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NCT Number: NCT07811947

Inspiratory Muscle Training During Hemodialysis

This study will evaluate whether inspiratory muscle training performed during hemodialysis improves inspiratory muscle strength in adults receiving regular hemodialysis. After an initial 12-week period without study-protocolized inspiratory muscle training, participants will be randomly assigned to inspiratory muscle training plus usual care or usual care alone for 12 weeks. The primary outcome is the change in maximum inspiratory pressure from baseline to Week 12. The study will also assess lung function, walking capacity, handgrip strength, electrical activity of inspiratory muscles, dyspnea, body composition, health-related quality of life, and daily physical activity.

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Key information

Conditions

Chronic Kidney Disease (stages 4 and 5) Chronic Disease Disease Attributes Female Urogenital Diseases Female Urogenital Diseases and Pregnancy Complications Hemodialysis Inspiratory Muscle Training Kidney Diseases Male Urogenital Diseases Pathologic Processes Pathological Conditions, Signs and Symptoms Renal Insufficiency Renal Insufficiency, Chronic Urogenital Diseases Urologic Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Tecsam - Tecnologia e Serviços Médicos

Mirandela, Braganza District, 5370-530, Portugal

Location contact

André Filipe Morais Pinto Novo

PRINCIPAL_INVESTIGATOR

Sónia Alexandra Claro Casado

PRINCIPAL_INVESTIGATOR

Sónia Casado

CONTACT

[email protected]

+351965364163

CONTACT

[email protected]

About this study

Individuals receiving regular hemodialysis may experience reduced inspiratory muscle strength, impaired lung function, dyspnea, reduced functional capacity, decreased daily physical activity, and changes in body composition. This single-center, open-label, randomized controlled study will evaluate the effect of intradialytic inspiratory muscle training on inspiratory muscle strength and related clinical and functional outcomes.

All participants will first complete a 12-week observational period without study-protocolized inspiratory muscle training. Following the T0 assessment, participants will be randomly assigned in a 1:1 ratio to inspiratory muscle training plus usual care or usual care alone for 12 weeks. Participants assigned to inspiratory muscle training will perform training during hemodialysis using the POWERbreathe KH2 device.

After the Week 12 assessment, participants initially assigned to inspiratory muscle training will undergo a second independent 1:1 randomization to either weekly maintenance inspiratory muscle training or discontinuation of study-protocolized training for 12 weeks. Participants initially assigned to usual care will continue usual care. Following the Week 24 assessment, no participant will receive study-protocolized inspiratory muscle training for 12 weeks. Follow-up assessments will be conducted through Week 52 after the initial randomization.

The primary comparison is between inspiratory muscle training plus usual care and usual care alone at Week 12. Analyses of the second randomization and later follow-up assessments are exploratory.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Age 18 years or older
  • Enrolled in a regular hemodialysis program for at least 3 months
  • Receiving hemodialysis three times per week
  • Able to understand study information
  • Able to provide written informed consent

Exclusion criteria

  • Recent history of clinically significant cardiac arrhythmia, acute myocardial infarction, unstable angina, severe valvular disease, or uncontrolled hypertension
  • Medical condition that contraindicates an increase in intrathoracic negative pressure or performance of inspiratory muscle training
  • Uncontrolled acute or decompensated medical condition that compromises participant safety or the validity of the assessments
  • Severe cognitive impairment that prevents provision of informed consent or completion of study procedures

Treatment and study plan

Inspiratory Muscle Training

Behavioral

Intradialytic inspiratory muscle training will be performed using the POWERbreathe KH2 electronic device. Training will begin approximately 30 minutes after the start of the hemodialysis session after confirmation of clinical and hemodynamic stability. Participants will be seated in the hemodialysis chair with the backrest raised to at least 45 degrees.

The initial program will be performed three times weekly for 12 weeks, for a total of 36 planned sessions. Each session will include three sets of 30 inhalations against a resistance corresponding to 50 percent of maximum inspiratory pressure, with a two-minute rest between sets. Maximum inspiratory pressure will be reassessed after every six completed sessions, and resistance will be adjusted to 50 percent of the newly measured value.

Training will be interrupted for chest pain, intolerable dyspnea, desaturation, hypotension, arrhythmia, intolerable fatigue, participant request, or any sign or symptom raising clinical concern.

Usual Care

Other

Usual care consists of the regular hemodialysis schedule and the clinical and nursing care routinely provided by the hemodialysis unit. No study-protocolized inspiratory muscle training will be administered.

Primary outcomes

  1. Change in Maximum Inspiratory Pressure From Baseline to Week 12

    Time frame: Baseline at T0 and post-intervention at Week 12

    Maximum inspiratory pressure will be measured using the POWERbreathe KH2 device with the participant seated with back support before the second or third weekly hemodialysis session. The outcome is the change in maximum inspiratory pressure, expressed in cmH2O.

