RACP Flashcards
What is Cotinine?
Metabolic product of nicotine - provides quantifiable method of assessing nicotine exposure (via smoking, passive, or NRT). Detectable in blood, saliva or urine.
What is the DECAF score?
What are its components?
Score used to assess COPD exacerbations ?home vs inpatient management.
Score 0-1 –> early dc
Score 2 = intermediate
Score >= 3 –> admit / palliate
Components:
- eMRC dyspnoea scale on typical day (2 points if too dyspnoeic to leave house)
- eosinophils
- consolidation on CXR
- acidaemia (pH <7.30)
- presence of AF
What is Loeffler Syndrome?
Transient passage of helminth larvae (mainly Ascaris) from blood to alveoli through to proximal airways and then into digestive tract. Manifest on CXR as migrating / self-resolving opacities. Associated with blood eosinophilia.
Which cells produce surfactant?
Type 2 pneumocytes
Cause of non-infective endocarditis
Libman-sacks disease (from SLE)
Bohr Effect
Increase in acidity (decrease pH) or increased pCO2 in a tissue causes RIGHT shift –> decreased O2 affinity –> increased O2 delivery to metabolically-active tissue.
Haldane Effect
Increased oxygen binding makes CO2/H+ bind less well to Hb molecule (increases CO2 delivery to the lungs)
Zero Order Kinetics
Clearance by easily saturated enzyme system. Once saturated, the rate of clearance plateaus, and does not vary no matter how much drug is present. Results in a constant rate of elimination predisposing to high levels of the drug and toxicity.
Examples: phenytoin, alcohol and salicylates.
First Order Kinetics
Linear process, where the rate of elimination is proportional to the drug concentration. This means that the higher the drug concentration, the higher its elimination rate.
What is Pompholyx?
Eczema of soles of hands / feet.
Often triggered by heat / humidity.
Amiodarone-induced Thyrotoxicosis:
Type 1 vs Type 2
Type 1:
Excess iodine load –> excess thyroid hormone made
Goitre present
Rx = carbimazole
Type 2:
Destructive thyroiditis
No goitre
Rx = prednisone
Key Stain for Lymphoblasts (ALL)
TdT (staining for DNA polymerase)
Key surface markers for B cells
CD10, CD19, CD20
Acute Promyelocytic Leukaemia
- Marker
- Key Receptor
- Key Complication
- Treatment
t(15;17)
Retinoic acid receptor
Widespread DIC
All-trans retinoic acid (ATRA) –> encourages cell differentiation
Auer Rods
Crystal ‘rod’ seen in myeloblasts in AML
Definition of ‘pulmonary nodule’
<3cm lesion, completely surrounded by lung parenchyma.
Larger lesions called ‘masses’
Most common causes of benign lung nodules (2)
Infectious granulomas
Pulmonary harmartomas
Criteria for not further following up a pulmonary nodule (2)
Initial size <6mm (i.e. =<5mm) (and no other high risk features)
OR
No growth over 2 years
Diagnosing BK Nephropathy:
- Typical approach
- Gold standard approach
- Viral load (via PCR) in context of allograft dysfunction
2. Renal biopsy (especially if DDx includes transplant rejection, which has opposite management approach…)
Eculizumab:
- MoA
- Indications
Binds C5 (i.e. the terminal complement component) - prevents formation / activation of C5a and C5b
PNH, aHUS, NMO (if anti-AQP4 +)
Emicizumab
- Indication
- MoA
Haemophilia A
Cross-links F9a and F10 –> leading to F10a formation. (F10a then converts prothrombin –> thrombin, (along with F5)).
Clopidogrel Mechanism
Irreversibly inhibits P2Y12 of ADP receptors on platelets → prevents activation of GPIIb/IIIa complex → no fibrinogen cross-linking → no platelet aggregation
(Whereas ticagrelor is reversible)
HIV Binding Molecules
GP 120 on virus –> CD4 on host
Then GP41 –> CCR5 (acute) or CXCR4 (chronic)
HIV Protective HLA and mechanism
HLA B57*01
Allows binding of MHC-1 to HIV core protein (which can not be mutated) –> strong CD8 response –> slower progression to AIDS (and less hypersensitivity to Abacavir)
HIV Prophylaxis cut-offs and drug to use
- PJP
- Cryptococcus
PJP; give cotrimoxazole if CD4 count <200
Cryptococcys; give fluconazole if CD4 count <100
HIV pre-exposure prophylaxis medications
Tenofovir + emtracitibine given daily
HIV post-exposure prophylaxis (3)
Must be started <72h, 28 day course
If risk <1 / 1,000 –> 2x drug therapy (tenofovir + emtracitabine / lamivudine)
If risk >1 / 1,000 –> 3x drug therapy (2x drug Rx + dolutegravir)
Rasburicase - mechanism, caution scenario
Supplies uricase enzyme
Converts uric acid to allantoin (water soluble –> renal clearance)
- I.e. can acutely LOWER urate concentration (whereas allopurinol just stops production)
Caution in G6PD deficiency
Azathioprine Metabolism
Active compound = 6-TGN
- Levels > 235 a/w better clinical response (but more myelotoxicity)
Inactive metabolite = 6-MMP
- Levels > 5,700 a/w hepatotoxicity
Conversion to 6-MMP can be reduced by allopurinol - give for ‘shunters’ / hypermethylators
Check TPMT enzyme beforehand
Binding site in Heparin-induced Thrombocytopaenia (HIT)
Antibodies against heparin-platelet factor 4 complex
which can also activate platelets, leading to thrombotic tendency
Kings College Criteria for Liver Transplant (Paracetamol OD)
Arterial pH <7.30
Or all of:
- PT >100sec (INR > 6.5)
- Creatinine > 300
- Grade 3 or 4 encephalopathy
(Whereas PT >100sec = absolute criteria for non-paracetamol liver failure)
G6PD Inheritance Pattern
X-linked recessive
Tocilizumab Mechanism
Binds soluble- and membrane-bound IL-6 receptors
Rheumatoid Arthritis Susceptibility Genes
HLA-DRB1
Subtypes (i.e. different alleles of DRB1):
HLA-DRB104:01 and HLA-DRB104:04
RA: Shared epitope concept
HLA alleles that confer increased risk for RA all have similar amino acid sequence at position 70-74 (even in completely different HLA subtypes).
(QKRAA)
RF vs ACPA; which has stronger correlation with extraarticular disease severity?
