Epidemiology And Risk Factors Of Intradialytic Hypotension In Maintenance Hemodialysis Patients (IDH-MHD)

Epidemiologic Characteristics And Risk Factors Of Intradialytic Hypotension In Maintenance Hemodialysis Patients: A Prospective Multicenter Cross-sectional Study

This prospective, multicenter observational study aims to describe how often intradialytic hypotension (IDH) occurs and to identify its risk factors in adult patients receiving maintenance hemodialysis. Intradialytic hypotension is a common complication during dialysis that can lead to symptoms, organ hypoperfusion, and interruption of treatment.

Participants will be adults on regular maintenance hemodialysis who meet predefined inclusion and exclusion criteria. Routine clinical information will be collected, including demographics, primary kidney disease, comorbidities, medications, dialysis vintage, dialysis prescription (ultrafiltration volume and rate, dialysate composition, treatment time), and standard laboratory tests. During a defined observation period, blood pressure and related symptoms will be recorded across dialysis sessions to document the frequency, severity, and patterns of IDH.

The main goals are to estimate the incidence and prevalence of intradialytic hypotension in maintenance hemodialysis patients and to explore potential risk factors, such as patient characteristics, cardiovascular status, volume status, and dialysis-related parameters. The findings may help clinicians better recognize patients at high risk of IDH and optimize dialysis prescriptions and monitoring strategies to reduce the occurrence of IDH and its adverse consequences.

Study Overview

• Status: Completed
• Conditions: Hemodialysis; End-stage Renal Disease (ESRD); Chronic Kidney Failure; Intradialytic Hypotension; Chronic Kidney Disease, Stage IV (Severe)

Detailed Description

This is a prospective, multicenter, observational study designed to characterize the epidemiology and risk factors of intradialytic hypotension (IDH) in adult patients undergoing maintenance hemodialysis. No study-specific interventions will be assigned; all dialysis treatments and medical therapies will be conducted according to routine clinical practice at each participating center.

Eligible participants are adults receiving thrice-weekly or regular maintenance hemodialysis for end-stage kidney disease. After obtaining informed consent (as required by local regulations), baseline data will be collected from the medical record and patient interview. Baseline variables will include:

Demographics (age, sex, body mass index, smoking status) Primary kidney disease and dialysis vintage Comorbidities (e.g., diabetes mellitus, hypertension, cardiovascular disease, heart failure, arrhythmia) Usual medications, with a focus on antihypertensive agents, diuretics, and cardiovascular drugs Pre-dialysis clinical parameters (weight, dry weight, interdialytic weight gain, pre-dialysis blood pressure) Routine laboratory values (e.g., hemoglobin, albumin, electrolytes, calcium-phosphate metabolism indices, markers of inflammation and nutrition, as available) Dialysis prescription and treatment-related parameters will be documented, including dialyzer type, blood flow rate, dialysate flow, dialysate composition (sodium, calcium, bicarbonate), treatment duration, and planned and achieved ultrafiltration volume and ultrafiltration rate.

During the observation period (covering a predefined number of consecutive dialysis sessions per patient), blood pressure will be monitored according to local standard practice (for example, before dialysis, at regular intervals during dialysis, and at the end of treatment). Episodes of intradialytic hypotension will be identified using a pre-specified definition (e.g., absolute blood pressure thresholds and/or drop from baseline, with or without associated symptoms), which will be applied consistently across all centers. When feasible, associated symptoms (such as dizziness, cramps, chest discomfort, nausea) and interventions (e.g., reduction or cessation of ultrafiltration, saline infusion, change in dialysate temperature, adjustment of position, or early termination of dialysis) will be recorded.

The primary analyses will describe:

The incidence and prevalence of intradialytic hypotension in this maintenance hemodialysis population The distribution of IDH episodes by dialysis session phase (early, middle, late), severity, and need for intervention

Secondary analyses will evaluate potential risk factors for IDH. These may include:

Baseline patient characteristics (age, sex, body mass index, primary disease, comorbidities) Indicators of cardiovascular function and volume status (pre-dialysis blood pressure, interdialytic weight gain, dry weight assessment) Laboratory parameters reflecting anemia, nutritional status, mineral metabolism, and inflammation Dialysis-related factors (treatment time, ultrafiltration volume and rate, dialysate sodium and temperature, antihypertensive medications taken before dialysis) Multivariable regression models or other appropriate statistical methods will be used to examine associations between candidate risk factors and the occurrence of IDH, while adjusting for potential confounders. Subgroup or sensitivity analyses may be performed according to age groups, presence of diabetes or cardiovascular disease, or different ultrafiltration rate categories, depending on sample size and data completeness.

This study is not intended to test a specific therapeutic intervention but to provide a comprehensive, real-world description of intradialytic hypotension and its determinants in maintenance hemodialysis patients across multiple centers. The results may support the development of risk stratification tools and guide future interventional studies aimed at preventing or mitigating intradialytic hypotension.

• Study Type: Observational
• Enrollment (Actual): 395

Contacts and Locations

Study Locations

• China
  • Anhui
    • Wuhu, Anhui, China, 241001
      • The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College)

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Adults with end-stage renal disease receiving routine maintenance hemodialysis at participating centers. Consecutive eligible patients will be observed during one scheduled dialysis session to estimate single-session IDH incidence and explore associated factors.

