What effect does obesity have on anaesthesia?

Obesity is defined as body mass index (BMI) greater than 30kg/m2 and poses a number of problems for anaesthesia.
Firstly, obesity is associated with high blood pressure and heart disease.  Heart disease may be secondary to coronary artery disease or due to enlarged heart with reduced function.
Secondly, oxygen delivery to tissues is decreased in obese patients, which makes obese people more prone to oxygen lack if there are additional difficulties in delivering oxygen to them.
Thirdly, obesity may be associated with hiatus hernia of the stomach and there is a higher risk of regurgitation and aspiration.
Obtaining intravenous access and performing regional anaesthesia may be difficult.
For these and other reasons, it is advisable for patients who are overweight or obese to lose weight prior to elective surgery.
If significant weight loss is not possible, even small weight loss is beneficial. Where patients are able to do so, light exercise, such as a 30 minute walk each day before surgery, will be helpful and make postoperative recovery easier for the patient. You can start with walking 10 minutes each day and increase to 20 minutes per day and then achieve 30 minutes per day.

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