Conduct of General Anaesthesia and Pre-operative Assessment Flashcards
What are the stages and phases of general anaesthetic?
Pre-operative assessment and planning
Preparation
Induction
Maintenance
Emergence
Recovery
What monitoring is done in anaesthetics?
ECG, Oxygen saturation, non-invasive blood pressure, end tidal CO2 and airway pressure monitoring
Why is supplemental oxygen given pre-operatively?
Increases time to desaturation
Reduced functional residual capacity under anaesthesia
What is given for induction?
Analgesic - fentanyl or alfentanil
Hypnotic - propofol, thiopentone or ketamine
Possibly plus muscle relaxant
What are the planes of anaesthesia?
Analgesia and amnesia
Delirium to unconsciousness
Surgical anaesthesia
Apnoea to death
Why is airway management done in anaesthetics?
Loss of airway reflexes and relaxation of tissues
What is included in airway management during anaesthesia?
Triple airway manoeuvre
Oropharyngeal airway
Laryngeal mask airway (LMA)
Endotracheal tube (ETT) - fully protects the airway
Laryngoscope
How is circulation controlled during anaesthesia?
Control of haemodynamics - BP at least every 5 mins
Vasoactive drugs
What are the reasons to intubate?
Protection from aspiration, need for muscle relaxation, shared airway, need for tight CO2 control and minimal access to patient
What are the risks of anaesthesia?
Anaphylaxis, regurgitation, aspiration, airway obstruction, hypoxia, laryngospasm, cardiovascular instability and rarely cardiac arrest
What are more common risks under anaesthesia?
Awareness, eye trauma, hypothermia, pressure injury, nerve injury and thromboembolism
What is included in maintenance of the anaesthesia?
Vapour - ‘gas’
Intravenous anaesthesia (TIVA)
What is involved in the emergence phase?
Reversal of neuromuscular blockage
Anaesthetic agent is stopped
Return of spontaneous breathing, airway reflexes, suctioning + removal of airway device and transfer to recovery room
What is general anaesthesia?
Drug induced reversible coma
CNS, cardiac and resp. distress
Drug interactions
What is regional anaesthesia?
Profound sympathectomy
Neurological sequelae
What are the considerations pre-operatively?
Patient - co-morbidities (known and unknown)
Nature of surgery
Anaesthetic techniques
Post-op care
What is the anaesthetist role pre-op?
Assess, identify high risk, optimise, minimise risk, inform + support patients decisions and consent
What is involved in the history and examination pre-op?
Known and unknown co-morbidities
Ability of withstand stress - exercise tolerance and CVD
Drugs and allergies
Previous surgery and anaesthesia
Potential anaesthetic problems
What investigations are done pre-op?
Detect unknown conditions, severity of known disease, establish a baseline, detect complications, assess risk, guide management and document improvement
What are some cardio investigations are may be done pre-op?
ECG, exercise tolerance test, echo, myocardial perfusion scan, stress echo, cardiac catheterisation and CT coronary angiogram
What are some resp. investigations that may be done pre-op?
Saturations, ABG, CXR, peak flow measurements, FVC/FEV, gas transfer and CT chest
What is ASA grading?
ASA1 - otherwise healthy patient
ASA3 - severe systemic disturbance
ASA4 - life threatening disease
ASA5 - moribund patient
ASA6 - organ retrieval
What are some risk assessment tools used?
GUPTA, surgical outcome, STOP-BANG, Nottingham hip fracture score, P-POSSUM, CR-POSSUM, Q-POSSUM, V-POSSUM and resp. failure calculator
What is included in the cardiac risk index?
High risk surgery, ischaemic heart disease, congestive heart failure, cerebrovascular disease, diabetes and renal failure
Describe pre-op medication
Most continue as normal
Esp. - inhalers, anti-anginals and anti-epileptics
Exceptions - anti-diabetic medications and anticoagulants
