Effect of progressive muscle relaxation on the vital signs and oxygenation indexes in patients under coronary artery bypass graft surgery: A triple blinded randomized clinical trial

Cardiovascular diseases are the most common cause of death in the most countries and Iran, and are the main disability cause, those induced stress, anxiety and changes in vital signs in patients under coronary artery bypass graft (CABG) surgery. This study was conducted to determine the effect of progressive muscle relaxation on the vital signs and oxygenation indexes of patients under CABG. In the randomized triple-blind clinical trial, 80 patients under CABG surgery after sampling by convenience method, randomly selected and assigned by random allocation method to 40 patients either the control or intervention groups. An orientation session was held to explain the research goals and intervention. The intervention group did the progressive muscle relaxation technique, two 20-30 minutes' sessions daily for 2 months (120 sessions). Correspondingly, data collection tools were demographic information questionnaire, vital signs, oxygenation indexes, and self-report checklists. Systolic blood pressure and respiratory rate within intervention group and main arterial pressure, pain and cardiac rhythm between two intervention and control groups had significant differences (P<0.05). Interaction effects time and group of systolic blood pressure and pain variables were significant (P<0.05). From oxygenation indexes perspective, PaO2/FiO2 and SPO2/FiO2 indexes within intervention group, PALVO2/FiO2 within control group, and PALVO2/ PaO2 within both intervention and control groups had significant differences (P<0.05). Except SPO2/FiO2 index, other oxygenation indexes had interaction effects of time and group (P<0.05). Applying progressive muscle relaxation technique on the various aspects of vital signs and oxygenation indexes of coronary artery bypass graft surgery was effective and using the technique to improve and stabilize of those is applicable and practical.