SOE Flashcards
Risk factors AAA?
Male, >65, smoking, HTN, MI/stroke, genetic-marfans etc
Atypical symptoms of AAA?
back pain (renal colic like), mimicking sciatica, chronic severe back pain (contained), transient LL paralysis
What is a aorto-enteral fistula associated with?
a previous graft that has eroded into the GI tract
How prognosticte AAA?
APACHE and POSSUM not up to much. Use Hardman index or Glasgow Aneurysm score
Complications following emergency AAA?
Early/late, graft and non-graft related. Early graft- distal embolism, AKI, leak Late graft- infection, aorto-enteral fistula, pseudoan Early non-graft- MI, ARDS, ileus etc Late non-graft- SBO, incisional hernia
What is the most important factor in predicting outcome post AAA repair?
Age followed by shock at presentation and AKI
When is AAA electively repaired?
Male >5.5, Female >5cm or >1cm/year
What are the indications for spinal drain insertion post AAA?
If complex case and concern or to rescue delayed paraplegia
Where are lumbar drains inserted?
Into sub-arach space
Absolute and relative contra-indications for lumbar drain insertion
Absolute- pt receving anticoags, bleeding
Rel- non-comm hydroceph, large SOL or infection
Normal IAP?
5-7mmHg
Grades of abdominal HTN?
Grade 1- 12-15
2 16-20
3 21-25
4 >25
Define abdominal compartment syndrome
IAP>20 with or without APP<60 with new organ dysfn or failure
Risk factors for getting abdominal HTN?
Reduced wall compliance -trauma, burn, prone
Inc abdo contents- Intra or extra mural
Capillary leak
Other- Mech vent, high PEEP, inc head of bed, shock
How can measure abdo pressure?
Needle though abdo wall (direct)
Or indirect- bladder ut also stomach, colon, uterus
Effect of high abdo pressure on other organ systems?
Resp-basal atelectasis- VQ mismatch
CV- reduced venous return, inc afterload
Neuro- says inc ICP but not sure if I believe it
Renal- direct compression, up-reg RAAS
GI/hepatic- hypoperfusion, biliary stasis
Indications for open abdomen?
Severe necrosing pancreatitis
Abdo sepsis
Damage control post trauma
Emergent vascular surgery
The complication of open abdomen>
Nursing- skin, pain Fluid loss Malnutrition Infection Adhesions Ileus Longer term hernias High risk of enterocutaneous fistula
What temporary closure devices for abdomen?
Bogota bag- 3L plastic bag fixed to gascia or skin
Negative pressure therapies
Sythetic mesh
Velcro-type sheath Whittmann patch
What is the Bamford classification?
TACS/PACS, LACS and POCS s
When does the National Institute of Neurology and Stroke (NINS) say thrombolysis is contra-indicated?
prev ICH BP >185 or DBP>110 Trauma/stroke in last 3/12 Coagulopathy- plt <100, PT >15 on anticoags Major surgery within 14/7 GI haem within 21/7 Severe hyper or hypogly Seizures at onset or SOL Isolated mild deficits or recent MI
What studies have looked at decompressive craniectomy for malig MCA?
DESTINY, DECIMAL and HAMLET <60 and DESTINYII >60
Sig reduction in mortality but nearly all had significant impairment. And over 60 is not recommended.
When should decompressive craniectomy be considered?
If <60, MCA infarct, NIHSS >15, CT evidence of infarct of at least 50% MCA territory.
Therapeutic hypothermia in ischaemic stroke?
No benefit- hyperthermia should be avoided. Most recent trial EuroHYP-1
Interventional radiology in ischaemic stroke- what can be done and timings?
Clot retrieval can be considered up to 8 hours post in some situations but rare.
More common is those with carotid or MCA clots not responding to thrombolysis
When does focal cerebral ischaemia result in coma?
Brainstem affecting the reticular activating system
Malig MCA with oedema and herniation
Cerebral venous thrombosis- raised ICP, cerebral oedmea and seizure
Mechanism of contrast induced AKI?
