Electrolyte imbalance Flashcards
(44 cards)
What is considered mild hypokalaemia
3.1 - 3.5mmol/l
What is considered moderate hypokalaemia
2.5-3.0 mmol/l
What is considered Severe hypokalaemia
<2.5mmol/l
What are the causes of hypokalaemia
- Profuse diarrhoea
- High stoma/fistula output/excess vomting
- Diuretics
- burns
- metabolic alkalosis
- hyperaldosteronism - Conns
- Renal tubular acidosis
- drug induced tubual damage
- excess liquorice
what ECG changes can be seen in hypokalaemia
- flat, broad T waves
- ST depressoin
- Long QT interval
- Ventricular dysrhythmias
- U waves
What is the management of mild hypokalaemia
- Compare with previous results
- Repeat Cr, HCO3 and sodium
- Ambulatory replacement when indicated
What is the management of moderate hypokalaemia
- Compare with previous, repeat if inconsistent
- Assess risk
- ECG
- Ask for advice if symptoms/high risk
- Ambulatory replacement
What is the management of severe hypokalaemia
- Admit, discuss with med team
- Repeat urgently if inconsistent
- ECG
- Oral/IV potassium dose 20 - 40mmol 2-4x a day
- NEVER bolus KCL - fatal arrythmias
What are the cardiac complications of hypokalaemia
- arrhythmia
- ## Sudden death
What are the renal complications of hypokalaemia
- Increase chloride excretion
- Increased bicarb absorption - metabolic alkalosis
- Nephrogenic diabetes insipidus
Other complications of hypokalaemia
- iatrogenic hyperkalaemia
- Hepatic
- mm weakness rhabdomyolysis
What are the symptoms of severe hypokalaemia
- Severe muscle weakness
- respiratory failure
- ileus
- parasthesia
- tetany
What are the symptoms of moderate hypokalaemia
- constipation
- muscle weakness and pain
- lassitude
What Drugs cause hyperkalaemia
- sprionalactone
- amiloride
- heparin
- NSAIDs
- ARBs/ ACEi
- NSAIDs
- Ciclosporin
What causes an increase in potassium circulation
- supplementation
- tumour lysis syndrome
- burns
- trauma
- rhabdomialaysis
What are the mechanisms of hyperkalaemia
- Intracellular to extracellular shift
- Renal
- drugs
- Increase in potassium in circulation
- pseudohyperkalaemia
- endocrine - Addisons
What causes pseudohyperkalaemia
- Prolonged tourniquet
- Haemolysis of blood in sample in transit
What causes an intracellular to extracellular shift in potassium
- Drugs: suxamethonim, beta blocker, digoxin toxicirt, theophylline
- DKA
What are the renal causes of hyperkalaemia
- Hyperkalaemia renal tubular acidosis
- mineralocorticoid deficiency
- AKI/CKD
What are the ECG changes in hyperkalaemia
- Loss of P waves
- Broad QRS complex
- Tall tented T waves
- Sine waves
- Cardiac arrest rhythms
What are signs of hyperkalaemia
- fatigue
- muscle weakness - paralysis
- Decreased/absent reflexes
- palpiations
- chest pain
- SOB
What is the management of hyperkalaemia
- ABCDE - confirm with ABG
- ECG - changes means URGENT
- Hx what is causing/stop offending drugs
- Calcium gluconate
- insulin + glucose (salbuatmol nebs)
- recheck potassium in 30 mins
What dose and when do you give calcium gluconate
- ONLY if ECG changes
- 10% over 10-30 mins
- Only a transient effect 30-60 mins
How do you shift potassium into the cells
- Insulin + glucose
- 10 units insulin (named) +25g of glucose (10 units in 250ml 10% glucose)
- salbutamol nebs
