potassium disorders

1. Potassium imbalance and
management.
Lecture-3.
By Dr-C

2. Normal serum electrolytes.
Sodium (Na) 136-145 mEq/L 136-145 mmol/L
Potassium (K) 3.5-5.0 mEq/L 3.5-5.0 mmol/L
Chloride (Cl) 95-105 mEq/L 95-105 mmol/L
Bicarbonate (HCO3) 22-28 mEq/L 22-28 mmol/L
Magnesium 1.5-2.0 mEq/L 0.75-1.0 mmol/L

3. Urinary and serum potassium levels
 Adults: 3.5-5.1 mEq/L or mmol/L
 Children: 3.4-4.7 mEq/L or mmol/L (age dependent)
The reference ranges of urinary potassium levels are as follows:
 Adults: 25-125 mEq/L/day
 Children: 10-60 mEq/L/day
 There is a special role in potassium in human body. Think about the
sodium potassium pump and potassium hydrogen pump.

4. hyperkalemia
 Higher potassium concentration in serum. >5mmol/L(in Sri Lanka this taken as
5.5mmol/L)
 Classification of hyperkalemia

5. hyperkalemia
 Severe hyperkalemia is a medical emergency it might cause
arrhythmias and cardiac arrest unless identified and treated.
 Always try to find or understand the underlying cause of
hyperkalemia. It makes much easier to treat the condition.

6. Causes of hyperkalemia
 Renal failure
 Addison's disease
 Metabolic acidosis and DKA
 High platelet count and high WBC artificially raise the potassium level
 Cardio pulmonary bypass
 Another cause of hyperkalemia is tissue destruction, dying cells release
potassium into the blood circulation. Examples of tissue destruction
causing hyperkalemia include:
 Hypokalemic periodic paralysis

7. Causes of hyperkalemia(due to tissue
destruction continued.)
 Trauma including crush injury
 Rabhdomyolysis
 massive lysis of tumor cells (tumorlysis syndrome)
 Surgeries.
 Hemolysis
 Burn injuries.

8. Hyperthermia causes continued.
 Malignant hyperthermia
 A hemolysis of the blood sample might shows values of
hyperkalemia
 Blood transfusions.
 Due to excessive oral potassium tablets

9. Commonly met drugs that can cause
hyperkalemia
 ACEs-captopril, enlapril
 ARBs-losartan
 Potassium sparing diuretics-Spironolactone, amlioride
 Digoxin
 Nonselective beta blockers
 NSAIDs
 KCl tablets it self a cause.
 Heparin

10. What to do initially?
 Is the patient already have a history of hyperkalemia?
 May be the clinical presentation is a cardiac arrest. So follow ABC approach.
 Take a detailed history, specifically ask about the recent complaints, drug history,
and past medical history.
 Take an ECG.
 When taking blood for investigations send a serum electrolyte also.
 There are many other investigations that could be done in a hyperkalemia state,
but as a start do above mentioned first.
 And don’t forget to ask the patient to reduce/stop food that might cause
hyperkalemia.
 Omit the drugs that might cause hyperkalemia

11. ECG changes in hyperkalemia

12. Principles of treating hyperkalemia.
 Limit oral intake of potassium.
 Stabilize the cell membrane potential-IV calcium gluconate.
 Shift potassium in to cells-inhaled beta2 agonists(salbutamol). IV
glucose+insulin and iv bicarbonate therapy
 Removal of potassium from the body-IV furosemide and N.saline.
Ion exchange resins orally or rectally. Hemodialysis

13. Management of severe hyperkalemia
 Potassium level is higher than 6.5mmol/L
 It is a medical emergency. Need urgent medical intervention.
 Arrange 12 lead ECG and cardiac monitoring.
 Sometimes hyperkalemia may present without evidence of ECG changes. Even if the
ECG changes not present start treatment. ECG changes suggest a quick medical
response.
 Protect the myocardium(cardiac cell membrane)-give 10ml of calcium chloride
(Ca2+ 6.8 mmol/ml) or give 30ml of 10% calcium gluconate ( Ca2+ 2.26
mmol/ml) via peripheral large vein or a central venous catheter over 5-10 minutes.
 Continue cardiac monitoring and do 12 lead ECG monitoring. With the therapy given
above ECG changes must reverse in 1-3 minutes.

