INTRAVENOUS ANAESTHETIC AGENTS Flashcards
What are IV Anaesthetic Agents / Induction drugs?
These are drugs that, when given intravenously in an appropriate dose, cause a __________________________.
Often described as occurring within “________________________________ time”
rapid loss of consciousness
one arm-brain circulation
One-arm brain circulation time
that is simply the time taken for ____________________________________________ , where they have their effect; normally ___________
the drug to travel from the site of injection (usually antecubital) to the brain
10 -20 secs
Properties of an ideal IV induction drug
Physical / Chemical properties
• _________-soluble & _________ in solution
•(Cheap or Expensive?)
• Stable on exposure to ______
• ________ shelf-life
• No ________ on intravenous injection
• Not painful when injected into _________
• _________ when injected subcutaneously
• Low incidence of _________
• Water ; stable
Cheap; light
Long; No pain; an artery
Non-irritant ; thrombophlebitis
Properties of an ideal IV induction drug Pharmacokinetic properties
•_____________ in one arm-brain circulation time
•_________________ to vessel rich tissue
• Rapid __________ and ————-
• No _____________
Rapid onset
Rapid redistribution
clearance and metabolism
active metabolites
Properties of an ideal IV induction drug
Pharmacodynamic properties
• _______________ ratio (ratio of ________:____________ dose)
• Minimal ___________ and ————- effects
• No _________________/___________ reactions
High therapeutic
toxic dose : minimally effective
cardiovascular and respiratory
histamine release; hypersensitivity
Properties of an ideal IV induction drug
Pharmacodynamic properties
• No _________ effects
• No _____________ movements
• No emergence __________
• No ________ effect
• No ___________ ____________
• Safe to use in ________
emetic; involuntary
nightmares; hang over
adrenocortical suppression
porphyria
List 2 ideal Intravenous Anaesthetic agents
There is however No ideal Intravenous Anaesthetic agent.
Intravenous anaesthetic agents
Advantages
• rapid and smooth ________ of anaesthesia
• little ________ requirement (syringes, needles, catheters)
•easy _____________ of drugs
induction
equipment
administration
Intravenous anaesthetic agents
DisAdvantages
•difficult ________________ once administered
• less control of _________________ of anaesthesia
•lack of ____________ support
•poor tolerability in ________,___________, or ____________ individuals.
retrieval of drug
depth and duration
ventilatory
debilitated, dehydrated or toxic
Classification
A. Rapidly Acting (1o) Induction agents
__________
__________
__________ Compounds
__________
Barbiturates
Alkyl phenols
Imidazole Compounds
Eugenols
Classification
A. Rapidly Acting (1o) Induction agents
Barbiturates -3
Alkyl phenols-1
Imidazole Compounds-1
Eugenols -1
Methohexital
Thiopental Thiamylal
Propofol
Etomidate
Propanidid
__________ rapidly acting (1•) induction agent has been withdrawn from market
Propanidid- withdrawn from market
Slower Acting (___________) agents
__________ derivatives
__________
__________
basal narcotic
Phencyclidine
Benzodiazepines
Opioids
Slower Acting (basal narcotic) agents
Phencyclidine derivatives
___________
Benzodiazepines
_________ , _________
Opioids
_________, _________, _________, _________
Ketamine
Diazepam Midazolam.
Fentanyl Alfentanil Sufentanil morphine
General uses of IV anaesthesia agents
As __________ agents
__________________ (TIVA)
________ Sedation
________ to ________ Anaesthesia ________
________ protection
________ therapy
Induction
Total IntraVenous Anaesthesia
ICU Sedation
Supplement ; Regional Anaesthesia Anticonvulsant
Brain protection
Electroconvulsive therapy
TIVA- both ________/_________ of anaesthesia
ICU Sedation: _________,_________
Anticonvulsant: _____,__________
Brain protection: ___________ ( causes reduced ________ )
Electroconvulsive therapy esp. _________ preferred to __________
Induction/Maintenance
Propofol,Midazolam
STP, midazolam
Propofol; CMRO2
methohexithal; propofol
Most commonly used iv induction agent is ????
Thiopentone
A thiopentone
thio____________
Physical properties:
_______ powder, (soluble or insoluble?) in water with PH of ____, PKa of 7.6 Solution not stable for > ______ after reconstitution in _____ to a 2.5%
Best prepared fresh
barbiturate
Yellow ; soluble
10.8 ; 24 hrs
water