1. Department of Respiratory Medicine, University Hospital of Leicester , Leicester LE1 , UK
2. Department of Endocrinology, Hamad General Hospital, Hammad Medical Corporation , PO BOX 3050 , Doha , Qatar
3. Department of Internal Medicine and Pulmonology, Hammad Medical Corporation , Doha , Qatar
4. Department of Adult Cardiology, Chaudhary Pervaiz Ilahi Institute of Cardiology , Wazirabad , Pakistan
5. Department of Medicine, Punjab Medical College , Faisalabad , Pakistan
6. Respiratory Department, Derriford Hospital, University Hospitals Plymouth , Plymouth , UK
7. Intensive Care Unit, Department of Anaesthesia, Jinnah Hospital , Lahore , Pakistan
8. Critical Care Department, St. Luke’s Aurora Hospital , Milwaukee , Wisconsin , USA