PERI - Pre/Peri-Op Management

Question 1

Pre-Op Assessment

History
Examination
ASA
Investigations/Imaging

Answer 1

1. ) History
   - presenting complaint, PMH, FH, SH
   - surgical history, anaesthetic history
2. ) Examination - general and anaesthetic examination
   - general examination for presenting complaint
   - anaesthetic examination includes airway assessment
3. ) ASA - American Society of Anaesthesiologists Grade
   - correlates to risk of post-op complications/mortality
   - I: healthy, II: mild systemic disease, III: severe systemic disease, IV: illness constant threat to life
   - V: will die w/out surgery, E: suffix if an emergency
   - 2: smoker/drinker, pregnancy, obesity, well-controlled asthma/DM/HTN
   - 3: poorly controlled asthma/DM/HTN, ESRD w/ dialysis, BMI >40,
4. ) Investigations/Imaging
   - bloods: FBC, U/Es, LFTs, clotting, G/S or crossmatch
   - ECG, CXR

Question 2

Pre-Op Management (RAPRIOP)

Reassurance 
Advice
Prescriptions
Referral
Investigations 
Observations
Patient Understanding and Follow Up

Answer 2

1.) Reassurance - to relieve anxiety

2. ) Advice - fasting
   - no food or dairy products 6hrs before surgery
   - no clear fluids 2hrs before surgery
3. ) Prescriptions
   - drugs to stop: CHOW
   - drugs to alter: insulin, steroids
   - drugs to start: LMWH, TED stocking, antibiotics, bowel preparation

4.) Referral - patient may need a HDU/ITU bed

5. ) Investigations and Observations
   - pre-op investigations and basic obs
6. ) Patient Understanding and Follow Up
   - ensure patient has all the information they need

Question 3

Prescriptions in Pre-Op Management

Drugs to Stop (CHOW)
Drugs to Alter
Drugs to Start

Answer 3

1. ) Drugs to Stop - CHOW
   - Clopidogrel: stopped 7 days prior to surgery
   - Hypoglycaemics (not metformin)
   - Oral Contraceptive or HRT (DVT risk) (4wks)
   - Warfarin: 5 days before surgery, INR must be <1.5, can be reversed using vit K, FFP, or prothrombin complex concentrate
2. ) Drugs to Alter - insulin and long term steroids
   - long term steroids must be continued to prevent addisonian crisis, can be switched from PO to IV
3. ) Drugs to Start
   - LMWH and TED Stockings: prevent VTEs
   - antibiotic prophylaxis: GI, vascular, and ortho surgery (cefuroxime is often favoured)
   - bowel prep: left hemi-colectomy, sigmoid colectomy, abdominal-perineal resection, anterior resection

Question 4

Peri-Op Management of Diabetes

Susceptible Diabetics
Basal Insulin
Variable Rate IV Insulin Infusion (VRIII)
Dextrose and Potassium
Stopping the VRIII

Answer 4

1. ) Susceptible Diabetics
   - type 1 diabetics: should be 1st on morning list
   - diet controlled diabetes dont need any interventions
2. ) Basal Insulin - 80% of usual dose
   - should be done the day before the surgery and continued throughout the intra-operative period
3. ) VRIII (‘sliding scale’) - insulin infusion at infusion rate determined by bedside CBG measurement
   - for patients with poorly controlled diabetes (HbA1c > 69%) or will have long starvation period (>1 missed meals)
   - target range is 6-10mM (6-12 acceptable)
   - BG should be measured hourly for first 12 hours
4. ) Dextrose and Potassium - given alongside VRIII
   - IV infusion of 5% dextrose along with potassium
   - K+ needed to prevent hypokalemia (insulin)
   - dextrose need to also prevent hypos
5. ) Stopping the VRIII - needs overlapping to prevent DKA since half-life of IV insulin is only 5 mins
   - VRIII is continued until the patient can eat and drink
   - give SC rapid acting insulin 20 mins before a meal and stop the VRIII 30-60mins after they have eaten

Question 5

Peri-Op Management for Patients on Steroids

Normal Stress Response
HPA Axis Suppression
IV Steroids

Answer 5

1. ) Normal Stress Response - due to surgery
   - activates HPA axis, ↑ACTH –> ↑cortisol
2. ) HPA Axis Suppression - surgical patients often NBM so they abruptly stop taking their oral steroids
   - this causes secondary adrenal insufficiency since their body cannot make their own cortisol and ACTH
   - detected using short synacthen testing
   - can lead to addisonian crisis: fever, N/V, abdo pain dehydration, hypotension, hypovolaemic shock
3. ) IV Steroids - given to cover the operative phases
   - often 25mg of IV hydrocortisone QDS