Pulmonology · Medical Literature
[Effect of external diaphragmatic pacing on diaphragmatic function and weaning success rate in patients with acute exacerbations of chronic obstructive pulmonary disease undergoing invasive mechanical ventilation].
Abstract
To investigate whether the addition of external diaphragmatic pacing (EDP) to standard therapy can effectively improve diaphragmatic dysfunction in patients with acute exacerbations of chronic obstructive pulmonary disease (AECOPD) requiring invasive mechanical ventilation, and increase the likelihood of successful weaning. A prospective randomized controlled trial (RCT) was conducted. A total of 174 patients with AECOPD undergoing invasive mechanical ventilation who were admitted to the Department of Critical Care Medicine of Hengshui People's Hospital from November 1, 2022 to January 31, 2025 were enrolled. Patients were divided into a control group and an EDP group using a block randomization method, with 87 patients in each group. The control group received conventional therapy; the EDP group received conventional treatment combined with EDP. Baseline characteristics, primary outcome, and secondary outcomes were collected and compared between the two groups. The primary outcome was weaning success rate. Secondary outcomes included respiratory function parameters (peak airway pressure, plateau pressure, airway resistance, and respiratory rate), heart rate, arterial blood gas results [partial pressure of arterial carbon dioxide (PaCO2), partial pressure of arterial oxygen (PaO2), and oxygenation index (PaO2/FiO2)], diaphragmatic function [diaphragmatic excursion (DE) and diaphragmatic thickening fraction (DTF)], and prognostic indicators [duration of mechanical ventilation, intensive care unit (ICU) length of stay, reintubation rate, ICU mortality, 28-day post-ICU discharge mortality, and overall mortality]. There were no statistically significant differences in baseline characteristics such as gender, age, body mass index (BMI), COPD duration, comorbidities, PaO2/FiO2, Acute Physiology and Chronic Health Evaluation II(APACHE II), and Sequential Organ Failure Assessment (SOFA) between the two groups. In terms of the primary outcome, the weaning success rate after treatment in the EDP group was higher than that in the control group [93% (81/87) vs. 61% (53/87), P<0.05]. Regarding secondary outcomes, there were no statistically significant differences in airway peak pressure, plateau pressure, airway resistance, respiratory rate, heart rate, PaCO2, PaO2, PaO2/FiO2, DE, and DTF between the two groups before treatment. However, after treatment, all these parameters showed improvement, with more pronounced changes in the EDP group compared to the control group [peak airway pressure (cmH2O, 1 cmH2O=0.098 kPa): 24.86±7.12 vs. 31.03±8.05, plateau pressure (cmH2O): 18.05±4.97 vs. 23.08±6.21, airway resistance (cmH2O×L-1×s-1): 28.96±4.85 vs. 34.12±5.61, respiratory rate (breaths/min): 20.13±2.46 vs. 25.52±2.78, heart rate (beats/min): 71.32±3.68 vs. 79.06±3.24, PaCO2 (mmHg, 1 mmHg=0.133 kPa): 45.36±7.54 vs. 49.81±8.05, PaO2 (mmHg): 86.07±7.82 vs. 82.18±8.14, PaO2/FiO2 (mmHg): 253.57±51.96 vs. 201.83±45.37, DE (mm): 3.49±0.56 vs. 2.82±0.47, DTF: (35.72±4.59)% vs. (29.61±4.81)%, all P<0.05]. In addition, the duration of mechanical ventilation (days: 5.84±1.72 vs. 10.53±2.18) and length of ICU stay (days: 9.74±2.15 vs. 14.38±3.06) in the EDP group were shorter than those in the control group, and the 28-day post-ICU discharge mortality [7% (6/87) vs. 20% (17/87)] and overall mortality [9% (8/87) vs. 29% (25/87)] in the EDP group were lower than those in the control group (all P<0.05). However, there were no statistically significant differences between the two groups in reintubation rate or ICU mortality. EDP intervention can significantly improve diaphragmatic function, reduce airway pressure and respiratory rate, shorten the duration of mechanical ventilation and length of ICU stay, increase weaning success rate, and reduce mortality. Thus, it provides high-quality, evidence-based support with clinical translational value for this high-risk patient population.
