Anaesthetic preoperative assessment

Question 1

How long before surgery should a patient ideally have a pre-operative assessment?

Answer 1

2-4 weeks

Question 2

What is the most important additional test that should be performed for a woman of reproductive age prior to proceeding with surgery?

Answer 2

Pregnancy test

Question 3

What classification is used to assess the potential difficulty of a patient’s airway for intubation?

Answer 3

Mallampati scoring

Question 4

Importance of CV disease questions for a patient before their surgery?

Answer 4

• Previous CV disease: specifically hypertension and exercise tolerance
• Risk of acute carduac event is increased during anaesthesia

Question 5

Importance of respiratory disease questions for a patient before their surgery?

Answer 5

Adequate planned oxygenation is imoprtant in reducing risk of acute ischaemic events in peri-operative period

Question 6

Importance of renal disease questions for a patient before their surgery?

Answer 6

• Anaemia, coagulopathy, biochemical disturbances can increase the incidence of surgical complications
• Blood loss / IV contrast given during a procedure could cause significant renal dysfunction

Question 7

Importance of endocrine disease questions for a patient before their surgery?

Answer 7

• DM and thyroid disease
• Medications often require changing in peri-operative period

Question 8

Name some significant questions that could be useful to the anaesthetist when assessing a patient?

Answer 8

• Female of reproductive age
  
  • Could they be pregnant?
• African or Afro-Caribbean descent
  
  • Could they have undiagnosed sickle cell anaemia?

Question 9

Describe a past anaesthetic history?

Answer 9

• Have they had anaesthetic before?
• If so, were there any issues?
• Were they well post-operatively?
• Previous post-op nausea and vomiting?

Question 10

What is a inportant condition to ask about in terms of family history of a patient who is going for surgery?

Answer 10

• Malignant hyperpyrexia
  
  • Malignant hyperthermia

Question 11

Describe malignant hyperthermia?

Answer 11

• Autosomal dominant
• Muscle rigitidy, despite NM blockade, followed by a rise in temperature

Question 12

What examinations are normally performed in the pre-operative examination?

Answer 12

• General examination
• Airway examination

Question 13

Describe the ASA grade?

Answer 13

• American society of anaesthesiologist grade
  
  • Correlates with their risk of post-op complications and mortality

Question 14

Describe the pre-operative blood tests which should be performed?

Answer 14

• FBC
  
  • Assess for undiagnosed anaemia or thrombocytopenia
• U&Es
  
  • Baseline renal function
• LFTs
  
  • Ass liver metabolism and synthesising factors
• Clotting screen
• G&S or Cross match

Question 15

Describe pre-operative imaging which can be performed?

Answer 15

• ECG
• ECHO if murmur, cardiac symptoms or signs of cardiac failure
• CXR (only when necessary)

Question 16

Name some miscellaneous tests that can be performed before surgery?

Answer 16

• Pregnancy test
• Sickle cell test
• MRSA swabs
• Urinalysis

Question 17

Describe the airway examination which should be performed by an anesthetist?

Answer 17

• Do they have a receeding mandible (retrognathia)?
• Ask patient to open their mouth and assess:
  
  • Degree of mouth opening (favourable if inter-incisor distance >3cm)
  • Degree of dentition
  • Oropharynx. Ask patient to stick their tongue completely out and use Mallampati classification
• Flex, extend and laterally flex their neck to assess ROM
• Ask them to maximally extend their neck and measure distance between thyroid and chin (thyromental distance) If <3 finger breadths, intubation witll be difficult

Question 18

Describe Mallampati classification?

Answer 18

• Correlates with difficulty of intubation
• Ask patient to fully stick out their tongue

Question 19

Describe the relevance of anti-coagulants when planning surgery?

Answer 19

• Balance risk of haemorrhage with risk of thomrbosis
• Avoid epidural, spinal and regional blocks

Question 20

Describe the relevance of anti-epileptic drugs when planning surgery?

Answer 20

• Give as usual
• Post-op give IV or via NG tube if cannot tolerate orally

Question 21

Describe the relevance of OCP/HRT drugs when planning surgery?

Answer 21

• Stop 4 weeks before major / leg surgery
• Restart 2 weeks post-op if mobile

Question 22

Describe the relevance of beta blocker drugs when planning surgery?

Answer 22

Continue as usual

Question 23

Describe the nil by mouth (NBM) protocols before major surgery?

Answer 23

• ≥2h for clear fluids
• ≥6h for solids

Question 24

What procedures are prophylactic antibiotics given for and when are they given?

Answer 24

• GI surgery and joint replacement
• 15-60 minutes before surgery

Question 25

Describe the DVT prophylaxis post surgery?

Answer 25

• Stratify patient risk
  
  • Low risk: early mobilisation
  • Moderate risk: early mobilisation + TEDS + 20mg enoxaparin
  • High risk: early mobilisation + TEDS + 40mg enoxaparin