Misc PSA 1 Flashcards
Why is LMWH generally preferred to UFH for VTE prophylaxis?
More specific for Xa than thrombin when given subcut so has predictable properties and activity
How does LMWH work?
Activates anti-thrombin III, which in turn inactivates Xa and thrombin
When is UFH sometimes preferred to LMWH for VTE prophylaxis and why?
In the renally impaired - UFH is excreted via liver and RES
4 side effects of subcut LMWH delivery?
Haemorrhage
Injection site reactions, skin necrosis
Heparin induced thrombocytopenia
Osteoporosis if given long term
What is Fondaparinux and how does it differ to other LMWH? What benefit does it have?
Synthetic Xa inhibitor
Lower risk of thrombocytopenia
What are apixaban and rivaroxaban?
Direct Xa inhibitors
How does dabigatran work?
Direct thrombin inhibitor
What side effects are more common in NOACs than LMWH/UFH and warfarin?
GI upset - nausea, vomiting, abdo pain
If a COPD patient has a PMH of requiring NIV, what does this suggest about their disease?
Suggests that they are CO2 retainers, and therefore caution should be paid when administering O2 (target sats of 88-92% with a satisfactory PaO2)
How should nebulisers be driven in CO2 retaining COPD patients?
Air
What are the advantages and disadvantages of IV morphine vs other routes?
Quickest onset - 5 mins
Biggest side effects - hypotension, depressant effects
What is dose stacking in relation to IM/SC morphine? How do you get around this?
Peak dose takes longer to achieve so doses can stack if given too close together
Leave at least 1 hour between IM and 2 hours between SC morphine doses
What effect does circulatory compromise have on the absorption of SC/IM drugs? What clinical effect can this have when circulation is restored?
Reduces it
So when circulation is restored can get a pool of drug released into bloodstream - e.g. Opioid intoxication
Is PO morphine suitable for acute severe pain?
No - takes too long to activate (at least 30 mins)
Which delivery method of morphine is most suitable for acute severe pain and why?
IV - quickest onset and therefore also easy to titrate
3 contraindications to mechanical VTE prophylaxis (stockings)?
Marked oedema
Peripheral arterial disease
Neuropathies
What two classes of drugs should be prescribed alongside morphine?
Anti-emetic e.g. Ondansetron, cyclizine
Laxative
Why is metoclopramide best avoided in GI patients?
It increases GI motility
When prescribing for acute AF, what do you need to prescribe to prevent early clot?
Short term treatment dose LMWH
What is the conc, dose, and method of adrenaline administration for anaphylaxis?
1:1000 (1g in 1000ml, or 1mg in 1ml)
500 micrograms so 0.5ml
IM route
After how long can you give a second dose of adrenaline in anaphylaxis?
5min
How much water, Na and K does the average person need per day?
30ml/kg water -> 2-2.5L
1mmol/kg Na
1mmol/kg K
4 examples of crystalloid fluids?
Saline
Dextrose
Dex-saline
Hartmanns
3 examples of colloid fluids?
HAS
Gelofuscine
FFP
What is the difference between crystalloids and colloids?
Colloids contain something osmotically active e.g. Albumin and so the fluid remains in the intravascular space (in theory)
How is daily maintenance fluid often given?
3 bags:
1 salty - 500ml 0.9% saline over 8 hours with 20ml of KCl
2 sweet - 1L each bag of 5% dextrose over 8 hours with 20ml of KCl
