Pharm Exam 1- S3 Flashcards
1
Q
Neurotransmission is ?
A
Process of cellular communication
2
Q
2 ways of cellular communication?
A
Chemical-neurotransmitters
Electrical- passive / active conduction
3
Q
Which form of cellular communication is faster?
A
Electrical
4
Q
Input from nerves can synapse on what?
A
Dendrites
cell body
axon
nerve terminal
5
Q
Repolarization occurs naturally from what?
A
Na-K ATPase
6
Q
Stored vessicles in nerve terminal are release by what?
A
Exocytosis after depolarization impulse from Axon.
7
Q
What gives the impulse for depolarization?
A
Axon
8
Q
Passive Conduction?
A
Brownian motion causes ions to disperse evenly and Diminish. Diffusing out and even. The longer the tube the more fluid= lower concentration at end.
9
Q
Active Conduction?
A
Pass the signal down the axon itself, “moving”. Constantly regenerated voltage and marching down. Does not diminish. Voltage-gated Na goes in and K goes out at the same time.
10
Q
NA goes _____?
K goes ______?
A
in
out
11
Q
Active conduction leads to _____ to restore negative polarization?
A
Na-K pump. 3:2 pump. 3 NA out and puts 2 K back in to make more negative.
12
Q
Chloride ions influx cause ?
A
hyperpolarization. -90mv
13
Q
Normal resting membrane potential?
A
-70mv or -80mv
14
Q
Sodium is higher in ?
A
Extracellular fluid
15
Q
Potassium is higher in ?
A
Intracellular fluid
16
Q
Chemical compounds are stored where?
A
In vessicles in the nerve terminal or Bouton.
17
Q
The cell body (Soma) action?
A
Decides “to fire or not fire” based on signal. Biochemical reaction inside that releases binding substances.
18
Q
Dendrites action?
A
Passively transmit information to the cell body.
19
Q
Axon Hillock action?
A
Ligand receptor zones associated with Na ion channel. Reacts to intracellular substance.
NOT voltage-gated.
20
Q
Axon action?
A
Voltage-gated Na channels that are stimulated by axon hillock.
21
Q
Nerve terminals (Bouton) action?
A
Voltage-gated Ca channels that trigger the fusion of Ca and Na ions to pinch vesicles off.
22
Q
Calcium is higher where?
A
Extracellular
23
Q
Dendritic Conduction is a ?
A
Passive electrical process
24
Q
Axonal Conduction is a?
A
Active electrical process, involves voltage gated Na and K channels. Na-K ATPase pump to restore chemical equilibrium.
25
Signal is initiated where in Axonal conduction?
Axon hillock, by internally ligand-gated Na channels.
26
Nonmyelinated axons?
Slower, more likely to be disrupted or blocked.
27
Myelinated axons?
Surrounded by myelin sheaths formed from Schwann cells. FASTER, use less energy. Not as much Na-K ATPase needed.
28
Ion penetration in myelinated axons is where?
At the Nodes of Ranvier or gaps.
29
Saltatory Conduction?
Through myelinated axons which allows jumping charge to occur. Rapid conduction.
30
Cellular changes are due to ?
Differential ionic concentrations
31
Normal ion concentration of Na?
15mM Intracellular
145mM Extracellular
32
Normal ion concentration of K?
145mM Intracellular
5mM Extracellular
33
Normal ion concentration of Cl?
10mM Intracellular
150mM Extracellular
34
Normal ion concentration of Ca?
0.0001mM Intracellular
2mM Extracellular
35
What is the second messenger released intracellularly to increase concentration to initiate biochemical reactions?
Calcium
36
Maintenance of internal voltage is done by?
Potassium
37
Peripheral nerves are?
Myelinated.
38
Motor nerves synapse where?
in Muscle
39
Diffusion vs Electromotive force balance?
Diffusion is driven by High to low
Electromotive force repulsion due to negative charges
40
Which ions are under electromotive force?
Potassium and Sodium
41
The primary contributor to resting charge is what?
Potassium channels
42
The only channel open at rest is ?
Potassium
43
The ability to balance diffusional flow of potassium and electromotive retention of potassium at equilibrium is what?