RF - e.g. ILD, vasculitis
Whereas ACPAs predict more severe/erosive articular damage
Antiphospholipid Abs
Anti-cardiolipin
Lupus anticoagulant
Anti-beta-2-glycoprotein
(Need to be present in serum on 2x occasions at least 12 weeks apart)
Most specific auto-antibody for SLE
Anti-Sm
Auto-antibody that goes up/down with SLE disease severity e.g. nephritis, vasculitis
Anti-dsDNA
Th1 cytokines
IFNy
IL-2
IL-3
Th2 cytokines
IL-4 IL-5 IL-6 IL-10 IL-13 TGF-beta
Tumour markers:
- Ovarian cancer
- Breast cancer
- Pancreatic cancer
CA12-5
CA15-3
CA19-9
Half life formula
T1/2 = 0.693 x Vd/CL
Can be rearranged to give CL value, units L/h
Anti-phospholipase A2 Receptor Antibodies are associated with which GN?
(Anti-PLAR2)
Idiopathic Membranous GN
Key CJD features (3)
Rapid dementia
Myoclonus
Periodic, triphasic sharp waves on EEG
VZV post-exposure prophylaxis
Immunocompetent –> VZV vaccine
Immunocompromised –> VZV Ig (within 10 days)
Medications causing acute interstitial nephritis (3)
PPIs
Antibiotics
NSAIDs
Key test for urea cycle disorders
Elevated ammonia (with normal BSL and anion gap)
Aprepitent receptor target
Neurokinin 1 Receptor –> blocks substance P
Used for pruritis and chemo-induced N+V
BRCA gene inheritance
Autosomal dominant
Syphilis cardiolipin tests / ‘non-treponemal’ tests
VDRL and RPR
Become negative after treatment, used for monitoring treatment / recurrence
Syphilis ‘treponemal’ tests (3,1)
E.g. Treponema pallidum haemagglutination test (TPHA)
Enzyme immunoassay (EIA)
T. pallidum particle agglutination test (TPPA)
Stay positive after treatment
Most common cause of inherited thrombophilia
Factor V Leiden (activated protein C resistance)
Due to mutation, protein C can not inactivate factor 5 –> procoagulant status
(Protein C normally inactivates F5 and F8)
Extra-intestinal IBD features associated with disease activity (4)
Pauciarticular arthritis (asymmetric) / large joint
Erythema nodosum
Episcleritis
Osteoporosis
Extra-intestinal IBD features NOT associated with disease activity (5)
'APUPS': Axial / ank spond Pyoderma gangrenosum Uveitis PSC Symmetric, small joint (polyarticular) arthritis
Key areas for lesions on MRI in MS diagnosis
Periventricular - ‘Dawson’s fingers’
Juxtacortical - ‘U fibre’ / cortical
Infratentorial (cf. vascular)
Spinal cord
ESCAPPM Organisms
- Definition
- Transmission of resistance
- Management (2)
- Organisms
ESBL Subgroup with inducible beta-lactamase activity
AmpC chromosomally-mediated
Management:
Carbapenems
Piptaz
Enterobacter species Serratia spp Citrobacter freundii (and braakii) Acinetobacter and Aeromonas spp Proteus (not mirabilis) Providencia spp Morganella morganii
Ann Arbor Staging
I - single node
II - 2x nodes on same side of diaphragm
III - nodes on either side of diaphragm
IV - extra-lymphatic organ involved
A - no systemic Sx (other than pruritis)
B - >10% weight loss, fever, night sweats
AML poor prognosis markers (2)
Deletions of chromosomes 5 or 7,
FLT3
Pendred syndrome
Autosomal recessive
Bilateral SNHL + hypothyroidism + goitre
MRI shows 1.5 turns of cochlea (cf 2.5)
Rx = thyroxine and hearing aids
In what ILD would biopsy show hyaline membranes?
Acute interstitial pneumonia
What is the main determinant of drug plasma concentration at steady state?
Drug clearance
MODY3 mutation
HNF1a
Most common form of MODY
MODY2 mutation
glucokinase
MODY1 mutation
HNF4a
Define nonsense mutation
Base change that causes a stop codon
Mutation in MDS with good prognosis
Deletion (5q) - responds to lenalidomide
Gitleman syndrome
Defect in distal tubule Na/Cl transporter, like being on a thiazide
Bartter syndrome
Defect in thick ascending limb Na-K-2Cl transporter, like being on frusemide
Liddle syndrome (3)
Gain of function mutation –> ENaC can no longer be broken down –> excess sodium absorption / potassium loss –> HTN / hypo-K / alkalosis
Hyper-aldosterone-like state, (but low renin AND low aldosterone levels (cf. Conn’s))
Spironolactone not effective in Rx (use amiloride or triamterene which block ENaC). Salt restriction also effective at maintaining normal sodium / bicarb levels.
Autosomal dominant
Gefitinib mechanism
EGFR inhibitor - used in lung adenoca.
Well’s criteria for PE (7) + scores
PE leading DDx - 3 Limb swelling - 3 HR > 100 - 1.5 Immobilisation - 1.5 Previous PE - 1.5 Haemoptyisis - 1 Malignancy - 1
Acute Interstitial Nephritis urine findings
+ve white cells
- ve red cells
- ve protein
Ipilimumab mechanism
Inhibition of CTLA-4 co-stimulator on T-cells / Treg cells
MRI ‘hummingbird sign’ is seen in…
PSP (due to midbrain atrophy)
Pre-op insulin: prior to major surgery
Give IV insulin at variable rate
True/False: correcting vitamin D deficiency may help prevent SLE flares?
True
Anion gap formula
(Na + K) - (Cl + HCO3)
Ref range 4 - 12
If high, implies presence of unaccounted for anions (that have consumed bicarb)
True/False: osteoarthritis is a risk factor for osteoporosis?
False (may even be protective)
Predictor of reactive arthritis recurrence or persistance
HLA-B27 gene
ACEi benefits:
- Renal
- Ophthal
If microalbuminuria, then ACEi/ARB slow progression to proteinuria (may initially see a creatinine rise)
If no microalbuminuria, there is no renal benefit but protects against retinopathy
Implication of decreasing insulin requirement in GDM
Could suggest placental failure (the placenta is often a cause of insulin resistance) –> needs obstetric input
What agent causes cold-aggravated neuropathy?
