CPAP in Patients With Severe Obesity After Anesthesia

NCT06287632 | Not Yet Recruiting

• 1 other identifier: 2024P000451
• Study Type: interventional
• Target: 60
• Locations: 0 countries
• Sites: N/A

Brief Summary

The goal of this study is to compare two continuous positive airway pressure (CPAP) settings on heart and lung function in patients with severe obesity after anesthesia. The main questions it aims to answer are:

• Intervention 1: Recruitment maneuver and CPAP will set to the level of intrathoracic pressure
• Intervention 2: CPAP set to home settings (if OSA is present) or between 8-10 cmH20 (if OSA is not present).

Conditions

Obesity, Abdominal; Anesthesia Morbidity; Apnea, Obstructive Sleep; Atelectases, Postoperative Pulmonary; Ventilator Lung

Keywords

clinical trial; crossover studies; continuous positive airway pressure; electrical impedance tomography; esophageal pressure monitoring; transthoracic echocardiography

Outcome Measures

Primary Outcomes (1)

• End expiratory lung impedance

  End expiratory lung impedance, a surrogate of end expiratory lung volume, measured from EIT

  Assessed at baseline during atmospheric pressure breathing (no CPAP), assessed at the end of intervention A (20 minutes), assessed at end of intervention B (20 minutes)

Secondary Outcomes (8)

• Regional lung ventilation

  Assessed at baseline during atmospheric pressure breathing (no CPAP), assessed at the end of intervention A (20 minutes), assessed at end of intervention B (20 minutes)

• Right ventricular function

  Assessed at baseline during atmospheric pressure breathing (no CPAP), assessed at the end of intervention A (20 minutes), assessed at end of intervention B (20 minutes)

• Mean pulmonary artery pressure

  Assessed at baseline during atmospheric pressure breathing (no CPAP), assessed at the end of intervention A (20 minutes), assessed at end of intervention B (20 minutes)

• Inspiratory effort

  Assessed at baseline during atmospheric pressure breathing (no CPAP), assessed at the end of intervention A (20 minutes), assessed at end of intervention B (20 minutes)

• Abdominal muscle thickness

  Assessed at baseline during atmospheric pressure breathing (no CPAP), assessed at the end of intervention A (20 minutes), assessed at end of intervention B (20 minutes)

Study Arms (3)

Recruitment and ITP-CPAP

EXPERIMENTAL

Recruitment maneuver followed by CPAP set to intrathoracic pressure (ITP)

Device: Recruitment/ITP-CPAP (Intervention A)

Standard CPAP

ACTIVE COMPARATOR

CPAP set to home level of CPAP (if known) or CPAP set to standard levels (8-10 cmH20)

Device: Standard CPAP (Intervention B)

Atmospheric pressure

PLACEBO COMPARATOR

Breathing without CPAP

Device: Atmospheric Pressure

Interventions

Recruitment/ITP-CPAP (Intervention A) DEVICE

Participant will receive a recruitment maneuver followed by CPAP set to the level of end-expiratory esophageal pressure (measured during atmospheric pressure breathing). The intervention will last for 20 minutes.

Recruitment and ITP-CPAP

Standard CPAP (Intervention B) DEVICE

Participant will receive their home CPAP (if on CPAP at home) or CPAP at 8-10 cmH20 (if not on CPAP at home or no known diagnosis of OSA). The intervention will last for 20 minutes.

Standard CPAP

Atmospheric Pressure DEVICE

Participant will breathe at atmosphere pressure (no CPAP) with supplemental oxygen as needed per clinical guidance.

Atmospheric pressure

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Adult patients (≥ 18 years old) scheduled for elective non-cardiothoracic surgery requiring general anesthesia with an endotracheal tube
• Planned admission to the post-anesthesia care unit (PACU) after surgery
• BMI ≥ 40 kg/m2
• At the time of baseline measurements in the PACU, patients meet the following criteria:
• Receiving ≤ 6 liters of supplemental nasal cannula oxygen
• Alert as defined by a Richmond Agitation Sedation Scale of 0 or -1
• Oriented to person, place, and time

You may not qualify if:

• Pregnancy, suspected pregnancy or less than six weeks postpartum Known or current pneumothorax
• Hemodynamic instability at the time of study assessment in the PACU defined as:
• systolic blood pressure \<90 mmHg or \>180 mmHg
• mean blood pressure \<60 or \>130 mmHg
• Any use of intravenous vasoactive agent
• heart rate \< 50 or \> 120 beats per minute
• Respiratory insufficiency in PACU defined as:
• Respiratory rate \> 30
• Oxygen saturation \< 92%
• Receiving \> 6 liters of supplemental oxygen
• Known chronic lung disease requiring supplemental oxygen at home
• Known systolic heart dysfunction (left ventricular ejection fraction ≤ 30%)
• Contraindication for esophageal catheter placement:
• Known esophageal varices
• Known bacterial sinusitis

Sponsors & Collaborators

• Massachusetts General Hospital: lead

MeSH Terms

Conditions

Obesity, Abdominal; Sleep Apnea, Obstructive; Pulmonary Atelectasis

Condition Hierarchy (Ancestors)

Obesity; Overweight; Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Sleep Apnea Syndromes; Apnea; Respiration Disorders; Respiratory Tract Diseases; Sleep Disorders, Intrinsic; Dyssomnias; Sleep Wake Disorders; Nervous System Diseases; Lung Diseases

Central Study Contacts

Timothy Gaulton, MD, MSc

CONTACT

617-643-7733; tgaulton@mgh.harvard.edu

Lorenzo Berra

CONTACT

lberra@mgh.harvard.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: PREVENTION
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Member of the Faculty of Anesthesia

Study Record Dates

• First Submitted: February 16, 2024
• First Posted: March 1, 2024
• Study Start (Estimated): June 1, 2026
• Primary Completion (Estimated): November 1, 2026
• Study Completion (Estimated): June 1, 2027
• Last Updated: November 18, 2025

Record last verified: 2025-11

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ANALYTIC CODE
• Time Frame: Individual participant data and supporting information will be available after data analysis and manuscript publication.
• Access Criteria: Individual participant data can be accessed from a data use agreement once data is uploaded on vivil