Fluid and Electrolytes K and Mg Flashcards Preview

GI Exam 1 > Fluid and Electrolytes K and Mg > Flashcards

Flashcards in Fluid and Electrolytes K and Mg Deck (51):
1

Normal Potassium

3.5-5 mEq/L

2

Hypokalemia Sytpoms

Cardiac arrhythmias
Muscular myalgia/weakness
Constipation

3

Action Potential Explained

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

4

AV Node is predominately

Ca

5

P wave =

Depolarization of atrium

6

PR interval =

Evaluates the AV node

7

QRS Interval =

Depolarization of ventricle

8

T wave =

Repolarization

9

In potassium changes we should look at?

T wave

10

Low K + T wave =

Flattened

11

High K + T wave =

Spikes

12

Urine potassium readings

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

13

Most common causes of hypokalemia are:

Drugs
Diarrhea
Vomiting

14

Intracellular shift of K causes

Albuterol & other B2 agonists
Bicarbonate
Insuline

15

Enhanced renal excretion of K causes

Diuretics
High dose pencillin
AG and Amp B

16

***Enhanced fecal elimination of K causes

Sodium polystyrene sulfonate

17

1 mEq/L drop i K =

200 mEq depleted

18

Dietary content treatments for hypoK

Dried figs, molasses, dried fruits, avovados, nuts

19

Oral supplements for hypoK

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

20

IV Treatment of HypoK

Symptomatic ONLY or unable to tolerate oral
Mix with NaCl instead of dextrose

21

Peripheral vein infusion:

No more than 40 mEq/L

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Central vein infusion:

No more than 100 mEq/L

23

Infusion rate

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

EKG = telemetry

24

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

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

25

Hyperkalemia Symptoms

Muscles Weakness
EKG changes

26

Sever hyperkalemia =

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

27

Causes of Hyperkalemia

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

28

Drugs that can cause hyperkalemia

ACEi
ARBS
Trimethoprim
Spironolactone
Heparin

29

1) Membrane Stabilization for HyperK

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

30

2) Shifting K from extracellular to intracellular via

Insulin
Nebulized B2 agonists
Sodium bicarbonate

31

Insulin Treatment of HyperK

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

32

Nebulized B2 agonists Treatment of HyperK

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

33

Sodium bicarbonate

Increases blood pH
Not effective

34

3) K Removal from Body

Ion exchange resins or Dialysis

35

Ion exchange resins

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

36

Treatment of Severe Hyperkalemia Flow Chart

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

37

Normal Mg

1.4-1.75
Primarily intracellular and eliminated by kidneys

38

Normal daily requirement is

15-30 mEq/day

39

GI causes of hypoMg

Malnutrition
Increased requirements
Bowel resection
Severe diarrhea

40

Renal cause of hypoMg

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

41

Endocrine causes of hypoMg

SIADH
Hyperthyroidism
Hyperaldosteronism
Post-parathyroidectomy

42

Symptoms of HypoMg

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

43

Asymptomatic with mild hypoMg treatment:

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

44

Symptomatic HypoMg treatment

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

45

Life-threatening Hypo Mg treatment

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

46

HyperMg Causes

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

47

Symptoms of HyperMg

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

48

Mild HyperMg Treatment

Withhold all Mg

49

Severe HyperMg Treatment

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

50

SERUM LEVELS OF MAGNESIUM,

DO NOT REFLECT TOTAL BODY STORES

51

Mg summary

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