Revision Flashcards
1
Q
Definition pyrexia of unknown origin
A
Fever >38.3 multiple occasions
Fever > 3 weeks
One week of appropriate investigations in hospital
2
Q
DDx pyrexia of unknown origin
A
Infection (BOATS) -bacterial endocarditis (coxiella, HACEK) -osteomyelitis -abscess (abdominal/pelvic) -TB Connective tissue disease -adult still -giant cell -PAD/takayasu/ANCA Malignancy -lymphoma -leukemia -RCC -hepatocellular Drugs (drug fever) -antimicrobials -antihistamines
3
Q
History pyrexia of unknown origin
A
DETAILS
- Drugs
- Exposures (contacts, occupational)
- Travel
- Animals
- Immunosuppression (HIV)
- Localising symptoms
- Sexual Hx
4
Q
Investigations pyrexia of unknown origin
A
Urinalysis
Urine culture
3x Blood culture
FBC -differentials -film EUC LFT ESR/CRP
PEP ANA RF Mantou or IGRA HIV serology Heterophile antibody
CXR
Abdo ultrasound
Nuclear medicine (consider)
- FDG PET CT
- gallium-67 or indium-111–labeled leukocyte scintigraphy
5
Q
Pathophys fever
A
Pyrogens
- exogenous
- > endotoxin (lipopolysaccharide on G neg bacteria)
- > superantigens for staph aureus
- endogenous cytokines
- > IL-1
- > IL-6
- > TNF alpha
- > can be induced or released by micro-organisms
- > can be released in sterile inflammatory conditions (eg. pericarditis)
Elevation of hypothalamic set point
- Endogenous/exogenous pyrogens enter systemic circulation
- interact with endothelium of organum vasculosum of lamina terminalis
- > network of englarged capillaries
- > surrounds hypothalamus regulatory centers
- Release of PGE2 on hypothalamus side of endothelium
- Binding to EP-3 receptor on glial cells
- > release of cAMP
- Acts as neurotransmitter
- > activates neuronal endings from thermoregulatory center
- Elevation of set point
6
Q
AKI ddx
A
PRE Hypovolaemia Decreased cardiac output Decreased effective circulating volume -CCF -Cirrhosis Impaired autoregulation -NSAIDs -ARBs -ACEI
INTRINSIC
Glomerular (Mindful Sailors Invest In A Good Anchor):
- membranoproliferative
- SLE
- IgA
- infectious (eg. post strep)
- anti GBM
- good pastures
- ANCA (polyangitis with granulomatosis, microscopic polyangitis, eosinophilic granulomatosis with polyangitis)
Vascular (Some Honest Virgins Admit Masturbating Every Day They Can):
small:
- Scleroderma
- Hypertension (malignant)
- Vasculitis
- Atheroemboli
- Microangiopathies
large:
- Embolus (systemic/renal)
- Dissection (aortic)
- Thrombosis (renal vein)
- Compartment syndrome (abdo)
Tubulointerstitial (Indoor Dogs Should SIT on their MAT)
interstitial nephritis:
- Infections (legonella)
- Drugs (antibiotics, NSAIDs)
- Systemic (sarcoid, srjogens, SLE)
ATN:
- Sepsis
- Ischaemia
- Toxins (vanc, aminoglycosides, contrast)
tubular obstruction:
- Myeloma
- Acyclovir
- Tumor lysis syndrome
POST
Prostate -BPH -neoplasia Bladder -neurogenic -anti-cholinergics Urethra intraluminal -clots -calculi -necrotic papillae intramural -neoplasia extramural -neoplasia -iatrogenic -retroperitoneal fibrosis -abscess
7
Q
AKI investigations
A
VBG/ABG -high anion gap = decreased GFR and retention of acids -normal anion gap with high urine pH = renal tubular acidosis (Type 1 with impaired distal H secretion; Type 2 with impaired proximal bicarb reabsorption) Urinalysis Urine chemistries -FENa (<1 = pre-renal, >2=ATN) -FEUrea when diuretics (<35=pre-renal, >65=ATN) Urine osmolality -increased = pre-renal -decreased = ATN ECG -hyperkalaemia
FBC -anaemia (haemolysis, microangiopathies, myeloma) -eosinophilia (interstitial nephritis, emboli, vasculitides) -thrombocytopenia (microangiopathy) EUC -eGFR -urea:creatinine ratio >20 = pre-renal -hyperkalaemia CMP -hyperphosphataemia -hypocalcaemia
Renal ultrasound/CT -obstruction -architecture Chest xray -CCF -Pulmonary oedema
Consider (in glomerulonephritis)
- ANA/anti-DSDNA = lupus
- C3/4 = immune complex GN types
- anti-GBM antibodies
- ANCAs
- cryoglobin
- anti-streptolysin O (post strep), hep (membranoproliferative) and HIV serology based on Hx
- biopsy
8
Q
ddx haematuria
A
NIICCKSS
neoplasm
- kidney (RCC, transitional)
- bladder (urothelial, squamous)
- penile (squamous)
- ureter
- prostate (BPH/cancer)
Infection
- UTI
- pyelonephritis
Inflammation
- prostatitis
- cystitis
- diverticulitis
Cysts
-PCKD
Coagulopathy
- medical (eg. von willebrand, platlete (MAID FLUID), haemophilia, vessel wall)
- drugs
Kidney injury (glomerular) -Mindful Sailors Invest In A Good ANCA
Stones
- renal
- bladder
Staining
- beets
