Respiratory Mechanics and Gas Exchange in Patients With COVID-19 and Hypoxemic Acute Respiratory Failure

Respiratory Mechanics and Gas Exchange in Patients With COVID-19 and Hypoxemic Acute Respiratory Failure: Multicentral Observational Study

Data on respiratory mechanics and gas exchange in acute respiratory failure in COVID-19 patients is limited. Knowledge of respiratory mechanics and gas exchange in COVID-19 can lead to different selection of mechanical ventilation strategy, reduce ventilator-associated lung injury and improve outcomes. The objective of the study is to evaluate the respiratory mechanics, lung recruitability and gas exchange in COVID-19 -associated acute respiratory failure during the whole course of mechanical ventilation - invasive or non-invasive.

In December 2019, an outbreak of a novel coronavirus (SARS-CoV-2) emerged in Wuhan, China and rapidly spread worldwide. The World Health Organization (WHO) declared the outbreak a pandemic on March 11th, 2020. The clinical disease (COVID-19) results in critical illness in about 5% of patients with predominant acute respiratory failure.

The goal of the study is the evaluation of the respiratory mechanics (peak inspiratory pressure (PIP), plateau pressure (Pplat), static compliance (Cstat), driving pressure (DP) at different positive end-expiratory pressure (PEEP) levels and different tidal volumes (Vt) (6-8 ml/kg ideal body weight), lung recruitability (by change of DP and oxygenation) and gas exchange (PaO2/FiO2 ratio and alveolar dead space) in COVID-19 -associated acute respiratory failure during the whole course of mechanical ventilation - invasive or non-invasive for selection of safe and effective PEEP level, Vt, respiratory rate (RR) and inspiratory oxygen fraction (FiO2) during the whole course of mechanical ventilation - invasive or non-invasive.

This study is multicentral observational trial in 3 University clinics.

Inclusion Criteria:

• all patients with COVID-19 and acute respiratory failure on invasive and noninvasive ventilation

Exclusion Criteria:

• Patients who reached the following goals at conventional oxygen therapy (oxygen flow < 15 l/min): peripheral capillary oxygen saturation(SpO2) > 93%, no visible work of auxiliary respiratory muscles, no fatigue, stable hemodynamics (no need in any catecholamines and/or life-threatening heart rhythm abnormalities),
• less than 24 ours in intensive care unit (ICU) by any reason,
• lung emphysema,
• primary lung diseases (chronic obstructive lung disease-COPD, interstitial lung diseases, etc) or tumour metastases in lungs,
• chronic decompensated diseases with extrapulmonary organ dysfunction (tumour progression, liver cirrhosis, congestive heart failure),
• atonic coma.