DHx in surgery

Question 1

DHx to continue in surgery

Answer 1

(most should be continued as a general rule, especially if you don’t recognise it and there’s no guidance on it)

• AEDs
• anti-PD
• anti-pyschotics
• anxiolytics
• B- blockers (ALWAYS)
• bronchodilators
• CCBs (ALWAYS)
• CVS DHx (except ARBs, ACEi, spirinolactone)
• thyroid/antithyroid
• glaucoma
• immunosuppressants
• drugs of dependence

Question 2

medications that need to be STOPPED before surgery

Answer 2

I LACK OP

• Insulin (except long acting)
• Li+ (24 hrs before)
• Anticoagulants (warfarin, heparin)/Antiplatelets (aspirin, clopidogrel, dihydramole) (aspirin: 7 days before)
• COCP/HRT (4 weeks before)
• K+ sparing diuretic (morning)
• Oral hypoglycaemics - metformin (24 hrs before, can substitute with sliding scale) (if metformin continued, can cause lactic acidosis)
• Perinodpil/ACEi, ARBs (morning)

Question 3

medications that need to be reviewed/ modified

Answer 3

• aspirin and antiplatelets (decision to be made by surgeon 5-7 days before)
• warfarin (converted to therapeutic tinzaparin)
• MAOIs and TCAs can interact with anaesthetics drugs (decision by anaesthetist)

Question 4

what to do with diabetics on the day before surgery?

Answer 4

• stop metformin
• give short as normal
• give 80% long as normal

Question 5

what to do with diabetics on the morning of the surgery?

Answer 5

• place on sliding scale of dextrose, insulin, K+

- take 80% of long acting

Question 6

what to do with diabetics after the surgery?

Answer 6

• convert to S/C insulin (when pt can eat w/t V)

- stop sliding scale 30-60 minutes after the first meal-time short acting dose

Question 7

DHx to ↑ during surgery?

Answer 7

steroids!

pts on long term corticosteroids (prednisolone) commonly have adrenal atrophy

their inability to mount a stress response to surgery means they require IV steroids at induction

to prevent profound ↓ BP

Question 8

why is metformin stopped day before surgery?

why other oral hypoglycaemics or insulin stopped?

how to replace?

Answer 8

NBM before surgery and will cause lactic acidosis

cause hypoglycaemia

start a sliding scale to monitor glucose hourly

Question 9

what if patient is on warfarin?

Answer 9

reversal of anticoagulation prior to elective surgery (after warfarin stopped)

1-5mg oral Vit K (phytomenadine) given day before surgery if INR>1.5

Question 10

if patient with renal impairment NEEDs CT (despite contrast)?

Answer 10

given bolus of saline

Question 11

when NOT to stop aspirin 7 days before surgery?

Answer 11

• main exemption from this would be a patient who had received recent vascular stenting
• surgery is usually held off until the crucial antiplatelet period has finished (high risk for stent thrombosis if stopped too early)