"Lung Barometric Measurements in Normal And in Respiratory Distressed Lungs"

Little is known about how lung mechanics are affected during the very early phase after starting mechanical ventilation. Since the conventional method of measuring esophageal pressure is complicated, hard to interpret and expensive, there are no studies on lung mechanics on intensive care patients directly after intubation, during the first hours of ventilator treatment and forward until the ventilator treatment is withdrawn. Published studies have collected data using the standard methods from day 1 to 3 of ventilator treatment for respiratory system mechanics, i.e. the combined mechanics of lung and chest wall. Consequently, information on lung mechanical properties during the first critical hours of ventilator treatment is missing and individualization of ventilator care done on the basis of respiratory system mechanics, which are not representative of lung mechanics on an individual patient basis. We have developed a PEEP-step method based on a change of PEEP up and down in one or two steps, where the change in end-expiratory lung volume ΔEELV) is determined and lung compliance calculated as ΔEELV divided by ΔPEEP (CL = ΔEELV/ΔPEEP). This simple non-invasive method for separating lung and chest wall mechanics provides an opportunity to enhance the knowledge of lung compliance and the transpulmonary pressure. After the two-PEEP-step procedure, the PEEP level where transpulmonary driving pressure is lowest can be calculated for any chosen tidal volume. The aim of the present study in the ICU is to survey lung mechanics from start of mechanical ventilation until extubation and to determine PEEP level with lowest (least injurious) transpulmonary driving pressure during ventilator treatment. The aim of the study during anesthesia in the OR, is to survey lung mechanics in lung healthy and identify patients with lung conditions before anesthesia, which may have an increased risk of postoperative complications.

NCT Number	NCT04484727
Lead Sponsor	Göteborg University Collaborators: Sahlgrenska University Hospital
Conditions	Ventilator-Induced Lung Injury, Ventilatory Failure, Ventilator Lung, Ventilation Therapy; Complications, Ventilator Associated Pneumonia
Enrollment	200 participants
Start Date	2022-05-01
Primary Completion	2026-05-01 (estimated)
Study Completion	2026-12-31 (estimated)
Updated on ClinicalTrials.gov	2025-03-17