Data Interpretation Flashcards
Why do panic attacks cause paraesthesias
Panic attacks cause numbness because the alkalosis from the hyperventilation drives calcium binding to albumin in the blood. Hypocalcaemia ensues and leads to parasthesiaes.
What is respiratory acidosis also known as
T2RF
What is T2RF also known as
Respiratory acidosis
What can cause metabolic alkalosis (2)
Vomiting (loss of hydrochloric acid leads to effective loss of hydrogen ions)
Bicarbonate drugs mop up hydrogen ions leading to an effective decrease in H+ concentration and alkalosis
Normal anion gap causes of metabolic acidosis (2)
Loss of bicarbonate in diarrhoeal illnesses
Renal tubular acidosis
Causes of a wide anion gap metabolic acidosis
KULT Ketones Uraemia Lactate Toxins (paracetamol, aspirin, ethylene glycol (anti-freeze) and isoniazid)
Which toxins can cause a wide- anion gap metabolic acidosis (4)
paracetamol, aspirin, ethylene glycol (anti-freeze) and isoniazid
Triggers for ADH release (2)
Reduced blood volume sensed via baroreceptors at the Carotid sinus
Decreased sodium concentration sensed via chemoreceptors at the hypothalamus
Does aldosterone affect Na concentration and why
Aldosterone does not change [Na]+ as water will follow when it is absorbed
What does ANP and BNP do and how
prevents the overloading of the heart due to excess water retention. It decreases water retention by promoting sodium loss at the kidney. It does this by increasing the kidney’s GFR and also by switching off the RAAS.
Causes of hypovolaemic hyponatraemia (7)
Vomiting Diarrhoea (particularly cholera) Diuretics Addisons Renal failure Cutaneous loss Third space loss (pancreatitis, small bowel obstruction)
Causes of euvolaemic hyponatraemia (3)
SIADH
Hypothyroidism
Psychogenic/iatrogenic DI
Causes of SIADH (5)
Surgery
Lung pathology (pneumonia)
Tumours (small cell lung carcinoma)
Drugs (SSRIs, TCAs, opiates, PPIs, carbamazepine)
CNS pathology (meningitis, encephalitis, SAH)
Which drugs can cause hyponatraemia (5)
SSRIs, TCAs, opiates, PPIs, carbamazepine
How come SIADH does not cause hypervolaemia
Due to the RAAS being activated so salt is reabsorbed with water (so we are still hyponatraemic) and BNP and ANP
How does hypothyroidism cause euvolaemic hyponatraemia
Hypothyroidism causes reduced CO, so ADH is released and RAAS tries to raise your fluid volume.
How does adrenal insufficiency cause hypovalaemic hyponatraemia
Natriuresis and water loss from lack of sodium reabsorption through aldosterone insufficiency
Causes of hypervolaemic hyponatraemia
‘Failures’
Heart failure
Liver failure
+ Nephrotic syndrome
How does liver failure cause hypervolaemic hypernatraemia
Causes release of NOS which vasodilates systemically causing pooling of blood.
Also hypoalbuminaemia occurs in cirrhosis which disrupts the oncotic pressure of the blood and promotes leaking
How does nephrotic syndrome cause hypervolaemic hyponatraemia
Causes hypoalbuminaemia which disrupts oncotic pressure of blood causing leaking into third space
What effect does nephrogenic/central DI have on blood sodium?
Hypernatraemia
What does an isolated raised bilirubin suggest
Haemolytic anaemia, Gilbert’s
What does AST > 2x ALT suggest
Alcoholic Liver Disease
What does ALP & GGT raised suggest
Biliary pathology
What does ALT & AST in 1000s suggest
Hepatitis: toxic, ischaemic, viral
What does α-fetoprotein (AFP) raised suggest
Hepatocellular carcinoma
What does hypoalbuminaemia suggest
Liver failure,
Nephrotic syndrome
What LFT pattern suggests:
Haemolytic anaemia
Isolated raised Bilirubin
What LFT pattern suggests: Gilbert’s
Isolated raised Bilirubin
What LFT pattern suggests:
Alcoholic Liver Disease
AST > 2x ALT
What LFT pattern suggests:
Biliary pathology
ALP & GGT raised
What LFT pattern suggests:
Hepatocellular carcinoma
α-fetoprotein (AFP) raised
What LFT pattern suggests:
Liver failure
Hypoalbuminaemia
What LFT pattern suggests:
Nephrotic syndrome
Hypoalbuminaemia
What LFT pattern suggests:
Hepatitis: toxic, ischaemic, viral
ALT & AST in 1000s
How do we measure synthetic liver function
Clotting factors (prolonged PT) Also albumin but its half life is 20 days so not useful in acute medicine
