written by Susan Tyler, Dal medical student, Feb 2009
last reviewed:
The four major diagnostic criteria are hyperglycemia, anion gap metabolic acidosis, hyperketonemia, ketonuria. It is due to low levels of insulin and increased levels of counter-regulatory hormones such as glucagon, epinephrine, and cortisol.
a simple case introducing clincial presentation and calling for a differential diagnosis to get students thinking.
DKA is more common in Type 1 DM than type II, due to complete insulin deficiency and counter-regulatory hormones.
It is precipitated by the 7 I’s:
An increase in fatty acid oxidation leads to ketone produce acetone, beta-hydroxybutyrate, and aceto-acetate.leads to an anion gap metabolic acidosis.
Increased glucose production in liver leads to hyperglycemia and osmotic diuresis, with glycosuria and ketonuria. The resulting dehydration and electrolyte changes can lead to a drop in Na (pseudohyponatremia).
Frequency of sugar checks
Previous meal.
Hyperglycemia, dehydration, and electrolyte disturbances can lead to:
Assess for signs of infection
Evaluate the course and control of his diabetes
dehydration
shortness of breath and Kussmaul respiration (laboured, tachypnic breathing in response to metabolic acidosis)
decreased LOC (drowsiness -> stupor -> coma)
fruity smelling breath (acetone)
signs of infection
Blood
causes
Urine: + glucose/ketones
Don't treat the blood sugar - treat the anion gap acidosis. Degree of DKA monitored by anion gap, but check the glucose hourly. Most institutions have a protocol - follow these instructions.
Monitor especially if patient is in a stupor/coma
The aim is to give 3-4L over 8 hours. 1L/h normal saline first 2 hrs, then 300-500 ml/h 0.45% NS. Once glucose reaches 13.9 mM, switch to D5W and keep in 13.9 to 16.6 mM range.
Caution: aggressive rehydration can lead to overhydration and even cerebral edema in pediatric patients! Carefully monitor HR, BP, urine output, JVP.
CRITICAL to reverse acidosis.
Bolus insulin R with 0.1-0.15u/kg, maintenance drip 0.1ukg/h insulin R
When AG is normal, switch over to subcutaneous insulin (overlap IV and SC 2-3 H)
Hypokalemia is a concern once acidosis is corrected, as K is globally depleted and further shifts into cells
If K 3.5 to 5.5 mM add KCl 20-40 mEq/L IVF (target range is 3.5 to 5)
Caution with K replacement in renal failure, may need to defer if Cr is high
If ph < 7.0, low BP, arrhythmia, or coma, give bicarbonate in half normal saline.
If severe vascular decompensation, give a 10 cc/kg bolus with 0.9% NaCl over 30 minutes. Reassess after bolus, repeat if necessary, and otherwise continue.
No vascular decompensation
Start insulin after first hour of initial rehydration. Use short-acting (regular) insulin infusion at 0.1 U/kg/h. Do not give a bolus, as this has been associated with cerebral edema.
Use 0.9% NaCl initially, then switch to 0.45% NaCl and add D5W when BG ~15-17
DKA carries a 2-5% mortality with marked morbidity from complications. Patients are at increased risk of
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