16 year old male has been treated all night for diabetic ketoacidosis. In the morning the blood gas printout is as follows:
Barometric pressure |
760mm Hg |
FiO2 |
0.21 |
pH |
7.32 |
pO2 |
100mm Hg (13.2 kPa) |
pCO2 |
30mm Hg (4kPa) |
HCO3- |
15.2mmol/L |
Standard base excess |
-11.4mmol/L |
|
Sodium |
136mmol/L |
(135 – 145) |
Chloride |
105mmol/L |
(100 -110) |
Potassium |
3.5mmol/L |
(3.2 - 4.5) |
Lactate |
1.3mmol/L |
(0.2 - 2.5) |
Glucose |
5.3mmol/L |
(3.6 – 7.7) |
a) Describe the acid-base status.
b) Does he need continuation of insulin therapy over the next 6 hours? Give your reasoning.
a) Describe the acid-base status.
Raised anion gap metabolic acidosis with appropriate respiratory compensation
b) Does he need continuation of insulin therapy over the next 6 hours? Give your reasoning.
The patient will require insulin therapy for the next few hours as the anion gap is raised, indicating ongoing ketoacidosis.
Let us dissect these results systematically.
This questions would seem identical to Question 7.1 from the first paper of 2009, but the examiners have changed the chloride and glucose. In 2009, this 16 year old patient has a normal anion gap and slightly raised glucose, forcing us to conclude that the ketoacidosis has resolved. No mention is made of insulin.
This time, the ketoacidosis persists. One would be tempted to continue the insulin/dextrose infusion until the anion gap is normal, and only the NAGMA remains.
UpToDate has a nice summary of this topic for the paying customer.
Oh's Intensive Care manual: Chapter 58 (pp. 629) Diabetic emergencies by Richard Keays
Umpierrez, Guillermo E., Mary Beth Murphy, and Abbas E. Kitabchi. "Diabetic ketoacidosis and hyperglycemic hyperosmolar syndrome." Diabetes Spectrum15.1 (2002): 28-36.