Miscellaneous Flashcards
what 4 things must a patient demonstrate the ability to do, in order to consent a procedure/refuse treatment?
1) understand relevant info 2) retain that info for long enough to make the decision 3) use/weigh that info 4) communicate their decision
what are the key underpinning principles of the mental capacity act?
presume capacity unless proven otherwise. encourage/enable them to make their own decision. have the right to make unwise decisions. proxy choices must consider best interests + what patient would have wanted.
what is valid consent?
1) given by a patient with capacity to make the decision 2) voluntary + free from undue pressure 3) sufficiently informed 4) continuing - patient may change their mind at any time
what must be included when informing a patient about a procedure?
risks and benefits. possible consequences of treatment and non-treatment. explain other options. disclose uncertainty. encourage questions!
amyloid deposition is a feature of which 2 diseases apart from amyloidosis?
Alzheimer’s and diabetes mellitus type 2.
what is happening in AL amyloidosis and what does it cause?
AL is primary clonal proliferation of plasma cells with production of monoclonal Ig - deposition causes nephrotic syndrome, proteinuria, angina, arrhythmias, neuropathies, carpal tunnel syndrome, malabsorption, periorbital purpura and macroglossia.
what is happening in AA amyloidosis and what does it cause?
AA is secondary to chronic inflammatory disorders, such as RhA, IBD and infections (e.g. TB, osteomyelitis) - presents wtih CKD and hepatosplenomegaly.
what is the amyloid in AA produced from?
serum A amyloid - acute phase protein
what features do you get in AL but NOT in AA?
cardiac involvement or macroglossia.
what is familial amyloidosis?
autosomal dominant mutation of a transport protein made in the liver causing sensory/autonomic neuropathy ± renal/cardiac involvement
what investigation would you perform to diagnose amyloidosis? what stain would you use?
biopsy affected tissue, stain with Congo red stain - used polarised light microscopy
how would you treat the different types of amyloidosis?
treat underlying disease in AA to slow progression. AL - myeloma treatment, so melphalan + prednisolone. liver transplant cures familial. prognosis is 1-2yrs.
what is amyloidosis?
group of disorders characterised by extracellular deposits of a protein in an abnormal fibrillar form, resistant to degradation
amyloid tissue deposition
usual pres - unexplained weight loss, fatigue and oedema resistant to diuretics
what is AL amyloidosis associated with?
myeloma, Waldenstroms, lymphoma
give a cause of primary and secondary lymphatic insufficiency
primary - inherited deficiency of lymphatic vessels (Milroy disease) secondary - obstruction by malignancy, filarial infection, post-irradiation therapy.
how do you treat lymphoedema?
compression stockings and physical massage
what is filariasis caused by?
mosquito infection causing lymphatic insufficiency
what does an acute filariasis infection cause?
fever, lymphadenitis, chyluria - elephantitis.
how would you treat filariasis and what complication could occur?
diethlycarbamazine. immune hyperreactivity - cough, wheeze, lung fibrosis
what is lymphoedema?
chronic non-pitting oedema due to lymphatic insufficiency, most commonly affecting legs. can cause cobblestone thickening of the skin.
what is Milroy disease?
autosomal dominant disease causing congenital lymphoedema. lower leg swelling from birth.
give 3 symptoms of opiate poisoning
coma, pinpoint pupils, depressed respiratory rate, convulsions, hypotension, cyanosis and apnoea
how would you treat opiate poisoning and how does the antidote work?
IV naloxone - competitive antagonist causes a rapid blockade, therefore rapid reversal of symptoms - short half life so need repeated doses, causes diarrhoea and cramps
how does paracetamol overdose present?
asymptomatic, then vomiting and RUQ pain and then jaundice/encephalopathy from liver damage
how would you treat a patient presenting with paracetamol overdose, both half an hour after taking it, and 4h later?
1h - activated charcoal 4h - N-acetylcysteine, which replenishes glutathione stores
what is the mechanism of benzodiazepine overdose and therefore what symptoms does it cause?
increases GABA so exerts an excessive inhibitor effect on neurons. symptoms - drowsiness, dizziness, ataxia, coma, respiratory depression.
how do you reverse the symptoms of benzodiazepine overdose?
IV flumazenil - competitive inhibitor of GABA receptor
what changes in the heartbeat can digoxin overdose cause and how do you treat that?
bradycardia, prolonged QRS and PR, AV block. can be corrected with atropine.
how does cyanide cause death with overdose?
binds to iron and inhibits cytochrome oxidase so no ATP produced - reduced aerobic respiration
if a patient has inhaled cyanide, how long will they survive?
death within minutes
if a patient ingests cyanide, what are the stages of overdose?
1st phase - anxiety and confusion. 2nd phase - pulse changes 3rd phase - fits and shock and coma
how do you treat cyanide overdose?
100% oxygen, GI decontamination. if GCS decreasing - IV dicobalt EDTA or sodium nitrite with sodium thiosulphate.
what are 5 clinical features of organophosphate overdose?
