Interactive cases in general internal medicine 3 part 2 Flashcards
When would you give IM vs IV adrenaline
IM- anaphylaxis
IV- cardiac arrest
Q fever is caused by what pathogen
Coxiella burnetii
What antibiotic is used in addition to amoxicillin if you suspect an atypical pneumonia
Macrolide e.g. clarithyromycin or erythromycin
What is the most common electrolyte disturbance in pneumonia
Hyponatraemia
Atypica organisms causing pneumonia.
What proportion of CAPs are they implicated in?
- Mycoplasma pneumoniae
- Chlamydia pneumoniae
- Legionella pneumophila
Implicated in up to 40% of CAP
What is dyspepsia vs indigestion
Oxford handbook:
It is defined as one or more of:
- Postprandial fullness
- Early satiety
- Epigastric or retrosternal pain or burning
Indigestion can refer to dyspepsia, bloating, nausea and vomiting.
Try to find out exactly what patient means!
When would symptoms of peptic ulcer disease typically occur
2-5hrs after a meal and on an empty stomach
What test for
- 50 yr old man
- Dyspepsia
- Wt loss
- Hb: 70
- MCV: 70
ODG
What is a haematinic
A hematinic is a nutrient required for the formation of blood cells in the process of hematopoiesis.[1] The main hematinics are iron, B12, and folate
Investigations for microcytic anaemia
Haematinics
Coeliac screen
Remember red flags
Top and tail
Order depends on upper/lower GI symptoms
What does a coeliac screen comprise
TTG Ab
But diagnosis confirmed on duodenal biopsy with villous atrophy
70 year old man
• Bloody diarrhoea
• Stool micro & culture: -ve
• Stool C. diff toxin: -ve
Likely diagnosis?
Ischaemic colitis is a likely cause of bloody diarroeah
What is the sign if there are periumbiliac veins with blood flow TOWARDS THE LEGS
Caput medusae
What occurs in portal HTN
- Encephalopathy
- Ascites
- Spontaneous bacterial peritonitis
- Variceal bleed
Cause of microangiopathic haemolytic anaemia
Disseminatied intravascular coagulopathy (e.g. due to infection)
Haemolytic uraemic syndrome (e.g. due to infection)
Thrombotic thrombocytopenic purpura (an AI cause)
Physical trauma (e.g. mechanical heart valves)
What are the findings in DIC
DIC can cause MAHA
Low platelets and fibrinogen (used to make clots)
Increased PT and APTT
Increased d-dimer/FDGs
What are the findings in haemolytic uraemic syndrome
How is this related to thrombotic thrombocytopenic purpura
HUS can causes MAHA. HUS is most often caused by E. Coli O157 bacteria (GI infection) , but also shigella.
Causes:
Haemolysis (reduced Hb and increased bilirubin)
Uraemia
Reduced platelets (because it causes lots of little clots in the kidney vasculature, as well as haemolytic anaemia)
TTP is an autoimmune cause
It results in the findings of HUS + fever + neurological manifestations
Causes of haemolytic anaemia
Hereditary:
Enzyme deficiency (G6PD deficiency)
Red cell membrane (hereditary spherocytosis)
Haemoglobinopathy (sickle cell, thalassaemia)
Acquired:
- AI
- Drugs
- Infection
- MAHA
Where do you find Valvulae conniventes and haustra.
How can you tell the difference
Valvulae conniventes in small intestine- they are lines that go all the way across the small bowel wall
Haustra are the pockets of large bowel but they don’t go across the whole bowel wall
Classifications of hyponatraemia
Hypervolaemic
- Heart failure
- Nephrotic syndrome
- Liver cirrhosis
Euvolaemic
- Hypothyroidism
- Adrenal insufficiency
- SIADH
Hypovolaemic
- Diarrhoea
- Vomiting
- Diuretics
What happens to the sodium in the urine if there is hypovolaemia
When can you not use the urine sodium
There will be low sodium in the urine because the kidneys will hang on to it because they’re good at detecting hypovolaemia
BUT you can’t measure if they’re on diuretics (which would well be the cause of their hypovolaemic hypontraemia!)
