Two Modes of Mechanical Ventilation for Intensive Care Patients With Low Blood Oxygen Due to Breathing Difficulties

Overview

The study examines individuals admitted to the intensive care unit due to breathing difficulties resulting in not getting enough oxygen into their bodies. These patient will receive mechanical ventilation and this study aims to determine how the pressure inside the lungs changes when using two different modes of mechanical ventilation. The goal is to improve management and care of breathing difficulties by gaining insight into changes in lung pressure during mechanical ventilation, as well as comparing the effectiveness of the two ventilator modes.

As hypoxic respiratory failure is an acute condition, this trial will enrol temporarily incompetent patients and obtain consent from the patient's next of kin and an independent medical doctor (trial guardian) as soon as possible after enrolment. When included in the study, patients will be randomized 1:1 centrally in the RedCap system, using a computer-generated concealed assignment sequence, with permuted blocks of varying sizes, to start with either the intervention (APRV) followed by control (volume controlled mechanical ventilation) or control followed by intervention. Esophageal manometry will be used as a surrogate to measure the transpulmonary pressure. Arterial blood gasses, blood samples and lung ultrasound will be used to investigate oxygenation, ventilation and aeration. Treatment targets for both groups during the study are pH \>7.20, saturation ≥ 88% and PaO2 ≥ 8.0 kPa, with FiO2 titrated as low as possible while complying to the oxygenation targets (PaO2 and saturation). Both arms start with an 'adjustment phase' where the ventilator is adjusted so the respiratory values are within the targets. The intervention adjustment phase is at least 30 minutes. The adjustments will follow standardized protocols. When the respiratory values are within range, the 'observation period begins' and no changes are made to the ventilator for 3 hours, unless it is necessary to achieve ventilatory treatment targets or deemed necessary by the treating physician. During the trial, the patient must be positioned in a supine position with the headboard elevated 0-30 degrees. After the first 'observation period', the patient is switched to the opposite ventilation mode and will go through an 'adjustment phase' and 'observation period' again. Once a patient regains competence, they will be provided with both written and oral information regarding the trial By comparing volume controlled mechanical ventilation and APRV and their transpulmonary pressures, valuable insight can be gained regarding optimal ventilation strategy for patients with hypoxic respiratory failure. Understanding how various ventilation modes influence transpulmonary pressure and their potential effects on respiratory mechanics can potentially inform designs of trials with individualized respiratory care.