Clinical trial NCT02492113: Effects of Different PEEP Levels on Work of Breathing in Morbidly Obese Patients Prior to and After Extubation
Official title: Effects of Different PEEP Levels on Work of Breathing in Morbidly Obese Patients Prior to and After Extubation
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: NA
Conditions: Obesity
Keywords: Mechanical ventilation
Positive end-expiratory pressure
Work of breathing
Morbidly obese
Lead sponsor: Massachusetts General Hospital
Sponsor class: OTHER
First posted: 2015-07-08
Enrollment: 39
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: NA
Intervention model: SINGLE_GROUP
Primary purpose: TREATMENT

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.

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.

Eligibility criteria: 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

Primary outcomes:
measure: Differences in WOB at titrated PEEP levels vs. ZEEP level
timeFrame: 24 hours
Secondary outcomes:
measure: Gas Exchange - Oxygenation
timeFrame: 24 hours
measure: Gas Exchange - Arterial carbon dioxide
timeFrame: 24 hours
measure: Respiratory Mechanics - Compliance
timeFrame: 24 hours
measure: Gas Volume Distribution
timeFrame: 24 hours
measure: Hemodynamics - Blood pressure
timeFrame: 24 hours
measure: Hemodynamics - Heart rate
timeFrame: 24 hours
Other outcomes:
Locations:
city: Boston
country: United States
facility: Massachussets General Hospital
state: Massachusetts
Study officials:
affiliation: Massachusetts General Hospital
name: Robert Kacmarek, RRT, PhD
role: PRINCIPAL_INVESTIGATOR
affiliation: Massachusetts General Hospital
name: Lorenzo Berra, MD
role: PRINCIPAL_INVESTIGATOR
References: