4. anaesthetic agents Flashcards
Propofol use
anaesthetic induction and maintenance
sedation
anti-emetic
propofol MoA
- enhance GABA, inhibit NMDA glutamate receptors
- fast acting
propofol side effects
- decrease respiratory: apnoea, RR
- decrease cardiac activity: CO, TV, BP
- decrease ICP, suppress seizures
what are barbiturates used for?
anxiolytic, anaesthetic, suppress seizures, sleeping air
examples of barbituates
thiopental
methohexital
phenobarbital
anxiolytics
main use of thiopental (barbiturate)
- fast acting induction agent
- cerebral protection in surgery (Reduces pain demand) - prevents status epileptics
e. g. in surgery when heart stopped and heart-lung machine can’t be used
methohexital uses (barbiturate)
induction for ECT (electroconvulsive therapy) due to rapid onset&recovery.
reduces seizure threshold
phenobarbital use (barbiturate)
seizure suppressant
adverse effects of barbituates
-bronchoconstriction in asthmatics
side effects of barbituates
- apnoea - needs ventilation
- increases HR, lower BP
- decreases cerebral O2 demand
- suppress seizures
main uses of ketamine
acute analgesia
pads sedation
bronchodilation
‘dissociative anaesthesia’
side effects of ketamine
maintains RR, maintains BP
bronchodilation - relaxes muscle
*good in haemodynamically unstable patients
hallucinations
contraindications for ketamine
- can trigger phychotic reaction in schizophrenia
- elderly can react badly
what happens to the metabolism of ketamine
metabolised in liver to norketamine which has less activity than ketamine
etomidate uses
IV induction agent
etomidate’s adverse effect
adrenal suppression: dampens stress response which isn’t ideal for surgery
etomidate side effects
decreased ventilatory response to CO2
-haemodynamically stable
acts like propofol for neuro (decreases ICP and O2 demand)
what can etomidate be used to treat
hypercorticolaemia
benzodiazepine use
*sedative (can't anaesthetise so safer than thiopental) anti-convulsant sleeping aid *anxiolytic *amnesic
Benzos side effect
amnesia
decreased respiratory: response to CO2, hypoxic response, muscular tone
stable CV
neuro:
adverse effects of benzos
lorazepam and diazepam can cause venous irritation and thrombophlebitis (basically superficial DVT)
-post-operative delirium
what is flumazenil
competitive agonist against benzodiazepines at GABA receptor
-used. in benzos overdose
