Electrolytes Flashcards
What is the normal amount of urea and what is it, where is it formed, caused of it being raised
- Waste produce of protein breakdown
- Produced by liver, excreted by kidneys
- 2.5-7.8 mmol/L
- CAUSE: renal dysfunction, dehydration, upper GI bleeding
Normal amount of sodium, what is it regulated by, what do abnormal levels reflect
- 135-145 mmol/L
- Regulated by: ADH (hypothalamus) and aldosterone (RAAS)
- Abnormal levels reflect water loss/imbalance
What do sodium levels indirectly effect
- Low Na levels are associated with hypotension (excess water lost from circulating volume)
- Conversely a large intake of salt from the diet can cause hypertension (excess what retained in circulating volume)
Define hypotension and hypertension
Hypotension - low bp caused by dehydration, low Na+, heart problems
Hypertension - high bp high salt, obesity, stress, genetics
Describe the Renin-angiotensin-aldosterone system
Causes, symptoms and treatment of hypernatraemia
- Main cause: dehydration
- Symptoms - fever, tachycardia (high heart rate, hypertension, dizziness, increased thirst
- TREATMENT: Replace fluid but not rapidly, if sever IV administration usually glucose
Drugs that cause hyponatraemia
- Diuretics
- PPI
- Antidepressants
- ACEi e.g. ramipril
Symptoms and treatment of hyponatraemia
- SYM: headache, confusion, vomiting, cramps, circulatory failure
- TREATMENT: Stop/switch causative drug, IV NaCl
- CAUSE: Drugs
Amount of normal K+, what is it for
- Extracellular < intracellular
- 3.5-5mmol/l
- Maintains cardiac muscle contractility
- Maintains fluid balance, nerve impulse, muscle function
Hyperkalaemia causes, symptoms and treatment
- K > 4.5
- CAUSE; Renal failure, Redistribution of intra and extracellular fluids, metabolic acidosis
- SYM: Arrhythmia, muscle weakness, tachycardia, asystole
- TM: Stop causative durg, protect heart IV Ca, Gluc IV to move k+ into the cell
Causes, symptoms, treatment of hypokalaemia
< 3.5mmol/L
Which drugs cause hyperkalaemia and cause hypokalaemia
Normal Ca amount and why its important
- 2.2 - 2.6 mmol/L
- Approx 40-50% of Ca is bound to albumin
- Levels effected by high or low albumin
- For bones, teeth hormones e.g. vutamin D metabolites
- Only free Ca is active
Hypercalcaemia cause, symptoms and treatment
- Ca > 3 mmolL
- CAUSE: Primary hyperparathyroidism (~50% cases) - excessive secretion of PTH, stimulating Ca uptake in the kidneys and intestines, as well as promoting bone reabsorption to release bound calcium
- Malignancy (20-30% of cases) - usually in advanced cancer
Can occur without skeletal metastases due to excessive secretion of PTH
Can occur with skeletal metastases which causes bone lysis and release of skeletal calcium
Hypocalcaemia cause, symptoms, treatment
- CAUSE: Hypoparathyroidism, low vitamin D, pharmacological chemo drugs, low Mg leves
Hyperphosphataemia causes, sym, treatment
Hypophosphataemia causes, symp, treatment
- Inadequate intake (malnourished patients, alcoholism, refeeding syndrome)
- Reduced absorption
- Drugse.g. phosphate binders, acetazolamide
bowel problems e.g. chronic diarrhoea, - Excessive loss (diuresis, dialysis)
- Redistribution (drugs, respiratory alkalosis)
Hypermagnesemia causes, sym , t
Hypomagnesemia causes, sym , t
