Air ambulances have been playing a big role in transporting critically ill Covid patients to medical hubs like Hyderabad and Chennai. These along with Bengaluru have sophisticated ECMO (extracorporeal membrane oxygenation) centres and also lung transplant expertise for those who need ultracritical care beyond ventilators or those who need a lung transplant. NDTV's Uma Sudhir reports that more than 100 critically ill patients have been flown into Hyderabad.