Obesity a global concern

Obesity

• Complex and multifactorial disease – Abnormal or excessive fat accumulation that may impair health – Genetic predisposition – Ethnic factors – Socioeconomic class (SEC) – Co-morbidities – Nutritional input v energy expenditure
• Worldwide obesity has increased 3 fold since 1975
• Affects approximately 15-20% of adults in Europe and 55% in the USA and is associated with the metabolic syndrome (hypertension, hyperlipidaemia, diabetes)
• Body mass index (BMI) is a simple index – Weight in kilograms (kg) divided by height in metres squared (m2) (kg/m2) – BMI of 25 to 29.9 kg.m−2 is classified as overweight or mildly obese – BMI of 30 to 39.9 kg.m−2 is classified as moderately to severely obese patients – BMI ≥40 kg.m−2 are classified as morbidly obese – BMI in children must be interpreted with reference to age and sex
• Prevalence of obesity varies with SEC and differs between countries – Developed countries lower SEC increased risk – Developing countries with higher SEC increased risk

TIVA and TCI in obese patients

• Data has been extrapolated from the non-obese population
• Inaccurate in the obese
• Excessive dosing is common
• Dosing strategies of IV anaesthetics need to account for the changes associated with obesity – Physiological – Pharmacokinetic – Pharmacodynamic