Potassium and dehydration treatment

Question 1

Daily requirement for potassium is __

Answer 1

2 mEq/kg/day

Question 2

Hypokalemia

Definition and causes and clinical scenario

Answer 2

<3.5 mEq/L

1. Poor intake
   Anorexia nervous
2. Losses
   - GI = V / D
   - renal = RTA, diuretics, excess aldosterone

Clinical: diarrhea, muscle pain, weakness, paralysis, polyuria, –> constipation, ileus.

Question 3

Hypokalemia EKG changes

Answer 3

Flattened T waves
ST depression
PVCs
U wave after T wave

Question 4

Hypokalemia treatment

Answer 4

Emergency: KCl 0.5 a 1.0 mEq/L/kg over one hour. With ekg monitoring. Max 40 mEq/L.

If mild, can do oral K
If dehydrated, can just add K to MIVF
If Acidosis, use K Acetate
If low phos, use Kphos

Question 5

Hypocalcemia presentation

Answer 5

Weakness

Prolonged QT interval

Question 6

Hypomagnesemia presentation

Answer 6

Weakness
Diarrhea
Prolonged QT interval
Prolonged PR interval

Question 7

Hypoglycemia presentation

Answer 7

Weakness

No EKG changes

Question 8

Hyponatremia presentation

Answer 8

Weakness

No EKG changes

Question 9

Hyperkalemia

Answer 9

> 5.0 mEq/L

Question 10

Hyperkalemia causes

Answer 10

Excess intake
Not enough out
-renal failure
-hypoaldosteronism
Redistribution
-acidosis (H goes into cell, K goes out)
cell breakdown- pseudohyperkalemia

Question 11

Hyperkalemia

EKG findings

Answer 11

Peaked T waves

If >10:
-absent p waves
-widened QRS
-electromechanical dissociation (EMD) -->
Muffled heart sounds and absent pulses!
Tricks are IBBB and VT

Question 12

Hyperkalemia tx

Answer 12

If >10 with EKG changes,
IV calcium chloride

Otherwise:
Glucose
Insulin
Albuterol 
IV furosemide 
PO polystyrene resin (sodium polystyrene sulfonate)

Question 13

What happens to Potassium during alkalosis?

Answer 13

H+ moves from IC to EC, K+ moves from EC to IC.
–>low serum K+ measured
TOTAL Body K is still the same.

Opposite is true for acidosis

Question 14

5% dehydration

Clinical description

Answer 14

Tachycardic
Decreased tear production
Decreased UOP
Increased urine concentration

Question 15

5% dehydration treatment

Answer 15

Need an extra 50 cc/kg
Can do this oral, or IV.

Add that to MIVF
Give half over 8hrs, 2nd half over 16 hrs

Question 16

10% dehydration

Clinical picture

Answer 16

Tachycardia
Sunken eyes
Poor skin turgid
Sunken fontanelle

Question 17

10% dehydration treatment

Answer 17

Need an extra 100 cc/kg
Add that to MIVF = what they need over 24 hours.
Give a 20 cc/kg bolus as needed
Whatever is left over give over 7 hrs, remainder half over 16 hrs

Question 18

15% dehydration clinical picture

Answer 18

Same as 10% plus shock

Delayed cap refill

Question 19

15% dehydration treatment

Answer 19

Need an extra 150 cc/kg
Add that to MIVF = 24 hr fluid requirement
Give 20 cc/kg bolus until clinical improvement.
Whatever is left over give over 7 hrs, remainder half over 16 hrs

Question 20

Oral rehydration fluid

Answer 20

For moderate to severe dehydration

Has 75 mEq/L Na

Give 50 cc/kg over 1-4 hrs

Question 21

Maintenance hydration fluids (oral)

Answer 21

For mild dehydration
Has 50 mEq/L Na

Can be used whenever cap refill is normalized.

Question 22

Isotonic dehydration

Answer 22

Na 135-145

Question 23

Hyponatremic dehydration

Answer 23

Na <135

Diarrhea
Grandmother gave kid tea or water

Usually these kids are the most symptomatic
Can present with seizures if Na <125 (water moves into brain cells)

Question 24

Hyponatremic dehydration treatment

Answer 24

1st normal saline boluses
2nd 3% hypertonic saline in ICU

Correct fluids AND Na over 24 hrs

(Desired Na - Measured Na) x wt x 0.6 = A

Add A to maintenance Na (3 mEq/kg/day)

Question 25

Hypernatremic dehydration

Answer 25

Na > 145

Due to water loss or Na gain
Lots of Na in ECF

Infant given improperly mixed formula
Rotavirus diarrhea

Irritable, lethargic, doughy skin, high pitched cry, seizures.

Assume 10% dehydration even if they look mild, because water is going into the ECF!

May have acidosis because cells are destroyed so H+ goes out into ECF

Brain cells shrink, can tear bridging blood vessels –> hemorrhage

Question 26

Idiogenic osmoles

Answer 26

In hypernatremic dehydration, they replace the Na leaving the brain cells, so brain doesn’t shrink as much.
Develop over 1-2 days
Leave slowly too.

This is why we have to correct Na slowly over 2-3 days, no more than 10-12 mEq/L/day.
Also so water doesn’t rush back into brain cells (edema)

Question 27

Hypernatremic dehydration treatment

Answer 27

Assume 10% dehydration even if they look mild, because water is going into the ECF!

Reduce Na by 0.5 mEq/L/hr if it’s chronic Hypernatremic dehydration

If Na > 170, correct over 2-3 days with 0.5 or 0.25 NS

If signs of overcorrection, use 3% hypertonic sailing as a brake to slow the correction.

Hold potassium until UOP is established.