New Delhi, The sudden deaths which have been noticed during the Covid-19 pandemic are due to cardiac arrest and silent hypoxia in which there is no visible breathing distress, but oxygen levels drop, and pulmonary thromboembolism or a blockage of the artery in the lungs.

The findings are part of the details released by the All India Institute of Medical Sciences' (AIIMS) e-ICUs which issued FAQs on Covid-19 and the treatment and care of the patients.

According to AIIMS, sudden deaths have been reported both during presentation to emergency departments (EDs) as well as in hospitals.

"The reasons that have been proposed include a sudden cardiac event/ACS, preceding silent hypoxia that went unnoticed or due to a thrombotic complication such as pulmonary thromboembolism," it said.

"Patients with risk factors to develop severe Covid or with prior comorbid conditions such as CAD or chronic lung disease should be strictly monitored for their saturation. They should not be allowed to move unattended. Anticoagulants should be used in all at-risk patients who do not have any risk factors of bleeding," AIIMS said.

On the role of the drug Favipiravir, AIIMS said that studies have used Favipiravir mainly in mild or asymptomatic Covid cases, claiming to prevent progression, whereas the majority of this cohort recover with just supportive care and monitoring and usually require no specific therapy.

"Evidence is weak for the use of Favipiravir and it is currently not recommended in the national guidelines," it said.

Several drug companies have launched this drug for the use of mild to moderate patients.

On Tocilizumab, AIIMS said that it has been approved by the DCGI on compassionate grounds in view of the ongoing pandemic.

"However, it is an experimental therapy, has a limited role, and should be used only in patients with cytokine syndrome after ruling out active infection," it said.

On Ivermectin, AIIMS said it has been found to be a potent inhibitor of SARS CoV2 replication in vitro, but the doses required to achieve this effect in vivo far exceeds the usual dose. It is currently not recommended in the national guidelines but can be used in patients in whom HCQ is contraindicated, the FAQs said.

On the role of plasma therapy, the FAQs advised that convalescent plasma collected from ABO matched donors with high neutralising titers can be given to patients at risk of developing severe Covid in early stages of the disease. However, it should also be considered an experimental therapy and should be used with caution, AIIMS said.

It said there is no evidence to support the use of antifibrotic agents like pirfenidone in preventing Covid related fibrosis and hence should not be used.

Pirfenidone is a novel anti-fibrotic agent with trivial adverse effects. Pirfenidone is approved for the treatment of Idiopathic Pulmonary Fibrosis (IPF) for patients with mild to moderate disease.

AIIMS said that Remdesivir/TCZ are experimental therapies, approved by the DCGI in view of the ongoing pandemic. "Therefore, they should not be used as empirical therapy for suspected cases. You should use these agents only in proven Covid patients," the FAQs said.

However, there is no evidence to support the use of Remdesivir/TCZ in asymptomatic patients with comorbidities.

Corticosteroids are currently indicated in moderate to severe Covid patients. Recovery trial has used dexamethasone. "However, both IV dexamethasone or methylprednisolone may be used based on their availability," AIIMS said.