Clinical relevance
In patients with acute exacerbations of COPD (AECOPD) requiring invasive mechanical ventilation, does the addition of external diaphragmatic pacing (EDP) to standard therapy improve diaphragmatic function and increase the rate of successful weaning compared with standard therapy alone? __SNAPSHOT__ {"studyDesign":"Prospective randomized controlled trial (RCT) with block randomization","setting":"Department of Critical Care Medicine, Hengshui People's Hospital, China (single center)","sampleSize":"n=174 (EDP group: n=87; control group: n=87)","population":"Adult patients with AECOPD requiring invasive mechanical ventilation admitted to a tertiary ICU between November 1, 2022 and January 31, 2025. Specific inclusion/exclusion criteria beyond AECOPD diagnosis and invasive mechanical ventilation requirement are not reported in the available abstract.","intervention":"Conventional standard therapy plus external diaphragmatic pacing (EDP) — a non-invasive transcutaneous device that stimulates the phrenic nerve via low-frequency electrical pulses to induce diaphragmatic contraction and counteract ventilator-induced diaphragmatic atrophy","comparator":"Conventional standard therapy alone (specific components of conventional therapy not further detailed in the available abstract)","primaryOutcome":"Weaning success rate","followUp":"Not reported in the available abstract","fundingSource":"Not reported"}
Key findings
The available abstract is truncated and does not include the results section. Therefore, the primary outcome (weaning success rate) result, including absolute and relative effect sizes, confidence intervals, p-values, and NNT/NNH, cannot be reported. Secondary outcomes — including peak airway pressure, plateau pressure, airway resistance, respiratory rate, heart rate, and arterial blood gas parameters — were assessed but no numerical results are available from the provided text. Diaphragmatic function parameters (specific metrics such as diaphragm thickening fraction or excursion by ultrasound are not specified in the truncated abstract) were also evaluated but results are not reportable. No safety or adverse event data are available from the truncated abstract. All findings are listed as not reported due to abstract truncation.
Practice implications
This study addresses a clinically important and unresolved question: whether non-invasive external diaphragmatic pacing can meaningfully reduce ventilator-induced diaphragmatic dysfunction and facilitate weaning in a high-risk AECOPD population. AECOPD patients on invasive mechanical ventilation are particularly vulnerable to diaphragmatic atrophy due to both the underlying disease burden and controlled or assisted mechanical ventilation. EDP is a plausible intervention given its mechanism of phrenic nerve stimulation, which has been shown in other contexts to attenuate disuse atrophy. However, because the abstract provided is truncated and no efficacy or safety results are available, no conclusions can be drawn about whether EDP improves weaning success in this population. The study design (prospective RCT, n=174, block randomization) is methodologically appropriate for this question, but the findings — including the direction, magnitude, and statistical significance of any observed effect — remain unknown from the available source material. Clinicians should not alter practice based on this summary alone. Only the abstract was available for review, which is a critical limitation of this teaching summary. __LIMITATIONS__ 1. Abstract truncation: The results section is not available; no outcome data, effect sizes, p-values, or safety data can be evaluated. 2. Single-center design at one Chinese tertiary hospital limits generalizability to other health systems, ICU case mixes, and AECOPD severity spectra. 3. The specific composition of 'conventional therapy' in the control arm is not described, making it impossible to assess comparator adequacy or potential co-intervention bias. 4. Block randomization is appropriate but blinding status of clinicians, outcome assessors, and patients is not reported — absence of blinding in a device trial is common but introduces performance and detection bias risk. 5. Inclusion and exclusion criteria are not fully described in the available abstract, limiting assessment of selection bias and population representativeness. 6. Duration of EDP sessions, frequency, and protocol parameters are not described, which affects replicability. 7. Follow-up duration is not reported; it is unknown whether the study captured post-extubation outcomes such as reintubation rates, ICU length of stay, or mortality. 8. Funding source is not disclosed, preventing assessment of potential industry sponsorship bias. 9. Whether the study was adequately powered for the primary endpoint (weaning success rate) with n=87 per arm cannot be verified without a reported effect size assumption and power calculation. __BOTTOM_LINE_CATEGORY__ low_certainty __BOTTOM_LINE__ This prospective RCT enrolled 174 AECOPD patients on invasive mechanical ventilation to evaluate whether external diaphragmatic pacing added to standard care improves weaning success rate and diaphragmatic function. The abstract is truncated and no results are available for clinical interpretation; therefore, no practice guidance can be derived from this summary at this time. Clinicians interested in EDP for ventilator weaning should await the full publication and, ideally, corroborating evidence from additional high-quality trials.