Fluid and Electrolytes K and Mg

Question 1

Normal Potassium

Answer 1

3.5-5 mEq/L

Question 2

Hypokalemia Sytpoms

Answer 2

Cardiac arrhythmias
Muscular myalgia/weakness
Constipation

Question 3

Action Potential Explained

Answer 3

0: sodium rushes in
1: Cl rushes in
2: Slow Ca channels open
3: K leaves cell
4: Plateau

Question 4

AV Node is predominately

Answer 4

Ca

Question 5

P wave =

Answer 5

Depolarization of atrium

Question 6

PR interval =

Answer 6

Evaluates the AV node

Question 7

QRS Interval =

Answer 7

Depolarization of ventricle

Question 8

T wave =

Answer 8

Repolarization

Question 9

In potassium changes we should look at?

Answer 9

T wave

Question 10

Low K + T wave =

Answer 10

Flattened

Question 11

High K + T wave =

Answer 11

Spikes

Question 12

Urine potassium readings

Answer 12

Less than 20 extrarenal losses like vomiting/laxative/diarrhea
Greater than 20 = renal losses due to drugs or acidosis

Question 13

Most common causes of hypokalemia are:

Answer 13

Drugs
Diarrhea
Vomiting

Question 14

Intracellular shift of K causes

Answer 14

Albuterol & other B2 agonists
Bicarbonate
Insuline

Question 15

Enhanced renal excretion of K causes

Answer 15

Diuretics
High dose pencillin
AG and Amp B

Question 16

***Enhanced fecal elimination of K causes

Answer 16

Sodium polystyrene sulfonate

Question 17

1 mEq/L drop i K =

Answer 17

200 mEq depleted

Question 18

Dietary content treatments for hypoK

Answer 18

Dried figs, molasses, dried fruits, avovados, nuts

Question 19

Oral supplements for hypoK

Answer 19

KCl (best in treating diuretic or diarrhea induced)
KPO4 (good in ↓ PO4)
K acetate (good in acidosis pts)

Question 20

IV Treatment of HypoK

Answer 20

Symptomatic ONLY or unable to tolerate oral

Mix with NaCl instead of dextrose

Question 21

Peripheral vein infusion:

Answer 21

No more than 40 mEq/L

Question 22

Central vein infusion:

Answer 22

No more than 100 mEq/L

Question 23

Infusion rate

Answer 23

EKG: 20-40 mEq/hr
No EKG: 10 mEq/hr

EKG = telemetry

Question 24

****If K doesn’t correct in 48-72 hours, then

Answer 24

consider Mg deficiency

- Reabsorption of K needs Mg in the kidney so if you have a Mg deficiency your kidneys will drop all the K

Question 25

Hyperkalemia Symptoms

Answer 25

Muscles Weakness | EKG changes

Question 26

Sever hyperkalemia =

Answer 26

Very symptomatic EKG Changes (peak t waves) >6.5 mEq/L

Question 27

Causes of Hyperkalemia

Answer 27

``` Pseudohyperkalemia due to hemolysis, leukocytosis, or thrombocytosis Drugs Renal failure (most common) ```

Question 28

Drugs that can cause hyperkalemia

Answer 28

``` ACEi ARBS Trimethoprim Spironolactone Heparin ```

Question 29

1) Membrane Stabilization for HyperK

Answer 29

Infusion of IV calcium bc it antagonizes the effects of hyperK Typically calcium gluconate Bolus over 2-3 minutes and effects for 30-60 minutes

Question 30

2) Shifting K from extracellular to intracellular via

Answer 30

Insulin Nebulized B2 agonists Sodium bicarbonate

Question 31

Insulin Treatment of HyperK

Answer 31

10 units with 50 mL of dextrose (only in euglycemic) Onset 10-20 minutes ***Decrease K by 0.6-1 mEq/L

Question 32

Nebulized B2 agonists Treatment of HyperK

Answer 32

Stimulate glucose Works immediately and last 1-2 hrs **Decrease K by 0.5-1 mEq/L

Question 33

Sodium bicarbonate

Answer 33

Increases blood pH | Not effective

Question 34

3) K Removal from Body

Answer 34

Ion exchange resins or Dialysis

Question 35

Ion exchange resins

Answer 35

Sodium Polysterene Exchanges K for Na in the gut Given with sorbitol to facilitate removal and prevent constipation **Decreases K by 1 mEq/L every 24 hours

Question 36

Treatment of Severe Hyperkalemia Flow Chart

Answer 36

See notes Abnormal EKG --> Adminster calcium gluconate if yes and if not keep monitoring Hyperglycemia --> give insulin and follow sugar if yes and administer insulin and glucose if no Now consider albuterol then consider bicarbonate (if acidotic) then give exchange resin or consider dialysis *****FOLLOW K LEVELS EVERY 2 HOURS UNTIL LESS THAN 5.5

Question 37

Normal Mg

Answer 37

1.4-1.75 | Primarily intracellular and eliminated by kidneys

Question 38

Normal daily requirement is

Answer 38

15-30 mEq/day

Question 39

GI causes of hypoMg

Answer 39

Malnutrition Increased requirements Bowel resection Severe diarrhea

Question 40

Renal cause of hypoMg

Answer 40

Mg wasting | Drugs (cisplatin, Ag, cyclosproine, LOOP AND THIAZIDE DIURETICS, ALCOHOL)

Question 41

Endocrine causes of hypoMg

Answer 41

SIADH Hyperthyroidism Hyperaldosteronism Post-parathyroidectomy

Question 42

Symptoms of HypoMg

Answer 42

Increased muscle spasiticity (tremors, seizures, tetany) Weakness N/V EKG (torsades de pointes)

Question 43

Asymptomatic with mild hypoMg treatment:

Answer 43

Oral 40 mEq/day with sustained-release prep | - Comes with lots of diarrhea

Question 44

Symptomatic HypoMg treatment

Answer 44

1-2 mEq/kg def: give 2-4 mEq/kg bc 1/2 is eliminated | Rate: 1 mEq/kg/24 hrs, .5 mEq/kg/2nd 24, continue for up to 4 days

Question 45

Life-threatening Hypo Mg treatment

Answer 45

16-32 mEq of Mg Sulfate as a short IV infusion over 2-4 minutes

Question 46

HyperMg Causes

Answer 46

Typically: renal insufficiency given Mg contain med (antacids/laxatives)

Question 47

Symptoms of HyperMg

Answer 47

Respiratory paralysis HypOTN Difficulty talking/swallowing Widening QRS and abnormal P waves

Question 48

Mild HyperMg Treatment

Answer 48

Withhold all Mg

Question 49

Severe HyperMg Treatment

Answer 49

IV calcium and repeat Normal renal function: IV furosemid + 1/2 NS Hemodialysis if renal impaired

Question 50

SERUM LEVELS OF MAGNESIUM,

Answer 50

DO NOT REFLECT TOTAL BODY STORES

Question 51

Mg summary

Answer 51

Not commonly checked but should be in alcoholic or if volume depleted