14. Severe hyperkalemia management
 Don’t let ca(cl)2 extravasation as it might cause tissue necrosis
 Effect of calcium chloride or calcium gluconate lasts for 30minutes
so deploy other methods of hyperkalemia management also same
time
 IV bicarbonate usually not given now. But if you give it don’t use
the same cannula. And contact a nephrologist or call nephrology on
call SR.

15. Severe hyperkalemia management
 Shift potassium from blood in to the cell-> 1)Do a capillary blood sugar analysis by
glucometer. 2) give 10U of soluble insulin [Actrapid or human soluble insulin] in 50% of
glucose 50ml over 15 to 30 minutes.
 Shift potassium from blood in to the cell-> or Add 10U of Soluble insulin [Actrapid
or human soluble insulin] 250 of 10% glucose and give to a large vein over 30 minutes.
 Above doses may repeat in 15 to 30 minutes.
 Blood glucose monitoring is essential for 6 hours of administering of insulin and
glucose.
 Don’t use hyperosmolar glucose in DKA situations.
 Shift potassium from blood in to the cell->nebulize 10mg of salbutamol [10ml of
salbutamol solution] effects seen in 15-30 minutes and effect lasts for 4 hours. Be
cautious when using to patients with IHD and open angle glaucoma. 40% of patients
not responding to salbutamol therapy. So don’t use it as a monotherapy.

16. Using sodium bicarbonate
 Routinely not recommended.
 Better to take a nephrologists opinion prior.
 But it can be used without any delay/reluctance to patients having
DKA
 It lowers potassium while increasing the sodium.
 It also cause significant volume overload and cause tetany in
patients with CKD and hypocalcaemia.
 Give 1.4% bicarbonate 500 mL IV over 2 hours

17.  IV furosemide given only if clinically useful situations.
 If all above mention methods fail hemodialysis or hemofiltration
will be the definitive treatment.

18. Management of non severe hyperkalemia
 Reduce potassium intake. Give a low potassium diet.
 Remove potassium from body using cation‐exchange resin examples Calcium
resonium, Kyexalate.
 Each gram of calcium resonium removes 1mmol/L potassium ions from the gut.
 Give calcium resonium orally 30g and continue 15g orally 4 times a day
 Give some lactulose to increase the potassium loss with the calcium resonium. When
you give the resin dissolve it in some water and give.
 If you give calcium resonium rectally it should be remain in rectum for 9 hours. Then
a rectal irrigation should be done to remove it from rectum (to prevent fecal
impaction due to resin)
 Minimally take 2 hours to give effects. So better use some calcium gluconate also.

19.  Monitor serum potassium closely ideally 1hr,2hr,4hr,6hr and 24hrs since identification
of problem
 Monitor blood glucose levels 0min, 15min,30min,60min,90min,120min and then hourly
for 6 hours. Treat hypoglycemia with bolus of 25-30g of glucose.
 Check renal functions twice a day
 Investigate the patient to identify a cause.
 Check vital signs.
 Check urine output
 Record input and output
 Check creatinine phosphokinase

20. Hyperkalemic cardiac arrest.
 This might be the initial presentation. It means you your first encounter is the
patient with cardiac arrest. When recovers always exclude hyperkalemia.
 Some times the cardiac arrest is shockable(VT or VF)
 Sometimes it is non shockable (pulseless electric activity or asystol.
 Patient might be resistant to defibrillation till the correction of hyperkalemia.
 So resuscitation might take much time.
 If resistance to medical treatments consider for dialysis.

21. Hyperkalemic periodic paralysis
 Periodic paralysis is a muscle disease that causes episodic muscle
weakness, in the family of diseases called channelopathies.
 This may be the initial presentation of hyperkalemia. So consider if
someone presents with symptoms of sudden muscle weakness or
paralysis. Do a Serum electrolyte and an ECG.

22. Following slides are taken from
recommendations by NHS UK.
 Following slides are from a recommendation article by NHS UK. (Nottingham
University Hospitals). Regarding hyperkalemia management.
 There are some obvious changes when comparatively with the Sri Lankan
guidelines. But those changes aren’t so significant. Those slides are added to
the lecture because of the comprehensive flow charts to explain the
management steps.
 Just read through. So it will be much easier to understand and memorize.
 Article is freely available in internet.

