Hypoxemic acute respiratory failure is one of the main COVID-19 patients complication that lead to in intensive care hospitalization. This complication determines a variable mortality from 25 to 30%. To correct hypoxemia (often severe) is often needed non-invasive or invasive mechanical ventilation. Mechanical ventilation is not a therapeutic strategy, but it allows to extend the time-to-recovery necessary to solve COVID-19 respiratory failure cause. Calibration of ventilatory support is essential to ensure adequate time-to-recovery without contributing to onset lung and / or diaphragmatic damage. Basal diaphragmatic activity assessment, device for administering the oxygenation support choice and setting ventilatory support parameters are decisive. Ultrasound is the best method for measuring diaphragmatic work. The aim of this study is to evaluate the diaphragmatic thickening fraction in COVID-19 patients admitted to Intensive Care Unit (ICU) for acute respiratory failure and to record its function on weaning.
Hypoxemic acute respiratory failure in COVID-19 patients often leads to necessity of
intubation and mechanical ventilation support. Complications may be severe as
Ventilator-Induced Lung Injury (VILI) and respiratory infections. Weaning process from
mechanical ventilation is based on respiratory work reduction and mechanical support to allow
patient's respiratory ability to recovery. Respiratory muscle strength give an important
contribute. Ultrasound diaphragmatic evaluation is essential to evaluate patients respiratory
capacity as diaphragm atrophy usually suggest a difficult process and weaning failure.
COVID-19 pneumonia represent a particular type of ARDS (acute respiratory distress syndrome),
in which different mechanism such as interstitial edema and diffuse alveolar damage,
ventilation-perfusion mismatch, intrapulmonary shunt play a role/attend The aim of this study
is to assess diaphragmatic function in weaning from mechanical ventilation in patients
affected from COVID-19 respiratory failure and his implications.
Device: Evaluation of diaphragmatic contractility by ultrasound
Lung ultrasound is performed during mechanical ventilation weaning. The diaphragmatic thickening fraction is evaluated positioning a linear probe in midaxillary line. Inspiratory and expiratory measurements are bilateral and are M-mode images. Right diaphragmatic thickening fraction has been considered as true and reproducible measurement.
Inclusion Criteria:
- Hypoxemic respiratory failure in COVID-19 patients during intensive care unit
hospitalization
- Age> 18 years
- Weaning by mechanical ventilation
Exclusion Criteria:
- tracheostomy,
- unstable clinical conditions;
- agitation (Richmond Agitation-Sedation Scale (RASS)≥ + 2) or non-cooperation (Kelly
Matthay scale ≥5);
- more than two organ failure
- consent refusal
Anesthesiology and Intensive Care Clinic - Department of Medicine - ASUIUD
Udine, Italy