Pre-op assessment

Question 1

What 3 main parts are there to pre-op assessment?

Answer 1

1. Identification of high risk factors
2. Optimisation of the patient to minimise complications
3. Consent

Question 2

What are the risks of GA?

Answer 2

-A - airway obstruction
-B - hypoventilation and hypoxia
-C - hypotension
-D - PONV
-E - Heat loss and hypothermia
-G - loss of airway reflexes and reflux risk

Question 3

What are the main features of assessment of high risk factors?

Answer 3

-ANAESTHETIC HX (prev? any issues? FHx of issues?)
-PRESENTING COMPLAINT (reason for surgery? trauma? H+N injury? vomiting? diarrhoea?)
-PMHx (cardio, resp, exercise tolerance, epilepsy/stroke/diabetes)
-DRUG HX (regular meds? anti-coags/hypertensives, time critical meds)
-SOCIAL HX (smoker? nicotine replacement?)
-EXAMINATION (CV/resp, airway/dental, obs, weight+height)

Question 4

What does an airway assessment involve?

Answer 4

-General inspection
-Mallampati grade (= relative size of the base of the tongue compared to oropharyngeal opening)
-Mouth opening
-Dental (teeth?)
-Neck movement)

Question 5

What is the ASA grade used for?

Answer 5

-To summarise and communicate pre-anaesthesia comorbities (Grade I-VI)
-Grade I = health patient with no systemic disease
-Grade V = moribund patient who is not expected to survive with or without an operation
-Grade VI = brainstem-dead patient whose organs are being removed for donor purposes

Question 6

What other important pre-op investigations should be done?

Answer 6

-Pregnancy test
-Sickle cell test (if FHx present)
-If CV symptoms present, ECG, echo, angio etc may be required

Question 7

What essential meds must be continued if a patient is having a procedure?

Answer 7

-Anti-epileptics
-Parkinson’s meds
-Steroids if on >5mg/day (risk adrenal crisis if stopped)

Question 8

What important meds should be continued if possible for a procedure?

Answer 8

-Beta blockers
-Aspirin
-PPIs

Question 9

What are the general rules for blood thinners (aspirin, clopidogrel, DOACs, warfarin, LMWH)?

Answer 9

ALDWAC
-Aspirin = continue
-LMWH = stop 12hrs prior (24hrs if treatment dose for VTE)
-DOACs = stop 24-72hrs prior depending on renal function
-Warfarin = stop 5 days prior (bridge with LMWH if high risk of VTE)
-Clopidogrel = stop 7 days prior (seek advice if stroke/MI in past year)

Question 10

What should be done for diabetes patients’ medications?

Answer 10

-T1 = continue long-acting insulin, give 80% of dose the day before and reduce oral intake
-T2 = omit agents with potential hypos
-Always prescribe PRN hypoglycaemia treatment

Question 11

What should be done in anticipation of haemorrhage?

Answer 11

-G&S and crossmatch - need 2 samples per patient to reduce transfusion error

Question 12

What should be done for VTE prophylaxis?

Answer 12

-Must balance RFs against bleeding risks
-If appropriate, patients should be prescribed at least 4hr after surgery or if admitted pre-operatively