Diffusion vs electromotive force balance
allows no net movement.
44
Action potential is initiated at what?
Axon hillock
45
Tri-state propagation?
Allows the system to reset itself back to refractory -50mv.
46
Hysteresis is what?
Structure goes from one form to another and back. 2 state system.
NOT NEUROTRANSMISSION
47
Sodium channels open(depolarize) at what mv?
-40mv
48
Refractory mv?
-50mv
49
Resting state mv?
-70 to -80mv
50
Hyperpolarization mv?
-90mv to -100mv
51
Factors that lead to increased conduction rates?
Myelination
High resting membrane potential(-40)
Increasing Na channel density
Increasing axonal diameter
52
Decreased capacitance?
Movement of ions across membrane increases the conduction rate.
53
Saltatory conduction?
Jumping of currents between nodes of Ranvier which increases speed of conduction.
54
Higher resting potential is what?
Less negative -60 or -50mv
55
Bigger axonal diameter =
Less resistance, increased conduction rate.
56
Synaptic transmission occurs at the end of a nerve terminal where?
Ca released from storage in sarcoplasm and leads to biochemical change allowing fusion of vesicles with inner cell membrane.
57
With synaptic transmission vessicles are?
Filled and pinched off.
58
Primary excitatory Neurotransmitters are?
Acetycholine
Norepinephrine/ Epinephrine
Dopamine
Serotonin (Ionophore 5-Ht3)
Glutamic acid
Aspartic acid
59
What are the two most common excitatory neurotransmitters?
Aspartic acid and Glutamic acid
60
Excitatory Serotonin neurotransmitters is where?
Ionophore 5-Ht3
61
Primary Inhibitory transmitters are?
GABA
Glycine
Serotonin (G-protein type receptor)
62
Functions as a diode that transmits the energy of an action potential from presynaptic to post synaptic.
Synapse
63
Principle inhibitory neurotransmitter in the spinal cord?
Glycine
Causes hyperpolarization of cell.
64
Principle inhibitory neurotransmitter in the brain?
GABA
Causes hyperpolarization of the cell.
65
What is the major excitatory neurotransmitter in the CNS?
Glutamate
66
Ligand-gated ion channels?
Transmit signal across the synapse
67
Voltage-gated ion channels?
Propagate action potentials
68
Francis Rynd in 1845
First hollow needles, injection of morphine to treat neuralgia.
69
Which IV anesthetic drug first administered?
Thiopental in 1934
70
Agent cause mild suppression of arousal and behavior, slight decrease in alertness and response to stimuli?
Sedative
71
Agent cause pronounced sedative effects and induction of sleep.
Hypnotic
72
Which drug is used to induce sleep?
Sedative or hypnotic
Hypnotic
73
Sedatives become hypnotics at higher doses
74
Alcohols?
Cause CNS depression, increased side effects and death with too much.
Ethanol and Chloral hydrate
75
Which drug builds up with its own metabolism. One persons dose may kill another person?
Phenobarbital
76
Barbituates are ?
Sedative, hypnotics, and not used much anymore due to low TI.
77
Benzodiazepines are?
Anxiolytics, cause CNS depressant, used for short term procedures, and require less anesthetic dose.
Cause anterograde amnesia!
78
Sedative/hypnotic MOA?
Complex, but most act on polysynaptic pathways. Increase presynaptic inhibition to shut off release. Seperate binding sites to GABA to increase Cl conduction.
79
Benzos/Barbs most believed effect?
Enhance the effects of GABA by decreasing depolarization.
Hyperpolarizing
80
GABA ionophore is a ?
Pentameric ligand-gated structure
81
Sedative/hypnotics need 2 binding sites on GABA in order to?
Open chloride channel allowing Cl flow in by diffusion to hyperpolarize the cell.
82
GABA binding site is ?
Alpha-1
Beta-2
83
What site blocks GABA and closes Cl channel?
Picrotoxin
84
Picrotoxin does what?
Blocks GABA, closes Cl channel to cause CNS stimulation leading to seizure.
85
Too much excitatory in brain leads to?
Seizure, epilepsy.
86
Steroid Site effect on GABA receptor complex?
