Electrolyte Disturbance Flashcards
An 82 year old woman is seen on the Acute Medical Unit with confusion. She has a PMH of Dementia, hypertension and type-2 diabetes. She is a are home resident and the staff report that she is more confused than usual.
She is taking Insulin, Furosemide, Ramipril, Paroxetine and Aripiprazole.
Blood results reveal:
Na+ 117 mmol/L, K+ 2.9 mmol/L, Creatinine 171 μmol/L, Urea 19 mmol/L, Hb 96 g/L.
Which abnormal blood result is most likely to be responsible for her confusion?
1 - Creatinine
2 - Haemoglobin
3 - Sodium
4 - Potassium
5 - Urea
3 - Sodium
Hyponatraemic
An 82 year old woman is seen on the Acute Medical Unit with confusion. She has a PMH of Dementia, hypertension and type-2 diabetes. She is a are home resident and the staff report that she is more confused than usual.
She is taking Insulin, Furosemide, Ramipril, Paroxetine. She has low Na+ and K+ and high creatinine.
Which is the most likely diagnosis?
1 - Acquired renal tubular acidosis
2 - Acute GI bleed
3 - Addison’s disease
4 - Cushing’s disease
5 - SIADH
5 - SIADH
- Acquired renal tubular acidosis = patient would be very acidotic
- Addison’s disease = patient has high K+ due to low aldosterone
- Cushing’s disease = high cortisol, where Na+ is likely to be normal
An 82 year old woman is seen on the Acute Medical Unit with confusion. She has a PMH of Dementia, hypertension and type-2 diabetes. She is a are home resident and the staff report that she is more confused than usual.
She is taking Insulin, Furosemide, Ramipril, Paroxetine. She has low Na+ and K+ and high creatinine, caused by SIADH. Which 2 medications can cause SIADH?
1 - Insulin
2 - Furosemide
3 - Ramipril
4 - Paroxetine
5 - Aripiprazole
4 - Paroxetine
5 - Aripiprazole
Malignancy and Medications are the most common causes of SIADH
Central acting medications can affect ADH release
An 82 year old woman is seen on the Acute Medical Unit with confusion. She has a PMH of Dementia, hypertension and type-2 diabetes. She is a are home resident and the staff report that she is more confused than usual with SIADH causing low Na+ and K+.
She is taking Insulin, Furosemide, Ramipril, Paroxetine.
Which is the most appropriate next management step?
1 - Blood transfusion
2 - Fluid restriction
3 - Intravenous normal saline (0.9%) with 40 mmol KCl
4 - Intravenous hypertonic saline (3%)
5 - Intravenous hydrocortisone
2 - Fluid restriction
Need to concentrate the Na+, but this is hard for patients to adhere to
What is recognised as a safe sodium so that they can be discharged?
1 - 115 - 135
2 - 125 - 130
3 - 135 - 145
4 - 145 - 155
2 - 125 - 130
There must be NO symptoms though
A 40 yr old man with chronic heart failure (EF 25%) is admitted to the hospital with increasing breathlessness. His CXR is shown:
Blood results reveal:
Na+ 118 mmol/L, K+ 5.3 mmol/L, Creatinine 115 μmol/L, Urea 9.8 mmol/L, Bicarbonate 21 mmol/L.
Which is the most likely cause of his hyponatraemia?
1 - Addison’s disease
2 - Dilutional
3 - Over-diuresis
4 - Pseudohyponatraemia
5 - SIADH
2 - Dilutional
Patient has CHF and is thus fluid overloaded and causing hyponatraemia
Hyponatraemia is a very bad prognostic marker in patients with heart failure, indicating severe CHF and a high mortality. Which two are the most appropriate treatments?
1 - Oral fluid restriction
2 - Intravenous Furosemide
3 - Intravenous hypertonic saline (3%)
4 - Oral Fludrocortisone
5 - Oral Demeclocycline
1 - Oral fluid restriction
2 - Intravenous Furosemide
Essentially removes fluid from the body and improve Na+ levels
Demeclocycline = antibiotic, BUT used off labels as a ADH antagonist in the treatment of SIADH
A 72 yr old man with chronic heart failure (EF 25%) is admitted to the hospital with increasing breathlessness and peripheral oedema. He is prescribed furosemide 240 mg daily by iv infusion. Ramipril 10 mg od, dapagliflozin 10 mg od and spironolactone 25 mg od are continued. Blood results after 5 days treatment reveal:
Na+ 118 mmol/L, K+ 2.8 mmol/L, Creatinine 160 μmol/L, Urea 18.8 mmol/L, Bicarbonate 32 mmol/L. Which is the best explanation for his high bicarbonate level?