- phenazopyridine
- rifampicin
9
Q
anaphylaxis pathophys
A
Type 1 (IgE) mediated hypersensitivity
- anaphylactoid
- > direct activation of mast cells by agents eg. vanc
- sensitisation
- > exposure to allergen
- > clonal expansion and class switching to IgE plasma/memory by cells
- > driven by Th2 cells and interleukins
- > IgE secreted systemically and constitutively occupies IgE high affinity receptor on mast cells (and basophils)
- second exposure
- > binding of allergen to IgE on mast cells causes receptor cross linking
- mast cell activation and degranulation
- > release of preformed mediators eg histamine and tryptase
- > formation of eicosanoids eg cysteinyl LT’s and PGD2
- > release of inflammatory cytokines eg TNF α
effect of mediators
- histamine
- > H1 and H2 receptors mediate hypotension, flushing, headache, vascular permeability
- > H1 mediates coronary vasoconstriction, slows AV nodal conduction and bronchospasm
- > H2 chronoptropy, ionotropy = tachycardia
- tryptase
- > relatively specific marker for mast cell degranulation
- PAF
- > bronchoconstriction
- > vascular permeability
- > chemotaxis
- eicosanoids
- > vasodilation
- > vascular permeability
- > bronchoconstriction (much more than histamine)
- inflammatory cytokines
- > drives delayed inflammatory response
- > influx inflammatory cells
- > mediator release acts directly on tissue causing allergic symptoms
- > further recruitment of inflamm cells in vicious cycle
- counter-regulatory mediators
- > renin and chymase
- > activation of RAS and angiotensin 2 formation
10
Q
anaphylaxis diagnostic criteria
A
1
- acute onset
- mucocutaneous symptoms with
- > resp symptoms
- > decreased BP and its manifestations
2
- exposure to likely allergen
- any two of following
- > mucocutaneous
- > GI symptoms
- > resp symptoms
- > decreased BP and its manifestations
3
- exposure to known allergen
- decreased BP and its manifestations
11
Q
anaphylaxis ddx
A
ASAP Fluids, Ventilation, Adrenaline
- anaphylaxis sub types
- shock
- > septic
- > cardiogenic
- > hypovolemic
- asthma/COPD exacerbation
- panic attack
- foreign body aspiration
- vasovagal reaction
- anaphylactoid reaction
- > drugs
- > contrast
12
Q
anaphylaxis treatment
A
lie patient down
- > sitting/standing up decreases venous return
- > PEA
A -patency -angioedema B -non rebreather -low threshold for intubate ->stridor C -two large IV canulas ->normal saline as fast as possible -IM adrenaline ->1:1000 ampule into 1mL syringe ->max dose for adult = 0.5mg (half syringe) ->repeat every 5-15 mins -IV adrenaline ->only when no response to several IM ->give as slow infusion not bolus ->1:10,000 syringe into 1L bag ->gives 1mcg/mL ->start at 1mcg/kg/min and increase ->safe upper limit unknown D -serially assess GSC E -remove allergen
13
Q
late management anaphylaxis
A
Adjuvant pharm
- bronchodilators
- > SABAs
- glucocorticoids
- > methypred
- > no evidence for use
- > prevent biphasic reaction
- antihistamines
- > predominantly H1
- > no role in acute treatment
- > may relieve mucocutaneous symptoms
Time to discharge
- usually 4 hours
- biphasic can occur up to 72 hours after
- > occurs in 20%
SAFE discharge
- seek support
- > education on anaphylaxis
- > informing family and carers
- > anaphylaxis emergency plan
- allergen avoidance
- follow up
- > with immunologist
- > allergy identification
- > anaphylaxis diagnosis often changed
- epinephrine
- > two scripts
- > urge to fill immediately
- > educate on proper use
14
Q
anaphylaxis investigations
A
ABG -resp failure -acidosis ->resp ->mixed with lactate build up ECG
FBC EUC -end organ damage -GFR LFTs -end organ damage tryptase -early collection -sensitive for anaphylaxis plasma histamine ->peaks within 15mins ->baseline within 60mins ->can support anaphylaxis
consider:
- CXR
- > ddxs
- trops
- > MI as complication
later
- in vitro IgE
- > quantitate allergen specific IgE
- skin test
- > eg scratch test
- > greater than 3cm
- challenge
- > avoid in anaphylaxis
15
Q
chronic cholecystitis path
A
macroscopic
- serosa is smooth and glistening
- > covered with dense fibrous adhesions
- wall
- > variable thickness
- > gray appearance
- lumen
- > greeny bile with gall stones
microscopic
- subserosal fibrosis
- mucosa
- > macrophage, plasma cells, lymphocytes
- > folds of mucosa with buried crypts
- > outpouching of epithelium into walls (rokitansky aschoff sinus)
- evidence of chronic complications