Secondary outcomes

  1. Change in Modified Borg Dyspnea Scale Score From Baseline to Week 12

    Time frame: Baseline at T0 and post-intervention at Week 12

    Dyspnea will be assessed using the Modified Borg Dyspnea Scale, with scores ranging from 0 to 10, at rest and after the 6-Minute Walk Test. Higher scores indicate greater perceived dyspnea. The outcome is the change in Modified Borg Dyspnea Scale score.

  2. Change in Dominant-Hand Handgrip Strength From Baseline to Week 12

    Time frame: Baseline at T0 and post-intervention at Week 12

    Handgrip strength will be assessed using the GripWise dynamometer with the participant seated with back support. Three attempts will be performed for each hand. The highest value obtained for the dominant hand, expressed in kilograms, will be used as the primary handgrip variable.

  3. Change in Body Composition From Baseline to Week 12

    Time frame: Baseline at T0 and post-intervention at Week 12

    Body composition will be assessed by bioimpedance using the InBody BWA 2.0 device at the end of the second or third weekly hemodialysis session. Outcomes are changes in fat-free mass, expressed in kilograms; skeletal muscle mass, expressed in kilograms; and fat mass, expressed as a percentage.

  4. Change in KDQOL-SF 1.3 Health-Related Quality-of-Life Scores From Baseline to Week 12

    Time frame: Baseline at T0 and post-intervention at Week 12

    Health-related quality of life will be assessed using the Kidney Disease Quality of Life Short Form, version 1.3 (KDQOL-SF 1.3). Scores will be calculated according to the instrument scoring instructions and converted to a 0 to 100 scale. Physical and mental summary measures derived from the SF-36 will be prioritized. Higher scores indicate better health-related quality of life in the respective domain.

  5. Change in Forced Vital Capacity From Baseline to Week 12

    Time frame: Baseline at T0 and post-intervention at Week 12

    Forced vital capacity will be measured by spirometry using the MIR Spirolab device with the participant seated with back support. The outcome is the change in forced vital capacity, expressed in liters and, when available, as a percentage of the predicted value.

  6. Change in Surface Electromyography Root Mean Square Amplitude of Inspiratory Muscles From Baseline to Week 12

    Time frame: Baseline at T0 and post-intervention at Week 12

    Surface electromyography will assess electrical activity of the scalene, sternocleidomastoid, intercostal, and diaphragm muscles using the Sessantaquattro+ system. Electromyographic signal amplitude will be quantified as root mean square amplitude and analyzed separately for each assessed muscle.

  7. Change in Average Daily Steps From Baseline to Week 12

    Time frame: Baseline at T0 and post-intervention at Week 12

    Daily physical activity will be assessed using a Garmin Forerunner 55 watch worn for seven consecutive days during each assessment period. The primary variable is the average number of steps per day, calculated from valid monitoring days. An assessment period requires at least four valid monitoring days.

  8. Change in Forced Expiratory Volume in 1 Second From Baseline to Week 12

    Time frame: Baseline at T0 and post-intervention at Week 12

    Forced expiratory volume in 1 second will be measured by spirometry using the MIR Spirolab device with the participant seated with back support. The outcome is the change in forced expiratory volume in 1 second, expressed in liters and, when available, as a percentage of the predicted value.

  9. Change in 6-Minute Walk Test Distance From Baseline to Week 12

    Time frame: Baseline at T0 and post-intervention at Week 12

    Functional capacity will be assessed by the distance covered during the 6-Minute Walk Test on a flat, straight 30-meter corridor. The outcome is the change in total walking distance, expressed in meters. Higher values indicate greater functional capacity. Participants may use their usual walking aid when routinely used in daily activities.

Study contacts

Contact information is provided by the study sponsor or research team.

André Filipe Morais Pinto Novo

CONTACT

[email protected]

+351917972163

Sónia Alexandra Claro Casado

CONTACT

[email protected]

+351965364163

Sponsors and collaborators

Lead sponsor

Tecsam - Tecnologia e Servicos Medicos

Other

Collaborators

  • Foundation for Science and Technology, Portugal
  • Instituto Politécnico de Bragança
  • Universidad de León

Registry information

Official study title

Impact of Inspiratory Muscle Training on Functional Capacity, Lung Volumes, Electrical Activity and Inspiratory Muscle Strength in Hemodialysed Patients

Acronym: RespDialysis

Important dates

Study start
2026
Primary completion
2026
Study completion
2027
First posted
Sep 10, 2026
Registry last updated
Sep 10, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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