Physiological Study of High PEEP in Noninvasive Ventilation

A Physiological Study of High PEEP During Noninvasive Ventilation in Patients With Hypoxemic Respiratory Failure

To investigate the physiological effects of high positive end-expiratory pressure (PEEP) during noninvasive ventilation in patients with hypoxemic respiratory failure, and to elucidate the mechanisms underlying high PEEP-induced improvement in oxygenation.

Study Overview

• Status: Recruiting
• Conditions: Respiratory Failure With Hypoxia
• Intervention / Treatment: Procedure: high PEEP

• Study Type: Interventional
• Enrollment (Estimated): 50
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Jun Duan; Phone Number: +86-89012680; Email: duanjun412589@163.com
• Study Contact Backup: Name: Yiwei Min; Phone Number: +8689012144; Email: 496996728@qq.com

Study Locations

• China
  • Chongqing Municipality
    • Chongqing, Chongqing Municipality, China, 400016
      • Recruiting
      • The First Affiliated Hospital of Chongqing Medical University
      • Contact: Jun Duan; Phone Number: 86-023-89012680; Email: duanjun412589@163.com

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

1. Age ≥ 18 years
2. PaCO₂ ≤ 50 mmHg
3. PaO₂/FiO₂ ≤ 300 mmHg
4. Use of a noninvasive ventilator with esophageal pressure monitoring capability (e.g., Mindray SV70) -

Exclusion Criteria:

1. Respiratory failure caused by heart failure, asthma, or acute exacerbation of chronic obstructive pulmonary disease (COPD) (COPD as a comorbidity may be included)
2. Pneumothorax
3. Patients who refuse to participate in this trial -

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• 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: High PEEP group; PEEP is increased stepwise from 5 cmH₂O, with increments of 5 cmH₂O every 10-20 minutes until reaching 20 cmH₂O. Once PEEP reaches or exceeds 20 cmH₂O, increments are made every 3-5 minutes until the recruitment level is achieved (i.e., stepwise increases to 5, 10, 15, 20, 25, and 30 cmH₂O). Inspiratory pressure is adjusted simultaneously to maintain a constant pressure difference.

Procedure: high PEEP; First, PEEP was set at 5 cmH₂O, and inspiratory pressure was adjusted to achieve a target tidal volume of 6-8 mL/kg. Fraction of inspired oxygen (FiO₂) was titrated to maintain peripheral oxygen saturation (SpO₂) between 88% and 92%. Subsequently, PEEP was increased in 5 cmH₂O increments every 10-20 minutes from the initial value of 5 cmH₂O. Once PEEP reached 20 cmH₂O or above, increments were made every 3-5 minutes until the recruitment level was achieved (i.e., PEEP was increased stepwise from 5 to 10, 15, 20, 25, and 30 cmH₂O). Inspiratory pressure was adjusted concurrently to maintain a constant pressure difference. Throughout the procedure, physiological parameters-including respiratory rate, oxygenation, work of breathing, and others-were collected.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Oxygenation	The changes of SpO2/FiO2 from 5 to 30 cmH2O of PEEP.	From enrollment to 2 hours post-intervention

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Respiratory rate	Changes of respiratory rate from 5 to 30 cmH2O of PEEP	From enrollment to 2 hours post-intervention
Blood pressure	Changes of blood pressure from 5 to 30 cmH2O of PEEP	From enrollment to 2 hours post-intervention
Heart rate	Changes of heart rate from 5 to 30 cmH2O of PEEP	From enrollment to 2 hours post-intervention
Diaphragmatic excursion	Changes in diaphragmatic excursion across PEEP levels from 5 to 30 cmH₂O. Diaphragmatic excursion refers to the movement of the thoracic diaphragm during breathing, as assessed by ultrasound.	From enrollment to 2 hours post-intervention
Diaphragm thickening fraction	Changes in diaphragm thickening fraction across PEEP levels from 5 to 30 cmH₂O. Diaphragm thickening fraction is calculated based on the change in diaphragm thickness from end-expiration to end-inspiration ([end-inspiration - end-expiration]/end-expiration), as assessed by ultrasound.	From enrollment to 2 hours post-intervention
Work of breathing	Changes in work of breathing across PEEP levels ranging from 5 to 30 cmH₂O were assessed by monitoring esophageal pressure with an esophageal balloon catheter.	From enrollment to 2 hours post-intervention
Electrical impedance tomography of the lung	Changes in lung electrical impedance tomography were recorded across PEEP levels ranging from 5 to 30 cmH₂O. The electrical impedance tomography belt was placed around the chest at the level of the 4th to 5th intercostal spaces, and data were collected after the patient's breathing had stabilized.	From enrollment to 2 hours post-intervention
Tidal volume	Changes of tidal volume from 5 to 30 cmH2O of PEEP	From enrollment to 2 hours post-intervention

Collaborators and Investigators

• Sponsor: Chongqing Medical University
• Investigators: Principal Investigator: Jun Duan, MD, First Affiliated Hospital of Chongqing Medical University

Publications and helpful links

General Publications

• Morais CCA, Koyama Y, Yoshida T, Plens GM, Gomes S, Lima CAS, Ramos OPS, Pereira SM, Kawaguchi N, Yamamoto H, Uchiyama A, Borges JB, Vidal Melo MF, Tucci MR, Amato MBP, Kavanagh BP, Costa ELV, Fujino Y. High Positive End-Expiratory Pressure Renders Spontaneous Effort Noninjurious. Am J Respir Crit Care Med. 2018 May 15;197(10):1285-1296. doi: 10.1164/rccm.201706-1244OC.
• L'Her E, Deye N, Lellouche F, Taille S, Demoule A, Fraticelli A, Mancebo J, Brochard L. Physiologic effects of noninvasive ventilation during acute lung injury. Am J Respir Crit Care Med. 2005 Nov 1;172(9):1112-8. doi: 10.1164/rccm.200402-226OC. Epub 2005 Aug 4.
• Yoshida T, Roldan R, Beraldo MA, Torsani V, Gomes S, De Santis RR, Costa EL, Tucci MR, Lima RG, Kavanagh BP, Amato MB. Spontaneous Effort During Mechanical Ventilation: Maximal Injury With Less Positive End-Expiratory Pressure. Crit Care Med. 2016 Aug;44(8):e678-88. doi: 10.1097/CCM.0000000000001649.
• Duan J, Han X, Bai L, Zhou L, Huang S. Assessment of heart rate, acidosis, consciousness, oxygenation, and respiratory rate to predict noninvasive ventilation failure in hypoxemic patients. Intensive Care Med. 2017 Feb;43(2):192-199. doi: 10.1007/s00134-016-4601-3. Epub 2016 Nov 3.

Study record dates

Study Major Dates

• Study Start (Actual): March 26, 2024
• Primary Completion (Estimated): June 30, 2026
• Study Completion (Estimated): June 30, 2026

Study Registration Dates

• First Submitted: March 21, 2026
• First Submitted That Met QC Criteria: March 25, 2026
• First Posted (Actual): March 31, 2026

Study Record Updates

• Last Update Posted (Actual): March 31, 2026
• Last Update Submitted That Met QC Criteria: March 25, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: noninvasive ventilation; respiratory failure; PEEP
• Additional Relevant MeSH Terms: Respiratory Tract Diseases; Respiration Disorders; Respiratory Insufficiency
• Other Study ID Numbers: ChongqingMU07

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: The informed consent form for this study clearly states that patients' data are only accessible to the research team and regulatory authorities when necessary, and shall not be disclosed to other individuals or institutions.Therefore, there is no plan to make data publicly available for this study.

Drug and device information, study documents

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