Anaesthetics Flashcards
What is the triad of anaesthesia?
Muscle relaxation
Analgesia
Hypnosis
Aside from the classic triad of anaesthesia, what else do anaesthetics monitor?
Temperature control
Fluid balance
Nausea
What are some major complications in anaesthetics?
Loss of airway
Malignant hyperthermia
Anaphylaxis
Catastrophic haemorrhage
What is an ASA score?
Score given to surgical pts to classify risk for anaesthetics
What is ASA 1?
A normal healthy pt
What is ASA 2?
A pt with mild systemic disease with no effect on daily life (i.e. well controlled disease)
Includes pt with BMI 30-40, smokers, and social drinkers
What is ASA 3?
A pt with severe systemic disease
What is ASA 4?
A pt with severe systemic disease that is a constant threat to life
What is ASA 5?
A pt who is not expected to survive without the operation
What is ASA 6?
Declared brain-dead pt whose organs are being removed for donor purposes
What analgesia do we give for short procedures?
Entonox
Fentanyl
Ketamine
What are the types of anaesthetic?
Local
General
Regional
What is the WHO checklist?
Safer surgery checklist performed outloud for all staff in theatre, done before, during, and after surgery
What does propofol do?
Induction agent so puts pt to sleep/hypnosis
What are the ADRs of propofol?
Respiratory depression (-> death if untreated)
What do we use for local anaesthetic?
Lidnocaine
Which drugs can potentially cause malignant hyperthermia?
Some volatile anaesthetic gases e.g. halothane
Muscle relaxants e.g. Suxamethonium and decamethonium
Post op, what is important to the pt that we need to manage?
PONV
Apart from “because its nasty for the patient”, why is PONV important to get on top of?
It can cause wound dehiscence, esophageal rupture, aspiration, dehydration, increased intracranial pressure, and pneumothorax.
What are the broad categories for causes of PONV?
Drugs
Central stimulation
Peripheral stimulation
What drugs can cause PONV?
Opiods and anaesthetics
What peripheral stimulation can cause PONV?
Direct gastric stimulation
Bowel surgery and blood in the gastrointestinal tract from oral or ear, nose, and throat surgery
Vagal nerve stimulation
What central stimulation can cause PONV?
Fear, pain, anxiety, conditioned nausea related to environmental cues, and stimulation of the vestibular system
How do we prevent PONV?
Treat according to risk of PONV with:
- Adjusted anaesthetic technique
- Anti-emetics at end of surgery
- Post-op pain control
- Adequate hydration
- Rescue anti-emetics
What are some of the risk factors for PONV?
Female Younger age Hx of PONV/motion sickness Opiod use in surgery Non-smoker Surgical and anaesthetic factors also
What agent is given at induction to prevent PONV?
Dexamathasone
How do we decide which anti-emetic to use?
According to what we think the cause of the N+V is
When should a pro-kinetic antiemetic be used?
Impaired gastric emptying or gastric stasis (as long as no bowel obstruction)
What prokinetic agent can we use?
Metoclopramide
If a pt has bowel obstruction, which agent can we use for PONV prevention? What does it do?
Hyoscine - antimuscarinic that reduces secretions
What do we use for opiod-induced N&V?
Ondansetron or cyclizine
What is lignocaine?
AKA lidocaine
Local anaesthetic agent
What is bupivicaine?
Na channel blocker anaesthetic agent used for topical wound infiltration
Why is adrenaline given with local anaesthetics?
It prolongs the duration of action at the site of injection and allows higher doses to be used as it limits systemic absorption.
