Fitness for Surgery

Basic assessment

For the majority of patients, simply assessing their overall health, their medications and their ability to exercise is often a very good marker of their fitness for anaesthesia and even major surgery.

For example, the ability to climb a flight of stairs without stopping roughly equates to the fitness needed for major abdominal surgery.

Simple measures such as blood pressure, urine assessment and some simple blood tests are often quite sufficient to make a judgement on a patient’s fitness.

Assessment of heart, circulation and lung function

More detailed assessment of pure heart function may require ECG (a trace of the heart), echocardiography (a scan of the heart) or dobutamine stress echocardiography (a method of assessing the heart’s ability to pump harder in response to being challenged).

Cardio-pulmonary exercise (CPEX) testing is a ‘dynamic’ method of assessing a patients ability to respond to a situation that requires a similar cardiac and respiratory function to that of major surgery.  CPEX testing may be used to quantify a patient’s fitness for major surgery in detail.

Drugs and surgery

Broadly speaking most drugs should be continued up to and through the period immediately after surgery. This includes most heart related drugs, drugs for epilepsy, drugs for acid reflux, and inhalers for chest conditions.

Exceptions to this may include:

-drugs for anti-coagulation (‘blood thinning’) may need to be temporarily stopped.

-drugs for diabetes may need to be reduced.

-steroids may need to be briefly increased.

-immunosuppressant drugs may need to be reduced or switched to alternatives.


Current guidelines indicate that patients undergoing major surgery should generally have blood thinning drugs for around 4 weeks after surgery. This is to reduce the risk of blood clots affecting the legs (‘DVT’s) or blood clots affecting the lungs (‘PE’s).