This single-center, parallel-group randomized controlled trial aims to evaluate the effect of a nurse-led intradialytic stretching program on the burden of muscle cramps in patients receiving maintenance hemodialysis (HD). Sixty adult patients on thrice-weekly HD with a history of lower-limb cramps will be randomized 1:1 to either an intervention group or a usual care control group.

The intervention consists of a standardized protocol of supervised lower-limb stretches (ankle dorsiflexion, gastrocnemius, soleus, and hamstring stretches). Each stretch will be held for 20-30 seconds and repeated three times per limb. The protocol will be delivered by HD nurses during dialysis sessions, twice a week for a total of 15 sessions over approximately eight weeks. Fidelity will be monitored using a structured checklist. The control group will receive routine care without structured exercises.

The primary outcome is the post-intervention cramp intensity category, measured using the Arabic Muscle Cramp Severity and Characteristics Questionnaire (MC-SCQ). Secondary outcomes include cramp frequency, duration, pain intensity, leg temperature perception, and discomfort/functional interference.

1. The Problem: The Burden of Intradialytic Muscle Cramps For patients undergoing maintenance hemodialysis (HD), the treatment is a life-sustaining necessity that comes with a significant symptom burden. Among the most common and disruptive of these symptoms are intradialytic muscle cramps-sudden, involuntary, and painful muscle contractions, primarily in the lower limbs. These episodes are not merely a minor inconvenience; they represent a serious clinical challenge. Cramps can be severe enough to forcibly halt a dialysis session, trigger distress calls to nurses, and necessitate urgent interventions such as sterile saline boluses or adjustments to the ultrafiltration rate. These reactive measures disrupt the dialysis process, can lead to hemodynamic instability, and increase nursing workload. For the patient, the experience is one of pain, anxiety, and a diminished quality of life. Estimates suggest these cramps affect a wide proportion, between 20% to 85%, of the chronic HD population.

2. The Proposed Solution: A Proactive, Nurse-Led Intervention Traditional management of these cramps has largely been reactionary. This study proposes to test a paradigm shift: moving from reactive treatment to proactive, nurse-led prevention. The intervention under investigation is a standardized protocol of lower-limb stretching exercises, administered during the dialysis session (intradialytically). The rationale is grounded in exercise physiology: sustained stretching is believed to improve muscle flexibility, enhance local circulation, and modulate neuromuscular excitability, potentially raising the threshold at which a cramp is triggered. By leveraging the time patients are already connected to the dialysis machine and the constant presence of a nurse, this strategy offers a low-cost, non-pharmacological, and patient-centric approach that aligns with nursing values of health promotion and continuity of care.

3. Study Design and Rigor

   To generate high-quality evidence, this study employs a single-center, parallel-group, randomized controlled trial (RCT) design. In this design, 60 eligible adult patients from the Beni-Suef University Hospital HD unit will be randomly assigned to one of two groups:

   The Intervention Group: Will receive the nurse-led intradialytic stretching program in addition to usual care.

   The Control Group: Will continue to receive usual care without any structured exercise program.

   This randomization process is intended to ensure that the groups are similar in all key aspects at the beginning of the study. To safeguard the integrity of the intervention, the research team will use a fidelity checklist to ensure every stretching session is delivered consistently and correctly.

4. The Intervention in Detail The stretching protocol is designed to be both effective and feasible within a busy dialysis unit. It targets the primary muscle groups involved in cramps: the ankle dorsiflexors, gastrocnemius, soleus, and hamstrings.

   Execution: During the first 1-2 hours of their dialysis session, patients in the intervention group will perform a series of supervised stretches. Each stretch will be held for 20-30 seconds and repeated three times for each limb.

   Safety: A paramount concern is patient safety, particularly regarding the vascular access site. Nurses will be trained to ensure all stretches are performed away from the access arm, with no compromise to needle security or tubing.

   Dosage: The program will be administered twice a week for approximately eight weeks, totaling 15 supervised sessions.

5. Measuring the Impact

The effect of the stretching program will be measured using the Arabic Muscle Cramp Severity and Characteristics Questionnaire (MC-SCQ). This tool is designed to capture the multi-dimensional burden of cramps by assessing:

Frequency of episodes Duration of cramps Pain Intensity Functional Interference and discomfort Leg Temperature Perception

Assessments will be conducted at baseline and at the end of the 8-week intervention period.

Inclusion Criteria:

• Adult patients aged 21 years or older.
• Undergoing maintenance hemodialysis on a thrice-weekly schedule.
• Have been on hemodialysis for at least 3 months.
• Clinically stable.
• Have a history of intradialytic lower-limb muscle cramps in the preceding month.
• Able to provide informed consent.

Exclusion Criteria:

• Musculoskeletal or neurological disorders that limit safe lower-limb stretching.
• Femoral vascular access or recent lower-limb vascular procedures.
• Undergoing their first or an emergency hemodialysis session.
• Inability to provide informed consent.

Baseline Characteristics: Age, sex, comorbidities, hemodialysis vintage, and baseline physiological parameters (e.g., blood pressure, calcium levels).

Primary Outcome Data: Individual post-intervention cramp intensity category scores (None, Mild, Moderate, Severe) from the Arabic MC-SCQ questionnaire.

Secondary Outcome Data: De-identified scores for all MC-SCQ sub-domains, including:

Cramp frequency

Cramp duration

Pain intensity

Discomfort/functional interference

Leg temperature perception

Intervention Data: Session-level adherence and fidelity checklist scores for participants in the intervention arm.

This data will be stripped of all direct identifiers (e.g., name, medical record number) to protect participant confidentiality.

Start Date: The IPD and supporting information will become available 3 months after the main results of the clinical trial are accepted for publication.

End Date: The data will be made available for a period of 5 years from the start date.

Who can access:

Researchers, including graduate students and investigators from academic institutions, healthcare organizations, and non-profit entities.

Access will be granted to those with a methodologically sound proposal for use in achieving the goals outlined in their approved proposal.

What they can access:

Individual Participant Data (IPD): De-identified dataset including baseline characteristics, primary outcome (cramp intensity category), and all secondary outcomes (frequency, duration, pain, etc.).

Supporting Information: The full Study Protocol and Statistical Analysis Plan (SAP).

How they can access it:

Mechanism: Data and documents will be shared via a secure file transfer service or a trusted data repository link upon approved request.

Process: Interested parties must submit a formal request via email to the corresponding author (Ahmed Mostafa).

Oversight: Requests will be reviewed by the study's principal investigators to ensure scientific validity & ethical approval.