Effects of Different PEEP Levels on Work of Breathing in Morbidly Obese Patients Prior to and After Extubation

Sponsor

Massachusetts General Hospital (Other)

Overall Status

Recruiting

CT.gov ID

NCT02492113

Collaborator

(none)

Enrollment

Location

Arm

79.9

Duration (Months)

0.5

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

The main purpose of this study is to define at the bedside the "Titrated-PEEP" level for obese patients that increases the likelihood of extubation and ventilator liberation.

The investigators hypothesized that a titrated level of PEEP ("Titrated-PEEP") during SBT will keep the lung recruited, maintain oxygenation, and decrease the work of breathing resulting in successful ventilator liberation. In addition, post-extubation the investigators hypothesize that these patients will require noninvasive ventilatory support in the form of CPAP at the level of "titrated-PEEP" used during the SBT.

Condition or Disease	Intervention/Treatment	Phase
Obesity	Procedure: Positive end-expiratory pressure (PEEP) Procedure: ZEEP	N/A

Detailed Description

The high WOB of morbidly obese patients is associated with respiratory muscle fatigue and failure in extubation. The investigators hypothesized that the use of a titrated PEEP level prior to and after extubation might improve successful extubation rates and avoid re-intubation.

In this study, patients will be awake and ventilated in the pressure support ventilation (PSV) mode. The investigators will apply different PEEP levels to measure WOB, transpulmonary pressure and characterize the response of the respiratory system to increasing or decreasing PEEP. The "Titrated-PEEP" will be identified as the PEEP level associated with the lowest value of respiratory system elastance and an end expiratory transpulmonary pressure of 2 cmH2O. Then the participants will have two spontaneous breathing trials; one at PEEP 0-5 cmH2O, and the other at the "Titrated-PEEP" level, with PSV=0 and FiO2 unchanged. After extubation, the participants will first receive CPAP set at "Titrated-PEEP", then spontaneous breathing. Electrical impedance tomography (EIT), respiratory system mechanics and gas exchange will be recorded during the study.

The investigators believe that the real-time determination of "Titrated-PEEP" can guide the treatment of mechanical ventilation and give us a better understanding of the physiology and pathophysiology of morbidly obese patients. As a result, this study will improve patient safety; reduce the duration of mechanical ventilation, complications and healthcare costs.

Study Design

Study Type:

Interventional

Anticipated Enrollment :

39 participants

Allocation:

N/A

Intervention Model:

Single Group Assignment

Masking:

None (Open Label)

Primary Purpose:

Treatment

Official Title:

Effects of Different PEEP Levels on Work of Breathing in Morbidly Obese Patients Prior to and After Extubation

Study Start Date :

Nov 1, 2015

Anticipated Primary Completion Date :

Jun 30, 2021

Anticipated Study Completion Date :

Jun 30, 2022

Arms and Interventions

Arm	Intervention/Treatment
Experimental: Patients with BMI > 35 ICU patients with a BMI > 35, on pressure support ventilation, scheduled for spontaneous breathing trial for evaluation of extubation After recruitment maneuver and decremental PEEP trial, the "Titrated-PEEP" is identified. Patients will have two spontaneous breathing trials (SBTs) in randomized order. Either the patient will receive SBT at PEEP = 0-5 cmH2O, with PSV=0 and FiO2 unchanged; or the patient will perform an SBT at "Titrated-PEEP", with the PSV=0 and FiO2 unchanged.	Procedure: Positive end-expiratory pressure (PEEP) "Titrated-PEEP". After recruitment maneuver and decremental PEEP trial, the "Titrated-PEEP" is identified. Patients will have two spontaneous breathing trials (SBTs). In this arm, patients will have SBT at "Titrated-PEEP", with the PSV=0 and FiO2 unchanged. Procedure: ZEEP After recruitment maneuver and decremental PEEP trial, the "Titrated-PEEP" is identified. Patients will have two spontaneous breathing trials (SBTs). In this arm, patients will have SBT at PEEP = 0-5 cmH2O, with the PSV=0 and FiO2 unchanged.