What investigations would you do for euvolaemic hyponatraemia
TFTs
Short synacthen test (if there is adrenal insufficiency, cortisol won’t rise when you give ACTH)
Plasma and urine osmolality
In hypovolaemic hyponatraemia, the urine sodium should be low (it will be being reabsorbed to increase BP), unless there’s diuretic. In euvolaemic, the urine sodium will be high (if it’s SIADH, then water not sodium is reabsorbed. If it’s adrenal insufficiency, then Na+ will end up in the urine too)
What will the investigations show in hypervolaemic hyponatraemia
Fluid overloaded
Low urine sodium
What will the urine sodium be in those with hypovolaemic, euvolaemic and hypervolaemic hyponatraemia?
hypovolaemic and hypervolaemic will have low urine sodium
euvolaemic will have high
Most causes of hyponatraemia are caused by what
Rarer causes?
Increased ADH
Rarer causes:
XS fluid intake
Sodium free irrigation solutions e.g. used in TURP
Why is SIADH euvolaemic?
With SIADH you get too much ADH secretion.
You’d think that, because this causes you to take up more water from the collecting ducts, you’d end up fluid overloaded
But this is not the case because the heart walls are stretched when ADH increases, and this leads to release of ANP, which allows you to excrete Na+ in the kidneys and you stay euvolaemia
What would investigations show for SIADH
You would have a high urine osmolality
But you would have a low plasma osmolality and a low serum sodium because of dilution
What are the causes of SIADH?
CNS: SAH, stroke, tumour, TBI
Pulmonary: pneumonia and bronchiectasis
Malignancy: lung (small cell)
Drug related
Idiopathic
Which drugs can cause SIADH
Carbamazepine and SSRIs, opiates and PPIs
What are the symptoms of SIADH
Can be asymptomatic
If Na<120mM, generalised weakness, poor mental function and nausea
If Na+<110mM confusion leading to coma and eventually death
SIADH treatment
Appropriate treatment for the cause
To reduce immediate concern of hyponatraemia:
1. Immediate fluid restriction
- Longer term: use drugs which prevent vasopressin actions in the kidneys (demeclocyline). This induces nephrogenic DI to reduce renal water reabsorption
Compare aqauresis vs diuresis
Diuresis involves exrectoion of sodium and water which is what diuretics do
Aquaresis is when you just get rid of water and not sodium. That’s what vaptans do as they are V2 receptor antagonists so block the effect of vasopression on the kidneys
What are the causes of onycholysis
Nail moving away from nail bed.
Trauma
Psoriasis
Thyrotoxicosis
Fungal infection
What are the causes of these nail signs:
Beau’s line
Nail pitting
Koilonychia
Onycholysis
Leukonychia
Beau’s line- chemotherapy
Nail pitting- psoriasis
Koilonychia- Fe deficiency
Onycholysis- see abvoe
Leukonychia- Albumin deficiency
Which cells make ALP
Osteoblasts
T/F ALP is normal in multiple myeloma
T. Plasma cells suppress osteoblasts so ALP doesn’t rise.
This can be used to distinguish multiple myeloma from boney mets as a cause of hypercalcaemia with a low PTH
What are the causes of cavitatinng lung lesion
- Infection- Staph, klebsiella (alcoholics), TB
- Inflammation (RA)
- Malignancy (squamous cell carcinoma of the lung)
- Infarction e.g. due to PE
What is the inheritence of hereditary haemorhagic telangiectasia
AD
Where are the abnormal blood vessels
Skin, mucous membranes, lung, liver brain
What other hormone would you expect to change in primary hypothyroidism
You can expect prolactin to go up slightly.
Because TRH will increas in primary hypothyroidism, and TRH also stimulates prolactin release
