Electrolyte Abnormalities Flashcards
What are some causes of hypocalcaemia?
- Vitamin D deficiency
- Hypoparathyroidism (inherited, post parathyroidectomy)
- Hyperphosphataemia (Tumour lysis syndrome, rhabdomyolysis)
- Acute pancreatitis
- Alkalosis
What are the clinical features hypocalcaemia?
SPASMODIC
Spasms,
Peripheral paraesthesia,
Anxiety/irritability
Seizures
Muscle tone increase
Orientation impairment
Dermatitis
Impetigo herpetiformis
Chvostek’s sign
What are the investigations for hypocalcaemia?
- ECG
- Bone profile,
- PTH,
- Magnesium,
- Vitamin D
- Amylase
- X-rays
What is the management of acute hypocalcaemia?
Mild - Oral calcium supplements
Severe - IV calcium gluconate
What are some causes of hypokalaemia
- Renal (if urine K+ is over 20) eg, diuretics, renal tubular acidosis, cushings)
- Extra renal (if urine K+ is under 20) g, poor oral intake, gut losses, insulin or alkalosis
What are the investigations for hypokalaemia?
ECG, UEs, Chloride, bicarb, glucose and urinary potassium and chloride
What is the management for mild hypokalaemia?
Oral slow release potassium chloride, treat the cause and check potassium regularly
What is the management for severe hypokalaemia
- Continuous cardiac monitoring,
- Check and correct magnesium as low magnesium causes renal potassium waiting
- IV infusion of 1L saline and 40mmol of potassium chloride
- Avoid glucose and bicarb
What are the causes of hyponatraemia?
- Hypovolaemic - Burns, sweating, D+V, Addison’s disease.
- Euvolaemic - SIADH or hypothyroidism.
- Hypervolaemic - Renal failure, heart failure, liver failure or nephrotic syndrome
What are the investigations for hyponatraemia
UEs,
Urine and plasma paired osmolalities to show inappropriate sodium conc in urine.
Urine dip
TSH and cortisol to exclude hypothyroidism and Addison’s.
What is the management of hyponatraemia?
Hypovolaemic - IV normal saline and treat underlying cause.
Euvolaemic - For SIADH = Fluid restriction, ADH receptor antagonist and oral sodium + furosemide. Hypothyroid - levothyroxine
Hypervolemia - Fluid restriction and treat underlying cause
What are some causes of hypomagnasaemia
- Reduced gut absorption - PPIs, Alcoholism, Diarrhoea
- Redistribution eg, refeeding syndrome, acute pancreatitis, alcohol withdrawal.
- Increased renal excretion eg, Diuretics, digoxin, gentamicin
What are some complications of hypomagnasaemia?
Weakness,
Paraesthesia,
Seizures,
Coma,
Hypocalcaemia as low Magnesium interferes with PTH release
Ventricular arrhythmias
What are some causes of hypercalcaemia?
Primary hyperparathyroidism - Tumour of parathyroid gland.
Tertiary hyperparathyroidism - Occurs due to sustained secondary hyperparathyroidism resulting in hyperplasia of glands.
Malignancy
What are the investigtions for hypercalcaemia?
ECG
LFTs
UEs
Bone profile
What is the management for hypercalcaemia?
Aggressive IV fluids and Bisphosphonates
What are some causes of hyperkalaemia?
Impaired excretion - AKI. CKD, ACE inhibitors, Spironolactone, NSAIDs, Addison’s disease
Increased release from cells - Lactic acidosis, rhabdomyolysis, beta blockers
What are the ECG changes seen in hyperkalaemia?
Tall tented T waves, flattened P waves, prolonged PR interval
What is the management for hyperkalaemia?
If K+ is between 5.5 and 6.5 then give calcium resonium.
If K+ is >6.5 and/or ECG changes then five calcium gluconate and insulin/dextrose infusion or nebulised salbutamol
What are the symptoms of hypernatraemia?
Lethargy, weakness, confusion, agitation, seziures, coma
What are the causes of hypernatraemia?
- Excess water loss - Diabetes insipidus, diurestics, diarrhoea, vomiting, sweating or burns.
- Excessive hypertonic fluid - IV infusions, total parental nutrition, enteral feeds
- Decreased thirst - old age or acute illness
What is the management of hypernatraeia?
oral or IV fluids
What are some causes of hyperphosphataemia and the management
Causes - CKD (most common), TLS, acidosis.
Management - Phosphate binders
Describe features of hypophosphataemia
Levels below 2.5 however not clinically significant until levels reach below 0.45
