Passmed Flashcards
Calculate breakthrough dose of morphine
1/6 of total daily dose.
Prescribe with laxative, potentially anti-emitic. Oral modified-release morphine is preferential to transdermal.
Difference b.w RAST and skin prick test
Skin prick test also tests for irritants. Useful for contact dermatitis.
Causes of hypercalcaemia
Primary hyperparathyroidism and malignancy are most common.
Sarcoidosis, thiazides.
How does achalasia present?
Dysphagia of solids and liquids from start + heartburn.
Regurg of food can = cough, aspiration pneumonia
RF for oesophageal candidiasis causing dysphagia
HIV
Steroid use
Tx with systemic AB
How does myasthenia gravis dysphagia present?
Solids and liquids,
Ptosis or extra-ocular muscle weakness.
How does oesophagitis present?
Odynophagia, possibly heartburn. No weight loss.
How does oesophageal cancer present?
Dysphagia + weight loss, possible vomiting during eating.
PMH: Barrett’s, GORD, smoker/drinker
Investigations for dysphagia
Upper GI endoscopy.
Fluoroscopic swallow studies for motility disorders.
Manometry for achalasia.
How is aplastic anaemia defined?
Bone marrow failure = pancytopenia
Normocytic anaemia + leukopenia + thrombocytopenia.
How does aplastic anaemia present? Causative drug?
May have bleeding.
Phenytoin
Drugs causing Parkinsonism
Anti-psychotics, metoclopramide
How do you differentiate tremor in idiopathic vs drug-induced Parkinsonism?
Idiopathic = unilateral resting tremor, older patient.
Drug-induced = symmetrical tremor, possibly hx of schizophrenia.
What do tear drop cells on a blood film indicate?
Thalassaemia, myelofibrosis or megaloblastic anaemia.
What is myelofibrosis and how may it present?
Blood cancer affecting bone marrow.
Old patient with anaemia, weight loss/night sweats (from hypermetabolism), early satiety (massive splenomegaly).
Mx of secondary pneumothorax
Over 2cm/sob- chest drain, otherwise aspirate if 1-2cm.
If under 1cm, admit with 02.
Mx of primary pneumothorax
Over 2cm = Chest drain.
Under 2cm, either discharge or aspirate if sob.
What is haematocrit?
Ratio of volume of rbc to the volume of blood
Status epilepticus mx
ABC
IV lorazepam, repeat after 10-20mins
If status is ongoing, start second line agent (phenytoin, phenobarbital).
If refractory, general anaesthetic.
Differentiating polycythaemia
A true polycythaemia can be primary (myeloproliferative disorder), or secondary (reactive to abnormal EPO or O2). Hypercoaguable state.
A relative polycythaemia is from dehydration/diuretics.
Acute interstitial nephritis: cause, presentation, mx
Usually drugs- AB.
Fever, rash, joint pain. Deranged Us and Es.
Most cases resolve when AB is stopped.
Recommended weekly alcohol intake
Max 14 units (men and women).
Pregnant women shouldn’t drink.
How much is one unit of alcohol?
10ml ethanol
strength x volume / 1000
How does neuroleptic syndrome present and in whom?
Pyrexia, muscle rigidity (raised CK and potential AKI), delirium, autonomic lability (tachy, hypertension)
Patients taking antipsychotics, or stopping levodopa suddenly
Mx of neuroleptic syndrome
Stop anti-psychotic
IV fluids to prevent renal failure.
MOA for furosemide and bumetanide
Block NaKCl co-transporter on ascending loop, so less is reabsorbed
SE: hyponat, k, magnesaemia
What does the facial nerve supply? (FETT)
Facial expression muscles
Ear- nerve to stapedius
Taste- anterior 2/3 of tongue
Tear- parasympathetic fibres to lacrimal glands and salivary glands
Differentiate UMN and LMN lesions
UMN lesion spares the forehead, LMN affects all facial muscles.
UMN = contralateral
LMN = ipsilateral
Causes of LMN lesion of facial nerve
Ramsay-hunt syndrome (due to Herpes Zoster)
Bell’s palsy
MS
Acoustic neuroma
Cause of UMN lesion of facial nerve
Stroke
What does APTT measure?
Intrinsic pathway (APTT- factor VIII, for which VWF is a carrier molecule)
vs
Extrinsic (PT- factor VII)
Who and how does haemolytic uraemic syndrome present?
Young children with a triad of:
AKI
Haemolytic anaemia
Thrombocytopenia
Cause of HUS
Most commonly due to E.coli producing shiga toxin. Causes diarrhoea that becomes bloody 1-3 days into onset.
Inv for HUS
FBC including film, Us and Es, stool culture
Mx of HUS
Supportive: fluids, dialysis, transfusion if required. AB little role.