23. Severe hyperkalemia management

27. Management of non severe hypokalemia
(NHS)

30. Management of hypokalemia
 Hypokalemia is defined as serum potassium <3.5 mmol/l.
 Mild to Moderate Hypokalemia (2.5‐3.5 mmol/l)
 Severe hypokalemia is when serum potassium < 2.5 mmol/l

31. Causes of hypokalemia-drugs
 diuretics (thiazides, loop diuretics)
 laxatives
 Glucocorticoids
 Fludrocortisone other steroids
 Penicillins
 Amphotericin
 aminoglycosides
 Salbutamol
 Theopyline.
 Insulin

32. GI loss of potassium
 diarrhoea,
 Vomiting
 Ileostomy
 intestinal fistula

33. Renal losses:
 renal tubular disorders[CRF, ARF]
 Dialysis
 diabetes insipidus

34. Endocrine disorders:
 hyperaldosteronism (Conn’s syndrome)
 Cushing’s syndrome

35. other
 Decreased dietary intake Anorexia,Bulimia
 Magnesium depletion (associated with increased renal potassium
loss)

36. Medical management
 Assess patient using ABCDE
 Patients on digoxin, heart failure and ischemia are at higher risk.
 Common symptoms are fatigue, weakness, leg cramps, paralytic ileus,
constipation……etc
 Prolonged hypokalemia less than 2,5mmol/L can cause rabhdomyolysis paralysis
and respiratory problems. Can have cardiovascular symptoms like hypotension,
tachycardia, bradycardia and arrhythmias.
 Take a ECG quickly.

37. ECG changes in hypokalemia

38.  Check previous serum electrolytes if available because severity
depends not only on the potassium level but also the duration of
the condition. [is the hypokalemia acute or chronic?]
 Do investigations to identify a cause for the hypokalemia.

39. Investigations to identify a cause.
 Urine potassium,
 Serum Magnesium
 Blood urea, serum creatinine, serum chloride, serum bicarbonate by an ABG, blood
sugar.
 Serum Aldosterone and cortisol.
 24 hour urine for renin, aldosterone and cortisol.
 Do a drug screen
 Imaging studies- pituitary for cushings, adrenal glands(adenoma) assess for renal
artery stenosis.
 17‐beta hydroxylase assay
 Assess thyroid functions.

40. Management of hypokalemia.
 Reduce loss by identifying the underlying cause.
 Increase oral intake of potassium containing food.
 Gradual replacement of potassium is appropriate
 Take oral potassium with plenty of fluids
 If patient can tolerate oral replacements (ex-vomiting) use IV
potassium.
 For iv rehydration use normal saline. Don’t use dextrose.
 Check serum Mg levels. If it is low replace. It will speedup the
recovery from hypokalemia.

41. Mild to moderate hypokalemia.
 First try oral potassium supplements. [KCL to tablets 3-4 times a day]
 Monitor potassium levels daily. Adjust drug dose appropriately
 Try IV potassium if oral route not tolerated or drugs given by NG tubes aren’t
tolerated or effective. Also if there is ECG changes(arrhythmias.)
 IV KCL 10mmol/L every hour.(monitor serum potassium levels regularly)
 if a central access available use 20mm/100ml
 Or in a peripheral large vein concentration not more than 20mmol/500ml
 Its better to use an infusion pump if available.
 Be attentive when you give potassium to patients with renal impairments.
Patients might develop hyperkalemia easily.

42. Severe hypokalemia ,2.5mmol/L or even
less.
 Give IV potassium with close monitoring.
 Give IV KCL in a 40mmol/hour infusion rate.
 Usually a 20mmol/hour is adequate and doses can be repeated with
monitoring of serum potassium levels.
 When giving to a peripheral IV line use lesser concentrations of KCL.
 Peripheral access 40mmol/L
 Central access 20mmol/100ml

43. Formula to assess potassium deficit
Potassium deficit in mEq= {(3.5 ‐ patient's
K) body weight}0.4
 In severe hypokalemia check serum Mg level and replace if it is
low same time.

44. Monitoring of patient while potassium
replacement.
 ECG monitoring if the infusion >10mmol/Hour
 Monitor for IV site extravasation
 Check blood glucose and ABG
When the potassium levels become normal use a regular dose of
potassium and find the cause of the hypokalemia.

45. Hypokalemic periodic paralysis
 Hypokalemic periodic paralysis (hypoKPP) is a rare, autosomal dominant
channelopathy characterized by muscle weakness or paralysis when there is a fall in
potassium levels in the blood.
 This might be the initial presentation. Management always depend on potassium
level. Assess Serum electrolytes and treat.

46. Than Q