Intervention group
Participants in the Acapella plus ACBT intervention group received a five-session combined ACTs program targeted at facilitating airway clearance on the day of admission, day before surgery, and POD 1–3 in the ward. Initially, the participants were asked to maintain a semi-recumbent position with the abdomen relaxed in a hospital bed, perform 3–4 thoracic expansion exercises with active inspiration, exhale through the Acapella device (frequency/resistance dial set gradually starting from the minimum setting to the maximum setting participants could tolerate) in a 4–6-second timeframe, and control breathing, with eight repetitions of the whole process. Finally, the participants performed the forced expiratory technique (huffing) to clear their airways. Once the participants had been treated for a maximum of 30 min, no longer expectorated sputum, or were too fatigued to continue, the treatment was considered as complete.In the Acapella plus EDP intervention, all participants and caregivers were instructed by the rehabilitation team on the necessary precautions and received a booklet with detailed instructions. The ACBT procedure in this group was consistent with that in the control group. All patients assumed the supine position, cleaned their neck and chest, and removed surface sebum and sweat before the intervention. The participants underwent EDP treatment, which was provided by physiotherapists, at a pacing frequency of 15 times per minute, pulse frequency of 40 Hz, and stimulation intensities gradually starting from 40 Hz to the intensities that participants could tolerate. Two pairs of electrode sheets were attached by the physiotherapists to the skin at the second intercostal space along the middle clavicular line and the distal one-third of the outer edge of the sternocleidomastoid muscles. The treatment, lasting an average of 30 min, was implemented on the day of admission, day before surgery, and POD 1–3 in the ward.