Oxaliplatin (via voltage-gated Na channels)
Maternal / peripartum HIV management
Mum should be on ART regardless of HIV load
Intrapartum Zidovudine if HIV RNA > 1,000
Infant should receive PEP
No breast feeding
C-section if maternal HIV RNA >400 at 36/40
SAAG interpretation
SAAG > 11 = portal HTN
i.e. despite high oncotic pressure, there is still ascites forming indicating the presence of hydrostatic pressure
Acanthocytes
- AKA
- Describe appearance
- Commonly found in…
AKA spur cells
Large red cell with spike-like projections
Severe liver disease
Light microscopy: ‘sub-epithelial deposits’ are seen in:
Membranous nephropathy
AKA spike and dome appearance
Gram negative cocci species (2)
Neisseria
Moraxella
Horner’s / eye sympathetic chain anatomy / neuron orders
1st order: posterior hypothalamus to spinal cord (ciliospinal centre of Budge) at C8-T2
2nd order: fibres exit at T1, cross lung apex, ascend in cervical sympathetic chain, terminate at superior cervical ganglion at level of bifurcation of common carotid artery (C3-4)
3rd order: ascend along internal carotid artery to eye
Mifepristone:
- Mechanism
- Use
Glucocorticoid receptor antagonist
Hyperglycaemia of Cushing’s
Ketoconazole use in adrenal disease:
- Mechanism
Inhibits androgen synthesis
Ambrisentan mechanism
Endothlin A + B ANTAGONIST
Sildenafil mechanism
Inhibits PDE-5
Riociguat mechanism
Sensitises guanlate cyclase to NO / activates gunalate cyclase
Iloprost mechanism
Prostaglandin analogue
Cell type activated in HLH
Macrophages (failed elimination by NK cells / CTLs)
Define: fraction excreted unchanged (Fe)
Proportion of active drug cleared renally in healthy person.
Genetic defect in Autoimmune Polyendocrine Syndrome type 1 (AKA APECED)
AIRE - involved in regulating T-cell selection in the thymus
Cell surface markers of Reed-Sternberg cells
CD15 (75%) and CD30 (100%)
RS cell is a ‘crippled’ germinal center B cell that has non-functional IgG gene arrangement
Pembrolizumab and Nivolumab mechanism
Inhibits PD-1
Adrenal gland zones / hormone synthesised (4)
Zona glomerulosa - mineralocorticoids
Zona fasciculata - glucocorticoids
Zona reticularis - androgens
Medulla - catecholamines
PBC associated diseases (2)
Sjogrens
Autoimmune thyroid disease
MRCP / ERCP ‘string of beads’ pattern refers to:
PSC
Multiple strictures in the biliary system
Red Man Syndrome mechanism
Direct mast cell stimulation by vancomycin –> histamine release
Castleman disease - characteristic finding:
Elevated IL-6
Treatment of latent TB (3)
3/12 of rifampicin + isoniazid (+pyridoxine)
OR
9/12 isoniazid (+pyridoxine)
OR
Rifapentine weekly for 3/12
Treatment of active TB
2/12 of ‘RIPE’ (+pyridoxine)
then
4/12 of rifampicin + isoniazid
Antibody target in ITP
GP IIb/IIIa complex
CHARTS Acronym for upper zone fibrosis
Coal worker's pneumocosis Hypersensitivity pneumonitis (AKA extrinsic allergic alveolitis) / histiocytosis Ank spond Radiation Tb Silicosis / sarcoidosis
OR: ‘everything you inhale except for ank. spond. and sarcoidosis’
Ventilation strategy for patients with ARDS
Low tidal volume (4-8ml/kg) with PEEP
Smouldering myeloma criteria
AKA ‘asymptomatic myeloma’
- Paraprotein >30
OR
Plasma cells >10% - AND no myeloma-relate end-organ impairment
MRI findings in CJD
Caudate and putamen T2 hyperintensity and diffusion restriction on DWI/ADC
Proven benefit(s) of pre-endoscopic PPI
Reduced endoscopic intervention (i.e. no difference in mortality, re-bleeding or surgery)
Home oxygen indications for COPD
PaO2 <55mHg (7.3 kPa)
OR
PaO2 <60mmHg (7.7 - 7.8 kPa) if cor pulmonale / right HF / erythrocytosis / pulmonary HTN
Group of patients that might particularly benefit from CABG (rather than PCI)
Diabetics
Treatment for BRAF V600E mutation in melanoma
BRAF inhibitor AND MEK inhibitor combination
e.g. Dabrafenib + Trametinib
Treatment for cerebral venous sinus thrombosis
Clexane + warfarin, then warfarin once INR therapeutic (even if small intracranial bleed)
NO evidence for DOACs
Skin complication of anti-TNF Rx
Psoriasis
MDR-TB definition
TB resistant to Rifampicin and Isoniazid
XDR-TB definition
MDR-TB + resistance of moxifloxacin and amikacin
5-FU-related chest pain mechanism
Coronary artery spasm
Usually associated with first infusion
Antibiotic inactivated by surfactant
Daptomycin (due to aggregating with phospholipids in surfactant)
Antibiotic with large volume of distribution, and so not useful in sepsis
Tigecycline
Hemibalism site of lesion
Contralateral sub-thalamic nucleus or basal ganglia
One interesting cause includes hyperglycaemia
Anti-epileptic that can worsen absence seizures
Carbamazepine
Anti-GAD Abs
- Found in:
- Results in (syndrome)
Breast, colorectal, SCLC
Stiff man syndrome (diffuse hypertonia)
Anti-Hu
- Found in:
- Results in:
SCLC, neuroblastoma
Limbic encephalitis, rapid peripheral neuropathy
Anti-Ma
- Found in:
- Results in:
Testicular cancer
Rhombencephalitis
Anti-Yo
- Found in:
- Results in:
Breast, ovarian
Cerebellar degeneration
Anti-Ri
- Found in:
- Results in:
Breast, SCLC
Ocular opsoclonus myoclonus, rhombencephalitis
Anti-amphiphysin
- Found in:
- Results in:
Breast
Stiff person syndrome
LGI1 Encephalitis
- What is it
- 2x key features
A subtype of anti-VGKC-mediated encephalitis
Rapid memory decline
Faciobrachial and dystonic seizures
Osteoprotegerin functions (2)
AKA Osteoclastogenesis Inhibitory Factor (OCIF)
Acts as decoy for RANK-L (thereby reducing stimulation of osteoclastic maturation)
Acts as decoy for ‘TRAIL’ (thereby inhibiting apoptosis of osteoclasts)
Hb-O2 curve: causes for RIGHT shift
E.g. in muscle:
- Increased temp
- Increased pCO2
- Lower pH (increased H+)
- Increased 2,3-BPG
Bohr Effect
Increased pCO2 / H+ make O2 bind Hb with less affinity (thereby increasing its delivery to metabolically-active tissue)
Components of HbA
2x alpha + 2x beta chains, i.e. normal adult Hb
Components of HbF
2x alpha + 2x gamma chain (foetal Hb)
What is HbS?
