Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Pharmacology Sem 1 > Inhaled Agents Part 2 > Flashcards

Inhaled Agents Part 2 Flashcards

1
Q

When is Ether day?

A

October 16, 1846

WTG Morton successfully demonstrates the use of ether in the removal of a jaw tumor at Mass Gen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Fresh gas flow is determined by

A

the vaporizer and flowmeter settings

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Fractional inspired gas concentration is determined by

A

FGF rate, breathing-circuit volume and machine absorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Fractional arterial gas concentration is affected by

A

ventilation/perfusion mismatching

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Fractional alveolar gas concentration is determined by

A

uptake, ventilation, and the concentration effect and second gas effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

The Fi/FA ratio is a

A

gas to gas ratio

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Factors that affect inspiratory concentration include

A

fresh gas flow, breathing system volume, & machine absorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Factors affecting alveolar concentration include

A

blood solubility of the agent, alveolar blood flow, partial pressure between alveoli and venous blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

If Fa is less than the end-tidal level it is possible that

A

venous admixture, alveolar dead space, or non-uniform distribution exists

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Ventilation/perfusion mismatch can occur in a situation such as

A

right bronchial intubation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

The overall effect for V/Q mismatch is

A

increase in alveolar partial pressure (highly soluble agents) and decrease in arterial partial pressure (low solubility agents)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the mechanism of action of inhaled gases?

A

unknown
possible targets may include: NMDA receptors, Tandem pore potassium channels, voltage-gated sodium channels, glycine receptors, & GABA receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the Meyer Overton Theory?

A

liphophilicity equates to potency

this is not absolute though

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the CNS effects of inhaled gases?

A

CMRO2 is decreased

cerebral blood flow is increased (dose-dependent)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What does “uncoupling” mean?

A

describes the phenomenon of a decrease in CMRO2 but an increase in cerebral blood flow
greater with sevoflurane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What does nitrous oxide do to the brain?

A

increases both CMRO2 and CBF
mild hyperventilation helps attenuate increases in
CBF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Clinically relevant doses of inhalational agents preserve this when ICP is a concern, mild hyperventilation 30-35 mmHg

A

cerebral vascular responsiveness to CO2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the effect of inhalational agents on evoked potentials?

A

inhalational agents decrease amplitude and increase latency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

EEG and evoked potentials

A

inhalational agents produce a dose-related suppression

burst suppression occurs at: 1.5 MAC of desflurane & 2 MAC with isoflurane and sevoflurane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

For neonates having surgery,

A

there is a concern for developmental neurotoxicity
it was demonstrated in rodents and non-human primates that they cause activation of extrinsic and intrinsic apoptotic cell death pathways

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

When giving gas to neonates it is recommended that

A

keep surgery as short as possible

use short acting medications and multimodal approaches

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

All volatile inhalation agents reduce

A

cardiac output and index in a dose-dependent fashion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Volatile agents and nitrous oxide induce HR changes via

A

SA node antagonism
modulation of baroreflex activity
sympathetic nervous system activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Reduced MAP secondary to

