1. American Society of Anesthesiologists (2014) Physical Status Classification System. www.asahq.org/resources/clinical-information/asa-physical-status-classification-system (Last accessed: 8 August 2018.)
2. Reducing anxiety in preoperative patients: a systematic review;British Journal of Nursing,2014
3. Promoting the dignity of patients in perioperative practice;Journal of Perioperative Practice,2010
4. British Association for Parenteral and Enteral Nutrition (2018) ‘MUST’ Calculator. www.bapen.org.uk/screening-and-must/must-calculator (Last accessed: 8 August 2018.)
5. British Medical Association (2018) Children and Young People Ethics Toolkit: 2. Assessing Competence. www.bma.org.uk/advice/employment/ethics/children-and-young-people/children-and-young-peoples-ethics-tool-kit (Last accessed: 8 August 2018.)