Sickle cell Hb - due to point mutation in beta chain
Mutated beta chains join with normal alpha chains to form HbS
If homozygous –> sickle cell anaemia
HbS has reduced solubility when deoxygenated → undergoes polymerisation → distorted shape → reduced flow/deformability + increased adhesion to endothelial cells
What is HbE?
Beta gene mutation causing structurally abnormal Hb
Weak union beta alpha/beta –> unstable Hb (behaves like beta-thal trait)
Implications if one parent has HbE and the other beta-thal
What is HbH?
Moderate-severe form of alpha-thal where only 1x functional alpha gene is present (i.e. -a / –)
HbH is made from beta chains (beta-4) that combine to each other
What is HbB?
Hb Barts
Hb made of 4x gamma chains
Seen in alpha-thal major (i.e. no functional alpha genes present)
Components of 4T score for HIT probability calculator
Thrombocytopaenia
Timing
Thrombosis
Other causes present
What is Gaucher Disease (1)
Most common manifestations (4)
Most common lysosomal storage disease; abnormal glycolipid build-up in macrophage lysosomes (‘lipid-laden macrophages’) due to deficiency in glucocerebrosidase enzyme.
Splenomegaly
Thrombocytopaenia
Neurological deficit
‘Flask’ appearance of long bones
Rx = enzyme replacement therapy OR substrate reduction therapy
Components of ‘Fried Frailty Tool’ (AKA Frailty Phenotype) (5)
Weight loss >5% Fatigue Reduced grip strength Reduced mobility speed Decreased weekly physical activity (based on energy expenditure)
What organism causes erythrasma?
Corynebacterium
pink/brown patches in groin/axillae
Interventions that improve COPD mortality (3)
Stop smoking Home O2 (if meets criteria) Lung reduction surgery in selected cases
True / False: Obesity increases BNP
False - along with standard HF Rx, obesity also decreases BNP
Gestational diabetes diagnosis thresholds for BSL:
- Fasting
- After 2h
> = 5.6
> =7.8
Muscarinic Receptors
G-protein coupled
M1 (Gq) - CNS
M2 (Gi) - Heart
M3 (Gq) - Other organs: gut, glands, eyes, blood vessels
Nicotinic receptors
Ligand-gated ion channels
N1 / Nm - NMJ
N2 / Nn - post-ganglionic cell body / adrenal gland
Th17 cytokines
IL-17
IL-22
(Small amount of IL-10)
What type of growth factor is produced by myxomas?
VEGF
Most common type of malignant primary cardiac tumour
Sarcomas
But metastatic cardiac tumours 20x more common
Example of ergot-derivative meds (2)
Mechanism
Key side-effects (2)
Bromocriptine, cabergoline
- Work as dopamine receptor agonists
Pulmonary / cardiac / retroperitoneal fibrosis
Impulse control disorders
In utero lithium exposure increases risk of the following cardiac abnormality:
Ebstein’s anomaly (low insertion of the tricuspid valve –> large RA, small RV)
See prominent TR and a-waves
Pathergy test:
- What is it?
- What condition is it found in?
Exaggerated skin injury after mild trauma
Behcet’s disease (also in pyoderma gangrenosum and Sweet syndrome)
What is the EMA test for?
Diagnosis of hereditary spherocytosis.
Test measures amount of fluorescence from a cell.
Lights criteria for exudative effusion
1 of:
Pleural:serum protein >0.5
Pleural:serum LDH >0.6
Pleural LDH >2/3 of serum LDH ULN
Haemorrhagic bullae are caused by what organism?
Vibrio vulnificus
Further info:
G-, seafood ingestion or contaminated wound, severe sepsis, particularly liver disease or haemochromatosis, tetracycline + 3rd gen cephalosporin
Key urine finding in ATN
‘Muddy-brown’ granular, epithelial cell casts and free renal tubular epithelial cells (that have been ‘shed’)
AML: cytogenetic changes with good prognosis (4, 1)
t(8;21) (which generates the RUNX1-RUNX1T1 fusion gene)
t(15;17) (APML)
inv(16)
NPM1 mutation
For these cases, can try cytaribine consolidation (rather than SCT)
AML: cytogenetic changes with poor prognosis (5)
-5, -7, del (5q), abnormal 3q, FLT3
PD-1 inhibitors
Pembrolizumab
Nivolumab
PD-1L inhibitors
Atezolizumab
Durvalumab
CTLA-4:
- Mechanism
- Examples of blockers
Preferentially binds co-stimulatory molecule CD80/86 (AKA B7) –> loss of T-cell activation
Ipilimumabc
MELD score components
Dialysis Creatinine Bilirubin INR Sodium
Child pugh components
Bilirubin Albumin INR Ascites Encephalopathy
Enterococcus endocarditis Rx (2)
Gent-sensitive / standard:
Amoxicillin 6/52 + gentamicin 2/52 (synergy)
Gent-resistance:
Amoxicillin + ceftriaxone (6/52 for both) (synergy)
- Amox covers PBP4 and 5
- Cef covers PBP2 and 3
Organisms that do not produce nitrites
Gram positives:
Enterococcus
Staph. saprophyticus
Riociguat
- Use
- Mechanism
Medical therapy of CTEPH (in rare cases where surgical intervention (thrombendarterectomy) is not done).
Guanalate cyclase agonist (which enhances the effects of NO binding)
What is erythromelalgia?
Intermittent red/hot extremities.
Associated with MDS
Conservative cooling measures and aspirin
Peritoneal dialysis-associated peritonitis management overview (5)
Most common organism: S. epidermidis
Either continuous or intermittent (at least 6h dwell) administration.
