Noninvasive respiratory support for acute respiratory failure due to COVID-19

Abstract

Purpose of review Noninvasive respiratory support has been widely applied during the COVID-19 pandemic. We provide a narrative review on the benefits and possible harms of noninvasive respiratory support for COVID-19 respiratory failure. Recent findings Maintenance of spontaneous breathing by means of noninvasive respiratory support in hypoxemic patients with vigorous spontaneous effort carries the risk of patient self-induced lung injury: the benefit of averting intubation in successful patients should be balanced with the harms of a worse outcome in patients who are intubated after failing a trial of noninvasive support. The risk of noninvasive treatment failure is greater in patients with the most severe oxygenation impairment (PaO 2 /FiO 2 < 200 mmHg). High-flow nasal oxygen (HFNO) is the most widely applied intervention in COVID-19 patients with hypoxemic respiratory failure. Also, noninvasive ventilation (NIV) and continuous positive airway pressure delivered with different interfaces have been used with variable success rates. A single randomized trial showed lower need for intubation in patients receiving helmet NIV with specific settings, compared to HFNO alone. Prone positioning is recommended for moderate-to-severe acute respiratory distress syndrome patients on invasive ventilation. Awake prone position has been frequently applied in COVID-19 patients: one randomized trial showed improved oxygenation and lower intubation rate in patients receiving 6-h sessions of awake prone positioning, as compared to conventional management. Summary Noninvasive respiratory support and awake prone position are tools possibly capable of averting endotracheal intubation in COVID-19 patients; carefully monitoring during any treatment is warranted to avoid delays in endotracheal intubation, especially in patients with PaO 2 /FiO 2 < 200 mmHg.

Parasternal intercostal muscle thickening as a predictor of non-invasive ventilation failure in patients with COVID-19

“…Despite the good outcomes of NIV in COVID-19, delayed detection of its failure carries serious hazards, such as patient-induced lung injury due to exaggerated swings in the pleural pressure due to high inspiratory efforts, alveolar flooding, and pulmonary oedema due to increased transmural pressure in lung vessels, unplanned emergency intubation which is life-threatening to the patient [2] , and carries the risk of disease transmission to healthcare providers. Therefore, it is essential to have easy and accurate monitoring tools to determine the optimal timing of invasive ventilation.…”

“…There is wide agreement on the use of non-invasive ventilation (NIV) to manage patients with COVID-19 [1] . However, NIV failure, if not detected early, carries several hazards such as patient self-induced lung injury and unplanned intubation [2] .…”

Non-invasive ventilation for acute hypoxemic respiratory failure, including COVID-19

“…[ 6 ] With the COVID-19 pandemic, its application in patients with hypoxemic respiratory failure has become increasingly common. [ 92 ] Traditionally, CPAP is administered through a high-flow generator (turbines, Venturi systems, or air/oxygen blenders) delivering fresh gas flow in an inlet port, and an adjustable PEEP valve connected to an outlet port. Its simplicity makes CPAP highly cost-effective in the emergency context and easily used outside of intensive care since ventilators are not strictly necessary.…”

“…CPAP was widely used at the outset of COVID-19, with conflicting results. [ 92 , 98 ] Recently, a large adaptive, parallel group randomized clinical trial showed reduced intubation rates in patients treated with CPAP compared with a standard oxygen therapy group. [ 99 ] Furthermore, Perkins et al.…”

Mechanical Ventilation for COVID-19 Patients

“…28 Moreover, the saturation of high-dependency units and ICUs has often forced the use of NIV also in patients with moderate-to-severe hypoxemia, with the application of high airway pressures and/or high FiO 2 and for prolonged periods of time. 29…”