Can enhance GABA binding.
ie: Anesthetics
87
How does Ethanol affect GABA receptor complex?
Decreases ratio of Inhibitory/Excitatory
Blocks more inhibitory than excitatory.
90I : 10E. now
45I: 5E
88
Where does propofol/etomidate/ barbituates bind on GABA receptor complex?
Alpha-1
Beta-2
89
NMDA glutamate receptor complex is a ?
Voltage-dependent ionophoric system.
Allowing Ca and Na ions to enter
90
NMDA glutamate receptor complex shape?
4 protein structure, Quadrameric
91
Ketamine acts on what receptor?
PCP binding site on the NMDA glutamate receptor complex. Inhibits the conductance of Ca (Excitation) in the thalamus.
92
What is also needed to bind for the Glutamate Receptor antagonist site?
Glycine
93
Glycine is in ?
the Spinal Cord, a similar action to GABA as an inhibitory neurotransmitter
94
Benzos cause mild muscle relaxant effects where?
Nicotinic ACh receptor inhibition.
95
2 phases of sleep?
Slow wave sleep (SWS)
Rapid eye movement sleep (REM)
96
Slow wave sleep (SWS) EEG shows?
High voltage synchronous activity.
97
Rapid Eye movement (REM) shows?
Skeletal muscle relaxation, 25% of overall sleep, 1-2hrs. eye movement
98
Changes to sleep pattern from hypnotic agents?
1. SWS patterns shortened
2. REM sleep depressed
3. Total sleep is prolonged
99
Barbituates MOA?
Augment GABA Cl- ionophore causing hyperpolarization. Decreasing dissociation of GABA.
Different location than benzos
100
Barbituates negative affect?
Heavily abused and altered sleep patterns.
Highly toxic with narrow TI
101
Which drug class inhibit oxidative phosphorylation?
Barbituates
Slowing of cellular function
102
Which drugs exist in keto and enol tautomers forms?
Barbituates
103
Replacement of C-2 oxygen with sulfur results in what?
(Barb)
Thiopental
Greater lipid solubility
104
Addition of a phenyl group at C-5 enhancing anticonvulsant activity?
(Barb)
Phenobarbital
105
Addition of a methyl group to the ring N shortens duration of action?
(Barb)
Methohexital
106
Long-acting barbituate?
Phenobarbital
107
Intermediate duration barbituate?
Pentobarbital
Secobarbital
108
Short-acting barbituate?
Methohexital
Thiopental
109
Base structure of a barbiturate?
Barbituric acid
110
The more lipid soluble the IV agent is the ____ its onset is?
Shorter onset due to rapid increase in brain concentration
111
Barbituates are_____ and packaged as ____?
Weak acids
Packaged as sodium salt in basic form
112
Barbituate primary metabolic pathway is?
Hydroxylation via PHASE 1
Potent inducers of the hepatic microsomal enzyme system.
OWN METABOLISM which can metabolism other drugs faster requiring higher doses.
113
Which drug class is used for Wada speech test prior to neurosurgery?
Barbituates
Slow brain function and slow metabolite buildup
114
Barbituates safe for pregnancy?
NO, placental transfer
115
Which has greater CNS specificity
BARBS or BENZOS?
Benzos
116
Ultra short-acting (10-15s)
High lipid solubility
Induction or short procedures
Metabolized by P-450 system
Half life- 6hrs
Lowers pain threshold- increase sensitive
POTENT RESP DEPRESSANT
DEPRESSES MYOCARDIUM
Neuroprotective
Unavailable in the US
Thiopental
117
2-3 more potent than thiopental
Metabolized faster by P-450 oxidation
Faster recovery
Used in ECT to Trigger seizures
Decreased seizure threshold
Methohexital
118
At high doses Benzos produce?
Hypnosis and unconsiousness
119
Half life of Midazolam?
1 hour
120
Half life of Diazepam?
Half life of effect of diazepam?
24-36 hrs
4 days (96hrs)
121
Midazolam is metabolized via ?
Microsomal hydroxylation
122
Diazepam is metabolized via ?
Microsomal N-demethylation
123
Oxazepam is eliminated rapidly by?
Glucoronide conjugation, PHASE II
124
Which benzo is converted into several active metabolites that increase clinical effect?