Empiric Rx = Gentamicin + Cefazolin
If vancomycin required, replace cefazolin with it
If suspected diverticulitis / intestinal perf, add metronidazole
If gentamicin contraindicated, use single-agent cefepime regimen
Duration 14-21 days
Spirometry: fixed obstruction flow-volume loop description
Plateaued inspiratory and expiratory phases
Spirometry: variable intrathoracic obstruction flow-volume loop description
Plateau of expiratory phase
Normal inspiratory phase
Spirometry: variable extrathoracic obstruction flow-volume loop description
Normal expiratory phase
Plateau of inspiratory phase
LADA one sentence description
Slowly progressive destruction of beta cells - gradual insulin deficiency (not as rapid as ‘traditional’ T1DM, but still a subtype of T1)
(NOTE: Starting insulin early may help to preserve beta cell function)
MODY one sentence description
Monogenetic cause of diabetes (with variable penetrance) due to genetic defect in beta cell function
Hepatitis B infection phases
- Immune tolerance
- High DNA, high HBe antigen - Immune clearance
- Falling DNA, +/- falling HBe antigen, rising AST - Immune control
- Anti-HBe +, low DNA, normal LFTs - Immune escape
- Rising DNA, rising LFTs, HBe still -ve
When to treat hep B: (2)
Liver injury and DNA > 20,000 (and +ve E antigen)
OR
DNA > 2,000 and negative HBe antigen (i.e. immune escape phase)
Contraindications for interferon therapy (4)
Thyroid disease
Psychosis
Child-Pugh B/C (can trigger decomp)
Autoimmune disease
Tenofovir complications (2,1)
Low BMD
Fanconi syndrome / renal impairment
(But safe in pregnancy)
Type of adenoma that secretes mucous and can result in diarrhoea with a rare ALKALOSIS
Villous adenoma
Cardiac action potential steps
0 (depol) - rapid Na influx 1 (notch) - K+ efflux 2 (plateau) - Ca++ influx, K+ efflux 3 (descent) - K+ efflux 4 (resting) - K+ influx (Na/K ATPase)
RANZCOG cutoffs for GDM after 2h OGTT
Fasting >5.1 - 6.9 (>7 = diabetes)
1h > 10
2h > 8.5 - 11 (>11.1 = diabetes)
(Different to NZ screening guide)
Note: Aus and WHO recommend one-step test with 75g OGTT (not 50g test as in NZ)
Osmolar gap formula
Osmolar gap = Osmolality (measured) – Osmolarity (calculated)
Normal <10
If high, implies presence of an abnormal solute present in significant amounts e.g. methanol, ethylene glycol
Bullous pemphigoid pathophysiology
IgG against hemidesmosomal proteins BP 180 and BP 230 (deep) –> eosinophil infiltrate –> dermal / epidermal splitting
Pemphigus vulgaris pathophysiology
IgG against desmoglein 1 & 3 –> loss of cell adhesion in epidermis (superficial) –> easily rupturing blisters
Bortezomib / carfilzomib mechanism / use
26s proteosome inhibitor (–> build-up of intracellular M-protein –> apoptosis)
Myeloma induction (along with lenalidomide and dexamethasone)
Daratumumab mechanism (and 1x laboratory complication)
mAb to CD38 on multiple myeloma cells (used in relapsed disease)
(Can cause pan-agglutination on antibody screen when looking for a cross-match, i.e. pan-reactive red cell antibody)
Chromosome translocation: follicular lymphoma / (some) DLBCL
t(14;18) –> BCL-2
BCL-2 inhibits apoptosis
Chromosome translocation: CML
t(9;22)
Chromosome translocation: Burkitt lymphoma
t(8;14) –> Myc
Disease with ‘starry sky’ appearance on node biopsy
Burkitt Lymphoma
AVRT - current directions and associated ECG appearance
Orthodromic - narrow complex
Antidromic - wide complex (due to LV being activated first)
SVT / IV adenosine special scenarios (3)
- Contraindicated in asthma
- Need higher dose if on theophylline
- Need lower dose if on dipyridamole
Typical vs atypical AVNRT
Typical: slow–>fast conduction, short R-P interval
‘Short and slow’
Opposite in atypical AVNRT
R-factor:
- Formula
- Interpretation
ALT / ULN : ALP / ULN
<2 = cholestatic --> US >5 = hepatocellular --> liver screen 2-5 = mixed --> biopsy
Effect of trimethoprim on potassium
Can increase K+ (usually in AIDS patients) due to inhibition of ENaC
Perhexiline prescribing considerations
7-10% of caucasians are slow metabolisers due to deficient CYP2D6 - check metabolite level 3/7 after starting; if no peak, change to 100mg per WEEK dosing.
Can also cause hypoglycaemia
Beta-blocker with additional effect of potentiating the vasodilatory effect of NO
Nebivolol
Beta-blockers that have low lipid solubility (don’t cause CNS effects)
Atenolol
Nadolol
Celiprolol
Sotalol
Drugs to avoid in WPW + AF (pre-excited AF)
AV node blockers e.g. CCBs, BBs, adenosine
One MET
4 METs
10 METs
Resting metabolic demands
Climbing 2x flights of stairs
Strenuous sports
Hallmark finding of ASD on exam:
Wide and FIXED splitting of S2
Mutation in familial pulmonary HTN
Bone morphogenetic protein receptor type 2 (BMPR2) (in the TGF-beta family)
(Also often found in 10% of ‘sporadic PAH’)
Role of hypocretin/orexin
A wakefulness promoting protein, deficient in narcolepsy. Coded by orexin gene.
FEV1 (volume) cut-off for lobectomy
> 1.5L usually used
Implication of blood in pleural fluid (in context of cencer)
Pleural invasion - hence also not curative via surgery
Mining exposure that increases TB risk
Silica (via impairment of macrophage function)
Main risk factors for chronic lung allograft dysfunction (2)
Acute cellular rejection
Lymphocytic bronchiolitis
These cause bronchiolitis obliterans syndrome
May be contributed to by silent aspiration
Idiopathic pulmonary fibrosis histology findings (1,3)
Pattern = usual interstitial pneumonitis (UIP)
Minimal inflammatory round cell infiltrate
Widening of alveolar septa
Fibrosis / fibroblastic foci
Bronchoalveolar lavage finding in pulmonary alveolar proteinosis (2)
Grossly turbid exudates
Periodic acid-Schiff (PAS)-positive material
(Disease due to abnormal accumulation of surfactant in alveoli and impaired GM-CSF function)
HRCT finding in pulmonary alveolar proteinosis
‘Crazy paving’
What does faecal immunochemical test bind to?
Globin part of Hb
More sensitive/specific than gFOBT
Doesn’t detect upper GI blood, but does react with lower GI bleed (commonly haemorrhoids or diverticular bleed)
‘Interface hepatitis’ or bridging necrosis on histology refers to:
Autoimmune hepatitis
(See plasma cells, rather than lymphocytes (as in chronic hep)).
