Surgery Drug Rules Flashcards
What should happen to HRT or the COCP beofre surgery?
Should be stopped 4 weeks before to reduce risk of DVT
What should happen to lithium before elective surgery?
Why?
Should be stopped the day before surgery (do not administer the day before and the day of surgery)
to avoid lithium toxicity caused by reduced renal clearance associated with dehydratioin during surgery
What should happen to metformin before elective surgery?
No changes day before surgery
Day of surgery
- Low risk of AKI and few meals missed
- if BD doses take both
- If TDS dosages omit lunchtime dose
- High risk of AKI/ more than one meal missed ( e.g. contrast is used or eGFR < 60)
- then omit on day of and 48h post procedure + variable rate insulin started if usually on >1 dose of Metformin ( or if normal renal function + no contrast re-start when eating and drinking)
What should happen to potassium sparing diuretics (AGII inhibitors) and ACE inhibitors before surgery?
Should not be taken on the day of surgery due to risk of hypotension during surgery
E.g. ACEi: Ramipril, Enalapril etc.
AGII inhibitors: Losartan, Candesartan
What should happen to bisphosphonates before surgery?
Omit dose on day of surgery
What are the rules for long-acting insuling the day before and the day of admission?
Different for different types of insulins and times of administration
Minor procedures
- reduce long-acting by 20% (otherwise as normal)
Major Procedures (aka >1 missed meal):
- Day before surgery: 80% of long-acting evening dose given
- usually 80% of long-acting insulin for day of surgery + variable rate insulin infusion
What should happen to short-acting insulin (taken with mealtimes) the day before/ the day of surgery?
No changes to the day before
Usually held on the day if patient is not eating, given once patients starts eating again
Should be started on sliding-scale during/ day of surgery
What is the guidance for most non-insulin diabetes medication before elective surgery?
Unless risk of indcing hypoglycaemia - take as normal on day of and day before surgery
Excpetions:
Sulphonylureas
SGLT-2 inhibitors
What are the rules for SGLT-2 inhibitors before elective surgery?
Omit on day before and day of surgery due to risk of DKA
E.g. dapagliflozin, canagliflozin etc.
What are the rules for sulphonylureas before elective surgery?
Take as normal the day before surgery
Omit dose on day of surgery
What are equivalent dosages of Hydrocortisone, Dexamethasone and Prednisolone (all oral)
Hydrocortisone (HC) 20 mg
Dexamethasone 0.5 mg
Prednisolone 5 mg
What are the rules for Warfarin before elective surgery?
Discontinue 5 days before surgery
If high risk of thrombosis –> bridge with deltaparin (prophylaxis or treatment, depending on risk) or unfractionated heparin
Discuss with senior if unclear
What should happen to Beta blockers and calcium-channel blockers before surgery?
No changes - can be dangerous to stop before surgery
What should happen to Aspirin before surgery?
Should be stopped 7 day before surgery due to risk of bleeding
(Exception: unless Aspirin is given post-cardiac stenting, in which the surgery should be held off until after the anticoagulation period due to risk of stent occlusion)
What is the target INR for patients on long-term warfarin before elective surgery the day before surgery?
What should be done if the INR is higher?
Warfarin should be stopped 1 week before surgery, Target INR < 1.5
If >1.5 the day before surgery: reversal with Vitamin K (phytomenadione) 1-5mg PO
