Chronic kidney disease (CKD) is characterised by kidney damage that persists for 3 months or longer or an estimated glomerular filtration rate (eGFR) below 60 mL/min/1.73 m² and is assessed in 6 categories. According to this categorisation, when stage 4 CKD progresses, patients are offered several options for renal replacement therapy. In the last stage of CKD, stage 5, renal replacement therapies including dialysis and kidney transplantation are used. Haemodialysis (HD) is a frequently used life-saving treatment method that removes harmful waste substances accumulated in the body, helps to maintain kidney function, provides fluid-electrolyte balance, prolongs life by managing uremic symptoms. Patients with ESRD are exposed to many health problems such as water-salt balance abnormalities, hypertension, hyperkalemia, metabolic acidosis, hyperphosphatemia, anaemia, cardiovascular disease. While the problems experienced are controlled with HD treatment, the treatment process and the continuation of life dependent on a machine cause life-threatening acute (hypotension, nausea, vomiting, muscle cramps, itching, pain, etc.) and chronic complications (pericarditis, hypertension, anaemia, hepatitis infections, etc.). In addition, due to these complications, HD patients may have problems that cannot be ignored such as deterioration in general health perception, sleep disturbance, anxiety, depression, stress, and difficulties in fulfilling responsibilities due to psychosocial problems. Intradialytic muscle cramp, which develops acutely during HD and is experienced at least once by patients, frequently manifests as involuntary muscle contractions in the lower extremities. The aetiology of intradialytic muscle cramp includes hypotension, electrolyte mineral disorders, high ultrafiltration (UF), excess weight gain between two HDs and carnitine deficiency. In the pharmacological treatment of this complication, which should be managed acutely, intravenous saline solution and hypertonic glucose administration are prominent, but high-quality evidence on the effectiveness of these treatments is needed. While the results of interventions such as aromatherapy, reflexology, massage, stretching-relaxation exercises, hot-cold applications etc. in intradialytic muscle cramp have been reached, the lack of evidence for vibration massage is striking. Management of intradialytic muscle cramp is important for the HD adequacy of patients and failure to manage it may lead to fatal complications such as hypertension, hypervolemia, pulmonary oedema and left ventricular failure due to inadequate HD sessions. It has also been reported that sleep and quality of life are adversely affected in cases where intradialytic muscle cramp cannot be managed; shortening of one HD session per week leads to increased mortality rates, depression and anxiety levels and stress. Salivary cortisol is a useful biomarker often used as a marker of psychological stress. Salivary cortisol levels peak approximately 20 minutes after an acute stress event. Massage, which is among independent nursing interventions, is a manipulation that provides physical and psychological relaxation by mechanically stimulating muscle tissues. During massage, nurses can apply euphlorage, petrissage, friction, tapotman and vibration. Vibration massage is applied to improve muscle atrophy and bone density caused by microgravity and immobilisation. Static stretching exercise, another intervention in intradialytic muscle cramp management, reduces muscle stiffness and tension by increasing muscle flexibility and range of motion by stimulating neural activities. These exercises reduce the risk of injury to joints, muscles and tendons by stimulating the formation of chemicals that allow the connective tissue to move easily and are recommended for the prevention of muscle cramps.

Key words: Vibration massage, Static stretching exercise, Intradialytic muscle cramp, Salivary cortisol level, stress.

Study design: Randomised controlled trial. Objectives:The aim of this randomised controlled clinical trial was to evaluate the effect of vibration massage and static stretching exercise on intradialytic muscle cramp (severity and duration) and salivary cortisol levels during intradialytic muscle cramp.

Phase of the study: For this study, permission was obtained from Eskişehir Osmangazi University Clinical Research Ethics Committee that there was no ethical objection. For the financial support of the study, an application was made to the Scientific and Technological Research Council of Türkiye (TUBITAK), a state institution in Turkey, and the result is awaited. After approval, the data collection phase will begin.

Interventional Study Model: Factorial Vibration massage group (Group A), Static stretching exercise (Group B), Control Group (Group C).

Masking: Outcomes Assessor. Allocation: Stratified Randomized. Enrollment: The total number of participants to be enrolled in the clinical study was determined as 30.

Biospecimen Retention: Collection of saliva for salivary cortisol testing at the time of intradialytic muscle cramp and at 20 minutes after the patients to be included in the study.

Target Follow-Up Duration: Participants will be followed up at the time of intradialytic muscle cramp and at the time of its termination.

Intervention First intervention group: Vibration massage (Group A).

• Initiation of the stopwatch with the onset of intradialytic muscle cramp,
• Taking a salivary cortisol test,
• 10 minutes of vibration massage,
• VAS questioning every 2 minutes during intradialytic muscle cramp,
• Stopping the stopwatch as soon as the patient states that the intradialytic muscle cramp has ended,
• Repeat salivary cortisol test at 20 minutes from the onset of intradialytic muscle cramp.

