It is Time to Revise the Ventilation Strategy in COVID 19 Affected Patients UE01-UE05
Dr. Shagufta Naaz,
Associate Professor, Department of Anaesthesiology, AIIMS Patna, Phulwarisharif, Patna-801507, Bihar, India.
COVID-19 infection has emerged as a pandemic. This infection is new to the world, and the management strategy is evolving daily. As per the current guidelines, the patients of COVID-19 infection requiring mechanical ventilation should be treated on the lines of management of Acute Respiratory Distress Syndrome (ARDS). However, it seems that the management of ventilation in the case of COVID-19 needs to be modified. With growing experience, many hospitals have turned to Non-invasive Ventilation (NIV) to ward-off severe respiratory failure and in keeping with the inadequate resources. The controversy in using NIV is whether the benefits of using such interventions are more than the potential risks of aerosolisation of the virus. There is a hope that helmet-based ventilation may help reduce the risk of nosocomial infection. Autopsy findings demonstrated that besides ARDS, the alveolar capillaries were clearly thickened, with fibrin thrombi within the capillaries and small vessels and surrounding oedema present in COVID-19 affected lungs. This virus attacks the beta chain of haemoglobin, dissociates heme, removing iron converting it to porphyrin. The cause of desaturation is the failure of the blood to carry oxygen leading to multiorgan failure and mortality. The cause of lung damage seen on Computerised Tomography (CT) scans is the release of oxidative iron, which in turn overcomes the natural defenses against pulmonary oxidative stress and causes what is known as the Cytokine Storm. The question is whether mechanical ventilation is harming the patient by traumatising their lungs leading to increased mortality. Prone ventilation is the next preferred step for COVID-19 patients who fail to achieve adequate oxygenation with low tidal volume ventilation. Hyperbaric oxygen therapy can help the leftover functioning haemoglobin to carry more oxygen. Blood transfusion and plasmapheresis provide symptomatic relief. Thrombolytic therapy is also being tried with some benefits. These may be promising in treating patients with COVID-19 infection. Researches are required on the other probability and to test newly emerging treatment modalities.