Arm

Intervention/Treatment

Experimental: Patients with BMI > 35

ICU patients with a BMI > 35, on pressure support ventilation, scheduled for spontaneous breathing trial for evaluation of extubation After recruitment maneuver and decremental PEEP trial, the "Titrated-PEEP" is identified. Patients will have two spontaneous breathing trials (SBTs) in randomized order. Either the patient will receive SBT at PEEP = 0-5 cmH2O, with PSV=0 and FiO2 unchanged; or the patient will perform an SBT at "Titrated-PEEP", with the PSV=0 and FiO2 unchanged.

Procedure: Positive end-expiratory pressure (PEEP)

"Titrated-PEEP". After recruitment maneuver and decremental PEEP trial, the "Titrated-PEEP" is identified. Patients will have two spontaneous breathing trials (SBTs). In this arm, patients will have SBT at "Titrated-PEEP", with the PSV=0 and FiO2 unchanged.

Procedure: ZEEP

After recruitment maneuver and decremental PEEP trial, the "Titrated-PEEP" is identified. Patients will have two spontaneous breathing trials (SBTs). In this arm, patients will have SBT at PEEP = 0-5 cmH2O, with the PSV=0 and FiO2 unchanged.

Outcome Measures

Primary Outcome Measures

Differences in WOB at titrated PEEP levels vs. ZEEP level [24 hours]
Work Of Breathing measured as J/L and J/min during a Spontaneous Breathing Trial at titrated PEEP vs. Work Of Breathing measured as J/L and J/min during a Spontaneous Breathing Trial at zero PEEP

Secondary Outcome Measures

Gas Exchange - Oxygenation [24 hours]
Difference in oxygenation as measured in mmHg of PaO2/FiO2 during a Spontaneous Breathing Trial at titrated PEEP and at zero PEEP.
Gas Exchange - Arterial carbon dioxide [24 hours]
Difference in arterial carbon dioxide as measured in mmHg (PaCO2) during a Spontaneous Breathing Trial at titrated PEEP and at zero PEEP.
Respiratory Mechanics - Compliance [24 hours]
Difference in Compliance, measured as ml/cmH2O, of the respiratory system, lungs and chest wall during a Spontaneous Breathing Trial at titrated PEEP and at zero PEEP.
Gas Volume Distribution [24 hours]
Difference in the images of Electric Impedance Tomography measured as relative variation of regional impedance (deltaZ) (i.e. distribution of ventilation) during a Spontaneous Breathing Trial at titrated PEEP and at zero PEEP.
Hemodynamics - Blood pressure [24 hours]
Changes in arterial blood pressures (BP, mmHg) during a Spontaneous Breathing Trial at titrated PEEP and at zero PEEP.
Hemodynamics - Heart rate [24 hours]
Changes in heart rate (HR, bpm) during a Spontaneous Breathing Trial at titrated PEEP and at zero PEEP.

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years and Older

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Inclusion Criteria:

Intubated and mechanically ventilated;
Weaning from mechanical ventilation;
BMI ≥ 35 kg/m2 with waist circumference > 88 cm for women; waist circumference > 102 cm for men.
A well functioning arterial line.

Exclusion Criteria:

Known presence of esophageal varices
Recent esophageal trauma or surgery
Severe thrombocytopenia (PTL ≤ 5,000/mm3)
Severe coagulopathy (INR ≥ 4)
Presence of pneumothorax
Pregnancy
Pacemaker and/or internal cardiac defibrillator

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	Massachussets General Hospital	Boston	Massachusetts	United States	02114

Sponsors and Collaborators

Massachusetts General Hospital

Investigators

Principal Investigator: Robert Kacmarek, RRT, PhD, Massachusetts General Hospital
Principal Investigator: Lorenzo Berra, MD, Massachusetts General Hospital