Diazepam
125
Diazepam potency value?
1
126
Diazepam is metabolized into ____ via CYP2C19?
Desmethyldiazepam
127
Desmethyldiazepam potency value?
1
128
Desmethyldiazepam is metabolized into _____ via CYP3A4?
Oxazepam
129
Oxazepam potency value?
0.5
130
Oxazepam becomes inactive via?
Glucoronidation
131
Diazepam is metabolized into _____ via CYP3A4?
Temazepam
and
Oxazepam
132
Temazepam potency value?
0.5
133
Temazepam becomes inactive via ?
Gluronidation
134
Metabolism
Diazepam→Desmethyldiazepam (via CYP2C19) then →Oxazepam (via CYP3A4) then →Glucoronidation to inactive.
Diazepam→ Temazepam(via CYP3A4) then → Glucoronidation to inactive.
Half life of effect= 4 days
135
Midazolam potency value?
Midazolam half life?
1
3 hours
136
Midazolam is metabolized into ____ via CYP3A?
1-Hydroxymidazolam
137
1-Hydroxymidazolam potency value?
1-Hydroxymidazolam half life?
0.5
6 hours
138
1-Hydroxymidazolam is metabolized to inactive via ____?
Glucuronidation(Phase II)
139
Metabolism of Midazolam
Midazolam→ 1-Hydroxymidazolam (via CYP3A) → Inactive glucuronide (via Glucuronidation) → Inactive compound
140
Lorazepam half life?
15 hours
141
Lorazepam metabolism to inactive via ______?
Glucuronidation
142
Benzos act on which subunits of the GABA receptor?
Alpha and Gamma
α. γ
143
Benzos receptors are found exclusively on what region of the CNS?
Post-synaptic
144
Benzos receptor density is greatest in _____ and associated with memory formation?
Cerebral cortex
(Neo cortex)
145
Benzos affect on
Cardiac?
Heart rate?
Respiration?
Skeletal muscle?
Mild cardiovascular effect, decrease in BP
HR may decrease or increase(reflexive)
Transient apnea with rapid infusion
Relaxation of skeletal muscles
146
Benzos safe for pregnancy/OB?
NO, crosses placenta wall, fetal depression.
147
Reversal drug for benzo overdose?
Flumazenil
Competitive antagonist
148
What is used as a counterirritant and rubifacient?
Ethanol
Rubifacient(increase blood flow to area by local irritation)
149
Bactericidal effect by disruption of cell membranes is caused by?
Ethanol
150
Decreases mental and physical abilities by a top-down CNS depression?
Ethanol
151
This causes cutaneous vasodilation via central mechanism leading to warming effect?
Ethanol
152
Ethanol metabolism?
Ethanol → acetaldehyde → Acetic acid
153
Ethanol is converted to acetaldehyde via ?
Alcohol dehydrogenase
154
Acetaldehyde is converted to Acetic acid via?
Aldehyde dehydrogenase
155
Which form of Ethanol metabolism is used as an energy source?
Acetic acid
156
Methanol metabolism?
Methanol → Formaldehyde → Formic acid
157
What damages retinal cells and leads to blindness?
Formaldehyde
158
Which drug binds to specific GABA receptors and has greater effects on sleep (weak alpha 2 agonist) but SE are sleep walking?
Escopiclone (Lunesta) = 7x
Zolpidem (ambien) = 1
159
Propofol (2, 6-diisopropylphenol) MOA?
GABA receptor agonist, decreasing the rate of GABA dissociation from the receptor. Selective modulator of γ-aminobutyric acid type A (GABAA) receptors.
160
Propofol allergic reaction are due to ?
Soybean allergy rather than egg allergy
161
Propofol induction and affects?
Rapid induction (15-30 secs)
Must be given slowly to avoid vessel irritation
DO NOT MIX with LIDOCAINE
Anti emetic, antipruritic, and anticonvulsant actions
162
Propofol metabolism?
Hepatic P-450 oxidative metabolism and phase II Glucuronide sulfate conjugation.
2-3 hour half life
163
Propofol duration of effect and half life?