Description

Inclusion Criteria:

• Adults (≥18 years) with end-stage renal disease on maintenance hemodialysis
• Receiving thrice-weekly (or routine) in-center hemodialysis for ≥3 months before enrollment
• Scheduled for a standard hemodialysis session of approximately 3-5 hours on the study day
• Able to provide informed consent (or via legally authorized representative, if applicable)

Exclusion Criteria:

• Acute medical instability precluding observation of a routine dialysis session (e.g., active sepsis requiring vasopressors, uncontrolled arrhythmias)
• Recent acute coronary syndrome or stroke within 3 months
• Pre-dialysis systolic blood pressure <90 mmHg on the study day before starting dialysis
• Ongoing active major bleeding or anticipated urgent transfusion during the session
• Pregnancy
• Participation in an interventional trial expected to alter intradialytic blood pressure during the observed session

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Maintenance Hemodialysis Cohort; Adults with end-stage renal disease receiving routine maintenance hemodialysis at participating centers. Prospective observation over approximately 3 months; no study-assigned interventions. Standard dialysis care per local practice. Data collected include demographics, comorbidities, medications, dialysis vintage, prescription (UF volume/rate, dialysate sodium/calcium/bicarbonate, temperature, treatment time), blood pressure before/during/after dialysis, IDH symptoms, and clinical responses (e.g., UF reduction, saline, cooling). Routine labs as available.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence Of Intradialytic Hypotension During A Single Maintenance Hemodialysis Session	Proportion of enrolled maintenance hemodialysis patients who experience intradialytic hypotension (IDH) during one observed hemodialysis session. IDH is defined as a decrease in systolic blood pressure (SBP) by 20-40 mmHg from pre-dialysis or during dialysis, with or without related symptoms, according to pre-specified criteria.	From the start of the observed hemodialysis session to the end of the same session (approximately 3.5-4 hours).

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence Of Asymptomatic IDH	Proportion of enrolled patients who develop asymptomatic IDH during the observed hemodialysis session. Asymptomatic IDH is defined as a decrease in SBP of 20-40 mmHg during dialysis without accompanying IDH-related symptoms	From the start of the observed hemodialysis session to the end of the same session (approximately 3.5-4 hours).
Distribution Of Time To Onset Of Intradialytic Hypotension	Proportion of IDH events that occur within each hour of the dialysis treatment (first, second, third, and last treatment hour), based on blood pressure measurements before dialysis, every 60 minutes during dialysis, and at the end of dialysis.	From the start of the observed hemodialysis session to the end of the same session (approximately 3.5-4 hours).
Association Between Pre-Dialysis Mean Arterial Pressure And IDH	Association between pre-dialysis mean arterial pressure (MAP, continuous and categorized by pre-specified cut-offs) and the occurrence of IDH during the observed session, quantified using multivariable logistic regression and reported as adjusted odds ratios (ORs) with 95% confidence intervals.	From pre-dialysis blood pressure assessment immediately before the session to the end of the same hemodialysis session (approximately 3.5-4 hours).
Association Between Interdialytic Weight Gain And IDH	Association between interdialytic weight gain (IDWG, kg) before the observed dialysis session and the occurrence of IDH during that session, assessed by multivariable logistic regression and expressed as adjusted odds ratios (ORs) with 95% confidence intervals.	From the pre-dialysis weight assessment immediately before the session to the end of the same hemodialysis session (approximately 3.5-4 hours).
Association Between Pre-Dialysis Serum Potassium And IDH	Association between pre-dialysis serum potassium concentration (continuous and dichotomized using a pre-defined cut-off) and the occurrence of IDH during the observed dialysis session, using multivariable logistic regression; reported as adjusted odds ratios (ORs) with 95% confidence intervals.	Based on the most recent pre-dialysis serum potassium value within 3 months prior to the observed session and IDH occurrence during that single hemodialysis session (approximately 3.5-4 hours).
Association Between Serum Albumin And IDH	Association between serum albumin level (continuous and categorized by pre-specified cut-offs) and the occurrence of IDH during the observed hemodialysis session, assessed using multivariable logistic regression models and expressed as adjusted odds ratios (ORs) with 95% confidence intervals.	Based on the most recent serum albumin measurement within 3 months prior to the observed session and IDH occurrence during that single hemodialysis session (approximately 3.5-4 hours).
Predictive Performance Of Traditional Clinical Indicators For IDH	Discriminative ability of traditional clinical and laboratory indicators (including pre-dialysis SBP, MAP, DBP, IDWG, ultrafiltration rate, pre-dialysis serum potassium, serum albumin, HDL, and pre-dialysis weight) for predicting IDH during the observed session, evaluated using receiver operating characteristic (ROC) curves and reported as area under the curve (AUC) with 95% confidence intervals.	Based on baseline measurements (collected within 3 months before the observed session or immediately pre-dialysis) and IDH occurrence during that single hemodialysis session (approximately 3.5-4 hours).

Collaborators and Investigators

• Sponsor: First Affiliated Hospital of Wannan Medical College
• Collaborators: Wuhu City Second People's Hospital; Wuhu County Traditional Chinese Medicine Hospital

Study record dates

Study Major Dates

• Study Start (Actual): February 15, 2025
• Primary Completion (Actual): February 28, 2025
• Study Completion (Actual): December 29, 2025

Study Registration Dates

• First Submitted: April 15, 2026
• First Submitted That Met QC Criteria: April 15, 2026
• First Posted (Actual): April 22, 2026

Study Record Updates

• Last Update Posted (Actual): April 22, 2026
• Last Update Submitted That Met QC Criteria: April 15, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Multicenter; Volume status; Blood pressure variability; Intradialytic hypotension (IDH); Dialysate sodium; Prospective observational; Maintenance hemodialysis; Ultrafiltration rate (UFR); Interdialytic weight gain (IDWG); Cardiovascular comorbidity
• Additional Relevant MeSH Terms: Urogenital Diseases; Pathologic Processes; Male Urogenital Diseases; Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Chronic Disease; Disease Attributes; Renal Insufficiency; Pathological Conditions, Signs and Symptoms; Kidney Failure, Chronic; Renal Insufficiency, Chronic
• Other Study ID Numbers: 2025-61-02

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No