Renal Physiology Associations

Question 1

CRUSH INJURY = what ion imbalance?

Answer 1

MYOGLOBINURIA

Cell Lysis -> HYPERKALEMIA

Question 2

What are the changes in the cardiac myocyte action potential and EKG due to hyperkalemia?

Answer 2

SLOW PHASE 0, PROLONGED QRS, Shortened Membrane Repolarization (PEAK T WAVE)

Question 3

Pt is HYPERKALEMIC, peak T waves are shown on the EKG. Pt is hemodynamically stable for the given time. What should be the best course of action? ON EXAM

Answer 3

ADMINISTER CALCIUM GLUCONATE

Question 4

How does Calcium treatment help restore cardiac membrane potential in a pt with HYPERKALEMIA?

Answer 4

Pt is hyperkalemic -> RMP is less negative
CALCIUM -> Threshold Potential shifted to LESS NEGATIVE value to match up the more positive RMP -> Rate of depol for given RMP is increased = Restore myocyte excitability

Question 5

What is the second line of treatment for a pt with HYPERKALEMIA? What is its mechanism of action?

Answer 5

INSULIN and DEXTROSE

INSULIN - Increases activity of Na+/K+ ATP-ase on the basolateral membrane -> Redistributes K+ Intracellularly