Effect of CPAP on Respiratory Load in COPD

Effect of CPAP on Respiratory Load and Lung Volume in Stable COPD

Both intrinsic positive end expiratory pressure (PEEPi) and dynamic hyperinflation are considered as inspiratory loads which increase work of breathing in patients with COPD. The application of extrinsic positive end expiratory pressure (PEEPe) supplied by CPAP has been claimed to reduce inspiratory load based on change in esophageal pressure which could be significantly affected by change in lung volume and airflow. The investigator hypothesized that CPAP could increase respiratory load because it increases lung volume.

Study Overview

• Status: Recruiting
• Conditions: Chronic Obstructive Pulmonary Disease
• Intervention / Treatment: Device: Continuous Positive Airway Pressure

Detailed Description

Objective: To assess the effect of CPAP on respiratory load and lung volume in stable COPD. Methods: Patients with COPD were recruited to breath under the atmosphere pressure and different levels of CPAP (4, 6, 8 and 10 cm H2O). Diaphragm EMG, esophageal pressure (Pes) and transdiaphragmatic pressure (Pdi) were recorded using balloon esophageal electrode catheter (Yinghui, Guangzhou, China). End inspiratory lung volume (EILV) was measured directly from a pneumotachograph combined with a three way valve under the different CPAP levels. Sensation of breathing difficulty was also assessed. In an additional study, the effect of airflow on pressure was investigated by a physical mode.

• Study Type: Interventional
• Enrollment (Estimated): 19
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Yuanming Luo, PHD; Phone Number: +8613570033081; Email: yluo15@bwh.harvard.edu

Study Locations

• China
  • Guangdong
    • Guangzhou, Guangdong, China
      • Recruiting
      • Guangzhou Medical University
      • Contact: Yuanming Luo, PHD; Phone Number: +86 (20) 34294136; Email: y.m.luo@vip.163.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Willing to participate after informed consent
2. Males and females, any race and aged 40-80 years
3. GOLD II-IV COPD (post-bronchodilator FEV1 < 80 % of the predicted normal, and a post-bronchodilator FEV1/FVC < 0.70)

Exclusion Criteria:

1. Patients recovering from acute exacerbation less than 4 weeks.
2. Patients with concomitant pulmonary disease (e.g. lung fibrosis, interstitial lung disorder).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: CPAP treatment; CPAP treatment in COPD patients	Device: Continuous Positive Airway Pressure; Patients with COPD were recruited to breath under the atmosphere pressure and different levels of CPAP (4, 6, 8 and 10 cm H2O).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Diaphragm EMG	assessment of the electrical activity of the diaphragm (EMG-di)	Around 5 minutes signals under the atmosphere pressure and different levels of CPAP (4, 6, 8 and 10 cm H2O) were recorded.
Lung volume	measurement of end inspiratory lung volume (EILV)	1-3 minutes after each CPAP level (0, 4, 6, 8 and 10 cm H2O)
Intrinsic positive end expiratory pressure (PEEPi)	PEEPi was calculated from the negative deflection in Pes from the onset of inspiratory effort to the point of zero flow during spontaneous breathing.	Around 5 minutes signals under the atmosphere pressure and different levels of CPAP (4, 6, 8 and 10 cm H2O) were recorded.
Inspiratory pressure	assessment of esophageal pressure and transdiaphragmatic pressure by caculating tidal variations in Pes (∆Pes) and Pdi (∆Pdi) relatived to initiation of effort.	Around 5 minutes signals under the atmosphere pressure and different levels of CPAP (4, 6, 8 and 10 cm H2O) were recorded.
Inspiratory work	the pressure-time product of the respiratory muscles (PTPes/min) and of the diaphragm (PTPdi/min) were calculated under the Pes and Pdi versus time curve and expressed per minute.	Around 5 minutes signals under the atmosphere pressure and different levels of CPAP (4, 6, 8 and 10 cm H2O) were recorded.
Sensation of breathing effort	Using questionnaire to assess the sensation of breathing effort. Sensation of breath effort of CPAP use was divided into three types corresponding to -1, 0, 1 score respectively, 0 refers to the same sensation as the feeling of breathing at the atmosphere without CPAP; 1 refers to the more difficult sensation to breath at the CPAP condition than at the atmosphere.; -1 refers to the easier sensation to breath at the CPAP condition than at the atmosphere.	5 minutes after each CPAP level (0, 4, 6, 8 and 10 cm H2O)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Respiratory rate (RR)	assessment of respiratory rate (RR)	Around 5 minutes signals under the atmosphere pressure and different levels of CPAP (4, 6, 8 and 10 cm H2O) were recorded.
Tidal volume (Vt)	assessment of tidal volume	Around 5 minutes signals under the atmosphere pressure and different levels of CPAP (4, 6, 8 and 10 cm H2O) were recorded.
Minute ventilation (VE)	assessment of minute ventilation	Around 5 minutes signals under the atmosphere pressure and different levels of CPAP (4, 6, 8 and 10 cm H2O) were recorded.
Peak inspiratory flow rate	assessment of peak inspiratory flow rate	Around 5 minutes signals under the atmosphere pressure and different levels of CPAP (4, 6, 8 and 10 cm H2O) were recorded.
Expiratory muscle EMG	assessment of the electrical activity of the internal oblique muscle (EMG-obl) and the rectus muscle (EMG-rec)	Around 5 minutes signals under the atmosphere pressure and different levels of CPAP (4, 6, 8 and 10 cm H2O) were recorded.
Expiratory pressure	The change in Pga resulting from the contraction of the abdominal muscles during expiration was analyzed	Around 5 minutes signals under the atmosphere pressure and different levels of CPAP (4, 6, 8 and 10 cm H2O) were recorded.

Collaborators and Investigators

• Sponsor: State Key Laboratory of Respiratory Disease
• Investigators: Principal Investigator: Yuanming Luo, PHD, Guangzhou Medical University

Study record dates

Study Major Dates

• Study Start (Actual): May 1, 2024
• Primary Completion (Estimated): June 30, 2024
• Study Completion (Estimated): July 10, 2024

Study Registration Dates

• First Submitted: April 25, 2024
• First Submitted That Met QC Criteria: April 25, 2024
• First Posted (Actual): April 30, 2024

Study Record Updates

• Last Update Posted (Actual): May 14, 2024
• Last Update Submitted That Met QC Criteria: May 12, 2024
• Last Verified: May 1, 2024

More Information

Terms related to this study

• Keywords: COPD; CPAP; Diaphragm EMG
• Additional Relevant MeSH Terms: Pathologic Processes; Respiratory Tract Diseases; Lung Diseases; Disease Attributes; Chronic Disease; Lung Diseases, Obstructive; Pulmonary Disease, Chronic Obstructive
• Other Study ID Numbers: 2020 No.38

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: The data will be shared after the paper of this study publishing.
• IPD Sharing Time Frame: The data will be shared after the paper of this study publishing.
• IPD Sharing Access Criteria: After the paper of this study publishing
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No