Obesity and Anaesthesia Dr Nick Woodall

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

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

Obesity Complications 184 reports received, 77 were obese 133 reports of anaesthesia, 53 were obese Deaths16 (4) Brain damage3(1) Emergency surgical airways25(19) ICU admission or prolongation of stay 33(29)

Body Mass Index >40kg.m -2 >30kg.m kg.m -2 <20kg.m -2 All reports18414(8%)77 (42%)89(48%)18(10%) Anaesthesia1338(6%)53 (40%)65(49%)15 (11%) ICU364(11%)17 (47%) 2 (6%) Emergency Department151(6%)7 (46%) 1(7%)

Body Mass Index >40kg.m -2 >30kg.m kg.m -2 <20kg.m -2 All reports18414(8%)77 (42%)89(48%)18(10%)

Body Mass Index >40kg.m -2 >30kg.m kg.m -2 <20kg.m -2 All adults17114(8%)76 (44%)77(45%)18(10%)

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

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

Obesity and Anaesthesia 53 reports

Obesity and Anaesthesia 53 reports Female 49%

Obesity and Anaesthesia 53 reports Female 49% Middle-aged

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

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

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 Primary Airway Problem

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

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

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

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

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

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

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

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

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

The End