To bolus or not to bolus in DKA

IVF and insulin drip

I recently saw an adult patient with diabetic ketoacidosis.  She was treated with intravenous fluids and an insulin drip and admitted to the ICU. There was some questioning among the nursing staff about whether or not she needed to receive an insulin bolus first.  I decided to look for some literature to share with the nursing staff, as well as educate myself.  Here is what I found:

In children with diabetic ketoacidosis, an insulin bolus is NOT recommended.  It is one of the factors that has been linked to increased risk of cerebral edema.  Do not bolus insulin in kids with DKA.

In adults the guidelines are less clear.  A recent review in Annals of Internal Medicine says that either a bolus followed by drip can be given, (regular insulin at 0.1 U/kg IV bolus followed by 0.1 U/kg/hr as continuous IV infusion), or simply an infusion started.  Tintinalli recommends just starting insulin infusion at 0.1 U/kg/hr.

A few pearls:
1.  Always give fluids before anything else, while awaiting lab results.  The average adult with DKA has a water deficit of 5-10 L.
2.  Wait for potassium level before starting insulin.  Many patients with DKA have a profound potassium deficit, even though serum levels can initially be normal or even high.  This is because the acidosis drives potassium out of cells in exchange for hydrogen ions, falsely elevating the potassium level. If initial [K+] level is <3.3, give potassium-containing fluids BEFORE starting insulin.  Otherwise life-threatening hypokalemia can result.
3.  Bicarbonate therapy is controversial due to risk of worsening hypokalemia, worsening intracellular acidosis.  Bicarbonate should not be routinely given, but should be considered for severe acidosis (pH < 6.9).
4.  Remember to look for precipitants of DKA, and treat any underlying conditions.



References:
1.  Rosenbloom, AL.  The management of diabetic ketoacidosis in children.  Diabetes Therapy 2010. 1:103-120.
2. From Tintinalli's Emergency Medicine: A Comprehensive Study Guide, 7th Ed. Tintinalli, JE, Ed, et al.  New York: McGraw Hill, 2011: p. 442-445.
3.  Wilson et al.  In clinic:  Diabetic ketoacidosis.  Annals Internal Medicine 2010.  152(1):ITC1-1.




The management of diabetic ketoacidosis in children.Source:Diabetes Therapy [1869-6953] Rosenbloom yr:2010 vol:1 iss:2 pg:103 -120