Anesthetics I Flashcards
Anesthesia
partial or complete loss of sensation with or without loss of consciousness
General Anesthesia:
anesthesia that produces complete loss of consciousness. “medically controlled coma”
loss of protective reflexes, cessation of respiration
Analgesia
insensitivity to pain
sedation
the process of allaying nervous excitement
conscious sedation
a minimally depressed level of consciousness during which he patient retains the ability to maintain a patent airway and respond appropriately to physical or verbal commands
Phases of Anesthesia
Induction
Maintenance
Recovery
depth of anesthesia
Stage 1 - Analgesia
Stage 2 - Excitement
Stage 3 - Surgical Anesthesia
Stage 4 - Medullary paralysis
Most popular agent for the induction of anesthesia
PROPOFOL
Usually given with lidocaine to prevent injection pain from venous irritation
Newer version of propofol
Fospropofol (Lusedrea)
less venous irritation
Maintenance of anesthesia is done how?
inhalation agents
Intravenous agents
Inhalation agents
Halogenated hydrocarbons
Nitrogen Oxide
Halogen Adverse Effects
Hepatic Toxicity
Decreased Cardiac Output
Malignant Hyperthermia
Malignant Hyperthermia
Rare but life threatening
Usually seen in conjucntion with use of succinylocholine
Dantrolene is main treatment choice
Nitrous Oxide
Strong analgesic but weak anesthetic
Frequently used as adjunct
MAC - minimal alveolar concentration
Concentration needed to suppress movement in response to standard incision
IV Anesthetics
Opiods
FENTANYL
Benzodiazepines
MIDLAZOPAM (conscious sedation)
KETAMINE
DEXMEDETOMIDINE
Ketamine
Dissociative agent
One of few agents which increase cardiac output
May cause post-op hallucinations
Neuromuscular blockade agents
Nondepolarizing agents
Depolarizing agents
to paralyze patients
Neuromuscular blockade agent utilization
facilitate endotracheal intubation
relax abdominal musculature to enhance surgical exposure
Depolarizing agent
Succinylcholine
fast acting short duration
Non depolarizing agent
Longer duration of action
Local anesthetic agents
Inhibit sensory nerve conduction via block of sodium ion channels
Pain nerves more sensitive
can block motor nerves at higher doses
Chemical types of local anesthetics
Esters
Amides
Amides
Lidocaine
Mepivicaine
Bupivicaine
Ropivacaine
popular ester
chloroprocaine
Duration of action for topical anesthetics
Lidocaine 15-30 min
Chloroprocaine 30-40 min
Mepivacaine: 60-90 min
Bupivacaine & Repivacaine: 120 min or more
adding epinepherine to topical anesthetics
extends duration of action, reduces bleeding
bad news: increases heart rate, increased anxiety
Adverse effects of local anesthetics
Allergic reactions
Cardiac Toxicity (bupivacaine)
Systemic effects are variable
altered CNS function
Cardiac changesallergy considerations in topical anesthetic
True allergy is rare
Allergic to one ester, usually means allergic to all esters
Amides or usually OK in patients allergic to esters
Allergic to one amide DOES NOT mean allergic to all amides
Insensitivity to local anesthetics
Insensitivity is usually rare
Conscious sedation
very frequently utilized
especially for endoscopic procedures
Elements of conscious sedation
Intravenous access
Patient monitoring
Variable medicaiton "cocktail"
sedative
analgesic
AnestheticConscious sedation medications
Most common: Benzodiazepine
esp midlazopam (versed)
Next: Fentanyl (short acting opiod)
Sometimes: propofol
Conscious sedation dangers
respiratory depression
adverse drug reactions
