Author: Tessa Dick / Codes: C3AP3, C3AP4, CC3, CMP5 / Published: 06/02/2018
When I 15 years old I was admitted to hospital with DKA and diagnosed with diabetes. I thought all the doctors had to do was start me on insulin to get me better. It was only when I became a medical student and started working as a doctor that it became apparent that the management of diabetic ketoacidosis needed a lot more than just insulin, and that treatments needed to be started in the right order.
It is also easy to forget how sick patients can get in DKA because with increased patient education, DKA is being picked up earlier and treatment started even before coming to hospital. This change cause mortality associated with DKA improvement from 7.96% to 0.67% over a 20 year period.
So here are a few key points that I think will make the management of DKA clearer.
Make the diagnosis
I know this sounds obvious but known diabetics can be in DKA with lower than expected blood sugars so if a patient with diabetes is unwell then don’t just check their blood sugar, do a gas to check their pH and check the ketones with a meter or a dipstick. To make the diagnosis of DKA, three diagnostic criteria need to be met.
It’s not just about Insulin
In adults the first thing used to treat DKA is fluid and electrolytes. Due to the elevated blood sugars, fluid is drawn out of cells and is lost in the urine meaning rehydration is really important – not only to replace what is lost- but it is also thought to help correct hyperglycaemia as well. The flip side is that there has been a link made between fast fluid replacement and cerebral oedema, although this has mostly been seen in young adults and children. It has meant adult guidelines suggest slow fluid replacement – aim to replace fluid losses over a 48 hour period. (a separate paediatric blog will be published in due course).
Potassium is the main electrolyte that seems to become deranged and cause problems in DKA. Refer to local DKA protocol to see how this is replaced in your trust, but be a little more cautious in anuric patients as they may have a raging AKI.
Keep monitoring ketones and blood sugar hourly, potassium and bicarbonate every 2 hours for the first 6 hours as treatment may need to be adjusted. In a busy Emergency Department this can be difficult but if you have referred to the medical team please keep an eye on this patient until they have been taken out of your department. It can sometimes take time for the medics to become available to see patients referred to them and even longer to find a bed on a ward or ITU. Please don’t expect someone else to do it and make sure the patient is safe.
Start an IV infusion of 0.1 unit/kg of insulin (no longer a sliding scale!) and continue long acting insulin if the patient is already on it as it is thought to reduce the incidence of rebound hyperglycaemia.
Have a look at your protocol, and stick to it adherance reduces the time to normoglycaemia.
Speak to ITU early if the patient isn’t responding to treatment. The box below shows some of the specific criteria to consider getting them to review your patient. Patients can deteriorate quickly so involve ITU early if you think they are a candidate.
There are non diabetic causes of keto-acidosis, so if it looks like keto-acidosis (and smells like it), treat it the same. Alcoholic ketoacidosis is a common differential.