Duration- 5-10 mins
Half life- 2-3 hours
164
Propofol safe for pregnancy?
Yes, Category B
165
Propofol affect on
BP
Cardiac
Respiration?
Decreased BP (sympathetic vasoconstriction)
Bradycardia
Depresses ventilation and apnea
166
When propofol is given continously over 24 hours what can happen?
Lactic acidosis.
Long term use can cause propofol infusion syndrome= severe metabolic acidosis, rhabdo.
167
What is the prodrug of propofol?
Fospropofol
168
Which form of propofol has no emulsion vehicle and is water soluble?
No pain on injection
Fospropofol
169
Toxic metabolite of Fospropofol?
Formaldehyde
170
Which form of propofol has no preservatives and short vial life with one time vial use?
Propoven
171
Propofol pumps?
Syringe mechanical infusion pump, bis monitor for CNS activity.
Outlawed in US
172
Etomidate MOA?
GABA receptor enhancement. Exact receptor is not clear although more selective than barbs.
Weak base, 99% unionized
173
Which drug is mixed with propylene glycol as vehicle?
Etomidate
very painful IV
174
Etomidate Metabolism?
Via hydrolysis of side chain ester by plasma esterase and hepatic P-450.
Half life- 2-5 hours
175
Etomidate effects on
Cardiac?
Respirations?
Neuro?
None, cardiac stable
Increase ICP, potent cerebral vasoconstrictor
176
Side effects of Etomidate?
Myoclonus with rapid IV
Dystonia
Depresses steroid (cortisol) synthesis in adrenals. NO long term use
177
Precedex MOA?
Alpha-2 Agonist works on presynaptic nerve terminals to shut off the release of norepinephrine. Mimics effects of clonidine but 7x more selective.
178
Precedex half life?
2 hours. Why continuous IV infusion is used.
179
Precedex metabolism?
Precedex side effects?
Mainly glucuronidation(34%) and P-450 hydroxylation.
Bradycardia/hypotension due to SNS decrease.
180
Remimazolam metabolism?
Via Plasma esterase, which is why it is 1/4 duration of midazolam
181
Ketamine MOA?
Binds to PCP site and Blocks glutamate excitatory NMDA receptors from release.
Blocks nACh receptors and Mu receptors
Agonist at Kappa receptors
182
Ketamine side effects?
Tachycardia
Hypertension
Increase CO
Increased ICP
Increased cerebral oxygen requirement
Dissociative Anesthesia (Catalepsy)
Emergence delirium
183
Ketamine affect on Glutamate?
Antagonist.
184
Ketamine metabolism?
N- demethylated P-450 to Norketamine
25% activity then further to inactive hydroxynorketamine by hydroxylation
185
Active metabolite of Ketamine?
Norketamine (25% activity)
186
Inactive metabolite of Ketamine?
Hydroxynorketamine
187
Best IV anesthetic for pediatric patients?
Ketamine
188
Increase in altitude does what to pO2?
Decrease
189
Biggest dropoff in PO2 is seen where?
Below 70mmHg
190
Increase in pH (Alkylosis)
Decrease DPG
Decrease Temperature
Nitrogen
Oxyhemoglobin shift where?
Left
Increase oxygen affinity for hemoglobin
191
Decrease in pH ( Acidosis)
Increase in DPG
Increase in Temperature
Increase in CO2
Oxyhemoglobin shift where?
Right
Decrease oxygen affinity for hemoglobin
192
What is the primary drive for ventilation?
pCO2
193
T or F
Increased inspired O2 conc does not greatly increase blood O2?
True, based on dissociation curve, can have low hemoglobin or low plasma volume
194
T or F
Too much oxygen can suppress respiration?
True, will decrease hypoxic drive due to decreased CO2
195
Too much oxygen can lead to ?
Peroxide formation
196
_____ can constrict cerebral vessels and decrease brain size in neurosurgery?
Hypocarbia
Increased RR (hyperventilation)
197
_____ is the main drive mechanism for vasodilation of arterioles?
Nitric oxide
198
Osmosis molecular weight cutoff?
150 mw
199
Based on Fick's Law
The diffusion rate is ____ to the partial pressure gradient, membrane area, and solubility of a gas in the membrane?
