GENERAL ANAESTHESIA Flashcards
Nitrous oxide and diethyl ether
NO synthesized by _______ in 1776
_________ wrote that the ________ of diethyl ether is NO-like
Except for ____________ to produce highs at ether frolics
Priestley; Michael Faraday
inhalation; carnival inhalation
Anaesthesia before 1846
(Common or Uncommon?) before 1846
(Many or Few?) operations were carried out
Mortality was (frequent or rare?)
Uncommon; Few
Frequent
Anaesthesia before 1846
•______________ for open fracture
•Drainage of an abscess
•Drugs like _______,________, and ______ derivatives
Amputation of a limb
alcohol, harshish and opium
Anaesthesia before 1846
Physical methods for the production of analgesia.
•_______
•Unconsciousness induced by __________ or —————-
•Restraint by _______
ice pack
a blow on the head or strangulation
force
GOALS OF ANAESTHESIA:
- To create a/an (reversible or irreversible?) condition of comfort
- _________
3._____________ in a patient before, during and after performance of a procedure that would otherwise be painful; frightening, or hazardous.
reversible
quiescence
physiological stability
General anaesthesia
The hallmark of General anaesthesia is _______________________ which equals __________
LOSS OF CONSCIOUSNESS
GOING TO SLEEP
General anaesthesia
QUALITIES OF GA:
List 5!!!!!
Hypnosis, Amnesia, Analgesia, inhibition of autonomic reflexes, Muscle Relaxation
General anaesthesia
Pre & Intra (_______,________, and ________) and Post operative periods
.
Induction, Maintenance and emergence
General anaesthesia
INTRAOPERATIVE PERIOD
•Hemodynamic effect- _____ease in systemic arterial blood pressure.
The causes include direct vaso_______, myocardial ________, a blunting of __________ , and a generalized _____ease in central sympathetic tone.
•The ____tensive response is enhanced by underlying volume ________ or preexisting ______________.
decr; dilation; depression
baroreceptor control; decr
hypo; depletion
myocardial dysfunction
Patients
To reduce complications;
- Minimizing the _________ effects of anesthetic agents and techniques.
- Sustaining ____________ during surgical procedures that may involve major blood loss, tissue ischemia, reperfusion of ischemic tissue, fluid shifts, exposure to a cold environment, and impaired coagulation.
- Improving ______________ by choosing techniques that block or treat components of the ______________, which may lead to short- or long-term sequelae
potentially deleterious
physiologic homeostasis
postoperative outcomes
surgical stress response
Anesthetic drugs and techniques have profound effects on human physiology. Hence, a focused review of all major organ systems should be completed prior to surgery.
T/F
T
Preoperative Evaluation
Goals of the preoperative evaluation is to ensure that ___________________
the patient is in the best (or optimal) condition.
Preoperative Evaluation
Patients with unstable symptoms should _________ for optimization prior to elective surgery.
be postponed
Steps of the preoperative visit :
_________ Identification
______________
___________ Preparation
Plan of _______________
Problem
Risk Assessment
Preoperative
Anesthetic Technique
Problem Identification through :
●__________
●________ examination
●__________ investigation
History
Physical
laboratory
Patients with an abnormal airway (including Class __________ airway) should be considered at higher risk “.
III or IV
Preoperative Preparation
•Anesthetic indications:
-Anxiolysis, sedation and amnesia. e.g. ________
-Analgesia e.g ______
-Drying of airway secretions e.g _______,______,_____
-Reduction of anesthetic requirements ,Facilitation of smooth induction
-Patients at risk for GE reflux : ________,________,__________
benzodiazepine
narcotics
atropine,glycopyrrolate,scopolamine
ranitidine ,metoclopramide , sodium citrate
Preoperative Preparation : Surgical indications
-Antibiotic prophylaxis for infective endocarditis.
-Prophylaxis against DVT for high risk patients : ________ or ________ intermittent calf compression, or warfarin.
low-dose heparin or aspirin
Preoperative Preparation
Co-existing Disease indications:
Some medications should be continued on the day of surgery e,g _____,__________.
Others are stopped e.g _________ and _________
Steroids within the last six months may require __________
B blockers, thyroxine
oral hypoglycemics and antidepressants
supplemental steroids
Preoperative medications
Anti_________,
_______ are controversial as well as _____/_______ (drug interaction)
Pre- and postoperative administration of ________(_____) = significant decrease in myocardial ischeamia and mortality
hypertensives
Diuretics; metformin/ MAO inhibitors
β-receptor antagonist (atenolol)
Preoperative medications
Anticholinergic- employed for their _____ and membrane _____ effect
Anti-acidity- (npo-no per os)- decreasing the volume of gastric contents reduces ____,______,________
Sedative-hypnotics/ anxiolytics + opioids- reduces _______________ release
Opioids - pain
vagolytic; drying
regurgitation, prokinetic agents, cimetidine
catecholamine release
Finally, we plan our anesthetic technique :
1._______ or ______ anesthesia
2. _______ anesthesia
3. ________________ with _______________
Local or Regional
General
Combined regional with general anesthesia.
