CLINICAL- SURGERY Flashcards
What factors are looked into in a pre-clerking clinic/ pre-admissions clinic?
History (e.g. DVT, problems with anaesthetics)
Examination: ECG, Lung function
Weight- for medication doses e.g. dalteparin, gentamicin: may not be able to get out of bed after op to weigh.
Blood Pressure
Blood Glucose- diabetes management pre-op
Blood Test: for blood group incase of infusion, anaemia (anaemia= more blood needed, if Hb is low then they may need an IV IRON INFUSION before the Op)
MRSA screen- Nose swab; If they have it give them a sterile wash an nose cream
It is vital to get a complete accurate record of patients medications before their operation as they may be drowsy after it and there is risk of missing doses.
Accurate history is essential for surgery.
DOCUMENT ALLERGIES
Should get it from 2 sources: ask patient for medication before surgery, use a summary care record or repeat prescription.
Patients must FAST before operations.
They must not EAT 6 HOURS before surgery.
Why is this?
There is a risk of ASPIRATION OF Stomach contents during general anaesthetic. This could result in choking in surgery.
We need an empty stomach for general anaesthetics.
What is the general rule for giving medicines on the morning of surgery?
All regular medication (except anticoagulants and oral hypoglycaemics e.g. Metformin) should be given on the day of surgery with small sips of water
Can you think of any of the medicines we need to think twice about before giving them to patients on the morning of their surgery?
Warfarin Oral Hypoglycaemics INSULIN Anti-platelets e.g. Aspirin Cardiac medicines e.g. Digoxin STEROIDS- May need to give more if patient has Addisons Oral Contraceptives Lithium Tamoxifen (used in breast cancer)
How many days pre-op should we stop warfarin?
Stop on the evening of 6 DAYS before!!
What should a patient on warfarin’s INR be below for surgery to proceed?
Below 1.5
With patients on warfarin that need to have emergency surgery, their INR needs to be below 1.5 and there is not time to wait 5 days, what can we give to achieve this?
Vitamin K for reversal within 4-24 hours
BERIPLEX for reversal within 1 Hour
Allows blood to be become thicker so there is less risk of a bleed.
Only if the surgery can be delayed for 6-12 hours (says BNF).
When should LMWH be started and stopped with warfarin bridging before surgery?
LMWH can be used in patients with Moderate VTE risk (3-4 Chads Vasc) or High VTE risk (5-6 Chads Vasc).
Start LMWH 2 days after warfarin stopped.
Stop LMWH 24 hours pre op (if treatment dose)
[12 hours pre op if prophylactic dose].
Do not give on morning of surgery!
If patients are given a UFH infusion as their warfarin bridging method [for those that are assessed as HIGH RISK score 5-6 on Chads Vasc], when should this be started and stopped?
UFH infusion started 2 days after patients warfarin stopped (so 4 days pre-op). Patient needs to be brought into hospital to receive this. Should only be started when INR is less than 2 or 3.
Stop the IV UFH infusion 6 hours pre-op
What is the CHADSVASC scoring system used for?
To determine Risk of VTE in PATIENTS WITH AF!!!!!
It is often weighed up against their HASBLED score to see if Anticoagulation using heparins is needed after surgery, and what to use before surgery.
What does a CHADS VASc score of 0-2 indicate in patients with AF on warfarin requiring surgery?
Low risk of VTE
No need for LMWH to be initiated before surgery!
What does a CHADS VASc score of 3-4 indicate in patients with AF on warfarin requiring surgery?
Moderate risk of VTE
Start a therapeutic (treatment) dose of LMWH two days after stopping warfarin.
What does a CHADS VASc score of 5-6 indicate in patients with AF on warfarin requiring surgery?
HIGH risk of VTE
Either:
Start a therapeutic dose of LMWH 2 days after stopping warfarin
OR admit them to hospital for UFH infusion once INR is less than 2 or 3.
What does LMWH doses vary with?
Patient weight
When do we re-start warfarin post-operatively?
