Investigation of the effect of Buteyko breathing technique on sleep quality, fatigue, and Peripheral blood oxygen saturation in patients with acute coronary syndrome(ACS)

Determining the effect of the Buteyko breathing technique on sleep quality, fatigue, and peripheral blood oxygen saturation in patients with acute coronary syndrome hospitalized in the cardiac intensive care unit.

This clinical trial is a randomized, triple-blind, controlled study with parallel groups. Patients with acute coronary syndrome are purposively selected and allocated to intervention (Buteyko breathing) and control (diaphragmatic breathing) groups using artificial intelligence. The sample size is 92 participants.

The study was conducted at Fatemeh Zahra Hospital in Khomain and Amir Kabir Hospital in Arak. Patients with acute coronary syndrome were purposively selected and randomly assigned to intervention (Buteyko) and control (diaphragmatic) groups. The study was triple-blinded, meaning participants, assessors, and intervention providers were unaware of group assignments.

Inclusion criteria include diagnosis of acute coronary syndrome by a cardiologist, age 30 years or older, and oxygen saturation (SpO2) above 90%. Exclusion criteria include a history of respiratory diseases or heart surgery within the past two months and the presence of cardiac dysrhythmia.

Buteyko Breathing Technique (BBT): Controlled, shallow nasal breathing with breath-holding after exhalation to reduce over-breathing and increase carbon dioxide tolerance. Patients in the intervention group perform this technique twice daily for 20 minutes each session over six weeks. Diaphragmatic Breathing: Deep breathing using the diaphragm muscle to improve oxygenation , taught to the control group and practiced during hospitalization.

The primary outcomes of the study include sleep quality, fatigue severity, and peripheral oxygen saturation.

Simple randomization and allocation of participants will be performed by an independent researcher using a list of patients and selection via artificial intelligence (Chatbot).

The blinding procedure in this study is implemented as a triple-blind design. Participants are completely unaware of their allocation to either the intervention or control group. The interventionists, who are responsible for teaching and administering the breathing techniques, have no knowledge of the patients’ group assignments. Randomization is carried out by an independent researcher using artificial intelligence software, ensuring that the interventionists deliver the assigned interventions without any information about group allocation. Data assessors, who collect questionnaires and perform physiological measurements such as peripheral oxygen saturation (SpO2), are also blinded to the type of intervention each patient receives and operate independently from the intervention team. The statistical analyst responsible for data analysis is likewise blinded to the group assignments to prevent any bias during interpretation of the results. Random allocation is performed by an independent supervisor, and coded labels are assigned to each group; these codes remain concealed until the completion of the study and all data analyses. The breathing technique trainings are provided to both groups in a standardized and visually identical manner, preventing participants and hospital staff from discerning any differences between groups. This rigorous blinding approach minimizes biases arising from the awareness of participants, interventionists, and assessors, thereby enhancing the internal validity and reliability of the study findings.