The Effect of Positive End-Expiratory Pressure on Functional Residual Capacity During Mechanical Ventilation

• ClinicalTrials.gov Identifier: NCT03511651
• Recruitment Status: Not yet recruiting
• First Posted: April 30, 2018
• Last Update Posted: May 29, 2020
• Sponsor: Capital Medical University
• Information provided by (Responsible Party): Jian-Xin Zhou, Capital Medical University

Study Description

Brief Summary:

Although positive end-expiratory pressure (PEEP) has been widely used in mechanical ventilated patients with acute respiratory distress syndrome (ARDS), how to select the "optimal" PEEP is far from consensus. The application of PEEP may result in beneficial effect by recruiting previously collapsed lung areas, harmful effect by over-distending previously aerated lung areas, or a combination of the both. The net effect of PEEP in a certain patient may depend on the recruitability. Because recruitability varies extremely in ARDS patients and strongly correlates with the response to PEEP, estimation of end-expiratory lung volume (EELV) may be essential for individualized setting of PEEP. Whether the FRC changes at different PEEP levels remains unknown.

Condition or disease	Intervention/treatment	Phase
Mechanical Ventilation; Acute Respiratory Distress Syndrome; Functional Residual Capacity	Procedure: PEEP	Not Applicable

Detailed Description:

Although positive end-expiratory pressure (PEEP) has been widely used in mechanical ventilated patients with acute respiratory distress syndrome (ARDS), how to select the "optimal" PEEP is far from consensus. The application of PEEP may result in beneficial effect by recruiting previously collapsed lung areas, harmful effect by over-distending previously aerated lung areas, or a combination of the both. The net effect of PEEP in a certain patient may depend on the recruitability. Because recruitability varies extremely in ARDS patients and strongly correlates with the response to PEEP, estimation of end-expiratory lung volume (EELV) may be essential for individualized setting of PEEP.

Passive spirometry has long been used to measure the lung recruitment volume (VREC). A prolonged expiration to zero end-expiratory pressure (ZEEP) or airway release maneuver is required and PEEP induced lung volume change above functional residual capacity (FRC) is measured. This technique assumes that FRC does not change at different PEEP levels.

This assumption that PEEP has no effect on FRC can date back to the study of Valta et al in the early 1990s. Using respiratory inductive plethysmography (RIP), they found that in ALI/ARDS patients, after expiring from different PEEP levels to ZEEP, the plethysmography signal returned to the same baseline value. They concluded that FRC does not change with PEEP, and that changes of EELV are attributable only to change in ∆EELV. Ranieri et al arrived at similar conclusions by measuring differences in lung volumes at different PEEP levels using standardized pressure-volume (P-V) curves derived from the ventilator circuit monitors. However, Patroniti et al found an elevation of FRC as increasing of PEEP in patients with ARDS. In this study, FRC was measured with the helium dilution technique, and concluded that neglecting this effect resulted in marked underestimation of VREC. Whether the FRC changes at different PEEP levels remains controversial. The aim of the study is to assess the effect of PEEP on FRC during mechanical ventilation.

Study Design

• Study Type: Interventional (Clinical Trial)
• Estimated Enrollment: 30 participants
• Allocation: Randomized
• Intervention Model: Crossover Assignment
• Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
• Primary Purpose: Other
• Official Title: The Effect of Positive End-Expiratory Pressure on Functional Residual Capacity During Mechanical Ventilation
• Estimated Study Start Date: August 1, 2020
• Estimated Primary Completion Date: February 28, 2021
• Estimated Study Completion Date: March 31, 2021

Arms and Interventions

Arm	Intervention/treatment
FRC at clinical PEEP level; Measuring FRC at clinical PEEP level	Procedure: PEEP; Two PEEP levels will be used during mechanical ventilation.
Experimental: FRC at clinical PEEP + 5cmH2O; Increasing PEEP to clinical PEEP + 5cmH2O	Procedure: PEEP; Two PEEP levels will be used during mechanical ventilation.

