Obesity: The Challenge for Anaesthesia

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ObesityThe Challenge for Anaesthesia

• Ciara Jean Murphy

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JF

• 34y Female
• Fell dislocated knee
• 182 cm/153 kg BMI 47
• Resultant vascular injury
• Poor wound healing
• Multiple trips to theatre
• Difficult Venous Access
• Poor Respiratory Reserve
• Potentially difficult central neuraxial block or
  peripheral nerve block

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How big is obese?

• BMI lt18.5 underweight
• BMI 18.5-25 ideal
• BMI 25-30 overweight
• BMI 30-35 obese
• BMI 35-55 morbidly obese
• BMI gt55super morbidly obese
• The distribution of fat is important also
• Anaesthesia 2001
  

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A growing problem

• In 2005 gt300 million people worldwide were obese
• By 2025predicted trends 50 of people living in
  the USA will be obese
• Here 39 of adults are overweight with 18 obese
• By 2050 predicted 90 of females will be
  overweight
• Slightly higher in males
• Slightly higher in lower socio-economic groups
• Department of Health Children 2007

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Anaesthetic Considerations

• Airway - OSA
• - BMV (BMI gt 26)
• - Intubation (40cm 15, 60cm 35)
• Breathing?FRC exponentially with ?BMI
• Ventilation (? compliance 30)
• Circulation
• Hypertension
• Ischaemic Heart Disease
• Hyperlipidaemia
• Cardiac Failure
• Cardiomyopathies
• Arrythmias
• Post Operative Mortality is X2 non obese patient

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Obstructive Sleep Apnoea

• Commonly undiagnosed
• gt 70 of obese patients
• Problems typically occur on 2nd/3rd postoperative
  night
• REM Rebound

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Other Problems

• ?incidence of diabetes
• Tight peri-operative glycaemic control
• Poor nutritional status
• GORD
• ? risk of thrombo-embolic events
• ? risk of 2 DVT PE
• Mechanical Pharmocological Thromboprophylaxis

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Intra-Op Mgt

• AAGBI Guidelines 2007
• Obese patients should only be anaesthetised in
  appropriate locations
• Equipment
• Trained Personnel
• Obesity Pack for out-of-hours

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Post Op Considerations

• Analgesia
• Avoidance of Opioids
• Central Neuraxial/Regional Analgesia
• Multi-Modal
• OSA
• Nurse Sitting Up
• CPAP
• Oxygen

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Preoperative AssessmentWhats the benefit?

• Identify patients at high risk for Ambulatory
  Surgery/St Josephs
• Optimisation
• Further Investigations
• Organisation in Advance of Equipment

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Ambulatory Anaesthesia

• Guidelines differ locally but patients with a BMI
  lt35 are generally considered suitable
• BMI gt35 should be reviewed by a specialist before
  acceptance
• BMI 35-38 may be suitable
• BMI 38-40 certain procedures second review
• BMI gt 40 not recommended
• St Josephs gt 35
• Acceptable if management would not be modified by
  inpatient admission
• Acceptable if no increased risk can be identified

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References

• Peri-operative Management of the Morbidly Obese
  Patient AAGBI 2007
• Davis KE, Houghton K, Montgomery JE (2001)
  Obesity in Day Case Surgery Anaesthesia 56 (11)
  1090-1105
• Report of the National Taskforce on Obesity
  Obesity the policy challenges (2007) Department
  of Health Children
• Peri-Operative Management of the Morbidly Obese
  Patient AAGBI 2007