Obesity and AnaesthesiaObesity and Anaesthesia

Dr Nick WoodallDr Nick Woodall

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.

0.0

5.0

10.0

15.0

20.0

25.0

30.0

BM

I

All Adults Males Female

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.

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)

Body Mass Index

>40kg.m-2 >30kg.m-2 20-30kg.m-2 <20kg.m-2

All reports 184 14(8%) 77 (42%) 89(48%) 18(10%)

Anaesthesia 133 8(6%) 53 (40%) 65(49%) 15 (11%)

ICU 36 4(11%) 17 (47%) 17 (47%) 2 (6%)

Emergency Department 15 1(6%) 7 (46%) 7 (46%) 1(7%)

Body Mass Index

>40kg.m-2 >30kg.m-2 20-30kg.m-2 <20kg.m-2

All reports 184 14(8%) 77 (42%) 89(48%) 18(10%)

Body Mass Index

>40kg.m-2 >30kg.m-2 20-30kg.m-2 <20kg.m-2

All adults 171 14(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

2

1213 13

22

19

14

30

2

5

01

0

5

10

15

20

25

30

<20 21-40 41-60 61-80 >80 Not stated

Anaesthesia events - age distribution of reports and BMI

BMI of ≥30 (n=53) BMI of <30 (n=80)

• 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 EndThe End