Outcome Measures

Primary Outcome Measures :

1. The change of FRC [ Time Frame: 1) One hour after using clinical PEEP 2) One hour after using clinical PEEP + 5cmH2O ]
   EELV measurement by ICU ventilator; PEEP Volume measured through airway release. FRC will be calculated as EELV minus PEEP volume. Correlation between EELV, PEEP volume, FRC at two different PEEP levels are tested by linear regression analysis.

Secondary Outcome Measures :

1. The change of PaO2/FiO2 Ratio [ Time Frame: 1) One hour after using clinical PEEP 2) One hour after using clinical PEEP + 5cmH2O ]
   Obtaining PaO2 according to blood gas analysis, and FiO2 according to the ventilator
2. The change of regional EELV [ Time Frame: 1) One hour after using clinical PEEP 2) One hour after using clinical PEEP + 5cmH2O ]
   Regional EELV will be measured at clinical PEEP and clinical PEEP +5cmH2O
3. The change of homogeneity of distribution of tidal volume [ Time Frame: 1) One hour after using clinical PEEP 2) One hour after using clinical PEEP + 5cmH2O ]
   EIT is used to monitoring the homogeneity of distribution of tidal volume that was divided into two contiguous regions of interest (ROI) equally, the dependent and non-dependent area. The ratio of relative distribution of tidal ventilation of two ROI was calculated.
4. The change of driving Pressure [ Time Frame: 1) One hour after using clinical PEEP 2) One hour after using clinical PEEP + 5cmH2O ]
   The change of driving pressure will be measured.
5. The change of regional FRC [ Time Frame: 1) One hour after using clinical PEEP 2) One hour after using clinical PEEP + 5cmH2O ]
   Regional FRC will be measured at clinical PEEP and clinical PEEP +5cmH2O
6. The change of blood pressure [ Time Frame: 1) One hour after using clinical PEEP 2) One hour after using clinical PEEP + 5cmH2O ]
   The change of blood pressure will be measured

Eligibility Criteria

• Ages Eligible for Study: 18 Years to 80 Years (Adult, Older Adult)
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: No

Criteria

Inclusion criteria include:

1. Diagnosed with ARDS according to the Berlin Definition;
2. Age 18-80 years;
3. Ventilated with volume-controlled ventilation using constant flow;
4. Deep sedation (RASS -4 to -5) and absence of spontaneous breathing (i.e., no triggering during tidal breaths and no inspiratory effort during a 5-second end-expiratory hold).

Exclusion criteria include:

1. Evidence of active air leak from the lung, including bronchopleural fistula, pneumothorax, pneumomediastinum, or existing chest tube;
2. Chest wall and/or abdominal injuries;
3. Evidence suggesting reduced chest wall compliance, such as existing large pleural effusion, thoracic trauma and intra-abdominal hypertension (i.e., intra-abdominal pressure > 20 mmHg).
4. Presence of pacemaker, defibrillator, and implantable pumps).

Contacts and Locations

Contacts

Contact: Jian-Xin Zhou, MD; 8610 67096579; zhoujx.cn@icloud.com

Locations

China, Beijing

Jian-Xin Zhou

Beijing, Beijing, China, 100050

Contact: Jian-Xin Zhou, MD 8610 67096579 zhoujx.cn@icloud.com

Sponsors and Collaborators

Capital Medical University

Investigators

• Principal Investigator: Jian-Xin Zhou, MD; Beijing Tiantan Hospital

More Information

• Responsible Party: Jian-Xin Zhou, Professor, Capital Medical University
• ClinicalTrials.gov Identifier: NCT03511651
• Other Study ID Numbers: KY2018-004-02
• First Posted: April 30, 2018
• Last Update Posted: May 29, 2020
• Last Verified: May 2020

• Studies a U.S. FDA-regulated Drug Product: No
• Studies a U.S. FDA-regulated Device Product: No

Additional relevant MeSH terms:

Respiratory Distress Syndrome; Respiratory Distress Syndrome, Newborn; Acute Lung Injury; Lung Diseases; Respiratory Tract Diseases; Respiration Disorders; Infant, Premature, Diseases; Infant, Newborn, Diseases; Lung Injury