Proportional
200
Based on Fick's Law
The diffusion rate is ____ to the membrane thickness and sq root of the molecular weight?
Inversely proprotional
201
Which has slower diffusion rate?
20 microns
40 microns
40 microns slower
202
Graham's law of diffusion states that
The rate of diffusion is ___ to the square root of the molar mass?
Inversely proportional.
Larger mass= Slower diffusion
203
Henry's Law states that the amount of gas that will disolve in a liquid is _____ to the partial pressure of the gas in the gas phase?
Proportional
204
Laminar Flow?
Moving smooth and well. Minimal resistance
205
Turbulent Flow?
Resistance, Disruption, slows down and cannot predict.
206
What type of flow is typically in bends and narrowings?
Turbulent flow
207
The biggest change in airway resistance is based on ?
Radius
208
Increased length does what to laminar flow?
Decreased
209
Increased viscosity does what to laminar flow?
Decreased flow
Increases resistance
210
Bronchodilation does what to laminar flow?
Increases laminar flow, decreases resistance.
211
T or F
Turbulent flow can be calculated?
False, it is due to random movement of molecules
212
Which flow is seen at high flow rates in rough tubing, or kink tubes?
Turbulent flow
213
Reynolds number
< 1000
Laminar Flow
Good
214
Reynolds number
> 1500
Turbulent Flow
Bad
215
In Poiseuille's law
Flow is directly proportional to ?
Radius
hydrostatic pressure gradient
216
In Poiseuille's law
Flow is inversely proportional to ?
Viscosity
Length
217
Based on Bernoulli's principle, Increasing the fluid viscosity (through a narrowing) will cause a pressure ____ in the narrowing?
Decrease
218
Based on Bernoulli's principle, Decreasing the fluid viscosity (through a narrowing) will cause a pressure ____ in the narrowing?
Increase
219
Venturi principle states that narrowing in a tube ____ pressure of fluid flowing through and ____ speed?
Ex: venti-mask
Decrease pressure
Increases speed
220
Dalton's Law?
Mixture of gases exert a pressure that is the sum of the pressures of each gas.
221
Boyle's Law?
If pressure increases then volume decreases.
222
Charles Law?
If temperature increases then volume increases.
223
Gay Lussac's Law?
If temperature increases then pressure increases.
224
Ideal gas law?
PV= nRT
P=Atm
V= L
n= moles
R= constant 0.0821
T= temp
225
All General anesthetics have a ___ TI?
Narrow or low TI
226
The goal of Anesthetics is to produce?
CNS depression sufficient for unconsciousness, lack of response to stimuli
227
Earliest recorded use may have been when?
500 BC
Oracle Delphi
228
OG discovery of Inhaled anesthetics?
1840s
William Morton
229
First Halogenated alkane agent that reduced flammability?
Halothane in 1956
230
Alkanes caused ?
Cardiac toxicity
231
The mixture of different compounds for their different required effects, thus allowing less toxic doses is known as ___ ___?
Balanced anesthesia
232
Anesthesia depends on the ______ of the agent in the inspired air?
Partial pressure
233
_____ is the agents solubility between the gaseous phase and solubility in blood?
Blood:Gas partition coefficient
234
A low blood:gas partition coefficient means what?
Fast induction and fast emergence
235
A high blood: gas partition coefficient means what?
Slow induction and slow emergence
236
Inhalational absorption is dependent on?
FI
FA (end-tidal)
Blood:Gas partition coefficient
Oil:water partition coefficient (lipid solubility)
237
Induction rate is increased by what 3 things?
1. Decreased blood solubility
2. Increased partial pressure (conc)
3. Increased breathing rate
238
Increased lipid solubility is a better measure for ___?
Potency due to movement into brain
239
MAC values compare what?
Potency of gases
240
MAC definition?
Minimum concentration at the alveolus that produces useful anesthesia in 50% of patients.
241
T or F
Mac values are related to the time to reach anesthesia?
False, MAC values are at equilibrium
242
A low MAC would mean?
High potency
High solubility
243
A high MAC would mean?
Low potency
Low solubility
244
The percentage of the inhaled air that is occupied by the anesthetic gas is the ___?