As soon as the surgeon deems the bleed risk to have gone [and is happy the patient won’t require more surgery!].
Until then, until the INR is in therapeutic range, the patient can be covered with LMWH/ UFH.
Post surgery, heparins can be used until the patient can start warfarin again [when INR therapeutic]. When is a prophylactic dose of LMWH used? What about a treatment dose of LMWH?
Prophylactic LMWH used if the patient has a LOW VTE risk
Treatment LMWH used if patient has a Moderate/HIGH VTE risk
Post surgery, heparins can be used until the patient can start warfarin again [when INR therapeutic]. When is UFH used?
When patients have a high VTE risk- mechanical heart valves.
When should we stop heparin post-operatively?
Once the patients INR has been therapeutic (in Target range) for 2 days.
There will be a heparin/ warfarin overlap as warfarin is started as soon as INR is therapeutic/ bleed risk is gone.
We can use the HASBLED score to determine patients bleed risk post op.
If they have a Low bleed risk: when should prophylactic LMWH (low clot risk) be started?
Low bleed risk: Evening post op
We can use the HASBLED score to determine patients bleed risk post op.
If they have a HIGH bleed risk: when should prophylactic LMWH (low clot risk) be started?
24-48 hours post op
We can use the HASBLED score to determine patients bleed risk post op.
If they have a Low bleed risk: when should therapeutic LMWH (High clot risk) be started?
Give a prophylactic dose of LMWH in the evening post-op
then give a treatment dose of LMWH 24-48 hours post op (whenever the surgeon feels risk of bleeding is lowest)
We can use the HASBLED score to determine patients bleed risk post op.
If they have a High bleed risk: when should therapeutic LMWH (High clot risk) be started?
Give a prophylactic dose of LMWH 24-48 hours before surgery and then a therapeutic dose 24-72 hours post operation (whenever the surgeon feels risk of bleeding is lowest).
What is the problems with NOAC’s in surgery?
THERE IS NO REVERSING AGENT for them: problem is they are requiring emergency surgery! (Cant give vit K like we do with warfarin!)
Also risks of bleeding
What should we do if a patient is on Dabigatran and requires emergency surgery?
Remember there is no established reversal agent…
1) STOP DABIGATRAN
2) Contact Haematologist/ surgeon/ Anaesthetist:
discuss with Surgeon the feasibility of delaying surgery, consider BERIPLEX
3) Take APTT, PT, FBC, renal function
4) Document time of Last Dabigatran dose
5) If APPT / PT is normal: there is no dabigatran anticoagulant effect present- fine to operate
6) APTT/ PT is PROLONGED: Dabigatran effects mat be present
7) Consider ORAL CHARCOAL is ingestion within 2 hours
8) Maintain patients blood pressure/ urine output
With Elective surgery, patients have their Dabigatran and Rivaroxiban stopped according to their RENAL FUNCTION.
Patients with good renal function (i.e. CrCl >80); should they stop their dabigatran/rivaroxiban earlier or closer to the surgery than patients with impaired renal function?
Patients with good renal function can keep on the dabigatran/ rivaroxiban closer to their operation.
Patients with poor renal function have to stop it earlier:
e.g. patients with a CrCl of under 30 have to stop Dabigatran/ rivaroxiban 6 days before major surgery with high risk of bleeding or 4 days before non-major surgery.
What patients require warfarin bridging therapy?
Patients stopping warfarin before surgery with a high risk of clotting:
Those with a VTE event within the last 3 months
AF with previous stroke/ TIA
Those with a mechanical heart valve (UFH required)
Should be given a treatment dose of LMWH.
This is all in the BNF
What do we usually do with Aspirin before surgery?
We usually carry on Aspirin if patient on it following a Stroke/ Myocardial Infarction (secondary prevention).
If its just being used for primary prevention then we stop it.
If patient has a very high bleed risk then stop it 7 DAYS before surgery.
Clopidogrel/ ticagrelor:
Usually stop 7 days before surgery unless bleed risk low.
But DO NOT STOP if there is high risk of a coronary stent clot!