21/10/2024 Flashcards
Which drugs can reduce the seizure threshold?
Beta lactam antibiotics
Isoniazid
Antimalarials
Opioids and NSAIDs
Antipsychotics
Antidepressants
Bupropion
Anaesthetics e.g. lidocaine
causes of optic disc pallor
Optic neuritis
Ischaemic optic neuropathy e.g. giant cell arthritis
Glaucoma
Direct trauma to optic nerve
Congenital e.g. lebers hereditary optic neuropathy
Tumours compressing on optic nerve prolonged papilloedema
Syphilis or Lyme can damage the optic nerve
Some deficiencies e.g. B12
What are the ECG signs of right ventricular strain?
Sinus tachycardia is most common
ST depression and T wave inversion in V1-3 and inferior leads
RAD
Dominant R wave in V1 and dominant S wave in V5/6
What causes. Slow rising pulse and why?
Aortic stensois
Obstruction to blood flow from the narrowed aortic valve means a low volume pulse with a delay in ejection of the blood
Whats the most effective treatment for infertility in PCOS?
Clomifene
MOA of clomifene?
A SERM - binds to esotrogen receptors in hypothalamus, blocking the normal negative feedback effect = secretion of GnRH is increased = Stimulates release of FSh and LH which leads to development and maturation of ovarian follicle, ovulation and subsequent development and function of corpus luteum
How do we diagnose cholecystitis?
US is first line
If unclear then a cholescintigraphy scan may be used
Management of cholecystitis?
IV antibiotics
Early lap cholecystectomy within 1 week
If you’re an adult with U/L glue ear, what might be done?
Referral to ENT for ?posterior nasal space tumour as it should be suspected to be this until proven otherwise
What are the rules with smoking and hormonal contraception?
All methods of combined hormonal contraception are contraindicated if >=35 and smoking >=15 a day
What drugs can cause urinary retention?
TCAs
Anticholinergics e.g. antipsychotics & antihistamines
Opioids
NSAIDs
Disopyramide
Results of a radioactive iodine uptake in de quervains thyroiditis?
Will be globally reduced uptake of iodine as the cells are damaged!
What are the 4 phases of de quervains thyroiditis?
phase 1 (lasts 3-6 weeks): hyperthyroidism, painful goitre, raised ESR
phase 2 (1-3 weeks): euthyroid
phase 3 (weeks - months): hypothyroidism
phase 4: thyroid structure and function goes back to normal
What is pyrexia of unknown origin?
Febrile illness of temps >38.3 on several occasions over at least 3 weeks, with no established diagnosis after 1 week of inpatient investigations
Can be classical PUO or… hospital-acquired PUO, neutropenia PUO or HIV-associated PUO
Causes of pyrexia of unknown origin?
Miscellaneous - drug fevers or factitious fever
Infections e.g. TB or abscess
Malignancy e.g. lymphoma, atrial myxoma or leukaemia
Non-infectious inflammation e.g. SLE, temporal arthritis, RA
What is the main caution for using Cyclizine?
Severe HF as can cause a drop in cardiac output and associated increase in HR
What vessel is occluded in buttock claudication?
Internal iliac artery or its branches
What is leriche syndrome?
Severe atherosclerosis affecting distal abdominal aorta, iliac arteries and femoropopliteal vessels = blood flow to pelvic viscera is compromised
Causes a triad of claudication, impotence and absence of femoral pulses
What causes myelofibrosis?
A myeloproliferative disorder thought to be caused by hyperplasia of abnormal megakaryocytes
bone marrow fibrosis = cytokines released and 1 particular cytokine is fibroblasts growth factor = anaemia, leukopenia and thrombocytopenia. Now bone marrow is repelaced by scar tissue extramedullary haemtopoesis occurs and blood cells are produced in liver and spleen = hepatosplenomegaly
Features of myelofibrosis?
Anaemia Sx e.g. Fatigue, SOB
Massive splenomegaly which may cause abdominal pain
Ascites, varices if portal hypertension
Bleeding and peetechaia if low platelets
Weight loss, night sweats
Blood film findings in myelofibrosis?
Tear drop poikilocytes
Dry tap on bone marrow biopsy so a trephine biopsy is needed
What are the stages of syphilis?
Primary - chancre, non-tender lymphadenopathy
Secondary - 6-10 weeks later systemic Sx, rash, condylomata lata
Tertiary - years or decades later… gummas, aortic aneurysms, general paralysis of the insane, tabes dorsalis, ARP
What are condylomata lata?
painless, warty lesions on the genitalia associated with secondary syphilis
What is hemiballismus?
