Impact of Decreasing Respiratory Rate on Lung Injury Biomarkers in ARDS Patients

Exclusion Criteria

• •Age \<18 years
• •Previous chronic respiratory disease (chronic obstructive lung disease, asthma, intersticial lung disease, pulmonary fibrosis, chronic bronchiectasis)
• •Hypercapnic respiratory failure, defined as PaCO2 \>60 mmHg or pH\<7.25 despite a RR \>30.
• •Concomitant severe metabolic acidosis: pH\<7.20
• •Catastrophic respiratory failure, defined as PaO2/FiO2 ratio \<80, despite optimization of ventilatory parameters, or need for ECMO.
• •Contraindication to hypercapnia, such as intracranial hypertension or acute coronary syndrome
• •Use of vasoconstrictor drugs in increasing doses in the last 2 hours (≥0.5 μg/kg/min of noradrenaline) or average blood pressure \<65mmHg
• •Pneumothorax or subcutaneous emphysema, not drained.
• •Pregnancy
• •Presence of mental or intellectual disability prior to hospitalization
• •Early limitation of therapeutic effort