Anaesthetic preoperative assessment Flashcards
How long before surgery should a patient ideally have a pre-operative assessment?
2-4 weeks
What is the most important additional test that should be performed for a woman of reproductive age prior to proceeding with surgery?
Pregnancy test
What classification is used to assess the potential difficulty of a patient’s airway for intubation?
Mallampati scoring
Importance of CV disease questions for a patient before their surgery?
- Previous CV disease: specifically hypertension and exercise tolerance
- Risk of acute carduac event is increased during anaesthesia
Importance of respiratory disease questions for a patient before their surgery?
Adequate planned oxygenation is imoprtant in reducing risk of acute ischaemic events in peri-operative period
Importance of renal disease questions for a patient before their surgery?
- Anaemia, coagulopathy, biochemical disturbances can increase the incidence of surgical complications
- Blood loss / IV contrast given during a procedure could cause significant renal dysfunction
Importance of endocrine disease questions for a patient before their surgery?
- DM and thyroid disease
- Medications often require changing in peri-operative period
Name some significant questions that could be useful to the anaesthetist when assessing a patient?
- Female of reproductive age
- Could they be pregnant?
- African or Afro-Caribbean descent
- Could they have undiagnosed sickle cell anaemia?
Describe a past anaesthetic history?
- Have they had anaesthetic before?
- If so, were there any issues?
- Were they well post-operatively?
- Previous post-op nausea and vomiting?
What is a inportant condition to ask about in terms of family history of a patient who is going for surgery?
- Malignant hyperpyrexia
- Malignant hyperthermia
Describe malignant hyperthermia?
- Autosomal dominant
- Muscle rigitidy, despite NM blockade, followed by a rise in temperature
What examinations are normally performed in the pre-operative examination?
- General examination
- Airway examination
Describe the ASA grade?
- American society of anaesthesiologist grade
- Correlates with their risk of post-op complications and mortality
Describe the pre-operative blood tests which should be performed?
- 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
Describe pre-operative imaging which can be performed?
- ECG
- ECHO if murmur, cardiac symptoms or signs of cardiac failure
- CXR (only when necessary)
Name some miscellaneous tests that can be performed before surgery?
- Pregnancy test
- Sickle cell test
- MRSA swabs
- Urinalysis
Describe the airway examination which should be performed by an anesthetist?
- 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
Describe Mallampati classification?
- Correlates with difficulty of intubation
- Ask patient to fully stick out their tongue
Describe the relevance of anti-coagulants when planning surgery?
- Balance risk of haemorrhage with risk of thomrbosis
- Avoid epidural, spinal and regional blocks
Describe the relevance of anti-epileptic drugs when planning surgery?
- Give as usual
- Post-op give IV or via NG tube if cannot tolerate orally
Describe the relevance of OCP/HRT drugs when planning surgery?
- Stop 4 weeks before major / leg surgery
- Restart 2 weeks post-op if mobile
Describe the relevance of beta blocker drugs when planning surgery?
Continue as usual
Describe the nil by mouth (NBM) protocols before major surgery?
- ≥2h for clear fluids
- ≥6h for solids
What procedures are prophylactic antibiotics given for and when are they given?
- GI surgery and joint replacement
- 15-60 minutes before surgery
Describe the DVT prophylaxis post surgery?
- Stratify patient risk
- Low risk: early mobilisation
- Moderate risk: early mobilisation + TEDS + 20mg enoxaparin
- High risk: early mobilisation + TEDS + 40mg enoxaparin
