Anesthesia - General Info Flashcards
General Anesthesia
Drug-induced unconsciousness
Characteristics of General Anesthesia
Controlled, reversible CNS depression with analgesia Patient can’t be aroused Sensory, motor, autonomic reflexes reduced
Dissociative anesthesia
Drugs that dissociate the thalamocortic & limbic systems Results in catatonic state Sensory input dissociated from perception
Describe a catatonic state
Eyes remain open, swallowing reflexes remain functional. Skeletal muscles maintain tone
Balanced anesthesia
Combination of unconsciousness, analgesia, muscle relaxation
How can balanced anesthesia be acheived
Single drug @ high doses Complimentary drugs @ lower doses
Anesthetic plan
Preanesthetic Induction agent Maintenance Recovery
Mechanisms of action of anesthesia
Mimic inhibitory neurotransmitters Suppress excitatory neurotransmitters Decrease neuronal ability to respond (Ca2+ & Na+ channels blocked)
Describe inhibitory neurotransmitter mimicry
GABA-a receptor activation Glycine receptor activation
Describe how to suppress excitatory neurotransmitters
nACh receptor blockade (neuronal nicotinic) NMDA receptor blockade (a glutamate receptor) 5HT3 receptor blockade (serotonin)
Stages of Anesthesia
Analgesia Excitement phase Surgical anesthesia (planes 1-4) Medullary Paralysis Death
Anesthetic protocol
Premedication Induction Maintenance Recovery
Premedication
Sedative Analgesic
Induction
Injectable anesthetic Inhalation anesthetic
Maintenance
Inhalation anesthetic (oxygen) +/- muscle relaxant +/- additional analgesia
Name the effects at each number
