2/27 - GA Flashcards
IV sedation definiti
administration of a drug which results in the depression of the CNS
the goal is to produce a state of sedation in which the patient maintains protective reflexes, and the respiratory and caridovscular systems are minmially affected
rapid onset of IV?
yes - the arm to brain circulation is approx 20-25 seconds
advantages of IV sedation
- rapid onset
- titration
- the drug dosage may be tailored
- suitable level of sedation
- shorter recovery periods - continous IV infusion
- patent vein is maintained throughout procedure - side effects of nausea and vomiting
- rare when administrated as suggested (titrated) - salivation
- control of salivary secretions is possible through the administration of antcholinergics - gag reflex
- is diminished - diminish motor disturbances
titration
titration
- the drug dosage may be tailored
- suitable level of sedation
- shorter recovery periods
advantage of IV sedation
titration
titration
- the drug dosage may be tailored
- suitable level of sedation
- shorter recovery periods
advantage of IV sedation
disadvantages of IV
venipuncture is necessary
complications may arise at the site of venipuncture
monitoring **– must be more intensive than that rewuired in most other conscious sedation techniques
revoery not complete – Escort is needed
most IV agents CAN NOT BE reversed – have to be metabolized first
indications for IV sedation
- anxiety
- amnesia
- med compromised patients
- angina
- HBP
- previous myocardial infarcatin
- previous cerebrovascular accident
- epilepsy - control of secretions
- analgesia
- diminished gagging
contraindications so IV sedation
lack of proper training
pregnancy - relative contra
- hepatic disease
- thyroid dysfunctin
hyper - thyroid strom could develop - adrenal insufficiency
- adrenal insufficiency
patients receiing MAOI’s or TCA’s
- go into seratonin syndrome
extremley obese
inadequte veins
allergy to medications
preganncy in IV sedaion
relative contraindication – bcause most CNS depressants cross the placenta – into the fetus and may produce birth defects in the developing fetus
briefly exaplin anesthesia as a continuum
can eassily move from a deep sedation to GA
ultra-light GA
outpatient general anesthesia using IV barbiturates
advantages of general anesthes eia
cooperation not essential
patient is unconscious
patient does not respond to pain
amnesia is present
GA may be the only technique that will prove successful for certain patients
rapid onset
tritration is possible
success rate is 100%
disadvantages of GA
patinet unconscious
protective reflexes are depressed
vital signs are depressed
advanced training
anesthesia team is required
special equipment
recovery area must be available
intra-operative and postanestetic complications are more common
patient receiving GA must receive nothing by mouth for 6 hours beore the procedure
patients receiving GA must be evaluated more extensively preoperatively than patients receiving minimal or moderate sedation
contraindications to GA
lack of trining
lack of adequatley trained personnel
lack of adequate equipment or facilitities
ASA IV and certain ASA III medically compromised patients
Hx of poliomyelitit in which chest muscles have been involved
Hx of Myasthenia gravis
obese
patients with significantly decreased cardiac and / or pulmonary reserve
patients with a history of malignant hyperthermia
ASA types contraindicated in GA
ASA IV and some ASA III
indications for GA
extreme anxiety o fear
mentally or physiclly disabled
age - infants and children
short or long traumatic procedures
benefits of outpatient GA vs inpatient
economics
psychological benefits
reduced exposure to nonsocomial infections
parental preference
types of GA
in - office outpateitn GA
- IV anesthesia - less than 30 minutes
conventional operating theater type of GA more than 30 mins - less than 4 hours
inpatient type
outpatient GA IV using?
propofol or barbiturates
N2O2-O2
bensodiaxepine
opiods
LA
outpatient GA -conventional type of operating room GA
used in cases 30 mins to 4 hours
patient undergoes same GA prep as the inpatient
limited to ASA I and II – selected III
completed training in anesthesiology
inpatient GA
patient admitted to hospital prior to procedure
undergoes workup to determine risk , undergoes procedure and then remains in hospital post-op
ANesthesiologist is responsible for the administration for the anesthetic
armamentarium
anesthesia machine IV equip ancillary anesthesia equipment monitoring equip emergency equipment and drugs
ancillary anesthesia equipment
face masks and appropriate connectors
laryngoscopes, blades
monitoring equipment
stethoscopes
- precordial
- pretracheal
- esophageal
pulse oximeter end-tidal CO2 blood pressure cuff ECG temperature
TIVA
total inervenous anestesethsai
endotracheal tubes and connectors
part of armamentarium
LMA
does not get fully patent airway
- used in the field more
Bispecteral electroencephalographic monitoring
BIS monitoring
-
intra arterial blood pressure
degree of accuracy is great but not really needed during outpaient sedation
indicaed in both general anesthetic proccedures involving greater degree of risk
- neuro or cardiac surgery
and when degree of risk presented by the patient (ASA IV or V) is significant
types of benzodiazepines used
diazepam - valium
midazolam - versed
mechanism of benzo’
becoming less excitebale
contraindications to benzo
allergy to diazepam
acute narrow glaucoma and wide angle glacuoma
contraindications to benzo
allergy to diazepam
acute narrow glaucoma and wide angle glacuoma
psychosis
pregnancy
versed aka
midazolam - benzo
used more versed vs valium
versed – need to know the comparisons of these
versed is more potent
barbiturates?
not used as much today
barbiturates?
not used as much today
pentobarbital
barbitruate
reversal agent to benzo
flumazenil
flumazenil
reversal agent to benzo
contraindicated in
- allergy to benzo or flumazenil
- if being treated for stuff on benzo’s like status epilepticus, or control of intracranial pressure
opioid antagonist
naloxone
most commonly used
nitrous
nitrous oxide not used for GA?
what is its use
not strong enough – not potent enough
MAC is not high enough to get to general
second gas effec**
primary function of nitrous oxide in GA?
in GA it is used to potentiate the actions of the other more potent drugs (IV or inalation) and thus permits a smaller dose or lesser concentration of this drug needed to produce the desired level of GA
neuroleptanesthesia
type of GA that is produced by the administration of
- neuroleptic drug (droperidol)
- opiod - fentanyl
- nitrous oxide -oxygen
- muscle relaxant
dissociative anesthesia
type of GA
- dissociative anesthesia and analgesia as produced by ketamine
patient appears to be awake
maintain many reflexes
unaware of,or dissociate from the environment
disadvantages of ketamine
increased heart rate, blood pressure and intraoclular pressure
eye movements and nystagmus can occur
no antagonist is available for it
can produce a confused state, associated with unpleasant dreams and frightening hallucinatins
(more common to occur with adults ) – so use with a benzzo
disadvantages of ketamine
increased heart rate, blood pressure and intraoclular pressure
eye movements and nystagmus can occur
no antagonist is available for it
can produce a confused state, associated with unpleasant dreams and frightening hallucinatins
(more common to occur with adults ) – so use with a benzzo
four mechanisms of muscle relaxants
- deficiency block
- nondepolarizing block
- depolarizing block
- dual block
no drug ever exerts a single action?
true