Fi
245
What % is controlled by the anesthesia machine?
The Fi or % inspired air
246
What is the determinant of the brain partial pressure?
PA
Alveolar partial pressure
247
Uptake into pulmonary capillary blood depends on what?
Tissue solubility,
Cardiac output
partial pressure differential
248
Inhaled partial pressure?
Pi
Delivery amount by the anesthetic machine
249
Rapid absorption of one gas will create a volume decrease with the concentration of the remaining gases is called what?
Second gas effect
One compound drags the other across in high concentration
250
What gas is best to use for second gas effect?
Nitrous oxide
251
The higher % of nitrous oxide used will lead to _____ equilibrium or Fa/Fi?
Faster
252
Fi and FD are similar except when?
Low flow delivery
253
A high blood:Gas solubility take ___ to reach equilibrium?
Longer
254
What is the most important factor for determining how quickly Fa/Fi ratio approaches a value of 1.0 and rate of induction?
Blood:Gas partition coefficient
255
The more soluble the agent is in blood, the ____ the rate of rise of FA?
Slower
256
MAC value?
Minimal concentration of the agent at 1 atm in the alveolus at steady state that will inhibit pain response to a one inch surgical incision in 50% of patients.
ED50
Used as measure of potency
257
Things that affect MAC value?
decrease with age
greater in red head women
additive with each agent in combo
decreased when opiods are administered
258
More lipid soluble agents tend to have ____ MAC values?
Lower
259
What is a prediction of induction time?
Blood:Gas partition coefficient
260
Steady state MAC correlates to ?
500 umoles per 100mL of membrane
261
All Anesthetics have a common method of action is what theory?
Unitary Theory of Narcosis
NOT TRUE
262
Meyer-Overton Theory states ?
Correlation between lipid solubility and potency.
More lipid soluble agents are more potent
263
According to Meyer-Overton theory the most likely site of anesthetic affect is?
Membrane, affecting fluidity.
264
Meyer-Overton linear correlation for anesthetics is between?
MAC and Oil:Gas partition coefficient
265
Critical Volume Hypothesis by Mullins states?
Binding of anesthetic agent into membrane cause expansion.
Still does not explain why hydrophobic substances are poor anesthetics
266
Current theory of Inhalational Anesthetics is?
Mainly due to interactions with specific receptor-binding sites. Different families act on different receptors.
267
Which isomer is more potent isomer for anesthetics?
L- isomer is more potent than D-isomer.
268
IV and inhalational agents depress ____ neurons, which are important in memory formation leading to amnesia?
Hippocampal neurons
269
Inhalational agents depression ____ neurons which are the gateway for sensory information?
Thalamic neurons
270
GABA mediated chloride ionophores are located in the ?
Brain
271
Glycine mediated chloride ionophores are located?
Brainstem and SPINAL CORD
272
GABA Ionophore is a ?
Structure?
Sites ?
Pentameric ligand-gated ionophore
Alpha-1 Beta-2 binding sites
273
What Anesthetics bind to the NMDA receptor complex?
Ketamine and Nitrous oxide
274
Stage 1 of GA?
Initiation to loss of consciousness
275
Stage 2 of GA?
Delirium phase
LOC to Restlessness to calm state
276
Stage 3 of GA?
Surgery performed
277
Stage 4 of GA?
Point of imminent death
278
Rapid respiration, dilated pupils and muscle contractions occur during stage?
Stage 2
279
Blockade of Na channels leads to expanded membrane that is caused by _____ and _____?
Lipid Fluidization
Protein Expansion
280
Non-irritating gas, sweet odor
Nonflammable
MAC= 104%
Strong 2nd gas effect
Good sedative/ excellent analgesic
MOA- Inhibit NMDA glutamate
Antagonist at AMPA, GABA and 5-HT3
Low solubility, rapid onset/emergence
RISK OF DIFFUSIONAL HYPOXIA
long term abuse inactive B12 leads to blood disorders
Nitrous Oxide
281
Which gas do you avoid pockets of trapped air and does not cause MH?
Nitrous Oxide
282
Which volatile anesthetic stimulated catecholamine release and cause arrhythmias. Very explosive and made peroxides?
