Obesity complicates anaesthesia

Under strict embargo until 12.01am Friday October 16, 2015

Obesity complicates anaesthesia

Anaesthetists are adjusting their best practice – and hospitals are under increasing pressure – to adapt to the complex and varied needs of the obese patient, according to the Australian and New Zealand College of Anaesthetists (ANZCA).

ANZCA President Dr Genevieve Goulding said over the last 20 years obesity had become one of the most compelling issues for anaesthetists in the management of their patients.

Among some of the adjustments being made:

• The newly-built Fiona Stanley hospital in Perth considered the comprehensive needs of the obese in the planning of its fixtures and equipment, including two patient rooms in each ward dedicated to appropriate facilities – including hoists that are designed to accommodate patients up to 450 kg in weight and full floor-to-ceiling doors.

• Tasmanian researcher and anaesthetist Dr Nico Terblanche is developing techniques to allow for accurate ultrasound-guided aid in giving epidurals to the morbidly obese, a group which experiences an epidural insertion failure rate of between 17 per cent and 42 per cent.

• Researchers in Melbourne are investigating the use of an easy, non-invasive test to ascertain a patient’s fitness for anaesthesia and surgery, the “six-minute walk test”.

• A growing obesity problem has resulted in the maternity pre-anaesthesia clinic at the Royal Brisbane & Women’s Hospital having to increase the minimum body mass index (BMI) of patients from 35 or greater, to 40 or greater and now 45 or greater.

Dr Goulding said ANZCA has recognised the significance of this issue as it faces anaesthetists and has begun to discuss establishing special guidelines for the management of the obese patient.

It is estimated that almost one in every three people across Australia and New Zealand is obese, and an increasing number of these are morbidly obese, (body mass index over 40). This group faces an increased risk of complications when they need an anaesthetic for surgery.

In Australia the latest report on national weight trends by the Australian National Preventive Health Agency found that in 2011-2012, one in four adults were obese compared with one in five adults in 1995. The most recent figures for children under five years of age show one in five is obese.

In New Zealand the prevalence of obesity in adults has increased threefold – from 10 per cent in 1977 to 30 per cent in 2011–2013. Between 2006-07 and 2011–2013, the rate of obesity among 2 to 14-year-olds increased from 9 per cent to 11 per cent.

Dr Goulding said excess weight:

• Is often associated with health problems such as type 2 diabetes, high blood pressure heart disease and sleep apnoea – conditions that compromise your procedure during anaesthesia and make it more difficult for you to heal during convalescence.

• Makes it more difficult to move and position a patient properly for surgery, to measure blood pressure, find veins and to keep airways open during anaesthesia.

• Puts the heart under extra pressure, especially under anaesthesia.

• Complicates maternity care – for instance, it can make it very difficult to accurately insert an epidural

• Can make some procedures under anaesthesia difficult to carry out, and may even mean that it is too risky for the patient to have the operation at all.

• Makes it more difficult to manage pain following surgery and anaesthesia.

Dr Goulding said:

“It is important for every patient expecting elective surgery to discuss the risk associated with excess weight with their medical team, including their anaesthetist. They can advise you about steps you can take to lower these risks, including reducing weight, ceasing smoking and increasing exercise where possible. Bariatric surgery (an operation on the stomach to help a patient to lose weight) might also be recommended”.

ANZCA is celebrating National Anaesthesia Day on October 16; once again marking the anniversary of the day ether anaesthesia was first demonstrated in 1846, in Boston, Massachusetts.

National Anaesthesia Day has the support of the Royal Australasian College of Surgeons.

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