electrolytes

Question 1

Hypernatremia

Answer 1

Na > 145 mEq/L

Causes

• excess sodium intake
• not enough water intake
• too much water loss
• 66666Disease: diabetes insipidus, primary hyperaldosteronism, Cushing, diabetes666666

Manifestations
-With low ECF: symptoms of low ECF as well as thirst,
changes in mental status
possible seizures and coma
-With normal or high ECF: twitching, weight gain, edema, flushed skin

Question 2

Hyponatremia

Answer 2

NA <136 mEq/L

Causes:

• sodium loss due to GI, Renal losees, or skin losses
• not enogh sodium intake
• too much water
• 6666Disease: SIADH, heart failure, primary hypoaldosteronism, cirrhosis6666

Manifestations

• mild: headache, irritability, difficulty concentrating
• severe: confusion, vomitting, seizures, coma

Question 3

How to deal with hyponatremia from fluid loss

Answer 3

replace fluid with isotonic sodium solution
encourage oral intake
withold diuretics

Question 4

how to deal with hyponatremia from water excess

Answer 4

fluid restriction
possibly loop diuretics and demeclocycline

acute hyponatremia allows for small amts of IV hypertonic saline solution

vasopressor receptor antagonists if can’t deal with fluid restriction (vaprisol from water excess and samsca for SIADH or heart failure)

IMportant not to corret faster than 6-12 mEq/l per hour during first day to avoid demyelination syndrome

Question 5

how to deal with hypernatremia in primary water defecit

Answer 5

replace fluid orally or with isotonic IV

Question 6

how to deal with hypernatremia from excess sodium

how fast?

Answer 6

dilute with sodium free IVS (5% dextrose in water)
diuretics
restrict sodium intake

Should not decrease by more than 8-15 mEq/L in 8 hrs to avoid cerebral edema

Question 7

Potassium
-where is it?
why is it important?
-where do we get it?
-how do we lose it?

Answer 7

• 98% of body potassium is in cells (sodium potassium pump)
• regulates membrane potential of nerve and muscle cells. Also regulates osmolality and cell growth. Also needed for glycogen deposit. Also acid-base balance
• diet (also IVs, transfusions, meds)
• kidneys lose 90% of K intake (inverse relationship bt Na and K reabsorption)

Question 8

Hyperkalemia causes

Answer 8

K > 5 mEq/L

Excess K intake

Shift of potassium out of cells

• acidosis
• tissue catabolism
• intense exercise
• tumor lysis syndrome

Failure to eliminate K

• renal disease ——————-> most common
• adrenal insufficiency
• Meds: Angio II blockers, ACE inhibitors, heparin, K sparing diuretics, NSAIDs

Question 9

Hyperkalemia manifestations

Answer 9

Dysrhythmias
Fatigue, confusion
Tetany, muscle cramps
Weak or paralyzed skeletal muscles
Abdominal cramping or diarrhea

Question 10

Hyperkalemia ECG changes

Answer 10

• Tall peaked T wave
• prolonged PR interval
• ST segment depression
• widening QRS
• loss of P wave
• Ventricular fibrillation
• ventricular standstill

Question 11

How to deal with hyperkalemia (Don’t really need to know this slide)

Answer 11

-stop potassium intake

Increase secretions
-loop or thiazide diuretics, dialysis, patiromer (Veltassa), Kayexalate

Force K from ECF to ICF

• use IV with dextrose insulin and B-adrenergic agonists (stimulates Na/K pump)
• can use IV sodium bicarb if patient is acidotic

Stabilize cardiac membranes
-IV CaCl2 or calcium gluconate (doesn’t lower K but reverses toxic effects on heart cell membrane –> protects from dysrhthmias

Monitor ECG and BP (Ca causes decrease)
Monitor for hypoglycemia if giving insulin

Question 12

Veltassa and Kayexalate

Answer 12

Kayexalate binds K in bowel –> each gram removes 1 mEq of K

Veltassa does same thing, but takes hours to days and is used in chronic cases –> careful! It also binds to other drugs

