BackgroundThere are limited reports available on preferred chest physiotherapy methods in patients with coronary artery graft (CABG) surgery.ObjectivesThe aim of this study was to compare the effect of active cyclic breathing technique (ACBT) and routine chest physiotherapy on pain and respiratory parameters in patients undergoing CABG surgery.MethodsThis randomized clinical trial was carried out from July to November 2018. Seventy patients were selected randomly after CABG according to inclusion criteria and then assigned in two groups (35 in ACBT and 35 in routine physiotherapy) by random minimization method. The arterial blood gas levels, pain, heart rate, and respiratory rate were measured for both groups before and after the intervention on two consecutive days after surgery. Data were analyzed by SPSS software V.22, at a significance level of 0.05.ResultsThe two groups were similar in terms of demographic variables. In within group comparison in the physiotherapy group, the level of PaO2, HR, RR, and pain increased significantly on both days (P = 0.001), SaO2 on the first day (P = 0.005) and second day (P = 0.001), and PaCO2 on the first day (P = 0.02). In ACBT group, the level of SaO2, HR, RR, and pain increased significantly on both days (P = 0.001), HCO3 on the first day (P = 0.021), and PaO2 on the second day (P = 0.001) post intervention. In between group comparison, on the first day, the level of PH (P = 0.034), and on the second day HCO3 (P = 0.032) decreased, while RR (P = 0.011) increased significantly in the physiotherapy group, at post-intervention phase.ConclusionsACBT and routine physiotherapy had similar effects on arterial oxygenation, HR, and pain perception following CABG surgery. The physiotherapy on the second day increased the RR to an abnormal range.