SLUDGEM - salivation, lacrimation, urination, defecation, GI motility, emesis (vomiting), miosis (pupil constriction)
how does the treatment for organophosphate overdose work?
atropine blocks ACh receptors. pralidoxime regenerates acetylcholinesterase.
how does carbon monoxide cause problems?
combines with haemoglobin to reduce oxygen carrying capacity of blood, can inhibit cytochrome oxidase
what are 3 symptoms of CO poisoning?
headache, mild exertional drowsiness, vomiting, stomach pains, anorexia, fits, coma, chest pain, metabolic acidosis
how do you treat CO poisioning?
100% oxygen. hyperbaric chamber.
give 4 reasons why you might suspect a soft tissue sarcoma in a patient with a swelling
presents = >5cm diameter, enlarging, painful, deep to fascia, solid mass (not cystic), recurrence at site of previous excision
some sarcomas are associated w/ specific gene mutations (esp. translocations - karyotype) e.g. synovial sarcoma and myxoid sarcoma
how would you investigate a sarcoma?
MR scan of primary, incisional biopsy, CXR, CT scan of thorax
name 3 familial sarcoma syndromes
neurofibromatosis-1/-2, retinoblastoma, Gardner’s syndrome, Werner’s syndrome, Gorlin’s syndrome
how would you treat a sarcoma?
primary - wide excisional surgery, adjuvant radiotherapy. metastatic - palliative surgery, radiotherapy or chemo.
what are the commonest primary bone tumours/sarcomas in adolescence/early adulthood?
osteosarcoma and Ewing’s sarcoma
what sarcomas are secondary to radiation damage?
chondrosarcomas and osteosarcomas
when would you suspect bone sarcoma?
night pain, non-mechanical and swelling not associated with the joint
how would you treat organophosphate overdose?
wear gloves, remove soiled clothes, wash patient. atropine + pralidoxime
what is sarcoma? what are the different types?
cancer of connective tissue - all look the same down the microscope.
present as soft-tissue swelling +/- pain (DDx - lymphoma, lipoma, neuroma)
- liposarcoma = good prog.
- leiomyosarcoma - causes dysunctional urterine bleeding
- fibrosarcoma
- GIST - upper/lower GI bleed, acute abdo
- synovial sarcoma
- Kaposi’s sarcoma - aids related, HHV8
very rare!!
what is sarcoidosis?
chronic granulomatous disorder characterised by accumulation of lymphocytes and macrophages in lung and other organs (can be any but usually - lungs, skin, eyes, lymph nodes)
characterised by non-caseating granulmoas with multinucleated giant cells. CD4 throughout the granulomas, CD8 in cluster at peripherary.
how is sarcoidosis classified?
- Systemic
- Pulmonary - 90% have lungs affected
- Cutaneous e.g. plaques, lupus pernio
- Ocular - anterior uveitis
- cardiac - heart block
- neurosarcoidosis - headaches, seizures
RFs = 20-40yo, FHx, non-smoker
how is pulmonary sarcoidosis staged?
- bilateral hilar lymphadenopathy
- BHL + pulmonary infiltrates
- pulmonary infiltrates only
- extensive fibrosis
how might sarcoidosis present?
- Lung symptoms - Cough (non-prod), dyspnoea, wheezing, rhonchi (airway hyperreactivity),
- LNs - Lymphadenopathy: enlarged and non-tender, cervical and submandibular
- Eye symptoms - Photophobia, red painful eye and blurred vision suggestive of uveitis, + conjunctival nodules
- Skin symptoms - Erythema nodosum, lupus pernio
- Joint symptoms - Arthralgia and chronic fatigue
what might investigations show for sarcoidosis?
- CXR - bilateral hilar lymphadenopathy, bilateral upper zone infiltrates, pleural effusions, egg-shell calcifications
- LuFT - restrictive, obstructive or mixed
- ECG - conduction defect
- FBC - bone marrow involvement - anaemia (20%), leukopenia (40%)
- Urea and creatanine - renal involvement
- Liver enzymes - liver involvement
- Serum calcium - disregulated production of calcitriol by activated MP and granulomas leads to hypercalcaemia
- Skin biopsy - non caseating granulomas
briefly outline management of sarcoidosis
1) Lung disease
a. Oral or inhaled corticosteroid (stage 1) - prednisolone, budesonide
b. (stage 2, 3, 4) + Cytotoxics - methotrexate (PO once per week)/azathioprine ±O2
c. Lung transplant
2) Cutaneous
a. Rash/papules -> topical corticosteroid ± oral corticosteroid
b. Lupus pernio -> oral corticosteroid ± cytotoxics
3) Ocular (anterior uveitis -> topical corticosteroid (prednisolone opthalmic)
4) CNS, peripheral nervous, CV -> oral corticosteroid
5) Acute resp failure -> IV/oral corticosteroid + vent support + O2