Question 13

Hypokalemia causes

Answer 13

K <3.5 mEq/L

K loss
-GI, Renal (hyperaldosteronism), skin (diaphoresis), dialysis

Shift of K into cells

• increased insulin release
• insulin therapy
• alkalosis
• increased epinephrine from stress

Lack of K intake

Renal loss from diuresis

Question 14

Hypokalemia clinical manifestations

Answer 14

-Cardiac most serious
Skeletal muscle weakness (legs)
Weakness of respiratory muscles
Decreased GI motility
Hyperglycemia

-hyperglycemia (from impaired insulin secretion)

Question 15

Hypokalemia ECG changes

Answer 15

• flattened T wave
• U wave
• ST segment depression
• prolonged QRS
• peaked P
• ventricular dysrhythmias
• first and second degree heart block

Question 16

How to deal with Hypokalemia

Answer 16

-increase K intake via food, oral KCl supplements, or IV KCl

IV infusion shouldn’t be more than 10 mEq/hr unless critical and constant ECG monitor –> USE infusion pump –> careful! it irritates skin!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

only give KCL if urine is 0.5 ml/kg body weight per hr

Monitor for digitalis toxisity (confusion, lazy, GI issues, nausea, bad appetite, blurry vision)

don’t eat a bunch of licorish

Question 17

Calcium

• why’s it important?
• what is needed for its absorbance?
• where is it?
• serum Ca levels reflect what?
• hormones that affect serum Ca levels?

Answer 17

• bones, blood clotting, nerve impulses, muscle contraction
• vit D
• 99% in bones –> of the rest, 50% bound to plasma prots, 40% free, and the rest is bound to ions
• all forms of plasma ca (including bound to albumin)
• PTH moves Ca out of bones, causes GI and kidneys to retain it
• calcitonin does the exact opposite

Question 18

Hypercalcemia causes

Answer 18

Ca> 10.5 mg/dL (2.62 mmol/L)

hyperparathyroidism
cancer

Acidosis

Question 19

Hypercalcemia manifestations

Answer 19

Fatigue, lethargy, weakness, confusion
Hallucinations, seizures, coma
Dysrhythmias
Bone pain, fractures, nephrolithiasis
Polyuria, dehydration

Question 20

Hypercalcemia ECG (IGNORE)

Answer 20

short ST
short QT
ventricular dysrhythmias
increased digitalis effect

Question 21

How to deal with Hypercalcemia (Only kinda relevant)

Answer 21

• stop taking meds related to hypercalcemia
• lower Ca intake
• weight bearing exercise
• maintain hydration 3000-4000 mL fluid per day (esp cranberry or prune juice) to avoid kidney stones

If severe:

• IV isotonic saline (beware fluid overload if kidneys cant excrete Na)
• bisphosphonate (interfere with osteoclasts, but takes 2-4 days
• calcitonin (quick Ca excretion, but temporary and risks tachycardia)
• denosumab (Prolia)

Question 22

Hypocalcemia causes

Answer 22

Ca < 9 mg/dL (2.25 mmol/L)

Low serum Ca levels caused by
Decreased production of PTH
Multiple blood transfusions - discuss
Alkalosis
Increased calcium loss 

tumor lysis syndrome

chronic alcohol use

Alkalosis

Excess citrated blood

Question 23

Hypocalcemia manifestations

Answer 23

Positive Trousseau’s or Chvostek’s sign
Laryngeal stridor
Dysphagia
Numbness and tingling around the mouth or in the extremities 
Dysrhythmias

Question 24

hypocalcemia ECG (IGNORE)

Answer 24

elongation of ST
prolonged QT interval
ventricular tachycardia

Question 25

How to deal with hypocalcemia

Answer 25

- eat more calcium and vit D and/or have supplements - IV calcium glutonate - breathe into paper bag to retain CO2 for muscle spasms or tetany - quit loop diuretics --> change to thiazide diuretics - make sure parathyroid gland isn't damaged - make sure they're not anxious

Question 26

Phosphorus where? what's it for? what regulates it?

