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
General Actions of Inhaled Anesthetics
Respiration
–___________ respiration and response to CO2
Kidney
–_________ of renal blood flow and urine output
Muscle
– High enough concentrations will _____ skeletal muscle
Depressed
Depression
relax
General Actions of Inhaled Anesthetics
Cardiovascular System
– Generalized ______ in arterial pressure and peripheral vascular resistance.
– _______ maintains CO and coronary function better than other agents
reduction
Isoflurane
General Actions of Inhaled Anesthetics
Central Nervous System
– ____eased cerebral blood flow and _____eased cerebral metabolism
Incr
decr
Nitrous Oxide
• widely used
• Potent __________
• Produce a ____ anesthesia
• Used as ______ to ___________
analgesic
light
adjunct
supplement other inhalationals
Nitrous Oxide depress the respiration/vasomotor center
T/F
F
Do not depress the respiration/vasomotor center
Halothane
flammable or non-flammable
____% metabolism by P450
(induction or inhibition?) of hepatic microsomal enzymes
non-flammable
20
induction
Halothane
Myocardial ———— (SA node)
___________ of myocardium to catecholamines - arrhythmia
depressant
sensitization
Halothane
Transient ______ damage
Liver _______ In repeated exposure Immuno____________
hepatic
necrosis
sensititation
Malignant Hyperthermia
Malignant hyperthermia (MH) is a pharmacogenetic ________ state of ________ induced in susceptible individuals by ____________ and/or _____________ (and maybe by stress or exercise).
hypermetabolic
skeletal muscle
inhalational anesthetics
succinylcholine
Malignant Hyperthermia
Genetic susceptibility- ____ channel defect (_________) or _______(_______ receptor)
Excess ______ ion leads to excessive ——————————
Ca+
CACNA1S
RYR1 ; ryanodine
calcium
ATP breakdown/depletion
Malignant Hyperthermia
Signs: ——-cardia, _____pnea, metabolic _______, ____thermia, muscle _______, _______, arrhythmia
tachy; tachy; acidosis
Hyper ; rigidity
Sweating
Malignant Hyperthermia May be fatal
T/F
T
Malignant Hyperthermia
Treated with ___________
dantrolene
Inhaled Anesthetics: Enflurane
(Slow or Rapid?) , (smooth or difficult?) __________________________
2-10% metabolized in liver
Rapid ; smooth
induction and maintenance
_________ is Introduced as replacement for halothane
Enflurane
Isoflurane
(Slow or Rapid?) , (smooth or difficult?) _____ and __________
very little metabolism (0.2%)
Smooth ; rapid
induction and recovery
Isoflurane
Few reports of hepatotoxicity or renotoxicity
F
no reports of hepatotoxicity or renotoxicity
________ is the most widely employed halogenated Inhalational anaesthetic
Isoflurane
Intravenous Induction Agents
Commonly used IV induction agents:
List 3
Propofol
Thiopental sodium
Ketamine
Intravenous Anesthetics
Most exert their actions by potentiating __________ receptor
GABAA
Intravenous Anesthetics
GABAergic actions may be similar to those of ______ anesthetics, but act at different ______
volatile
sites on receptor
Organ effect of Intravenous Anesthetics
Most ____ease cerebral metabolism
Most ____ease intracranial pressure
Most cause respiratory _________
May cause _____ after induction of anesthesia
decr; decr
depression
apnea
Cardiovascular Effects of Intravenous Anesthetics
Barbiturates, benzodiazepines and propofol cause cardiovascular ________.
depression
Thiopental sodium
(Slow or rapid?) onset (_____)
(short or long?) -acting
Rapid
20 sec
Short
Thiopental sodium
Effect terminated not by _________ but by _________
repeated administration or prolonged infusion approaches _________ at _________ sites
Build-up in adipose tissue = _______ emergence from anesthesia
metabolism; redistribution
equilibrium
redistribution
very long
Thiopental sodium
Side effects
_____tension
_________
_____ obstruction
Hypo
apnoea
airway
Propofol
(Short or Long?) -acting agent used for the ________ and _______of GA and sedation
Onset within __________ of injection
Short
induction
maintenance
one minute
Propofol
It is highly _______ in vivo and is metabolised by conjugation in the liver
Protein bound
Propofol
Side-effect
_____ on injection
______tension
transient ______ following induction
pain
hypo
apnoea
Ketamine
_______ Receptor Antagonist
NMDA
Ketamine
usually (stimulate or depress?) the circulatory system
usually stimulate rather than depress the circulatory system
Ketamine
Function
_________
_________ anesthesia
_______ appearance, eyes ____, reflexes are _______, ________ but ________ movement
Analgesic
dissociative
Cataleptic; intact
purposeless but coordinated
Ketamine
(Stimulates or Depresses?) sympathetic nervous system
Psychomimetic – “________ reactions”
——- dreaming _______ (___________) experience
mis________, mis_________, illusions
may be associated with euphoria, excitement, confusion, fear
Stimulates; emergence
vivid; extracorporeal; floating “out-of-body”
perceptions; interpretations
General anesthesia
__________
____________
Induction
Maintenance
For induction
Which has faster onset?
