To investigate the effect of sputum induction (SI) combined with the active cycle of breathing technique (ACBT) on pulmonary function and rehabilitation compliance in patients with chronic obstructive pulmonary disease (COPD).

A total of 96 COPD patients admitted to our hospital from August 2023 to July 2025 were selected and randomly divided into an observation group (48 cases) and a control group (48 cases) using a random number table. The control group received a conventional pulmonary rehabilitation nursing program, while the observation group received SI combined with ACBT in addition to the treatment given to the control group. The two groups were compared in terms of pulmonary function indices [forced expiratory volume in 1 second (FEV₁), FEV₁% predicted, forced vital capacity (FVC), FEV₁/FVC], total sputum volume and viscosity, 6-minute walk distance (6MWD), General Self-Efficacy Scale (GSES) score, COPD Assessment Test (CAT) score, pulmonary rehabilitation compliance, and adverse reactions.

After treatment, the observation group had significantly better pulmonary function than the control group: FEV₁[(1.49±0.37) L vs (1.23±0.23) L, P<0.001]; FEV₁% pred [(62.62±14.08)% vs (53.18±11.82)%, P<0.001]; FVC[(2.79±0.46) L vs (2.48±0.41) L, P=0.001]; FEV₁/FVC [(53.27±7.40)% vs (49.85±5.66)%, P=0.012]. After treatment, the observation group showed a lower total sputum volume than the control group [(20.99±3.57) ml vs (23.29±5.11) ml, P<0.05], and a significantly greater improvement in sputum viscosity [(grade Ⅰ: 20.83% vs 10.42%, grade Ⅱ: 75.00% vs 56.25%, grade Ⅲ: 4.17% vs 33.33%), Z=-2.561, P=0.001]. The observation group was also superior in 6MWD [(376.85±31.54) m vs (318.29±14.20) m, P<0.001], GSES score [(25.75±3.48) vs (21.77±1.61), P<0.001], and CAT score [(13.58±2.34) vs (20.71±4.59), P<0.001]. The complete compliance rate for pulmonary rehabilitation was 45.83% in the observation group, higher than 25.00% in the control group (χ²=-2.198, P=0.012). The incidence of adverse reactions in the observation group was 9 cases (18.75%), lower than the 19 cases (39.58%) in the control group (χ²=4.084, P=0.043).

SI combined with ACBT can effectively improve pulmonary function, reduce total sputum volume and viscosity, enhance exercise tolerance, self-efficacy, quality of life, and rehabilitation compliance, and reduce adverse reactions in COPD patients, demonstrating clinical significance.