Perioperative Prescribing Flashcards
(23 cards)
What drug types should you continue?
Drugs which have withdrawal symptoms
-Bb
What drug types should you stop?
Non-essential medicines that increase surgical risk
-increase bleed risk (1ary prevention aspirin 7 days before, 2ndary prevention risk vs benefit)
-increase hypotension risk (ACEi, MAOi 2wks
What are the rules around NBM?
-without GI disease
-with GI disease/starved postoperatively
No PO solids - 6hrs prior
No PO clear liquids - 2hrs prior
Routine medications with clear fluids - 2hrs prior
Alternative drug routes needed
-reduced oral drug absorption due to decreased blood flow to gut, postop ileus
When would antimicrobial prophylaxis be suitable?
Single full dose 30-60mins before incision
Intraoperative/post operative doses only used for prolonged procedures or major blood loss
What drugs are often missed in a drug history
OTCs
Non oral meds - eye drops, creams, inhalers
Oral contraceptives
Complementary and alternative therapies
Vitamins, food supplements
Recreational drugs
What are the key drugs you want to ask for in a surgical history
CASES
Contraception
-pregnancy
-VTE risk
Anticoag
-bleeding risk
Steroids
-prevent Addisonian crisis
Ethanol
-alcohol withdrawal
-anaesthetic interaction
Smoking
-lung disease
Herbal medicine management
Stopped 7 days before surgery due to uncertainty of contents and effects
Contraceptive pill management
Stopped if VTE risk high
-stop COCP 4wks before => normal levels of coagulation
-restart 2wks after => when procoagulant effects of surgery wears off
-can use POP inbetween
If N/V risk increased, contraceptive pill absorption may decrease => may need additional cover
Diabetes management
Long acting once daily insulin - reduced by 20% day before, even if sliding scale used
Long acting twice daily - stopped if sliding scale used
Short acting - stopped if sliding scale used
Metformin - as usual unless
-GFR U60, radiocontrast used, sliding scale used
Who will benefit from sliding scale insulin
When would you stop using sliding scale insulin
Multiple missed meals
No/unknown postop GI absorption
Labile blood sugars, HbA1c 69+
T1DM + major surgery
T1DM + not given background insulin
Infection
Emergency surgery
Stopped when patient can eat+drink normally without N/V
Sulphonylureas, pioglitazones, DPP4 inh use
Sulphonylureas - omit on morning of surgery
Pioglitazone - normal
DPP4 inh - normal
GLP1 agonist - normal
SGLT2 inh - day before surgery
DOAC management
24hrs before - low bleeding risk
48hrs before - high bleeding risk
48hrs+ before - high bleeding risk + renal dysfunction
Dabigatran stopping, starting, reversal
T1/2 - 12hrs
80% renal excretion
Avoid in creatinine clearance U30ml/min
Stopping - depends on renal function
-low bleed risk - 2 days
-high bleed risk - 4 days
Restart - 48-72hrs post surgery, depending on bleeding/clotting risk and renal function
Monitor through renal function
Dabigatran filtered out in haemodialysis
Idarucizumab antidote
Rivaroxaban stopping, starting, reversal
T1/2 - 5-13hrs
66% renal excretion
Taken with food to increase absorption
Stopping - 24hrs
-if high bleed risk/spinal or epidural anaesthesia => 48hrs
Restart - consider bleeding/clotting risk and renal function
24hrs - low bleed risk/minor surgery
48hrs - high bleeding risk/major surgery
No routine monitoring needed
Andexanet alfa if specific criteria met
Apixaban stopping, starting, reversal
T1/2 - 12hrs
25% renally excreted
Stopping - 24hrs
-if high bleed risk/spinal or epidural anaesthesia => 48hrs
Restart - consider bleeding/clotting risk and renal function (48-72hrs post surgery)
No routine monitoring needed
Andexanet alfa if specific criteria met
Edoxaban stopping, starting, reversal
T1/2 12hrs
50% renally excreted
Stopping - 24hrs
-if high bleed risk/spinal or epidural anaesthesia => 48hrs
Restarted as soon as adequate haemostasis achieved
No routine monitoring needed
No reversal agent
Use of vitamin K antagonists
-replacements for oral AC
4-5 days before surgery
-if needed give parenteral AC
Unfractionated heparin - assess AC with APTT
-drug of choice in high risk patients
Enoxaparin
-1x/2x SC injection
Stopped 24hrs before
Restart when risk of bleeding has passed
Use of steroids
-long term steroid management
Long term steroids should not be stopped
-flares from withdrawal
-HPA suppression from steroids
May need to increase dose depending on degree of surgical insult
May need to convert from PO to other forms
Use of lithium
Omitted day before
Restarted when U&E normal
Pain management good practice
Prescribing laxatives with opioids
VTE prophylaxis
Graduated compression stockings
Periperative mechnical calf compression
AC
Enoxaparin predominantly used
LMWH dosing calculated by weight
-stopped 12hrs before surgery, protamine is not a complete antidote
Who is at increased risk of PONV
Females
Anaesthetic gases
Opioids
Drugs causing GI irritation - FeSO4
Delayed gastric emptying - opioids
Abdo, ENT, gynae surgery