Direct reactive O2 species
Imbalance of constriction and dilatation
Contrast induced diuresis and increased viscocity of urine
Risk factors for getting contrast induced AKI?
Age >75, CKD eGFR<60, nephrotoxic drugs, IV contrast (as opposed to PO)
Define KDIGO stages
1- 1.5-2x creat or >26.5micromol/l or <0.5ml/kg urine for 6-12hrs
2. 2-3x < 0.5ml/kg/hr for more than 12 hrs
3- >354micromol/l or >3x creat or on RRT, <0.3 ml urine for 24hrs or anuria for 12 hrs
Potential protection from contrast induced AKI?
Fluid
NAC- though may reduce creatinine release rather than helping kidney
Bicarb- renal alkalinisation
What are the diagnostic criteria for contrast induced AKI?
Cr rise >44 or 25% from baseline within 48hrs
How manage a patient with AKI?
STOP Sepsis and hypoperfusion Toxins Obstruction Primary renal No evidence converting oliguria to polyuria using diuretics helps AKI
Types of RRT?
CVVHF, CVVHD, CVVHDF, CUF (slow cont ultra-filtration) and SLEDD (sustained low-efficiency daily dialysis)
Which trials have looked at dose of effluent in RRT?
RENAL 2009- 25 vs 35ml/kg no benefit
IVOIRE no benefit 70 vs 25
Disequilibrium syndrome- what is it and how avoid?
Cerebral oedema from urea shifts. Therefore aim reduce urea by 30% r less in first 24hrs
Commonest cause of ALF in developing world vs UK?
HAV, HBV and HEV in developing world. Paracetamol iin UK
Causes of ALF?
Infective- Hepatitis, CMV, EBV Drugs- paracetamol, AEDs, St John's wort, chemo, recreational drugs Toxins- amatoxin Malignancy Vascular- Budd-Chiari (HVein), ischaemia Preg- HELLP Metabolic- Wilsons Autoimmune
Kings criteria for paracetamol ALF?
pH<7.3 or all three of PT>100s Cr >300 G3 or 4 encephalitis
King’s criteria for non-paracetamol ALF?
PT>100s or any three of 1. Age <11, >40 2. Non A, Non B heptatis or idiosynchcratic 3. Jaundice to enceph >7/7 4. PT>50 5. TB >300
What is the system for grading encephalitis?
West-Haven criteria
What are the mechanisms for renal failure in ALF?
ATN most commonly due to hypo-perfusion or nephrotoxins
GN in HBV or HCV is possible
Intra-abdo HTN due to ascites
HRS
What is the management of ALF with regards to other organ systems?
Resp- G3/4 enceph usually need intubation. Low PEEP
CV- Use vasopressors and get euvolaemia
Neuro- neuro-protective measures CPP 60-80 but controversial as is hypothermia etc
Renal- RRT early to avoid overload and acidosis
Coag- DIC common
Paracetamol mechanism of ALF?
NAPQI is hepatotoxic. Paracetamol is metabolised largely by glucoronidation and sulphation but a very small amount is by CYP450 which is de-toxified by glutathoine. If the glucoronidation and sulphation is saturated more goes down the CYP system overwhelming the glutathione.
What are the risk factors for developing paractamol toxicity?
Cytochrome induction- chronic EtOH, inducing drugs
Glutathione depletion- malnutrition or alcohol
What is ARDS?
acute, diffuse inflammatory lung injury leading to increased pulmonary vascular permeability, increased lung weight and loss of aerated lung tissue with hypoxaemia and bilateral radiographic opacities associated with increased venous admixture, increased dead space and decreased lung complaince
Pulmonary causes of ARDS
Pneumonia, contusion, aspiration, inhalational injury, vasculitis, drowning
Non-pulmonary cause of ARDS
Sepsis, burns, trauma, TRALI, pancreatitis, bypass
What is the pathophysiology of ARDS?
