Nephrology Question 8

What does the term ‘TTKG’ mean and how do you calculate it? What assumptions are necessary for the formula to be valid?

Consider this case:

A 42 year old male with HIV is admitted with PCP pneumonia. They are treated with high dose Septra. On day 5 of admission, the following results are noted:

Serum K = 6 mmol/L
Serum osmolality = 300 mosmol/L
Urine osmolality = 480 mosmol/L
Urine K = 20 mmol/L.

In the preceding patient with hyperkalemia, calculate the TTKG. What does this tell you about their ability to excrete potassium? Can you explain why this is happening?

Subscribe to Pearls

Uncle Sam wants you to subscribe to Medical Pearls

Subscribe today! It’s always free, and you can easily unsubscribe at any time. We will never share your email address. Subscribe to...

Multiple Pearls
Cardiology Pearls
Endocrinology Pearls
Hematology Pearls
Nephrology Pearls
Rheumatology Pearls
Transplant Pearls
General Internal Medicine Pearls
Instructor Pearls

Subscribe to receive your pearls today—it's free!