A rare hyperkinetic movement disorder
Pronounced involuntary extreme limb movements on 1 side of the body
What part of the brain is afefcted to cause hemiballism?
Subthalamic nucleus of the basal ganglia
What part of the brain is afefcted in Huntington chorea?
Striatum of the basal ganglia
Most common type of ovarian cyst?
Follicular cysts
Cause of follicular cysts?
Non-rupture of the dominant follicle or failure of atresia in a non-dominant follicle
Commonly regresses after several menstrual cycles
How does an ovarian torsion present?
Usually sudden onset unilateral lower abdominal pain. Onset may coincide with exercise.
Nausea and vomiting are common
Unilateral, tender adnexal mass on examination
How might an ovarian cyst present?
Often asymptomatic
Unilateral dull ache which may be intermittent or only occur during intercourse.
Occasionally they can cause bloating, fullness in abdomen
Which tumour markers should you test for is suspecting a germ cell tumour?
LDH
AFP
HCG
CA125
Which type of ovarian cyst is torsion most likely with?
Dermoid cysts
What is the most common benign ovarian tumour in a woman under the age of 30?
Dermoid cyst
How should you manage all complex ovarian cysts e.g. if its multi-loculated?
Biopsy them to exclude mlaignancy
why can raised icp cause an abducens nerve palsy?
The abducens nerve is long and has a vulnerable intracranial path so when ICP rises and the brainstem herniates it’s susceptible to being compressed or stretched
why can raised icp cause an Occulomotor nerve palsy?
It’s often affected by uncal or even central herniation = compression of CN3
How do you calculate intracranial pressure?
Mean arterial pressure - cerebral perfusion pressure = ICP
Basically - to maintain adequate cerebral blood flow, CPP must be high enough to overcome ICP. If ICP increases but MAP stays constant, CPP will decrease which can lead to ischaemia!
What are the “young” stroke blood tests?
thrombophilia and autoimmune screening- performed in those under 55 with no obvious cause of a stroke
What is the ROSIER scale?
Recognition of Stroke in the Emergency Room - a tool to distinguish between acute stroke and stroke mimics
First you have to exclude hypoglycaemia then assess if LOC or seizure activity. If either of these then stroke is unlikely. Then is there new acute onset of either: asymmetrical arm weakness, leg weakness, facial weakness, speech disturbance or visual field defect. A stroke is likely if >0
Symptoms of lateral medullary syndrome (Wallenberg or PICA syndrome)?
Ipsilateral: facial pain and temperature loss
Contralateral: limb/torso pain and temperature loss
Ataxia, nystagmus
Symptoms of lateral pontine syndrome (AICA syndrome)?
Ipsilateral: facial pain & temperature loss, facial paralysis and deafness
Contralateral: limb/torso pain and temperature loss
Ataxia, nystagmus
MOA of clopidogrel?
It’s a prodrug that needs metabolising by CYP450 first to its active form. It then irreversibly binds to P2Y12 ADP receptor on the surface of platelets which blocks ADP-induced activation of the GP IIb/IIIa complex which is essential for platelets to bind fibrinogen and form a platelet plug = inhibits platelet aggregation
Why is it important to know that clopidogrel is irreversible effects?
Because its antiplatelet effects last the entire lifespan of platelets affected (7-10 days) so new platelets need to be generated to restore normal platelet function
Contraindications for clopidogrel?
Active bleeding e.g. peptic ulcer or intracranial haemorrhage
Allergy
What should BP be before thrombolysis of a stroke?
<185/110
What are the absolute contraindications to thrombolysis?
- Previous intracranial haemorrhage (may be more at risk of a bleed and thrombolysis increases this risk)
- Seizure at onset of stroke (this suggests an intracranial bleed)
- Intracranial neoplasm (tumours can cause fragile blood vessels increasing haemorrhage risk)
- Suspected subarachnoid haemorrhage (will worsen bleed)
- Stroke or traumatic brain injury in preceding 3 months (can weaken blood vessels so more susceptible to a bleed)
- Lumbar puncture in preceding 7 days (risk of bleed)
- Gastrointestinal haemorrhage in preceding 3 weeks (indicates at risk of further GI bleeds)
- Active bleeding
- Oesophageal varices (will increase risk of these bleeding)
- Uncontrolled hypertension >200/120mmHg (weakens blood vessels so at risk of haemorrhage)