Inhalation or intravenous anaesthetic
Intravenous
For induction
(Inhalation or intravenous anaesthetic ?) avoids the excitatory phase of anaesthesia
Intravenous
For induction
_______ is used where IV access is difficult
Inhalational
For induction
_______ anaesthetic is used based on patient preference (children)
Inhalational
Maintenance
In order to ______ anaesthesia for the required duration
______ to a carefully controlled mixture of _____,__________, and a________ anaesthetic agent
transferred to the patient’s _____ via the ——- and the _______, and the patient remains unconscious
prolong
breathe
oxygen, nitrous oxide, and a volatile
brain; lungs; bloodstream
For maintenance
________ agents are supplemented by _______ anaesthetics, such as _________ ( usually _______ or _______)
Inhaled
intravenous
opioids; fentanyl or morphine
What is Balanced Anesthesia?
Use specific drugs for each component
- Sensory
_____,______,________ for analgesia - Cognitive
•Produce _______, and preferably ______. •inhaled agent
•IV hypnotic - Motor
_____________
N20, opioids, ketamine
amnesia; unconsciousness
Muscle relaxants
Simple Combinations
____________
____________
____________
____________
Relaxant of choice
Morphine
Propofol
N2O
Sevoflurane
Relaxant of choice
Simple Combinations
__________
__________
__________
_________
Relaxant of choice
Fentanyl
Thiopental sodium
N2O
Halothane
Relaxant of choice
There are three broad types of Anesthesia
-______ anesthesia
– _____ anesthesia
– _____ anesthesia
General anesthesia
– Local anesthesia
– Regional anesthesia
PROCESS of an anesthesia
•_________
•Induction
– Transition of ________________ to __________
•Maintenance
– Maintenance of the _______________________
•________ & control of ______.
Premedication
an awake patient to an anaesthetized one.
desired depth of anaesthesia
Reversal; pain
The depth of anesthesia has been divided into four major stages
They includes
– Stage I: _________
– Stage II: _________
– Stage III: _________ anesthesia
– Stage IV: ________________
Stage I: Analgesia
– Stage II: Excitement
– Stage III: Surgical anesthesia
– Stage IV: Medullary paralysis
STAGE I/ ANALGESIA:
•From inhalation to _________
•Loss of _____ sensation occurs
•This results from interference with _________ in the ______________
•The patient is initially _______ and _______
•Then _______ and a reduced __________ occur as Stage II is approached.
loss of consciousness.
pain
sensory transmission ; spinothalamic tract.
conscious and conversational.
amnesia ; awareness of pain
Strage 2/ excitement
•From loss of consciousness to the beginning of __________.
•The patient experiences _________
•Possibly displays _____,_______ behaviour.
•_____ease in blood pressure.
•____ease in respiratory rate and jerky breathing
•____eased muscle tone
•______eased ocular movement
loss of consciousness ; regular respiration.
delirium; violent, combative
Increase; Increase; Increased ; Increased
STAGE III/ SURGICAL ANAESTHESIA
•From onset of __________ to cessation of ____________
•______ respiration and ________ of the skeletal muscles occur in this stage.
•Eye reflexes ____ease progressively
•Eye movements finally ____ and the pupil is ______.
regular respiration ; spontaneous breathing
Regular ; relaxation
decrease; cease; fixed.
Surgery may proceed stage ___
3(surgical anaesthesia)
STAGE IV/ MEDULLARY PARALYSIS
•_______ of breathing to __________ and _______
•Severe ______ of the _______ and ________ centres occur during this stage.
•______ can rapidly ensue unless measures are taken to maintain ________ and ___________
STAGE IV/ MEDULLARY PARALYSIS
Cessation ; failure of circulation and death.
depression ; respiratory and vasomotor centres
Death ; circulation and respiration.
MECHANISM OF ACTION
Bind and Stimulate GABA receptor
–______,_________, and ________
Bind and Block Nicotinic Cholinergic receptors – ———- ________
Bind and Block NMDA receptors – ________ and __________
Bind and Activate K+ channels – ______
Barbiturate, Benzodiazepines and Propofol.
Volatile Hydrocarbons
Ketamine and Nitrous oxide,
Others
MECHANISM OF ACTION
Bind and Stimulate ______ receptor
– Barbiturate, Benzodiazepines and Propofol.
