) and Cycle 3 (Mean difference = 4.96 mmHg, p < 0.001). Conclusion: Evaluating blood pressure and body weight trajectories across five consecutive hemodialysis cycles reveals critical intra-individual variability that isolated, single-point pre-dialysis metrics consistently fail to capture. Moving beyond static measurements toward short-term longitudinal profiling equips clinicians with actionable foresight to identify high-volatility phenotypes, refine dry-weight targets, optimize ultrafiltration strategies, and improve overall cardiovascular risk management in end-stage kidney disease.

Keywords: End-Stage Renal Disease, Maintenance Hemodialysis, Blood Pressure Volatility, Ultrafiltration, Dry Weight Target, Longitudinal Trajectory