1 - Contraction alkalosis
2 - Dilutional
3 - Metabolic compensation for lactic acidosis
4 - Metabolic compensation for respiratory acidosis
5 - Spironolactone therapy
1 - Contraction alkalosis
- Body loses a lot of fluid quickly due to anti-diuretics (high dose of furoesmide)
- Fluid lost is high in Na+ and low in HCO3-
May need to treat with some fluids to dilute the HCO3-
Which of the following factors can lead to Pseudohypontraemia?
1 - elevated glucose
2 - elevated triglycerides
3 - elevated urea
4 - all of the above
4 - all of the above
Serum osmolarity = 2x (Na + K) + urea + glucose
Therefore, if other features of formula are high the Na+ is reduced to balance osmolality, BUT Na+ is NOT the problem
If we raise the Na+ levels too quickly what can this cause?
1 - cardiac arrhythmia and sudden death
2 - central pontine myelinolysis
3 - increased intracranial pressure/haemorrhage
4 - cerebellum oedema
2 - central pontine myelinolysis
- also called osmotic demyelination syndrome
A 90-year-old man with a background history of advanced dementia and type-2 diabetes was admitted to hospital after the care home staff noticed a reduced oral intake, delirium and oliguria. Blood results reveal: Na+ 172 mmol/L, K+ 2.6 mmol/L, Creatinine 280 μmol/L, Urea 45.2 mmol/L, Bicarbonate 32 mmol/L.
Which is the most likely case of his hypernatraemia?
1 - Cranial diabetes insipidus
2 - Cushing’s syndrome
3 - Diabetic complications
4 - Insensible water loss
5 - Nephrogenic diabetes insipidus
4 - Insensible water loss
Inability to access water, or forgetting to ask for it.
Most common cause in older patients, especially those with dementia
Which of the following can cause hypernatraemia?
1 - Insensible and sweat water losses
GI water losses
2 - Diabetes Insipidus (both cranial and nephrogenic)
3 - Osmotic Diuresis – eg DKA or HHNK
4 - Hypothalamic lesions which affect thirst function
5 - Tumors, granulomatous diseases or vascular disease
6 - Sodium Overload (Infusion of hypertonic sodium bicarbonate for metabolic acidosis)
7 - all of the above
7 - all of the above
Do hypernatraemia and hyponatraemia present in very different ways?
- No
Present in a similar manner
All of the following are Initial symptoms of hypernatraemia:
- lethargy, weakness and irritability
- twitching, seizures, obtundation or coma
- osmotic decrease in brain volume can lead to rupture of cerebral veins leading to intracranial haemorrhage
- severe symptoms usually occur with a rapid increase to a sodium concentration of 160 mmol/L (or more)
- sodium concentrations >180 mmol/L are associated with high mortality
In the brain if there is hypernatraemia, fluid leaves the brain to dilute the intravascular Na+ concentration
This can cause shrinkage of the brain that can lead to rupture of cerebral brains and cause intracranial haemorrhage
Hypernatraemia = fluid moves out of cells to dilute blood
Hyponatraemia = fluid moves into cells down concentration gradient
In hypernatraemia, which of the following would be true?
1 - high serum osmolality and low urine osmolality and Na+ concentration
2 - high serum and urine osmolality and Na+ concentration
3 - low serum and urine osmolality and high Na+ concentration
4 - high serum and urine osmolality and low Na+ concentration
1 - high serum osmolality and low urine osmolality and Na+ concentration
Are the following features consistent with hypokalaemia or hyperkalaemia?
- Increased P wave amplitude
- PR interval prolongation
- ST segment depression
- T wave flattening and inversion
U waves - Long QT interval (due to fusion of the T and U waves)
- Hypokalaemia
A 79-year-old man with a background of chronic kidney disease stage 4 and long-standing poorly controlled type-2 diabetes presents to the hospital with malaise and palpitation. Blood results reveal: Na+ 136 mmol/L, K+ 7.3 mmol/L, Creatinine 271 μmol/L, Urea 23 mmol/L.
Which is the most important clinical concern with this blood profile?
1 - Cardiac arrhythmias
2 - Cerebral oedema
3 - Constipation
4 - Respiratory muscle weakness
5 - Skeletal muscle weakness
1 - Cardiac arrhythmias
Hyperkalaemia can cause arrhythmias:
- tall and peaked T waves
- QRS widening
- eventually, becomes a sine wave and then asystole
A 56-year-old woman with a background of stroke and dysphasia presents to hospital with generalised body pain. Blood results reveal: Na+ 123 mmol/L, K+ 3.3 mmol/L, Creatinine 88 μmol/L, Calcium 3.2 mmol/L, Phosphate 0.6 mmol/L (0.8-1.5). Her CXR is shown:
Which is the most likely diagnosis?
1 - Myeloma
2 - Squamous cell lung cancer
3 - Primary hyperparathyroidism
4 - Sarcoidosis
5 - Small cell lung cancer
2 - Squamous cell lung cancer
Need to identify if the cause is parathyroid hormone dependent or independent