(Can also see ‘piecemeal’ necrosis)
Immune-mediated destruction of intrahepatic bile ducts on histology refers to:
PBC
Deficiency in wet/dry beriberi
Thiamine (B1)
NAFLD weight loss effects:
3-5%
10%
Improves steatosis
Improves necro-inflammation
Plummer-Vinson syndrome
Iron deficiency and (keratinised) oesophageal webs
Periodic acid-Schiff-stained macrophages on small bowel biopsy indicates…
Whipple disease (Tropheryma whipplei)
Reason for low B12 but high folate in small intestinal bacterial overgrowth
Bacteria consume B12, but produce Folate
Foot process effacement is seen in…
Minimal change disease
Where in renal tract does ANP act to reduce sodium reabsorption?
Inner medullary collecting ducts
Which part of the tubule is most often involved in drug secretion?
Proximal tubule
Effect of FGF23 on phosphate
Lowers levels by inhibiting reabsorption in PCT
Hb Target in CKD
100-115
Higer levels have risk of:
- Stroke
- Thrombosis / VTE
- HTN
- Headache
- CHF
What causes dialysis-related amyloidosis?
Inability clear (or dialyse) beta-2 microglobulin which then deposits.
Most common manifestations of DRA are carpal tunnel syndrome and shoulder pain.
Also see cystic lesions on end of long bones.
Risk factors for aHUS (3)
Deficiency in factors H and I,
Low thrombomodulin
Activators of factors B and C3
Complication of gadolinium in CKD
Nephrogenic systemic fibrosis
(hence may need haemodialysis after MRI)
(See lots of CD-34 fibrocytes)
Post-transplant lymphoproliferative disorder:
- Main risk factor
- Most common transplant affected
- Management
EBV mismatch
Heart-lung or bowel (both 10-20%)
Reduce immunosuppression
Which glomerulonephritis is most likely to rapidly recur in a renal allograft?
Primary FSGS
Type of glomerulonephritis associated with highest VTE risk.
Idiopathic membranous nephropathy
What cell does PTH target in bone?
Osteoblast (which can then lead to osteoclast activation if constant PTH stimulation is present, but not intermittent PTH presence)
Effects of GLP-1 (4)
Stimulates insulin
Inhibits glucagon
Inhibits gastric emptying
Reduces appetite
Eyebrow-related sign in hypothyroidism
Loss of the outer 1/3 of the eyebrow
Does neurofibromatosis type 1 or type 2 typically present with vestibular schwannoma?
Type 2 (due to Merlin protein, AKA schwannomin), defect)
Gene / protein for Tay-Sachs disease
HEXA gene Hexosaminidase A (usually breaks down phospholipids / gangliosides)
Areas targeted by deep brain stimulation
Subthalamic nucleus
Internal segment of globus pallidus
Symptoms that respond to deep brain stimulation (4)
Levodopa-responsive Sx,
Tremor,
On-off fluctuations,
Dyskinesia
Alpha synucleinopathies (3)
Parkinson’s
Lewy body dementia
MSA
Management of myasthenic crisis
Plasmapheresis or IVIg
Regular bedside checks of ventilation
Oral prednisone
On nerve conduction study, prolonged/dispersed F-wave latency indicates…
Demyelinating disease
Examples of non-ergot dopamine agonists
Pramipexole, ropinorole
Risk of impulse control disorders
Neutrophil antigens that can cause false-positive pANCA result on indirect immunofluoroscopy (3)
Bactericidal permeability inhibitor (BPI)
Cathepsin G
Lactoferrin
‘Shared epitope’ predisposing to RA
Common amino acid motif: QKRAA
Usually found in HLA-DRB1, but sometimes in other alleles
Wide mouth diverticulae are pathognomonic for…
Scleroderma
Polyarteritis nodosa: what sized vessels are affected?
Medium (muscular) and small arteries (but no glomerulonephritis)
Polyarteritis nodosa: biopsy findings
Pan-mural necrosis, prediliction for bifurcations. Can lead to aneurysms/stenosis of arteries.
True/false: Polyarteritis nodosa affects the lungs?
False: affects all organ systems other than lungs
Suspect in systemic vasculitis, ANCA-negative, orchitis and abnormal renal angiography
Factors associated with a GOOD prognosis for RA (3)
Acute onset
Restriction to small number of large joints
Sero-negative
In patient with RA presenting with shooting pains / hyper-reflexia / hypertonia, consider…
Atlantoaxial subluxation (due to erosion/stretching of the transverse ligament)
(Often worsened by forward flexion of neck, which has anaesthetic implications)
Most common type of lymphoma associated with Sjogren’s
MALToma
True/False: Alopecia is included in diagnostic criteria for SLE.
False
Sunburn damage mechanisms:
- UVB
- UVA
UV B causes radiation to epidermis - the main cause of direct sunburn
- SPF is based on UV B blocking ability
UV A causes free radical generation (and can penetrate below the dermis)
Key features of fixed drug reaction (2)
Residual hyperpigmentation
Recurrence at previously-affected sites
Biopsy showing panniculitis and inflammation of septa in subcutaneous fat is suggestive of…
Erythema nodosum
Role of p53 / where it acts in cycle
Tumour suppressor via arrest of cell cycle at G1 (to allow DNA repair before progressing) and stimulation of apoptosis. I.e. stops entry into S-phase.
(Note, can have elevated levels of mutated p53 in cancer cells due to slow turnover)
True/False: Oestrogen receptor positivity is a favourable prognostic factor for breast cancer?
True
While HER2+ is negtive factor
Deficiency in nucleotide excision repair confers increased sensitivity to which type of chemo agents?
Platinum (due to reduced capacity to repair interstrand cross-links)
How does nucleotide excision repair work?
Removes helix-distorting adducts on DNA, e.g. those caused by UV or tobacco smoke
Main side effects of bevacizumab (2)
Hypertension (VEGF inhibitor)
(Can be managed with standard BP Rx)
Poor wound healing
When to give adjuvant chemo in breast cancer
Node positive
Or tumour >0.5cm
(Or other adverse prognostic features e.g. young age, negative hormone receptor status, high-grade tumour)
When to give RTx in breast cancer
All breast-conserving surgery
Or if tumour >5cm / node positive
Breast screening for women with BRCA mutation
Should start age 25-30, and may include MRI in addition to mammography
Cetuximab MoA
mAb to EGFR
Only works in wild-type KRAS, i.e. won’t work if there is a KRAS mutation
Erlotinib mechanism
TKI targeting EGFR (used in NSCLC and pancreatic cancer)
Risk group for EGFR-positive lung cancer (4 features)
Asian
Never smoker
Women
Adenocarcinoma (cf squamous)
(Also unlikely to be effective if there is a KRAS mutation)
Main side-effect of erlotinib
Acneiform rash (face/neck)
Correlation between severity of skin reaction and survival!
