13. Intro To Anaesthetics Flashcards
Name some IV general anaesthetics?
Propofol
Barbiturates
Etomidate
Ketamine
What are the stages in Guedel’s signs?
1 - analgesia and consciousness
2 - unconscious, breathing erratic but delirium could occur, excitement phase
3 - surgical anaesthesia
4 - respiratory paralysis and death without intervention
What is anaesthesia a combination of?
Analgesia
Hypnosis (loss of consciousness)
Depression of spinal reflexes
Muscle relaxation
What is MAC?
Minimum alveolar concentration - used to describe volatile anaesthetic potency
What affects MAC?
Age - high in infants low in elderly
Hyperthermia (increased), hypothermia (decreased)
Pregnancy (increased)
Alcoholism (increased)
Central stimulants (increased)
Other anaesthetics and sedatives (decreased)
Opioids (Decreased)
How is IV anaesthetic potency described?
Plasma concentration to achieve a specific end point (e.g. loss of eyelash reflex)
What is the main target of anaesthetics?
GABAa receptors - main inhibitory transmitter
What is the action of most anaesthetics?
Most potentials GABAa mediated Cl- conductance to depress CNS activity
Name some local anaesthetics
Lidocaine
Bupivacaine
Ropivacaine
Procaine
What is the action of local anaesthetics?
Block voltage gated Na+ channels
What are the side effects of general anaesthesia?
Post operative nausea and vomiting
CVS
Pos operative cognitive dysfunction
Chest infection