Diethyl Ether
283
Volatile Anesthetics ____ post-synaptic excitatory response and _____ post-synaptic inhibitory response?
Inhibit excitatory
Enhance inhibitory
284
Pleasant smelling, non-irritant, nonexplosive
Taken up into tubing and equipment
Rapid Induction
80% cleared by lungs with 20% Liver biotransformation
MAC= 0.76%
Short rapid breathing
Cardiac depression
CATECHOLAMINES, trigger arrhythmias
POST-OP HEPATITIS- Neoantigens
Halothane
285
This halogenated ether underwent 50% liver metabolism via P-450 2E1
Removed from market
NEPHROTOXICITY from Free fluoride
Methoxyflurane
286
Which 2 gases are isomers of eachother?
Enflurane and Isoflurane
287
This gas is isomer to Isoflurane
MAC= 1.68%
High dose stimulate CNS leading to SEIZURES (reason removed from market)
Increase epileptic waves
Enflurane
288
Which anesthetic gas lead to seizures?
Enflurane
289
This gas has pungent odor
MAC= 1.16%
Mild analgesic effects, skeletal muscle relaxation
Cardiac depression
Cerebral blood flow maintained
No seizure risk
High B:G partition coefficient
Slow induction/ Slow emergence
Isoflurane
290
This gas has Pungent irritating odor
Low solubility=0.42, rapid induction
MAC= 6.6%
VP= 700
Requires special vaporizer (heated)
Vd- 600L moves into tissues/fats
CO maintained, but decrease BP
No seizure risk
Weak muscle relaxant
Desflurane
291
This gas is best mask induction. Nonpungent
Low blood solubility- 0.65.
Rapid Induction/emergence
MAC= 1.71%
Expensive
Compound A risk/ renal damage
Decrease blood pressure
Sevoflurane
292
This gas is Inert
Odorless, nonpungent
Does not cause MH
MAC= 63-71%
NMDA glutamate receptor inhibition
Does not depress hemodynamics
No neurotoxic risk (neuroprotective)
HIGH cost
Closest to perfect Inhalational Ane
Xenon
293
The only anesthetic gas which alone has not shown signs of neurodegeneration?
Nitrous Oxide
294
Limit anesthetics given to ____ due to risk of decreased cognitive function and learning disabilities?
Young Children
295
____ can cause the breakdown of all halogenated anesthetics?
Soda Lime (now banned)
296
Compound A formed mainly by reaction of?
Sevoflurane with base catalysts
(NaOH or KOH)
297
Soda lime forms ______ with gas flows below_____ due to increased heat?
Temp 40-60 C
Carbon monoxide
2 L/min
Higher gas flows above 2L decrease temp which decreases risk.
298
Carbon monoxide degradation product of ____?
Known as ___?
Can lead to ____?
Desflurane by dry adsorbents
Worst on Monday morning phenomena
Lead to Carboxyhemoglobinemia (left curve)
299
All modern CO2 absorbents use ___ to trap CO2 as CaCO3?
Ca(OH)2
Calcium hydroxide
300
The higher the blood:gas partition coefficient, the _____ the anesthetic concentration in the blood?
Higher
doesn't want to leave blood, enters brain slow
High= slow induction
301
Solubility of the anesthetic gas in the blood ____ as body temperature decreases?
increases
302
FA/FI ratio is used to represent?
The equilibrium between body tissues and inspired concentration.
303
True or false
An increase in cardiac output reduces the rate of rise of FA/FI in high solubility agents?
True
304
True or false
All inhalation agents decrease cerebral metabolic rate and oxygen consumption?
True
305
Which anesthetic agent may prolong QT?
Sevoflurane
306
Which Anesthetic agent may result in Coronary Steal?
Isoflurane
307
How does chloride influx affect membrane potential?
Hyperpolarizes the cell, becomes more negative. -90mv
308
How does calcium influx affect membrane potential?
Depolarizes the cell, becomes less negative. -40mv
309
What is responsible for transmitting the signal across the synapse?
Ligand-gated ion channels
310
What is responsible for propagating action potentials?
Voltage-gated ion channels
311
Local anesthetics work through which channel?
Voltage gated Na channels.