Sunitinib MoA
VEGF inhibitor (as well as PDGFR B, FLT-3 and c_KIT)
Used in RCC
Intracellular bacterial pathogens (5)
Listeria Mycobacterium Brucella Rickettsia Chlamydia
Name the only Gram-positive bacterium to produce endotoxins
Listeria monocytogenes
What cell does JV virus affect in the brain to cause PML?
Oligodendrocyte
What does CD34 staining correspond to?
Haematopoietic progenitor cells
Mechanism of Cholera toxin
Persistent activation of adenylate cyclase –> increase cAMP –> increased chloride secretion / decreased sodium absorption –> secretory diarrhoea
Aflatoxin associations
Mycotoxin produced by Aspergillus, associated with:
- HCC
- p53 mutation
PCR marker for dengue
NS1 protein
HAART drug most responsible for lipodystrophy
Zidovudine
Treatment for Strongyloides
Ivermectin
(Consider Dx in patients with enteric bacterial pathogen with pulmonary/GI system involvement, particularly if co-existent immunosuppression or HTLV-1 present)
How does G-CSF facilitate collection of stem cells for transplantation?
Activates neutrophils –> Release MMPs –> mobilises stem cells from marrow into periphery –> collected
How does thrombopoietin (TPO) regulate platelet levels?
Via effect on megakaryocytes (promotes survival and differentiation).
(Binds to TPO receptor in bone marrow, with higher free TPO levels being present if there are low peripheral platelets present to bind it)
Roles of vWF (2)
Binds F VIII, reducing breakdown (increases T1/2 5-fold)
Helps platelets bind to exposed collagen in blood vessels (via GP1b)
Which factor activates protrhombin?
Factor X (in complex with factor V) (the prothrombinase complex)
F X is inactivated by protein-Z protease
Role of prostacyclin
Inhibits platelet activation.
Also acts as vasodilator
Gram positive rods
Acinetobater Bacillus Clostridium Diphtheriae Listeria
Lesion of angular gyrus causes…
Gerstman syndrome
‘Onion skin’ fibrosis on liver biopsy refers to…
PSC
Periductal fibrosis, intra- and extra-hepatic ducts
What cell releases surfactant?
Type 2 pneumocytes (main component = DPPC)
What is strongest -ve predictor for CLL
Medication to use if this is present.
Del 17p
Use ibrutinib or venetoclax if this mutation (or p53 mutation) is present
What is the mechanism of fomepizole
Competitive inhibitor of alcohol dehydrogenase (used in ethylene glycol and methanol poisoning)
What is found in Brodman’s area 22?
Wernicke’s area
At what level of factor 8 deficiency does APTT become prolonged?
<45%
APTT mixing studies that initially correct but then prolong again after 1-2h incubation due to…
Weak autoantibodies to factor 8
CLL cell surface CD markers (4)
CD 5 (aberrant, normally on T cells) + CD 19 + CD20 + CD23
Hereditary spherocytosis; affected proteins (3)
Ankyrin
Spectrin
Band 3 red cell protein
(Usually AD inheritance)
Key lineage to distinguish between MDS and aplastic anaemia
Megakaryocytes
Condition that aplastic anaemia overlaps with nearly 50% of the time
PNH
Which type of cryoglobulinaemia is hyperviscosity syndrome associated with?
Type I cryoglobulinaemia
(Which is associated with Waldenstrom’s, myeloma and CLL)
(Sx usually at viscosity > 4.0 centipoise)
Main factors guiding dosage of iron-chelating therapy (3)
Presence of cardiac iron overload
Rate of transfusional iron
Body iron burden
(Best measured by periodic MRI and ferritin)
What is Evan syndrome
Autoimmune haemolytic anaemia with ITP seen in pregnancy
Gene mutation causing PNH
Phosphatidylinositol glycan class A (PIGA)
This is required for synthesis of GPI-anchored proteins including CD55 and CD59.
CD 55/59 are complement regulators. If deficient, excess complement-mediated intravascular haemolysis of affected cells occurs
Main cause of death in PNH
Thrombosis e.g. abdominal or cerebral veins
Main presentations of GvHD (3)
Rash, GI tract, liver
Cell marker for plasma cells
CD138
Risk factor for warfarin-induced skin necrosis
Protein C deficiency (due to exaggeration of initial hypercoagulable state)
Malignancies associated with EBV (3)
Nasal NK cell lymphoma
Burkitt’s lymphoma
T-cell lymphoma
Common complication / differential in Sickle Cell disease
Salmonella osteomyelitis (which may be masked / mimicked during vaso-occlusive crises)
Key features of Autoimmune polyendocrine syndrome type I
2 of 3 of:
- Mucocutaneous candidiasis
- Hypo-PTH
- Addison disease
Likely due to AIRE mutation
Predisposed to many other AI conditions
Conditions associated with thymoma (2)
Myasthenia gravis
Pure red cell aplasia (see anaemia / absent erythroblasts on BM but normal myeloid cells and megakaryocytes)
Chromosome for HLA
Ch 6
Which HLA encodes MHC-II
HLA-D
And expresses slightly longer peptides 15-25 amino acids in length
Which HLA encodes MHC-I
HLA-A, -B and -C
And expresses shorter peptides, 8-10 amino acids
Which TLR is activated by lipopolysaccharide (LPS)?
TLR4
LPS is the ‘prototypical’ PAMP
Difference between IgA1 and IgA2
Their heavy chains
Main location for:
- IgA1
- IgA2
Airways and serum
Colon
(Similar levels in small intestine)
NK cell surface markers
CD56 +
CD3 -
Mechanism of immunotherapy
Alters T-cell reactivity to antigen, causing reduction in cytokine release
(no longer thought to be due to reduction in IgE or from induction of ‘blocking IgG Abs
Macrophage-released cytokines
IL-1 (responsible for stimulating hypothalamus causing fever)
TNF
Basiliximab
- Use
- Target
Immune suppression induction
Targets CD25 (part of the IL-2 receptor)
(Can also be used during periods of acute rejection)
What does icatibant do?
Bradykinin antagonist, used in hereditary angioedema
True / False: tryptase is more useful in venom- or medication-related anaphylaxis that food-related anaphylaxis.
