Capnography-assisted learned, monitored (CALM) breathing therapy for dysfunctional breathing in COPD: A bridge to pulmonary rehabilitation

Background: Although dyspnea is a primary symptom of chronic obstructive pulmonary disease (COPD), its treatment is suboptimal. In both COPD and acute anxiety, breathing patterns become dysregulated, contributing to abnormal CO₂, dyspnea, and inefficient recovery from breathing challenges. While pulmonary rehabilitation (PR) improves dyspnea, only 1–2% of patients access it. Individuals with anxiety who use PR have worse outcomes. Methods: We present the protocol of a randomized controlled trial designed to determine the feasibility and acceptability of a new, four-week mind-body intervention that we developed, called “Capnography-Assisted Learned, Monitored (CALM) Breathing,” as an adjunct to PR. Eligible participants are randomized in a 1:1 ratio to either CALM Breathing program or Usual Care. CALM Breathing consists of 10 core, slow breathing exercises combined with real time biofeedback (of end-tidal CO₂, respiratory rate, and airflow) and motivational interviewing. CALM Breathing promotes self-regulated breathing, linking CO₂ changes to dyspnea and anxiety symptoms and targeting breathing efficiency and self-efficacy in COPD. Participants are randomized to CALM Breathing or a Usual Care control group. Results: Primary outcomes include feasibility and acceptability metrics of recruitment efficiency, participant retention, intervention adherence and fidelity, PR facilitation, patient satisfaction, and favorable themes from interviews. Secondary outcomes include breathing biomarkers, symptoms, health-related quality of life, six-minute walk distance, lung function, mood, physical activity, and PR utilization and engagement. Conclusion: By disrupting the cycle of dyspnea and anxiety, and providing a needed bridge to PR, CALM Breathing may address a substantive gap in healthcare and optimize treatment for patients with COPD.