[Effects of external diaphragm pacing on early pulmonary function recovery in invasive mechanically ventilated patients with acute exacerbation of chronic obstructive pulmonary disease complicated by respiratory failure].

Abstract

To investigate the effect of external diaphragm pacing (EDP) combined with early mobilization on the outcomes of mechanically ventilated patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) complicated by respiratory failure. A randomized controlled trial was conducted. A total of 212 patients with AECOPD complicated by respiratory failure who required invasive mechanical ventilation and were admitted to Hengshui People's Hospital from December 2022 to May 2025 were enrolled. Patients were divided into control group and combined intervention group using a random number table, with 106 patients in each group. The control group received conventional treatment plus early mobilization rehabilitation; the combined intervention group received EDP in addition to the control regimen, initiated within 24 hours of starting mechanical ventilation, once daily, 30 minutes per session, and continued until extubation. The duration of mechanical ventilation, length of intensive care unit (ICU) stay, total hospital stay, weaning success rate, 28-day reintubation rate, and 28-day all-cause mortality were compared between the two groups. Diaphragm excursion (DE), diaphragm thickness (DT), and diaphragm thickening fraction (DTF) were assessed using bedside ultrasound at baseline, on day 7 of intervention, and at the time of successful weaning. Pulmonary function [forced expiratory volume in 1 second as percentage of predicted value (FEV1%)], exercise tolerance [6-minute walk distance (6MWD)], and quality of life [Chronic Obstructive Pulmonary Disease Assessment Test (CAT) score] were evaluated at hospital discharge and 1 month post-discharge. Spearman correlation analysis was used to examine the relationships between diaphragm function indicators and weaning success. Compared with the control group, the combined intervention group had significantly shorter duration of mechanical ventilation [hours: 98.00 (72.00, 124.00) vs. 134.50 (96.00, 162.75)], shorter length of ICU stay (days: 10.81±3.52 vs. 14.22±4.07), and shorter total hospital stay (days: 17.42±4.59 vs. 21.58±5.31), as well as a higher weaning success rate (86.8% vs. 73.6%) and a lower 28-day reintubation rate (7.5% vs. 17.0%), all with statistically significant differences (all P<0.05). The 28-day all-cause mortality was slightly lower in the combined intervention group than that in the control group, but there was no statistically significant difference (P>0.05). Linear mixed-effects model analysis showed significant time, group, and interaction effects for all diaphragm function indicators (all P<0.05). At day 7 of intervention and at successful weaning, DE, DT, and DTF were all significantly higher in the combined intervention group than those in the control group [DE (mm): 12.67±2.34 vs. 9.45±2.01, 14.82±2.56 vs. 10.89±2.15; DT (mm): 2.41±0.44 vs. 1.98±0.38, 2.68±0.47 vs. 2.10±0.41; DTF: (35.62±7.84)% vs. (21.45±5.92)%, (42.15±8.93)% vs. (26.78±6.87)%, all P<0.05]. At discharge and 1 month post-discharge, the combined intervention group showed significantly higher FEV1% and 6MWD and lower CAT score than the control group [FEV1%: (46.87±8.94)% vs. (42.36±8.15)%, (54.31±10.12)% vs. (48.92±9.23)%; 6MWD (m): 298.63±65.42 vs. 258.74±62.35, 368.52±75.16 vs. 312.45±71.28; CAT score: 19.02±4.93 vs. 22.15±5.46, 14.86±4.15 vs. 18.37±4.82, all P<0.05]. At successful weaning, all diaphragm function indicators were positively correlated with weaning outcome (ρ values for DE, DT, and DTF: 0.587, 0.524, and 0.632, respectively, all P<0.05), with DTF showing the strongest correlation. There was no statistically significant difference in the total incidence of adverse events between the combined intervention group and the control group (1.9% vs. 0.9%, χ ²=0.342, P=0.559). The integrated pulmonary rehabilitation strategy of EDP combined with early mobilization effectively improves diaphragm function in mechanically ventilated patients with AECOPD and respiratory failure, shortens the duration of mechanical ventilation and hospital stay, increases the weaning success rate, and promotes long term recovery of pulmonary function, exercise tolerance, and quality of life, with a favorable safety profile.