Hypokalemia Flashcards
How does hypokalemia typically present?
- Muscle weakness
- Paralysis
- loss of reflexes
Define Hypokalemia
Serum potassium<= 3.5 mmol/l
List 4 features of severe hypokalemia
- Rhabdomyolysis
- Cardiac arrhythmias
- Diaphragmatic weakness
- Paralysis
Name one physical exam finding of hypokalemia
Cardiac arrhythmias
What are the two most common causes of hypokalemia
1.GI losses through diarrhoea/vomiting
2. Renal losses through hyperaldosteronism/diuretics
State the treatment of chronic asymptomatic hypokalemia
Mainstays is to find and treat the cause
Symptomatic relief: KCl 600 mg 1-2 tablets 8 hourly
How much KCL does each 600 mg tablet contain
8 mmol/l
What is the maximum dose that should not be exceeded of KCL in management of hypokalemia
6 g daily
Review after 4 weeks
Is giving routine supplements of KCl in someone.using diuretics appropriate?
Nope
What medications are given in addition to furosemide/thiazines diuretics to prevent hypokalemia?
ACEi/Spironolactone
What is the treatment of mild to moderate hypokalemia(serum K 3-3.4 mmol/L)
KCL 600 mg til concentration is above 3.5 mmol/l
State the treatment for severe hypokalemia
KCl IV infusion by peripheral line, 40 mmol in 1 L of 0.9% or 0.45% sodium chloride, mixed thoroughly.
NOTE: Maximum allowed daily dose of K+ is 3 mmol/kg/day (or 400 mmol/day).
What do you need to be aware of when administering KCl IV?
Volume overload
Should KCl ampoules always be dilute before administration?
Yes, I mean always
What electrolyte abnormalities causes Hypokalemia and should be looked for?
Hypomagnesemia
What is the target goal when treating hypokalemia?
Serum potassium levels to be within normal range and symptoms resolve
What should be avoided by people with hypokalemia?
Glucose drinks
What is Bartter syndrome
Bartter syndrome is the inability of the loop of Henle to absorb sodium and chloride. It causes secondary hyperaldosteronism and renal potassium wasting
Which fungal medication causes Hypokalemia?
Amphotericin B by causing renal tubular acidosis
What is the best initial test for hypokalemia?
EKG: shows U.waves and flattening of T wave
What does a U wave indicate on an EKG?
Purkinje repolarization and it is seen in Hypokalemia
Should KCl IV infusion be administered fast/slow?
Slow to prevent arrhythmias
List 3 referral criteria for hypokalemia to a physician
- Persistent hypokalemia despite treatment
- Condition causing hypokalemia cannot be managed in your facility
- Investigations as part of the work up is not offered in your facility
What to do if you are unsure about referring someone with hypokalemia?
Call the physician who is at your closest referral facility
List 6 criteria that are part of the discharge criteria list
- Hypokalemia is resolved meaning potassium is within normal ranges and symptoms have resolved
- Underlying cause has been found and treated
- Drugs causing/aggravating hypokalemia has been stopped
- Advice on potassium containing foods
- Appropriate outpatient follow up has been arranged
- Consider oral K for patients who are at a very high risk of cardiac arrythmias
List 8 food products that contain potassium
- Bananas
- Spinach
- Dried fruit especially dried apricots
- Avocados
- White mushrooms
- Broccoli
- French fries
- Orange juice
Different kinds of potassium given to patients
- Potassium chloride
- Potassium bicarbonate
- Potassium phosphate
- Potassium citrate
What is the daily dosage of potassium used for prevention of hypokalemia
20 mmol/L per day
As compared to 40-100 mmol/l per day for treatment
When to give magnesium in Hypokalemia?
- When suspecting/have proven hypomagnesemia
- Refractory hypokalemia
How should high concentration of potassium chloride or rapid infusion be done?
Use central line and monitor the heart closely as it leads to arrhythmias
List 5 key management steps of hypokalemia
1.Stabilise ABCs
2. Find the cause
3. Stop drugs that aggravate or cause hypokalemia
4. Correct hypovolemia with isotonic fluids
5. Parenteral potassium chloride
Name two arrhythmias that arise as a complication of hypokalemia
- Asystole
- Pulse less electrical activity
Name one common cause of pseudohypokalemia
- Acute myeloid leukemia
Name 5 drugs that cause hypokalemia through shifting the K into the cell.
- Beta agonists
- Insulin used in DKA and HHS protocol
- Theophylline
- Caffeine
5.Chloroquine
How does CCF, nephrotic syndrome and hepatic insufficiency lead to hypokalemia?
Secondary hyperaldosteronism
What is hypokalemic periodic paralysis?
State of recurrent muscle weakness attacks associated with low potassium
List three rare causes of Hypokalemia
1.Liddle syndrome
2. Barter syndrome
3. Gitelman syndrome
How does hypomagnesemia lead to hypokalemia?
Increased renalmlosses
What is considered life threatening hypokalemia?
Potassium<=2.5 mmol/l
What is the intracellular levels of potassium
140-155 mmol/l
How much of potassium is extracellular?
2%
