Diabetic ketoacidosis or DKA is an interesting topic that has briefly come up for me in my clinical orientation. I was interested in learning more about this, especially prior to my PICU rotation. During the ADS each pair of residents had critically appraised a paper and discussed it. This allowed us all to have a greater understanding of the primary literature by discussing it with one another.
Pearls about DKA:
- DKA is defined as:
- Plasma glucose > 11.1 mmol/L + pH < 7.3 and/or HCO3 < 15 mmol/L + ketonuria or ketonemia
- + sx of diabetic complications e.g. polyuria, polydypsia, weight loss and fatigue
- Ketoacidosis of DKA is as a result of having increased fat usage for energy due to inability to appropriately utilize sugar sources for energy. Ketones are a breakdown product of fats, and are acidic and thus when there are too many of them it results in ketoacidosis.
- Causes of DKA: Undiagnosed type 1 diabetes, unmanaged type 2 diabetes, insulin omission or manipulation, inadequate insulin dosing/monitoring (inappropriate sick day management), pump misuse or infusion site disconnection.
The reason we are concerned with DKA is the morbidity of DKA-related cerebral edema. This is more common in those who are younger, more “sick”, new-onset diabetes, longer duration of symptoms, inc dehydration (sunken eyes, dec skin turgor, anuria) and high degree of acidosis.
Tx variables associated with DKA-related cerebral edema
- Too-rapid fall (>2 mmol/L/h) in corrected sodium
- Failure to correct or uncorrected sodium rise
- Too-rapid fall (>4 mOsm/kg/h) in active osmolarity
- Use of bicarbonate to treat acidosis
- Early insulin treatment of large insulin boluses
- Use of fluids: > 4 L/m2/24h or > 50 mL/kg in the first 4 hours
- 1st step: correct dehydration
- Typically done with NS (unless other electrolyte disturbances – e.g. hypokalemia -> then add KCl)
- 2nd step: insulin time (not within first 1-2 hours of DKA management)
- An IV fluid bolus is only RARELY used in the case of moderate – severe dehydration.
- IF a bolus is used, the policy recommends only 5 – 10 mL/kg over 1 – 2 hours
- 2 bag system is used to prevent a rapid fall in blood glucose – blood glucose goal is 10 – 15 mmol/L for the first 12 – 24 hours.