William Wang ¹ , Danish Iltaf Satti² , Amer Harky MSc, MRCS ³ , David Mayhew FRCA⁴

¹ Barts and The London School of Medicine and Dentistry, Queen Mary University of London, UK

² Shifa College of Medicine, Shifa Tameer-e-millat University, Islamabad, 44000 Pakistan

³ Department of Cardiothoracic Surgery, Liverpool Heart and Chest Hospital, Liverpool, UK

⁴ Department of Anaesthesia and Critical Care, Liverpool Heart and Chest Hospital, Liverpool, UK. University of Liverpool.

^# Correspondence to:

Dr David Mayhew MBBS BSc (hons) FRCA

Liverpool Heart and Chest Hospital

Liverpool, L14 3PE

United Kingdom

E-mail: David.mayhew@lhch.nhs.uk

Phone: +44-151-600-1616