Sleep & Oxygen Blog
The spread of the COVID-19 virus is placing unprecedented demands on our global healthcare systems. The number of patients experiencing respiratory failure from acute respiratory distress syndrome and requiring respiratory support has increased significantly. Countries around the world are racing against time to find efficient and practical solutions to manage patients in each stage of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, even if several therapies have shown to be effective, none have been a game changer so far. At present, severe cases of acute respiratory failure can only receive respiratory support therapies through invasive and non-invasive ventilators.
Patients with severe COVID-19 can develop respiratory symptoms that require an increasing number of interventions. Initially, the treatment for severe respiratory failure included early intubation and invasive ventilation, as this was deemed to be more effective than non-invasive ventilation (NIV). However, emerging evidence has shown that non-invasive ventilation may have a more significant and positive role than initially thought. According to Carter et al., in patients with acute respiratory failure, there is strong evidence for the use of non-invasive ventilation for treatment of acute hypercapnic respiratory failure due to acute exacerbation of COPD, and for acute hypoxic respiratory failure in congestive heart failure.
Non-invasive ventilation includes Continuous Positive Airway Pressure (CPAP) and Bi-Level Positive Airway Pressure (BiPAP). CPAP is the method of choice with the use of BiPAP for those with complex respiratory conditions who contract COVID-19. While the use of High Flow Nasal Oxygen (HFNO) remains contentious with different perspectives on how this modality can be used to treat respiratory failure in COVID-19. NIV and HFNO may be a supplementary treatment in the early stages of the SARS-CoV-2 disease progress and may prevent the need for intubation or invasive ventilation.
Non-invasive ventilation is an aerosol generating medical procedure (AGMP) and treatment should proceed with necessary precautions for an AGMP:
A good interface fitting NIV systems minimizes widespread dispersion of exhaled air and should be associated with low risk of airborne transmission from patients.
Fowler et al. showed that with the use of proper PPE in the ICU, the use of non-invasive ventilation during the 2003 severe acute respiratory syndrome (SARS) epidemic was not associated with an increased risk of transmission of the virus to health-care workers. On the other hand, endotracheal intubation was associated with an increased risk of aerosolisation and infection of health-care workers. Most recently, in Guangdong, China, no healthcare workers were infected during NIV management under the Chinese guidance of personal protection.
An early intubation of a patient with known or suspected COVID-19 with respiratory distress could also result in the intubation of a patient who would have otherwise improved on non-invasive ventilation. The capability of switching to NIV, is also required by the WHO for those patients with less need for respiratory support, or during weaning from invasive ventilation. Additionally, unnecessary intubation and ventilation of a patient might deny a life-saving treatment for another patient in a resource-limited setting.
Non-invasive ventilation may be an alternative for some patients but is not used extensively worldwide yet. One study by Sartini et al. described the feasibility of non-invasive ventilation in the prone position; pronation can recruit dorsal lung regions and drain airway secretions, improving gas exchange and survival in acute respiratory distress syndrome (ARDS).
In conclusion, non-invasive ventilation has significant advantages over traditional mechanical ventilation. But it must be remembered that even in experienced hands, non-invasive ventilation is not always effective and depends on many factors, such as:
As with many types of therapy, operations, and technologies, improvement in the results of this method can be expected as experience is gained.