Respiratory Mechanics Assessment at Different Head of the Bed Elevations in Mechanically Ventilated Patients
- Conditions
- Respiratory FailurePulmonary Disease
- Interventions
- Other: Sequencial increasing of head of the bed elevation and alveolar recruitment maneuver followed by a PEEP titration with 10° of head of the elevation
- Registration Number
- NCT06409897
- Lead Sponsor
- University of Sao Paulo General Hospital
- Brief Summary
The effects of different degrees of head-of-bed elevation on respiratory mechanics are poorly explored in the literature, and no study has investigated such effects using electrical impedance tomography, esophageal and gastric balloons to identify the ideal angle for optimizing respiratory mechanics. The hypothesis is that there is a optimal degree for the respiratory mechanics.
- Detailed Description
Respiratory mechanics and regional ventilation will be monitored using electrical impedance tomography (Enlight 2100, Timpel Medical®, Brazil) . Esophageal and gastric pressures will be obtained through esophageal and gastric balloon catheters (Nutrivent®) (validation concerning to modified Baydur maneuver - slope delta esophageal pressure/delta airway pressure (0,8-1,2). We are using the hardware Pneumodrive (Biônica, Recife, Brazil) to record and store the esophageal, gastric and airway pressures, these data will be analyzed using LabVIEW 7.1 (Pneumobench).
Initially, patients will be positioned at 0 degrees of head-of-bed elevation, and after stabilization of the plethysmogram, data from electrical impedance tomography, hemodynamics, and arterial blood gas will be collected (arterial blood will be drawn by a nurse or physician). Sequentially and in the same manner, the bed will be adjusted to 10, 20, 30, and 40 degrees (the same data will be collected, except for the arterial blood sample, which will only be collected at the 40-degree elevation). Then, an alveolar recruitment maneuver will be performed, followed by a PEEP titration with 10-degree of head-of-bed elevation.
Recruitment & Eligibility
- Status
- RECRUITING
- Sex
- All
- Target Recruitment
- 40
- Patients under invasive mechanical ventilation, intubated due to respiratory failure
- Hemodynamics instability, contraindication for monitoring with esophageal and gastric catheters, and Electrical impedance tomography, no authorization of medical team of the intensive care unit, and contraindication for lung recruitment maneuver
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- SINGLE_GROUP
- Arm && Interventions
Group Intervention Description Sequential head-of-bed elevation Sequencial increasing of head of the bed elevation and alveolar recruitment maneuver followed by a PEEP titration with 10° of head of the elevation Patients will be positioned at 0 degrees of head-of-bed elevation, and after stabilization of the plethysmogram, data from electrical impedance tomography, hemodynamics, and arterial blood gas will be collected (arterial blood will be drawn by a nurse or physician). Sequentially and in the same manner, the bed will be adjusted to 10, 20, 30, and 40 degrees (the same data will be collected, except for the arterial blood sample, which will only be collected at the 40-degree elevation). Then, an alveolar recruitment maneuver will be performed, followed by a PEEP titration with 10-degree of head-of-bed elevation, and the data will be collected just as in the 0° and 40° steps.
- Primary Outcome Measures
Name Time Method Respiratory system compliance At 0, 10, 20, 30, 40-degrees of head-of-bed elevation, and with titrated PEEP at 10-degrees of head-of-bed elevation Respiratory system compliance (mL/cmH2O) will be measured using electrical impedance tomography monitoring (Enlight 2100, Timpel Medical®, Brazil).
Lung compliance At 0, 10, 20, 30, 40-degrees of head-of-bed elevation, and with titrated PEEP at 10-degrees of head-of-bed elevation Lung compliance (mL/cmH2O) will be measured offline using the esophageal pressure tracings. By knowing the respiratory system and chest wall compliance, the lung compliance will be calculated. (1/respiratory system compliance = 1/chest wall compliance + 1/lung compliance)
Chest wall compliance At 0, 10, 20, 30, 40-degrees of head-of-bed elevation, and with titrated PEEP at 10-degrees of head-of-bed elevation Chest wall compliance (mL/cmH2O) will be measured offline using the esophageal pressure tracings.
Chest wall compliance = tidal volume / delta esophageal pressure
- Secondary Outcome Measures
Name Time Method Hemodynamics satefy of keeping low degrees of head of the elevation At 0, 10, 20, 30, 40-degrees of head-of-bed elevation Arterial blood pressure provided by the multiparameter monitor. Data will be noted in each degree.
Gastric pressure At 0 and 40-degrees of head-of-bed elevation, and with titrated PEEP at 10-degrees of head-of-bed elevation Gastric pressure will be measured offline using the gastric pressure tracings.
Oxygenation At 0 and 40-degrees of head-of-bed elevation, and with titrated PEEP at 10-degrees of head-of-bed elevation Oxigenation will be assessed using the partial pressure arterial oxygen/fraction inspired oxygen ratio. Partial pressure arterial oxygen measured in the blood sample at the of each step and the fraction inspired oxygen set during the blood sample collection will be used.
Pressure between patient skin surface and the mattress At 0, 10, 20, 30, 40-degrees of head-of-bed elevation ForeSite PT (XSENSOR Technology Corporation, Patient Monitoring System) will be used to measure the pressure between patient's skin surface and the mattress. A monitor connected to this sensor provides continuous pressure monitoring, and the data will exported for subsequent offline analysis of the sacral and occipital regions.
Trial Locations
- Locations (1)
Instituto do Coração do Hospital das Clínicas da Faculdade de Medicina da USP
🇧🇷São Paulo, Brazil