Bind and Block ________ receptors – Volatile Hydrocarbons
Bind and Block ______ receptors – Ketamine and Nitrous oxide,
Bind and Activate _____channels – Others
GABA
Nicotinic Cholinergic
NMDA
K+
PROPERTIES of the ideal anesthesia
Pro- PATIENT
Pleasant
Non ———-
Not associated with ______ and _______
(Slow or Fast?) induction and recovery
No _____________
irritating
nausea and vomiting
Fast
after effects
PROPERTIES of the ideal anesthesia
Pro- SURGEON
Adequate ________
Adequate _______
_______ relaxation
Non ______ and non ______
analgesia
immobility
Muscle
flammable; explosive
PROPERTIES of the ideal anesthesia
Pro- ANAESTHETIST
•Administration easy, controllable and versatile
•(Narrow or Wide?) margin of safety
•no _______
•No ________ on the major organs
•_____ – needing _____ concentrations
•Does not affect _______
•(Gradual or Rapid?) adjustment in depth of anesthesia
•Cheap, stable and easily stored
•Not react with ________ or ________
fall in BP
adverse effect
Potent ; low
oxygenation
Rapid
rubber tubing or soda lime
PRE-ANESTHETIC AGENT
List 7
Anticholinergic
Antiemetics
Antihistamines
Barbiturates
Benzodiazepine
Muscle relaxant
Opioid
PRE-ANAESTHETIC MEDICATION
It is the use of drugs _______ to make it _________________ .
prior to anesthesia
more safe and pleasant
PRE-ANAESTHETIC MEDICATION
To relieve ________ - benzodiazepines.
To prevent __________- antihistaminics.
To prevent _________ -antiemetics.
To provide __________ - opioids.
To prevent ______-protonpumpinhibitor
To prevent ______________- atropine.
anxiety
allergic reactions
nausea and vomiting
analgesia; acidity
bradycardia and secretion
PRE-ANAESTHETIC MEDICATION
To relieve anxiety - ________.
To prevent allergic reactions-_____.
To prevent nausea and vomiting-_______.
To provide analgesia- ________.
To prevent acidity-_________——
To prevent bradycardia and secretion- _________.
benzodiazepines
antihistaminics.
antiemetics.
opioids.
protonpumpinhibitor
atropine.
CLASSIFICATION of general Anesthesia
INTRAVENOUS
Slow Acting:
– __________
–______ analgesia Eg _______
–________ anesthesia Eg ________
Benzodiazepines
Opioid; fentanyl
Dissociative; ketamine
CLASSIFICATION of general Anesthesia
INTRAVENOUS
Fast Acting:
– _________
–___________
– _________
Barbiturates
Propofol
Etomidate
NITROUS OXIDE Also called LAUGHING GAS
Relatively (Cheap or Expensive?)
_______ and ______ gas
(Low or High?) potency anaesthetic
(Good or Bad?) analgesic
(Minimal or Maximal?) muscle relaxation
(Low or High?) blood solubility
(Slow or Fast?) onset and recovery
(Low or High?) MAC
Cheap
Colourless and odourless
Low ; Good
Minimal ;Low
Fast ; High
HALOGENATED HYDROCARBON
All contain ——-
________ is the most widely used volatile anaesthetic
fluorine
Isoflurane
HALOGENATED HYDROCARBON
Decrease in Solubility – _________> _________> _________ > _________ > _________ > _________
Decrease in Potency – _________> _________ > _________ > _________ > _________ > _________
Increase in MAC – _________> _________ > _________ > _________ > _________ > _________
Methoxyflurane> Halothane>Enflurane > Isoflurane > Sevoflurane > Desflurane
Methoxyflurane> Halothane > Isoflurane > Enflurane > Sevoflurane > Desflurane
Methoxyflurane> Halothane > Isoflurane > Enflurane > Sevoflurane > Desflurane
HALOGENATED HYDROCARBON
Adverse effect
– Specific
Isoflurane
–______ Phenomenon
Sevoflurane
–_________ ————
Desflurane
–___________
– ———-
Steal
Malignant Hyperthermia
Bronchospasm
Cough
INHALATIONAL ETHER
Highly _____ liquid
Highly _________ and _________
Highly _________ and _________
Very _________
Also a called a _________ _________ AGENT
(Mildly or Highly?) soluble in blood
(Slow or Fast?) and Prolonged induction
(Slow or Fast?) recovery
volatile
Inflammable and explosive
Irritant and Pungent
Potent
COMPLETE ANAESTHETIC AGENT
Highly
Slow ;Slow
Ether
No longer in used in developed countries because of _____________
Used in developing countries because it is ____________________
its unpleasant and inflammable nature
relatively safe and cheap
Propofol
Used for __________________
(Slow or Rapid?) induction and recovery
(Short or Long?) lasting
Patient becomes unconscious in _____-_____
both induction and maintenance
Rapid ; Short
15-45s
Propofol is irritant to the airway
T/F
F
Not irritant to the airway
KETAMINE
Is a _______ derivative, Hence a _________
Effect is describes as ———ANAESTHESIA
(Slow or Fast?) induction and recovery
Site of action – ______ and _______ regions
phencyclidine; Hallucinogen
DISSOCIATIVE
Slow
cortical and subcortical
THIOPENTAL
Is a ______
Commonly used for _______
Has (low or high?) lipid solubility
(Slow or Rapid?) action and (short or long?) duration
(Slowly or Rapidly?) metabolized
____ analgesic effect
Barbiturate; Induction
High; Rapid
Short
Slowly ; No
ETOMIDATE
Similar to _____ but (more or less?) quickly metabolised
(More or Less?) risk of cardiovascular depression
May cause _________ during induction
Possible risk of _________ suppression
thiopental; more
Less
involuntary movements
adrenocortical