Finally, we plan our anesthetic technique :
1.Local or Regional anesthesia with ‘______‘ monitoring with or without _______.
- General anesthesia; with or without _______. _______ or _______ ——— is used.
- Combined regional with general anesthesia.
standby; sedation
intubation; Spontaneous or controlled ventilation
Molecular Mechanisms of General Anesthetics
Most intravenous general anesthetics act predominantly through _______ receptors
GABAA
Molecular Mechanisms of General Anesthetics
some interactions with other ligand-gated ion channels such as ______ receptors and ___-pore ____ channels and ——- channels gated by the (inhibitory or excitatory ?) receptors
NMDA
Two; K+ ; Chloride
Inhibitory; GABAA
Molecular Mechanisms of General Anesthetics
At clinical concentrations, general anesthetics increase the ________ of the GABAA receptor to GABA
sensitivity
Molecular Mechanisms of General Anesthetics
______ -gated Cl− channels (_____ receptors) may play a role in mediating inhibition by anesthetics
_____________ anesthetics enhance the capacity of glycine to activate glycine receptors,
Glycine; glycine
Inhalational
Molecular Mechanisms of General Anesthetics
Subanesthetic concentrations of the inhalational anesthetics inhibit ______ classes of ________________ receptors
some classes of neuronal nicotinic ACh
_______,________, and ———— potentiate glycine-activated currents
Propofol, neurosteroids, and barbiturates
______,_______,_________, and _______ inhibit NMDA receptor
Ketamine, nitrous oxide, cyclopropane, and xenon
_________ inhalational anesthetics activate some members of a class of K+ channels known as ___-pore domain channels
Halogenated
two
Cellular Mechanisms of Anesthesia
General anesthetics produce two important physiologic effects at the cellular level:
Inhalational anesthetics can ____________ neurons.
Both inhalational and intravenous anesthetics have substantial effects on __________ and much smaller effects on _______________ or __________
hyperpolarize
synaptic transmission
action potential generation or propagation.
Cellular Mechanisms of Anesthesia
Neuronal hyperpolarization may affect ________ activity and —————————————
pacemaker
pattern-generating circuits.
Cellular Mechanisms of Anesthesia
Their predominant actions are at the ———-, where they have profound and relatively specific effects on the ____________ to released neurotransmitter
synapse
postsynaptic response
General Anaesthesia (GA)
A variety of drugs are given to the patient that have different effects with the overall aim of ensuring ____,_______, and _______
unconsciousness, amnesia and analgesia.
Stages Of General Anesthesia
Stage I: _______,________ consciousness
Stage II: _______ stage, delirium, ___________ movement, ______ breathing. Goal is to ______________________________________
Stage III: ________ anesthesia; return of ___________
Stage IV: ————-; essentially an _______ and represents _____. This is the stage between _______ and ________ due to ____________.
Disorientation, altered
Excitatory; uncontrolled; irregular; move through this stage as rapidly as possible.
Surgical; regular respiration
Too deep; overdose ; anesthetic crisis
respiratory arrest and death ; circulatory collapse.
Stages Of General Anesthesia
Stage III: Surgical anesthesia; return of regular respiration.
Plane 1: “______” anesthesia
Plane 2: Loss of _____ reflex, _______ respiration .
Plane 3:______ anesthesia. _____ breathing, ______ ventilation needed.
Plane 4: ________ respiration only, _______ ventilation is required. _________ impairment.
light
blink; regular
Deep; Shallow; assisted
Diaphragmatic; assisted; Cardiovascular
Stages Of General Anesthesia
Level of anesthesia for painful surgeries is ????
Stage 3 plane 3
Earliest stage in which Surgical procedures can be performed is??
Stage 3 plane 2
Anesthetics divide into 2 classes
_______ Anesthetics
___________ Anesthetics
Inhalation
Intravenous
Inhalation Anesthetics
______ or ———-
Usually ___________
Gasses or Vapors
Halogenated
Intravenous Anesthetics
Given by _______
Anesthetics or ______ agents
Injections
induction
Inhalation Anesthetics
_________
_____________
Nitrous oxide
Halogenated anaes
Halogenated Anaes
List 4
Isoflurane
Halothane
Sevoflurane
Enflurane
Mechanism of Action of Inhalation Anesthetics
Interaction with ______ receptors
Volatile A – increase ______ and ________
protein
GABA and Glycine
MAC(__________________________)
A measure of _______________________
minimum alveolar concentration
potency of inhaled anesthetics
MAC is the concentration necessary to __________________________
prevent responding in 50% of population.
Pharmacokinetics of Inhaled Anesthetics
Amount that reaches the brain
Indicated by ______ ratio (lipid solubility)
Solubility of gas into blood
The (lower or higher?) the blood:gas ratio, the more anesthetics will arrive at the brain
oil:gas
Lower
