If you aren’t diabetic then jump straight to Blood Pressure
Diabetes is increasingly common and not only comprises raised blood sugar, but has long term effects on the heart, large blood vessels, and small blood vessels relevant to surgery. Poor control before and during surgery can have adverse effects in terms of these effects, so heart attacks, chest and wound infections, and slow speed of healing are all more common (as circulation to the wound site might be reduced). Furthermore your actual diabetes will be put under stress by the starvation, stress and other effects of the surgery and anaesthetic. Specific actions and planning around your surgery will be undertaken at the time, but if you start off with the best control possible this is obviously beneficial.
How to measure “diabetes control” / what is HbA1c
For your annual review, and at other times, you will have had a blood test to find out how your diabetes is going. This test will be your HbA1c. This test tells us what your blood sugar levels have been over the last 100 days or so. Normal HbA1c levels are below 42, and good control for diabetes is below 59. We aim for surgery to be at least below 69 as this the level when problems get worse.
What can I do?
It is sensible to arrange a fresh check of your diabetes control (HbA1c blood test) as soon as possible. This will allow time for change as this test takes about 3 months to reflect any changes you make. If your HbA1c blood test is more than 69 at the time of your operation (and could be better) it is likely the anaesthetist will wish to postpone your surgery for your own benefit. Therefore it is in your best interest to get it down as early as possible (and is a good idea in any case).
Action to take
- Check when your last test was and ask for a fresh HbA1c test if appropriate (usually in the previous 2-3 months is OK).
- If your HbA1c reading is more than 69 speak to the surgery/specialist nurse/hospital team to discuss what action is needed.
- Sometimes we accept that people have readings that are higher than ideal but are the best that can be achieved. (People who are very old, frail or on maximal treatment levels). This can be discussed and choices considered as to the best way forward.
It is important that any changes to your medication and lifestyle are done in a considered fashion, and remember that any sudden changes may even be more dangerous if you end up with unstable control.
You may be aware of our general target to keep the HbA1c below 59 and this is correct. The higher limit here is because we can show that the problems for surgery go up particularly above this level.
What is the evidence