Triphasic-
- Exudative- days 2-40 inflammation and leak with microthrombus causing VQ mismatch and reduced complaince
- Proliferative- days 4-7 proliferation of type II pneumocytes and fibroblasts with fibrin deposition, scar formation
- days 7-14 fibrotic stage
What trials looking at NMBAs in ARDS?
ACURASYS severe ARDS with cisatra or placebo showed a 90day mort benefit in patients with PF<120 and inc ventilator free days with no inc in ICU weakness
What studies have looked at prone ventilation in ARDS?
PROSEVA showed 50% reduction in mortality with NNT 6.
What trials have shaped the use of HFOV?
OSCAR- no benefit
OSCILLATE- harm NNH 9
Steroids in ARDS?
Conflicting evidnce. Thought that low dose long course later in disease process may be of help. in 2006 Steinberg gave methylpred and showed reduced ventilator days but no mort benefit and increase in myopathy and neuropathy.
In 2007 Meduri gave steroids early which showed a great improvement but with septic shock as a complication. Underpowered.
Components of Murray score?
PF ratio, PEEP, Compliance, CXR findings
Types and causes of adrenal insufficiency?
1, 2 and 3ary. Primary is Addison's of which 70-90% autoimmune. Others inclue TB infection, HIV and CMV, mets, drugs (etomidate) and others including waterhouse-Friderichsen syndrome Also 2ary (pituatary) and tertiary (hypothalamus) from seroids down regulation, infarction (Sheehan's) and malig
Type of shock in Addison’s or similar?
High CO distributive
Triad of amniotic fluid embolism?
CV collapse, coagulopathy and hypoxia
Phases of amniotic fluid embolus
phase 1 RV failure and anaphylaxis type picture followed by LV failure and DIC with sepsis type leaky capillaries
Risk factors for amniotic fluid embolism?
No RF but association like mechanical delivery, older mum, placetnal pathology, multiparity, trauma
Types of hypersensitivity reactions? What type is anaphylaxis?
Types 1-4
Type 1 is anaphylaxis IgE mediated
What are types 2,3 and 4 hypersensitivity reactions and give examples
2- IgG or M mediated ab-mediated . Eg, autoimmune haemolytic anaemia, Goodpasture’s
3- Immune complex mediated- IgG or complement- Lupus, RA
4- Delayed,T-cells- contact derm, chronic rejection
How is tryptase taken in anaphylaxis?
ASAP and 1-2hrs post then 24hrs
When test for cause if anaphylaxis?
Send all to clinic in 4-6/52 to allow mast cells to make histamine again
What other tests apart from prick tests in allergy?
RAST- measures IgE ab in serum
ImmunoCAP- enzyme assay more sensitive than RAST but both of these have a low sensitivity.
Examples of bacteriostatic and cidal abx?
bateriacidal- Pens, cephs, aminoglyc, glycopep, quinonlones, nitroimidazole, Rifiampicin, Nitro
Static- Macrolides, tetracyclines, Trimethoprim, Clindamycin
Mechanism of action of abx?
Inhibit cell wall
Inhibit DNA snthesis of fn
Inhibit tetrahydrofolate
Inhibit protein synthesis
What is time dep and conc dep killing of bacteria?
Time dep is time above MIC
Conc dep- killing correlates with peak conc such as aminoglyc
Which abx inhibit cell wall?
Penicillin, cephalosporins and glycopeptides (Vanc)
What abx inhibit DNA synthesis/fn
Metronidazole Cipro, Rifampicin
Which abx inhibit protein synthesis?
Erythro etc, clinda, linezolid, Gent
Give G-cocci
Neisseria and Moraxella
G+ve rods?
ABCDL
Actinomyces, Bacillus, clostridia, Diptheria and listeria
Mechanism of abx resistance?
Intrinsic-lack of target, lack of transport mechanism, impermeable membrane
Acquired- Drug inactivation (b-lactamases), efflux of drug (pseudomonas), alternative pathyway or altered molecular target
How is resistance to abx acquired?
Mutation or horizontal gene transfer eg free DNA, bacteriophages, plasmid conjugation
