Preoperative Assesment - ASA classification, Preop Assessment, Bloods, Imaging, Medication Management, Fasting

Question 1

ASA classification - I

Answer 1

Normal healthy patient

Healthy
Non smoker
No/mininal alcohol use

Question 2

ASA classification - II

Answer 2

Mild systemic disease without substansive functional limitations

Current smoker
Social alcohol drinker
Pregnany
Obese
Controlled DM, HTN, mild lung disease

Question 3

ASA classification - III

Answer 3

Severe systemic disease with substantive functional limitations

1+ moderate/severe diseases
-poorly controlled DM, HTN, COPD
-Morbid obesity BMI 40+
-active hepatitis
-alcohol dependence/abuse
-implanted pacemaker, moderate reduction of ejection fraction
-ESRF with regular dialysis
-MI, CVAs 3months+ ago

Question 4

ASA classification - IV

Answer 4

Severe systemic disease that is a constant threat to life

-MI, CVA within last 3months
-ongoing cardiac ischemia, valve dysfunction
-severe reduction of ejection fraction
-sepsis, DIC, ARD
-ESKF without regular dialysis

Question 5

ASA classification - V

Answer 5

Moribund patient not expected to survive without the operation

Ruptured abdominal/thoracic aneurysm
Massive trauma
Intracranial bleed with mass effect
Ischemic bowel in the face of significant cardiac pathology or multiple organ dysfunction

Question 6

ASA classification - VI

Answer 6

Brain dead whose organs are being removed for donor purposes

Question 7

Preoperative assesment
-history - purpose and areas to cover
-examination

Answer 7

Assess fitness for surgery
Anticipate difficulties/requirements and plan for these

PC, HPC
SurgHx, AnaestheticHx
PMHx
DHx
-current medications, doses, timings
-allergies, reactions
-medications that need to be stopped - OCPs, AC, AP
SH
-smoking, drinking
-mobility, ADLs

General examination - overall wellness
-habitus
-anemia, jaundice, cyanosis

Auscultate lungs and heart - assess for undetected resp problems
-assess for undetected murmurs which may need intervention

Question 8

Preop bloods and imaging

Answer 8

Establish a baseline to allow for post-op assessment and monitoring

FBC - identify low RBC,PLT to assess bleeding risk
-if anemic and likely to have significant blood loss, may have pre-op Fe or transfuions

G&S, X - especially in emergencies or procedures likely to cause significant blood loss

Coagulation - assess bleeding risk

U&E -baseline renal function, creatinine, electrolytes

LFTs if
-gallbladder or liver surgery
-RUQ pain, jaundice, known hepatic dysfunction
-Hx of alcohol abuse

Urinedip if
-emergency presentation of abdo/pelvic pain
-any surgery in diabetics
-women of childbearing age with abdominal symptoms or if they need radiography

Pregnancy test!

Lung function testing
-assess for any issues with ventilation

ECG, CXR if
-Cardiac or CVD Hx
-cardiovascular surgery
-Resp symptoms, signs, Hx
-risk factors for TB, thyroid enlargement, malignancy

Imaging based on procedure

Question 9

Medications to stop/adjust before surgery

Answer 9

OCP
AP, AC
Diabetic drugs
Steroids

Question 10

Management of OCP

Answer 10

Stop 4 weeks before major or limb surgery

Restart 2 weeks after surgery or full ambulation

Question 11

Management of AP and AC

Answer 11

AP - stop 7-14 days before surgery

Restart 24hrs after surgery

Warfarin stopped 3-5 days before, replaced with heparin
Heparin stopped 6-12 hours before

Restart warfarin 12-24 hours after

Question 12

Management of steroids

Answer 12

Continued or increased if concerns over Addisonian crisis

Question 13

Importance of managing diabetes during surgery

Answer 13

Undetected hypoglycemia under GA
Increased risk of wound and respiratory infections
Increased risk of post-op AKI
Increased LOS

Question 14

Insulin management
-Lantus, Levemir (once daily)
-Novomix, Humulin (twice daily biphasic or ultra long acting)

Answer 14

Rationale - MUST HAVE SOME FORM OF BASAL INSULIN!
But as would be effective during preop period, should reduce dose

Lantus, Levemir (once daily
Day before - reduce dose by 20%
AM or PM surgery - reduce dose by 20%

Novomix, Humulin (twice daily biphasic, ultra long acting)
Day before - no change
AM or PM surgery - 1/2 morning dose, full PM dose

Question 15

Metformin management

Answer 15

Rationale - don’t directly affect BMs but increased doses when dehydration lead to increased lactic acidosis risk, especially if eGFR is U60

Day before - normal
AM or PM surgery
-OD or BD => normal
-TDS => omit lunchtime dose

Avoid if missing more than 1 meal or risk of AKI

Question 16

Sulphonylurea management

Answer 16

Rationale - oral hypoglycemics are risky when NBM

Day before - normal
AM surgery
-OD => omit
-BD => omit AM dose

PM surgery
-OD => omit
-BD => omit AM and PM

Question 17

DPP4inh and GLP analogue management

Answer 17

Rationale - don’t directly affect BMs

Day before - normal
AM or PM surgery - normal

Question 18

Fasting times

Answer 18

Non clear liquids, foods - 6hrs before

Clear fluids - 2hrs before

Question 19

Drugs not to stop before surgery

Answer 19

AEDs
Anti-Parkinson meds
SSRIs, SNRIs, TCAs
Anxiolytics
Bronchodilators
Statins
CCB (but not ACEi, ARBs)
Bb

Question 20

Preparing for blood loss
-chance of transfusion and action needed
-example of operation

Answer 20

Unlikely - G+S
-simple hysterectomy
-appendicectomy
-thyroidectomy
-elective lower segment CS
-lap chole

Likely - Cross match 2U
-salpingectomy for ruptured ectopic
-TKR

Definite - Cross match 4-6U
-total gastrectomy
-oophorectomy
-esophagectomy
-elective AAA repair
-cystectomy
-hepatectomy

Question 21

Management of surgical diabetic patients if
-major surgery
-poorly controlled diabetes

Answer 21

Major surgery - long fasting period omitting 1+ meal
Poorly controlled
=> VRIII