The second group of intervention: Static stretching exercise (Group B)

• Initiation of the stopwatch with the onset of intradialytic muscle cramp,
• Taking a salivary cortisol test,
• Perform static stretching exercise for 10 minutes,
• VAS questioning every 2 minutes during intradialytic muscle cramp,
• Stopping the stopwatch as soon as the patient states that the intradialytic muscle cramp has ended,
• Repeat salivary cortisol test at 20 minutes from the onset of intradialytic muscle cramp.

Control group: Usual care (Group C)

• Initiation of the stopwatch with the onset of intradialytic muscle cramp,
• Taking a salivary cortisol test,
• Usual care,
• VAS questioning every 2 minutes during intradialytic muscle cramp,
• Stopping the stopwatch as soon as the patient states that the intradialytic muscle cramp has ended,
• Repeat salivary cortisol test at 20 minutes from the onset of intradialytic muscle cramp.

Outcome Measures

Primary Outcome Measure Information:

• The effect of vibration massage on the severity, duration and salivary cortisol level of intradialytic muscle cramp.
• The effect of static stretching exercise on intradialytic muscle cramp severity, duration and salivary cortisol level.
• To determine which intervention (vibration massage and static stretching exercise) is more effective on intradialytic muscle cramp severity, duration and salivary cortisol level.

Secondary Outcome Measure: The effectiveness of vibration massage and stretching exercise interventions for acute stress management will be determined.

Age Limits: Patients aged 18 years and older. Eligibility Criteria: 18 years of age and over, conscious, Turkish speaking and understanding, accepting the research, With a normal body mass index (18.5-24.9), Patients with intradialytic muscle cramps in the lower limb.

Statistical Analysis Plan: The data obtained in the study will be analysed using SPSS (Statistical Package for Social Sciences) for Windows 22.0 programme. The statistician performing the statistics of the data will not be informed which group the patients are in and the interventions applied to the groups, thus statistical blinding will be ensured. Kolmogorov Smirnov Test will be used to determine whether the research data are normally distributed. According to the Kolmogorov Smirnov Test, if p>0.05, it is determined that the distribution is normal. However, if p<0.05, it is determined that the distribution is not normal and the Skewness and Kurtosis values of the data are examined. If Skewness and Kurtosis values are between +2 and -2, it is accepted that the variable shows normal distribution. Homogeneity of descriptive characteristics between groups will be tested by chi-square analysis. For the difference between group averages, one-way analysis of variance will be used if the data are normally distributed, and Kruskal Wallis test will be used if the data are not normally distributed. Changes in measurements within the group will be analysed by repeated measures ANOVA test if the data are normally distributed, and by Friedman test if the data are not normally distributed.

Informed Consent Form: Informed Voluntary Consent signature will be obtained from patients who agree to participate in the study. The research will be conducted in accordance with the Declaration of Helsinki.

Inclusion Criteria:

• 18 years of age and over, conscious, Turkish speaking and understanding, accepting the research,
• Patients with normal body mass index (18.5-24.9) [Since body mass can affect the distribution of vibration and cortisol level, it was planned to include patients with normal body mass index in the sample].
• Patients with intradialytic muscle cramp in the lower extremities will be included [Although intradialytic cramp often occurs in the lower extremities, vibration massage and static stretching exercise will be applied to the same muscle group (gastrocnemius and soleus muscles) in the lower extremities to keep the variables under control].

Exclusion Criteria:

• Intradialytic muscle cramps in the upper extremity,

• Intradialytic muscle cramps, those with incomplete tissue integrity in the region and thrombophlebitis, hematoma, etc. [In order for vibration massage to be performed, individuals must have skin integrity and normal blood characteristics.]

• Those with foot deformation,

• Those who use anti-inflammatory, analgesic drugs and those who additionally use adjuvant therapy (antidepressants, anticonvulsants, muscle relaxants, etc.) up to 4 hours before the HD session, as intradialytic muscle cramps and their duration may be affected,

• Those who are taking routine cortisone treatment and medications with hormonal effects (oral contraceptives, steroid-containing bronchodilators, etc.) so that the salivary cortisol test is not affected.

  --Alcohol users,

• Hypoglycemic patients,

• Patients with psychiatric diagnosis and those using medication related to this diagnosis,

• Patients with mouth ulcers, inflammation, etc.

• Patients who ate or drank anything other than water, chewed gum, or consumed foods or beverages containing citric acid 15 minutes before intradialytic muscle cramping,

• Patients who use high doses of biotin (>5 mg/day) and whose last biotin treatment has not passed 8 hours.

Summary data can be provided starting 6 months after publication.

July - December 2025

Academic staff can request this information. Data can be shared with the permission of all researchers involved in the study.