you need to be very careful using the anion gap to guide your insulin therapy in DKA. The problem arises when the DKA patient receives large amounts of NS which contains Na and Cl. Because there will be a relative increase in Cl from the NS the gap Na-(HCO3+Cl) can look like it has closed just because of the extra Cl given for treatment and the patient can still be met acidosis. It is much better to follow the HCO3 as a guide, a general rule would be to use a value of 20 and stop the insulin at that value. just a thought that I just recently came across in an ICU patient.
Forgive my ignorance. I am only an RN, but did my time in ICU enough to understand the conversation. And yes, my experience is limited(I am no CCRN),but I also was a chemist before I was a nurse. So when I can apply my core science to my trade.. it brightens my day - beats the hell out of passing so many freakin pills all day!
anions - negatively charged ions.
cations - positively charged ions.
Acid/base also fall on this- not just the 0.9% NS they may have been receiving.... or any other salt.
rules; ROME. DKA= metabolic acidosis. I have metabolic acidosis, my respiratorations will be rapid and shallow do "breathe off" the carbon or rather... 'create bicarb.' Fruity breath.
Of course.... they will be urinating like no tomorrow, thirsty, and hungry.
Im going to presume we already have ABG's going as a matter of rule and are giving insulin, per order, watching blood PH, as well as anion gap.
(If I recall correctly the CCRN I was working with was pointing directly to the HCO3 levels for guidance on insulin therapy DKA)
HCO3- as DKA is an acidic state, I will expect it to be low. Since the kidneys may take time ... vs the respiratory... I expect a high RR.
Remember the thing that caused the DKA to begin with.
CAUSES FIRST.
If DKA was caused by an infection rather than just noncompliance... this could be an entirely different beast. the osmolality is also a concern.
As if High Blood sugar was the problem - as we know... it isnt a life threatening problem unless it triggers DKA. Thing of it is... 99.9% of the time we are gonna see those high sugars on our Type I- the type II... we arent monitoring if they are asymptomatic - but that depends on the level of care as well.
Now imagine my concern knowing all this... when another RN tells me just to keep on giving insulin- and not even send the patient to the ICU???!
Plus "more insulin" can turn into problem - it will not always be the answer. The entire reason we are watching the HCO3 levels is to ensure we d/c insulin at the proper time (IV being a little more direct than SC). Probably another reason we should be doubly sure to check for any kind of infection as a cause in the first place.
