For many hemodialysis patients, fatigue and sleep disturbances are common and debilitating side effects that severely impact daily life and quality of life. In this study, patients will be taught a simple breathing exercise called the 4-7-8 technique to help manage these symptoms. A total of 80 adult patients undergoing regular hemodialysis at Izmir Atatürk Training and Research Hospital will be randomly assigned to two groups: an intervention group and a control group. Participants in the intervention group will receive a face-to-face training session from a research nurse and a short instructional video sent to their smartphones to encourage daily home practice, especially before bedtime. The program will be continued over the study period. Participants in the control group will continue with their current routine hemodialysis care without any structured breathing exercises. Fatigue levels, sleep quality, and daytime sleepiness will be measured in both groups before and after the program using validated questionnaires. The results of this study may provide nurses and patients with a safe, cost-effective, non-drug option to improve symptom management and overall well-being in hemodialysis patients.

This study was designed as a randomized controlled trial. The estimated sample size was calculated using the G*Power 3.1.9.7 software. The calculation was based on parameters from a preliminary study on the effects of breathing exercises in hemodialysis patients. For the independent two-group t-test, an analysis was conducted assuming 95% power (1-β), a significance level of α=0.05, and a large effect size (d=0.80). As a result, it was determined that 35 participants were needed in each group, for a total of 70 participants. Taking potential dropouts into account, the study will begin with a total of 80 participants, and analyses will be conducted using data from at least 70 participants who have completed the follow-up.

Inclusion Criteria: Age between 18 and 85 years; receiving hemodialysis treatment for at least 3 months; no diagnosis of malignant respiratory disease (e.g., bronchial or lung cancer); no pathological condition affecting consciousness or focus (e.g., dialysis dementia or uremic encephalopathy); native Turkish speaker.

Exclusion Criteria: Advanced reading comprehension problems; advanced hearing impairment; presence of sleep apnea; known psychiatric illness.

Intervention Group Protocol: Participants in the experimental group will be taught a standardized program consisting solely of the 4-7-8 breathing technique. The intervention will last four weeks. The technique will be demonstrated face-to-face by a research nurse, and patients will be provided with a short instructional video that explains the technique step by step. The video will be sent to patients' smartphones to encourage them to practice independently at home.

4-7-8 Breathing Technique Instructions:

Patients will be asked to sit or lie down in a comfortable position and follow the cycle below:

4 seconds: Take a slow, deep breath in through the nose.

7 seconds: Hold the breath.

8 seconds: Exhale slowly and completely through the mouth, with lips slightly pursed (making a slight hissing sound).

This cycle will be repeated 10 times consecutively per session, with a total duration of approximately 10-15 minutes. Participants will be asked to perform the technique twice daily (once during the day and once before bedtime). To monitor adherence, patients will be given a simple practice log, and weekly reminders will be provided via phone calls or messages. On hemodialysis session days, the exercise will be performed during the HD session under the supervision of the research nurse.

Control Group Protocol: Participants in the control group will continue with their current routine hemodialysis care and will not be included in any structured breathing exercise program.

Assessment: Fatigue (Chalder Fatigue Scale), sleep quality (Jenkins Sleep Scale), and daytime sleepiness (Epworth Sleepiness Scale) will be assessed at three time points: at baseline (pre-test), at the end of the second week, and at the end of the fourth week of the intervention.

Inclusion Criteria:

• Age between 18 and 85 years
• Receiving hemodialysis treatment for at least 3 months
• No diagnosis of malignant respiratory disease (e.g., bronchial or lung cancer)
• No pathological condition affecting consciousness or focus (e.g., dialysis dementia or uremic encephalopathy)
• Native Turkish speaker

Exclusion Criteria:

• Advanced reading comprehension problems
• Advanced hearing impairment
• Presence of sleep apnea
• Known psychiatric illness.

Due to the nature of the interventions (listening to music and looking in a mirror), participants and the nurses providing care will not be blinded to the group assignment. However, the statistician conducting the final data analysis will be blinded to the group assignment.