Anaesthetics - pre-op assessment Flashcards
- Appreciate the importance of the role of history taking, examination and routine investigations in assessing and preparing patients for surgery.
- Discuss the possible effect of concurrent medical disease on the progress of anaesthesia and surgery and how this should tailor further investigation.
- Discuss the role of routine preoperative investigation and list the advantages and disadvantages of this practice.
The interaction of coexisting morbidity (particularly cardiovascular and respiratory).
Preoperative investigations.
Preoperative optimisation - detection of remediable conditions and useful interventions.
What to do with concurrent medications.
The importance of timing of surgery with regard to the urgency of the surgical condition and the need for preoperative investigation and intervention.
Considerations during pre-op assessment
Known (AND unknown) co-morbidities
Concurrent medications
Nature of surgery
What anaesthetic technique to use
What level of post-op care needed
3 principles of pre-op assessment (same as assessment of any illness)
History
Examination
Investigations
What to ask about in history during pre-op assessment?
Known co-morbidities
Unknown co-morbidities - do systematic enquiry + examination
Ability to withstand stress - any cardioresp disease, exercise tolerance
Drugs + allergies
Previous surgery and anaesthesia
Potential cardio pre-op investigations (wouldn’t do all for every patient) (7)
ECG Exercise tolerance test Echo Myocardial perfusion scan Stress echo Cardiac catheterisation CT coronary angiogram
Potential resp pre-op investigations (wouldn’t do all for every patient) (7)
Saturations ABG – not routine CXR Peak flow measurements FVC/FEV Gas transfer CT chest
The ASA physical status classification system is a system for assessing the fitness of patients before surgery.
What are the 6 ASA grades
ASA 1 - normal healthy
ASA 2 - mild systemic disease
ASA 3 - severe systemic disease
ASA 4 - severe systemic disease that is life threatening
ASA 5 - moribund (terminal) who’s not going to survive without surgery
ASA 6 - brain dead and organs being removed for donation
As well as history, examination and investigations, also need to risk assess how the surgery will affect them
What are some risk assessment tools
Cardiac risk index - more commonly used
Surgical outcome risk tool (TOOL)
‘POSSUM’ tools
Cardiac risk index is one of the more routinely used risk assessment tools. For each of the following co-morbidiites (6), you score 1 point, 4 or more points indicate high risk of cardiac complications post-surgery
High risk surgery Ischaemic heart disease Congestive heart failure Cerebrovascular disease Diabetes Renal failure
Exercise tolerance can be assessed in the history by using the ‘metabolic equivalent of task (MET)’ measure which asks about what sort of activity they can undergo without getting breathless
What are the activities and what MET does it correspond to
Walk around house - 2 METs Light housework - 3 METs Walk 100-200m flat - 4 METs Climb stairs or walk up hill - 5 METs Walk briskly on flat - 6 METs Any form of exercise - 7 METs Run short distance - 8 METs Strenuous exercise/ heavy physical work - 9 METs
Medication should be optimised pre-op, esp for what conditions
Hypertension Ischaemic heart disease Heart failure Asthma COPD Diabetes Epilepsy
What lifestyle measures will affect success of surgery
Smoking
Alcohol
Obesity
Exercise
Why is exercise recommended pre-op
Better ability to withstand stress so better outcomes
For a high risk emergency patient, what is an important factor before planning any surgery
Informed consent - permission granted in full knowledge of the possible consequences
Most pre-op medications continue as normal after surgery, what are the exceptions to this? (2)
Anti-diabetic medication (oral hypoglycaemics)
Anticoagulants