Answer 26

- most in bones as CaPO4; the rest metabollically active as salts - helps muscles, RBCs, and nerv syst to func --> acid-base buffer, ATP formation, glucose uptake, carb/prot/fat metabolism - PTH and kidneys --> if PTH low, kidneys reabsorb more ---> reciprocal relationship bt phosphate and calcium

Question 27

Hyperphosphatemia causes

Answer 27

PO4 > 4.5 mg/dl (1.45 mmol/L) Acute kidney injury or chronic kidney disease Excess intake of phosphate or vitamin D Hypoparathyroidism

Question 28

Hyperphosphatemia manifestations

Answer 28

Tetany, muscle cramps, paresthesias, hypotension, dysrhythmias, seizures (hypocalcemia) Calcified deposition in soft tissue such as joints, arteries, skin, kidneys, and corneas (cause organ dysfunction)

Question 29

How to deal with hyperphosphatemia

Answer 29

restrict phosphorus foods phosphate binding agents (CaCo3) limits abosorbtion and increases secretion If serious -hemodialysis loop diuretics to increase secretion Almost always happens with low Ca, so watch out for that

Question 30

Hypophosphotemia causes

Answer 30

PO4 < 3 mg/dL (0.97 mmol/L) Malnourishment/malabsorption Diarrhea Use of phosphate-binding antacids Inadequate replacement during parenteral nutrition

Question 31

Hypophosphatemia manifestations

Answer 31

CNS depression Muscle weakness and pain Respiratory and heart failure Rickets and osteomalacia Most of these due to low cellular energy and O2 delivery Chronic hypophosphatemia alters bone metabolism

Question 32

How to deal with hypophosphatemia

Answer 32

eat more phosphorus and dairy or take supplements -dairy supplements are better bc they won't fuck up GI If serious - IV sodium phosphate or potassium phosphate - watch for hypocalcemia, hyperkalemia, hypotension, dysrhythmias Monitor serum calcium and phosphorus levels every 6 to 12 hours

Question 33

``` Magensium abundance? what's it for? where's it stored? what regulates it? ```

Answer 33

- 2nd most abundant intracellular cation - cofactor in enzyme systs (carb metabolism, DNA snth, blood glucose contr, BP regulation) ---> ATP production, muscle contraction, neurologic func - 50-60% in muscle/bone; 30% in cells; 1% ECF - Kidneys and GI syst regulate through ascending loop and distal tubules

Question 34

Hypermagnesemia causes

Answer 34

Mg > 2.1 mEq/L (1.05 mmol/L) Increased intake of products containing magnesium when renal insufficiency or failure is present Excess IV magnesium administration

Question 35

Hypermagnesemia manifestations

Answer 35

Inhibits acytylcholine at myoneural junc and Ca movement into cells ``` Hypotension, facial flushing Lethargy Nausea and vomiting Impaired deep tendon reflexes Muscle paralysis Respiratory and cardiac arrest ``` super severe: paralysis, coma, respiratory/cardiac arrest

Question 36

How to deal with Hypermagnesemia

Answer 36

- avoid Mg drugs and limit intake - more fluids and diuretics if kidneys are ok - dialysis if kidneys aren't ok If serious -IV calcium gluconate or CaCl to help cardiac muscles

Question 37

Hypomagnesemia causes

Answer 37

Mg <1.3 mEq/L (0.65 mmol/L) ``` Prolonged fasting or starvation Chronic alcoholism Fluid loss from GI tract Prolonged parenteral nutrition without supplementation Diuretics, proton-pump inhibitors Hyperglycemic osmotic diuresis ```

Question 38

Hypomagnesemia manifestations

Answer 38

Resembles hypocalcemia ``` Muscle cramps, tremors Hyperactive deep tendon reflexes Chvostek’s and Trousseau’s signs Confusion, vertigo, seizures Dysrhythmias ```

Question 39

How to deal with Hypomagnesemia

Answer 39

oral supplements and increased dietary intake If severe or hypocalcemia - IV magnesium - CAREFUL: rapid infusion can lead to hypotension or cardiac/respiratory arrest