GENERAL ANAESTHESIA Flashcards by Iseoluwa Ojo

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

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Anaesthesia before 1846

(Common or Uncommon?) before 1846

(Many or Few?) operations were carried out

Mortality was (frequent or rare?)

Uncommon; Few

Frequent

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Anaesthesia before 1846

•______________ for open fracture

•Drainage of an abscess

•Drugs like _______,________, and ______ derivatives

Amputation of a limb

alcohol, harshish and opium

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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

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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

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General anaesthesia

The hallmark of General anaesthesia is _______________________ which equals __________

LOSS OF CONSCIOUSNESS

GOING TO SLEEP

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General anaesthesia

QUALITIES OF GA:
List 5!!!!!

Hypnosis, Amnesia, Analgesia, inhibition of autonomic reflexes, Muscle Relaxation

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General anaesthesia

Pre & Intra (_______,________, and ________) and Post operative periods
.

Induction, Maintenance and emergence

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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

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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

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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

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Preoperative Evaluation
Goals of the preoperative evaluation is to ensure that ___________________

the patient is in the best (or optimal) condition.

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Preoperative Evaluation

Patients with unstable symptoms should _________ for optimization prior to elective surgery.

be postponed

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Steps of the preoperative visit :

_________ Identification
______________
___________ Preparation
Plan of _______________

Problem

Risk Assessment

Preoperative

Anesthetic Technique

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Problem Identification through :

●__________
●________ examination
●__________ investigation

History

Physical

laboratory

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Patients with an abnormal airway (including Class __________ airway) should be considered at higher risk “.

III or IV

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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

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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

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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

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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)

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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

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Finally, we plan our anesthetic technique :

1._______ or ______ anesthesia
2. _______ anesthesia
3. ________________ with _______________

Local or Regional

General

Combined regional with general anesthesia.

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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

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Molecular Mechanisms of General Anesthetics

Most intravenous general anesthetics act predominantly through _______ receptors

GABAA

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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

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 1. Sensory _____,______,________ for analgesia 2. Cognitive •Produce _______, and preferably ______. •inhaled agent •IV hypnotic 3. 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