True
Type of tryptase found after mast cell degranulation
Beta-tryptase (the mature form)
Usual circulating tryptases are pro-alpha and pro-beta tryptase
Tests in hereditary angioedema (2)
Low C1inh level or function
Low C4 (due to persistent breakdown by C1 esterase, which isn’t being inhibited)
What measurement is used to calculate / compare a drug’s bioavailability?
Area under the curve
True / False: the dose of a drug affects its bioavailability.
False
Key pharmacodynamic property that guides efficacy of beta-lactams and lincosamides
Time the concentration is above the MIC (T > MIC)
I.e. time-dependent killing
Key pharmacodynamic property that guides efficacy of aminoglycosides and fluoroquinolones
Ratio of area under the curve over 24-h dosing (AUC0–24) to minimum inhibitory concentration (MIC);
AND the ratio of maximal concentration (Cmax) to MIC
I.e. concentration-dependent killing
Related to volume of distribution and clearance
Key pharmacodynamic property that guides efficacy of vancomycin (glycopeptides)
Total body exposure to the antibiotic (ratio of AUC0-24 to MIC)
(Also relevant to aminoglycosides)
Related to VoD and clearance
Is rifampicin a CYP inducer or inhibitor?
Inducer
E.g. reduces antiepileptic levels
Key CYP enzyme for warfarin (and examples of drugs that affect it)
CYP2C9 - which gets inhibited by:
- Omeprazole
- Metronidazole
- Cimetidine
- Amiodarone
How does ivabridine work
Slows heart rate via action on If channel in sinus node
What 2 parameters affect steady state drug concentration during an constant rate infusion?
Dose rate
Clearance
Caspofungin mechanism
Inhibits synthesis of fungal cell wall beta(1-3)-D-glucan component
(Low oral bioavailability, must be given IV)
Amphotericin B mechanism
Forms artificial pores in membranes by binding to ergosterol
‘Azole’ mechanisms
Inhibit CYP system, thereby stopping synthesis of ergosterol from lanosterol
Morphine receptors (4)
Mu - analgesia, euphoria, miosis, respiratory depression
Kappa - analgesia, miosis, respiratory depression, sedation
Sigma - dysphoria, hallucination, psychosis
Delta - Unclear
Mechanism of Tacrolimus
Binds FK506-binding protein –> inhibits calcineurin –> stops T-cell activation and IL-2 release
Mechanism of Cyclosporin
Activates cyclophilin –> inhibits calcineurin –> stops T-cell activation / IL-2 release
Which immunosuppressant causes cytokine-release syndrome
Anti-thymocyte globulin
Immunosuppressant that causes pneumonitis
Sirolimus (mTOR inhibitor, which stops cytokine signaling from activating the cell)
Also binds FK506 (like tacrolimus but doesn’t inhibit calcineurin).
Role of tRNA
Small RNA chain that transfers a specific amino acid to a growing polypeptide chain during translation.
What do microRNAs do?
Bind to complementary mRNA, reducing their expression or translation.
Which DNA nucleotide is the target for methylation / inactivation?
Cytosine
What is heteroplasmy?
The tendency for a mitochondrial mutation to be present in only a proportion of the cell’s mitochondrial genome copies.
Familial Adenomatous Polyposis:
- Gene
- Inheritance pattern
- When to start screening
- How frequently to sceen
APC (tumour suppressor)
Autosomal dominant
Sigmoidoscopy at age 12
Annually
Scenario with peripheral neuropathy, angiokeratomas, corneal whirls and murmur/hypertrophy is likely to refer to…
Fabry disease
(X-linked lysosomal storage disorder with accummulation of glycosphingolipid)
(Can also see renal failure and clots in the brain)
Diseases displaying anticipation (5)
Huntingtons Fragile X syndrome Spinocerebellar ataxia Myotonic dystrophy Friedreich ataxia
Huntingtons allele and number of copies causing disease
CAG
Normal <34 repeats
Variable penetrance 35-39
Disease > 40
Early onset >60
Acute intermittent porphyria:
- Inheritance pattern
- Enzyme affected
- Accummulated products
Autosomal dominant
Porphobilinogen deaminase
ALA and PBG
von Willebrand’s disease inheritance:
- Type 1
- Type 2
- Type 3
Autosomal dominant
Autosomal dominant
Autosomal recessive
Disease with co-dominant inheritance pattern
Alpha-1-anti-trypsin deficiency
Largest gene
Dystrophin
On x-chromosome
Location of magnesium absorption
Small intestine (via passive uptake)
Uptake is dependent on Mg levels, rather than intake
Role of magnesium in muscle contraction
Stimulates calcium reuptake by the sarcoplasmic reticulum
Site of Magnesium reabsorption
Thick ascending limb of loop of Henle
Mechanism of cocaine
Inhibits reuptake of:
- Dopamine (euphoria)
- Serotonin (confidence)
- Norepinephrine (energy)
Mechanism of ezetimibe
Inhibits transport of cholesterol across intestinal wall (increasing cellular LDL-R expression –> increased LDL uptake)
Mechanism of fibrates
Activates PPAR –> alter lipoprotein synthesis and catabolism
Gordon syndrome
- Mechanism
- Inheritance
- Key features (4)
- Treatment
WNK4 mutation –> increased sodium-chloride co-transporter expression
(‘opposite of Gittleman’)
Autosomal dominant
HTN, hyper-K+, low renin, NORMAL aldosterone
Thiazide diuretic
Examples of drugs that inhibit CYP2D6 (3)
Fluoxetine, paroxetine, bupropion
Drugs that rely on CYP2D6 for activation (2)
Codeine,
Tamoxifen
Main ECG finding in hypothermia
J-waves (AKA Osbourne waves)
Other findings include absent P-waves, PR interval prolongation, prolonged QRS, prolonged QT
Toxic metabolic product of methanol
Formaldehyde –> formic acid –> retinal / optic nerve damage
Toxic metabolic product of ethylene glycol
Glycolic acid –> acidosis / calcium crystals –> AKI
Which feature of Wernicke’s encephalopathy is first to resolve with thiamine administration?
Ocular palsies (within hours)
Smoking effect on clozapine / which CYP
Smoking induces CYP1A2 which increases clozapine clearance - may need up to double dose.
(Reverse applies with CYP1A2 inhibitors e.g. theophylline, cipro)
Which antiepileptic can cause encephalopathy secondary to high ammonia levels?
Valproate
How to calculate Variance (stats)
Standard deviation squared
