- Correspondence to Dr Ian Smith, Directorate of Anaesthesia, University Hospitals of North Midlands, Royal Stoke University Hospital, Stoke-on-Trent, ST4 6QG Staffordshire, UK;
- Received 28 March 2017
- Revised 26 September 2017
- Accepted 18 October 2017
- Published online 2 November 2017.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.