Introduction to electrolyte balance DSA Flashcards
Normal K+ range
3.5-5 mEq/L
How much K+ in the body?
3500 mEq K+
K+ distribution in 70 kg human
IC
EC
IC - 98%
-> 80% muscle cells
-> 20% other cells
EC - 2%
Hypokalemia level and causes (4)
[K+] < 3.7 Vomiting/diarrhea Insulin excess Deficiency Alkalosis
Hyperkalemia level and causes (2)
[K+] > 5.2
Excessive intake
Shifts from ICF to ECF
Pseudohyperkalemia and cause (1)
Artificially high [K+] due to lysis of RBCs while blood is drawn.
Erythrocyte lysis.
What is hypokalemia’s effect on RMP
Shifts more negative (decreases)
What is hyperkalemia’s effect on RMP
Shifts closer to threshold (increases)
Hyperpolarization leads to:
Bradycardia
Hypopolarization leads to:
Tachycardia
Ca++ daily needs
About 1000 mg/day
Which groups are at highest risk for for Ca++ deficiency? (4)
Adolescents
Post menopausal women
Vegeterians
Lactose intolerant
Hypocalcemia’s impact on neuromuscular excitability
Increases neuromuscular excitability
Hypercalcemia’s impact on neuromuscular excitability
Decreased neuromuscular excitability
What regulates Ca++ levels? (3)
PTH
Calcitrol
Calcitonin
Daily required intake of Phosphorus
About 1500 mg phosphorus
Where does Phosphate exists in the body (3)
85% bone
14% cells
1% serum
4 regulators of phosphate metabolism
Dietary phosphate intake/absorption.
Calcitriol (increases resorption form bone and intestines)
PTH (resorption from bone and indirectly acivates intestinal absorption via calcitriol production).
Renal tubular reabsorption of phosphorus.
Mg++ overview
50% in bone
49% in ICF
1% in ECF
Associated w/ migraine, depression, epilepsy, arrhythmias, etc.
