Potassium Homeostasis Flashcards
How is K+ Homeostasis Regulated?
5-1000 K+ mmol/day Excreted by the kidney (Excrete little or a lot)
What are the causes of Hypokalemia?
Dec intake
Inc Entry to Cells: Inc pH/ insulin/ B-adr
Inc GI loss: V/D
Inc Urine loss: diuretics/Mincort excess/ HypoMg
What are the abnormalities caused by Hypokalemia?
Muscle weakness or paralysis Cardiac Arrythmias Rhabdomyolysis Renal Dysfunction Hyperglycemia
What are the EKG signs caused by Hypokalemia?
Increase in Amplitude of U waves
What is the Tx of Hypokalemia?
Tx Cause Assess pathophys effect Oral or IV K+ KCl****, K Phos, K Citrate IV DOSE SHOULD NOT EXCEED 10-20mmol/hr Cardiac monitoring
Why is KCl given for Hypokalemia?
Metabolic Alkalosis (HCl Depletion) Admin of KCl wil help treat HypoK and Metabolic Alkalosis
What drugs can induce Hyperkalemia?
NSAIDS ACE Inh Aldosterone Antagonists -Spironolactone, Amiloride, eplerenone Renin inhibitors
What are S and S of Hyperkalemia?
Muscle Weakness
Cardiac Conduction Abnormalities
S/S depend on RATE of rise and ABSOLUTE level of K+
What is the first EKG change seen in Pts with HYPERkalemia?
A tall, peaked T wave. in Leads II, III, V3 and V4
What is the Tx of Hyperkalemia/Ca?
Antagonize membrane action of hyperkalemia
ONLY in SEVERE HyperK when IMMEDIATE intervention needed
What is the Dose of Ca++ Gluconate given in Hyperkalemia?
10ml 10% over 2-5 min
What is the action of Insulin on Hyperkalemia/Ca?
Shifts K+ into cells by inc activity of Na/K ATPase
What is the action of NaHCO3 on Hyperkalemia/Ca?
Shifts K+ to intracellular space
Best in Pts with Metabolic Acidosis
What is the action of B2 Agonists on Hyperkalemia/Ca?
Shifts K+ to IC space
Albuterol
What is the action of Diuretics on Hyperkalemia/Ca?
Inc Urinary K+ Losses
