History and Examination

Question 1

What points should be covered while taking a verbal history from a patient during a peri-operative assessment?

Answer 1

• Recent changes in a medical state
• Limitations to physical activity
• Information not present in the notes e.g. from hospital admissions elsewhere
• Particular fears or concerns of the patient

Question 2

What information from a patient’s record are important to take during the peri-operative assessment?

Answer 2

• Who has the patient previously consulted (cardiac and respiratory problems)?
• What do the letters between primary and secondary care say?
• What do anaesthetic records say?
• What drugs does the patient take?

Question 3

Components of peri-operative examination

Answer 3

• General condition – frailty, obesity
• The airway and dentition
• Range of movements of neck and other joints – particularly with conditions such as rheumatoid
• The pulse – others may have measured the pulse rate using an automated device which will not detect arrhythmias
• The heart and lungs – identify any new murmurs, proceeding to an echocardiogram if aortic stenosis is suspected
• Relevant anatomy if a regional block is planned e.g. the back for spinal anaesthesia

Question 4

What’s the most important reason for the peri-operative assessment?

Answer 4

to assess the risk of not surviving the surgery

Question 5

Nine major factors that influence peri-operative risk

Answer 5

Question 6

Conditions that increase the risk of death in relation of having a surgery

Answer 6

• Myocardial infarction (MI)
• Heart failure
• Stroke
• Renal failure (creatinine >150 μmol/L)
• Peripheral arterial disease
• Angina
• TIA
• Type 1 diabetes
• Type 2 diabetes

Question 7

How long should the surgery be delayed after having MI?

Answer 7

At least 3-6 months

Question 8

What AF control should be considered before the surgery?

Answer 8

In patients with atrial fibrillation (AF) a marked sudden increase in ventricular rate may compromise adequate ventricular filling.

• ideally, rate controlled to <100 bpm pre-operatively
• warfarin may need to be switched to heparin for the peri-operative period (depending on the nature of the surgery)

Question 9

Warfarin and surgery - do we stop?

Answer 9

• should be continued if surgery can be performed with elevated INRs (most dental surgeries and most eye surgeries, as well as most endoscopies within bowel, bladder and uterus)
• The last dose of warfarin should be taken five days before surgeries for which the risk of bleeding exceeds the risk of thromboses

*

Question 10

We stop Warfarin before the surgery. Do we always need to replace it with heparin?

Answer 10

• for a patient with atrial fibrillation, a normal mitral valve and no previous cardiovascular events, additional thromboprophylaxis is usually not recommended
• when the risk is higher, warfarin can be replaced by subcutaneous high dose fractionated heparin, given at home before admission.

Question 11

What about insulin and surgery?

Answer 11

• avoiding the risk of perioperative hypoglycaemia is the main priority

(as many of the signs are masked by anaesthesia)

• Long-acting drugs are normally stopped and a short-acting insulin administered by infusion if needed

Question 12

Are ACE-inhibitors stopped peri-operatively?

Answer 12

Most anaesthetists would stop enalapril pre-operatively – it has a high incidence of producing potent hypotension intra-operatively

Question 13

Assessment of reserve function - what simple question to ask

Answer 13

• an assessment of reserve function (exercise tolerance
• As a general rule, if the patient can walk up a flight of stairs in one go without stopping, this is an indication of reasonable functional reserve

*Find out if there are other reasons for limitations e.g. joint pain/immobility issues as they make this assessment more problematical

*Looking for other symptoms of cardiovascular or respiratory disease → to include orthopnoea, ankle swelling or dyspnoea with other forms of exertion

Question 14

Before performing any nerve block, what abnormalities should be considered?

Answer 14

Abnormalities in:

• neurological system
• coagulation

Question 15

Risks of the surgery in an early pregnancy

Answer 15

• increased risk of spontaneous miscarriage
• theoretical risk of teratogenicity with anaesthetic drugs, but there has been no evidence of this with the current commonly-used agents

Question 16

Risk of the surgery in late pregnancy

(third trimester)

Answer 16

• There is also an increased risk of pre-term labour
• There is a risk of regurgitation and acid aspiration
• There is an increased risk of failed intubation (1 in 300)

Question 17

Why is it important to enquire about gastro-oesophageal reflux in individuals with increased risk?

Answer 17

Gastro-oesophageal reflux → risk of aspiration of liquid stomach contents (in the starved patient) into an unprotected anaesthetized airway→ chemical pneumonitis (Mendelson’s syndrome)

*There are manoeuvres that can be performed to reduce this risk

Question 18

What to do in a patient with GORD to reduce the risks of gastric content aspiration?

Answer 18

• starvation before the surgery → to reduce the risk of aspiration of solid content (still need to address the issue of liquid content)
• rapid sequence induction with cricoid pressure

Question 19

Should all patients with a history of gastro-oesophageal reflux be given H2 antagonists/proton pump inhibitors prior to induction?

Answer 19

• their use has not convincingly been shown to actually reduce the incidence of aspiration pneumonia.
• Currently, H2 antagonists and proton pump inhibitors are used in obstetric practice on the same evidence base as the use of sodium citrate

Question 20

What points to ask about in a previous anaesthetic history?

Answer 20

The airway

Were there any problems with maintaining the airway or delivering oxygen?

The drugs used

allergies and side-effects from the agents used, and any idiosyncratic effects, e.g. malignant hyperthermia

Problems with prior anaesthetics

The patient may have had an unpleasant experience including postoperative nausea and vomiting (PONV) and even awareness

Repeat anaesthetics

Halothane is now almost never used in the UK, and its use was restricted to more than three months between anaesthetics

Question 21

What about to ask further if a patient has a history of post-operative nausea and vomiting (PONV)?

Answer 21

• Type of surgery (previous and current): some types of surgery (e.g. ophthalmic, gynaecological) have a higher risk of PONV
• Drugs used during previous anaesthetics, including analgesics (e.g. opioids) have a significant risk of PONV
• Anti-emetics given on previous occasions for prophylaxis and treatment

Question 22

If you elicit a history of a previous difficult intubation, which of the following is the single most important piece of information from the anaesthetic record?

Answer 22

An ability to bag a patient with a face mask

• the ease of face mask ventilation of the patient is critical as it means that the patient can be kept safe and well-oxygenated while other methods are used to assist intubation

*If the patient is not easy to oxygenate with face mask ventilation, then the safest course is to plan for an awake fibreoptic intubation

Question 23

What genetic conditions may make anaesthesia difficult? (to ask in a FHx)

Answer 23

• Re to anaesthesia: suxamethonium apnoea, malignant hyperthermia and inherited porphyria
• influence on the outcome of anaesthesia: Dystrophia myotonica in close family members
• Any anaesthetic complications experienced previously by family members. It is important to be aware of such complications as reassurance may need to be given to the patient