Managing Obesity in Anaesthesia: Risks and Strategies

1. Obesity and Anaesthesia Dr Nick Woodall NAP4 Wednesday March 30th 2011

2. Obesity – UK Prevalence 24.5% Information Centre for health and social care. The health survey for England - 2009 trend tables. London: Health and Social Care Information Centre, 2010.

3. Morbid Obesity - Prevalence 2% Information Centre for health and social care. The health survey for England - 2008 trend tables. London: Health and Social Care Information Centre, 2009.

4. Obesity Complications • 184 reports received, 77 were obese • 133 reports of anaesthesia, 53 were obese • Deaths 16 (4) • Brain damage 3 (1) • Emergency surgical airways 25 (19) • ICU admission or prolongation of stay 33 (29)

5. Body Mass Index

6. Body Mass Index

7. Body Mass Index

8. Obesity Inclusion • Obesity • BMI > 30kg.m-2 • Obese body habitus • Morbid obesity • BMI > 40kg.m-2

9. Obesity • Co-morbidities • Aspiration risk • Potential airway problems • Bag mask ventilation • Tracheal intubation • Difficult surgical airway • Increased oxygen demand • Reduced oxygen reserve • Alternatives available • Awake intubation • Regional anaesthesia • SAD selection

10. 53 reports Obesity and Anaesthesia

11. 53 reports Female 49% Obesity and Anaesthesia

12. Obesity and Anaesthesia • 53 reports • Female 49% • Middle-aged

13. 53 reports Female 49% Middle-aged Co-morbidities HT/IHD (47%) OSA (17%) DM (17%) Asthma (15%) Obesity and Anaesthesia

14. 53 reports Female 49% Middle-aged Co-morbidities Reduced consultant input Obesity and Anaesthesia

15. Primary Airway Problem Reported more commonly in the obese • LMA/SAD problems • Failed mask ventilation • Difficult or delayed intubation/CICV • Iatrogenic airway trauma • Problems on emergence • Conversion of regional or local anaesthesia to GA

16. Case Review - Areas of Interest • Assessment and preparation • Regional anaesthesia • Awake intubation • Supra-glottic airway use • Conduct of general anaesthesia • Organisational factors

17. Case Report • Male 150kg • OSA HT/IHD • Minor hand surgery • Needle phobic GA • Self removal of LM • Cardiac arrest • ICU trach, full recovery after 7days

18. Case Report • Male, morbidly obese • Reduced palatal view, limited neck mobility • Urgent perineal surgery • Limited pre-oxygenation • Trainee anaesthetist • GA Difficult LM/BMV • Tracheal/oesophageal intubation • Cardiac arrest, failed resuscitation

19. Assessment and preparation • Co-morbidities were common • Signs of airway difficulty may be absent • Airway assessment not performed in 30% • Recognised airway problems were ignored

20. Loco-regional anaesthesia • Not used or not considered • Inappropriate techniques/sedation • Failure of regional anaesthesia • Intra-operative conversion is high risk in the presence obesity

21. Awake intubation • Not used • Failed • lack of co-operation • airway obstruction • bleeding • apnoea • Problems with sedation

22. Conduct of General Anaesthesia • Poor anticipation of problems • Preparation • Planning of a response to difficulty • Inappropriate techniques • SV, lithotomy with trendellenburg • Supra-glottic airway devices (SAD) • Usage similar in obese and non-obese • Inappropriate patient selection • Inappropriate device

23. Organisational Factors • Obesity not recognised as a risk factor at all levels • Poor communication • Insufficient time allocated • Inadequate assessment • Inappropriate location • Inappropriate staff deployed

24. Recommendations • Greater level of awareness of additional risks posed by obesity is required • Morbidly obese patients require thorough POA without time constraints • Airway assessment should include feasibility of rescue techniques with consideration of awake intubation • Plan for management of conversion to GA

25. The End