Misc PSA 1

Question 1

Why is LMWH generally preferred to UFH for VTE prophylaxis?

Answer 1

More specific for Xa than thrombin when given subcut so has predictable properties and activity

Question 2

How does LMWH work?

Answer 2

Activates anti-thrombin III, which in turn inactivates Xa and thrombin

Question 3

When is UFH sometimes preferred to LMWH for VTE prophylaxis and why?

Answer 3

In the renally impaired - UFH is excreted via liver and RES

Question 4

4 side effects of subcut LMWH delivery?

Answer 4

Haemorrhage
Injection site reactions, skin necrosis
Heparin induced thrombocytopenia
Osteoporosis if given long term

Question 5

What is Fondaparinux and how does it differ to other LMWH? What benefit does it have?

Answer 5

Synthetic Xa inhibitor

Lower risk of thrombocytopenia

Question 6

What are apixaban and rivaroxaban?

Answer 6

Direct Xa inhibitors

Question 7

How does dabigatran work?

Answer 7

Direct thrombin inhibitor

Question 8

What side effects are more common in NOACs than LMWH/UFH and warfarin?

Answer 8

GI upset - nausea, vomiting, abdo pain

Question 9

If a COPD patient has a PMH of requiring NIV, what does this suggest about their disease?

Answer 9

Suggests that they are CO2 retainers, and therefore caution should be paid when administering O2 (target sats of 88-92% with a satisfactory PaO2)

Question 10

How should nebulisers be driven in CO2 retaining COPD patients?

Answer 10

Air

Question 11

What are the advantages and disadvantages of IV morphine vs other routes?

Answer 11

Quickest onset - 5 mins

Biggest side effects - hypotension, depressant effects

Question 12

What is dose stacking in relation to IM/SC morphine? How do you get around this?

Answer 12

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

Question 13

What effect does circulatory compromise have on the absorption of SC/IM drugs? What clinical effect can this have when circulation is restored?

Answer 13

Reduces it

So when circulation is restored can get a pool of drug released into bloodstream - e.g. Opioid intoxication

Question 14

Is PO morphine suitable for acute severe pain?

Answer 14

No - takes too long to activate (at least 30 mins)

Question 15

Which delivery method of morphine is most suitable for acute severe pain and why?

Answer 15

IV - quickest onset and therefore also easy to titrate

Question 16

3 contraindications to mechanical VTE prophylaxis (stockings)?

Answer 16

Marked oedema
Peripheral arterial disease
Neuropathies

Question 17

What two classes of drugs should be prescribed alongside morphine?

Answer 17

Anti-emetic e.g. Ondansetron, cyclizine

Laxative

Question 18

Why is metoclopramide best avoided in GI patients?

Answer 18

It increases GI motility

Question 19

When prescribing for acute AF, what do you need to prescribe to prevent early clot?

Answer 19

Short term treatment dose LMWH

Question 20

What is the conc, dose, and method of adrenaline administration for anaphylaxis?

Answer 20

1:1000 (1g in 1000ml, or 1mg in 1ml)
500 micrograms so 0.5ml
IM route

Question 21

After how long can you give a second dose of adrenaline in anaphylaxis?

Answer 21

5min

Question 22

How much water, Na and K does the average person need per day?

Answer 22

30ml/kg water -> 2-2.5L
1mmol/kg Na
1mmol/kg K

Question 23

4 examples of crystalloid fluids?

Answer 23

Saline
Dextrose
Dex-saline
Hartmanns

Question 24

3 examples of colloid fluids?

Answer 24

HAS
Gelofuscine
FFP

Question 25

What is the difference between crystalloids and colloids?

Answer 25

Colloids contain something osmotically active e.g. Albumin and so the fluid remains in the intravascular space (in theory)

Question 26

How is daily maintenance fluid often given?

Answer 26

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