A

SVR reduction

nitrous oxide used in combination with anesthetics reduces this

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Reduced cardiac output is caused by
reduction in free intracellular Ca2+ contractil state | As MAC hours increase, there is slight increase of CI and HR
26
Emergence delirium in children
is more common with sevoflurane and desflurane | & can cause injury & delay discharge
27
Emergence delirium in children can be prevented by
having a quiet, stress-free environment and giving medication adjuncts
28
Postoperative cognitive dysfunction is of
great concern in the elderly | there is no clinically significant association between major surgery and anesthesia with long-term POCD
29
Nitrous oxide causes a slight increase in
PVR and it worsens in patients with pulmonary hypertension
30
The volatile agents affect pulmonary circulation
by decreasing pulmonary artery pressure
31
Gases are able to affect the pulmonary circulation by
mildly depressing hypoxic pulmonary vasoconstriction | isoflurane has the greatest effect
32
All inhalational agents produce some
vasodilation (SVR) | in hypotensive patients this can result in a 'reverse-Robin Hood' syndrome (isoflurane)
33
Preconditioning is
a phenomenon in which the heart is exposed to a cascade of intracellular events that protect it from ischemic and reperfusion insult
34
Sensitization is
when volatile agents reduce the quantity of catecholamines necessary to evoke arrhythmias Less common in ASA I & II classifications
35
The CO, SVR, MAP, and HR in isoflurane:
CO: decreased SVR: decreased MAP: decreased HR: increased
36
The CO, SVR, MAP and HR in desflurane:
CO: --- SVR: decreased MAP: decreased HR: increased
37
The CO, SVR, MAP, and HR in sevoflurane:
CO: -- SVR decreased MAP: decreased HR: no change
38
The CO, SVR, MAP, and HR in nitrous oxide:
CO: decreased SVR: increased MAP: no change HR: increased
39
The CO, SVR, MAP, and HR in xenon is:
CO: no change SVR: no change MAP: no change HR: decreased
40
The gases do what to the airways?
relax airway muscle and produce bronchodilation
41
Volatile agents cause dose-dependent decreases in (respiratory related)
tidal volume- compensated by increase in RR (but not sufficient to offset TV) Responsiveness to carbon dioxide -increases apneic threshold -exacerbated by co-administration of an opioid
42
What volatile agent has the potential to impair hepatic function?
Halothane halothane hepatitis (rare) caused by trifluoracetyl-containing metabolites binding to proteins and forming antibodies re-exposure of the patient to halothane cause massive hepatic necrosis
43
What gas was historically associated with increased production of haloalkene, compound A?
sevoflurane This occurs with the use of older absorbents (CaOH or lithium OH) newer agents (NaOH and KOH do not have this issue should not exceed 2 MAC hours at flows <2L per minute Fresh gas flow <1 L per minute not recommended
44
Autoregulation of renal circulation remains relatively intact
decrease in renal SVR leads to decline in GFR ultimately a decrease in urine output desflurane has least impact on renal function
45
Action of volatile agents on hepatic function
possible impairment although extremely rare sevoflurane undergoes the greatest metabolism (5-8%) however it does not cause hepatic toxicity
46
Neuromuscular effects of volatile agents include
dose-dependent relaxation on skeletal muscle additive effect on non-depolarizing NMBDs delays recovery from non-depolarizing NMBDs
47
The ideal anesthetic agent properties:
non-irritating to the respiratory tract, rapid induction and emergence, chemically stable (non-flammable), produce amnesia analgesia and areflexia, potent, not metabolized and excreted by respiratory tract, free of toxicity and allergic reactions, minimal systemic changes, uses a standardized vaporizer, affordable
48
The four properties that affect how agents work include
vapor pressure, boiling point, partial pressure, and solubility
49
Boiling point is
the temperature at which vapor pressure exceeds atmospheric pressure in an open container
50
Vapor pressure is
the pressure exerted inside a container between liquid and vapor at room temperature, most volatile agents have a vapor pressure below atmospheric pressure it is directly proportional with temperature
51
The partial pressure is
fraction of pressure within a mixture (Dalton's Law)
52
Solubility is
the tendency of a gas to equilibrate with a solution (Henry's Law) anesthetic gases administered to the lungs diffuse into the blood until the partial pressures of the alveoli and blood are equal
53
The concentration of anesthetic in tissue is dependent on
the partial pressure and solubility
54
For most drugs, concentration is measured as
mass (mg/mL) but it can be expressed in percent by weight or volume
55
Gas is expressed as
a fractional concentration | fractional volume= Panesthetic/Patmospheric
56
MAC awake is
the MAC in which 50% of the populations opens eyes to command
57
MAC 'BAR'
the MAC necessary to block adrenergic response to stimulation usually 1.3 of MAC value can be reduced by administering a narcotic prior to incision
58
MAC requirements decrease with age
age 6% decline (of a normal MAC) each decade after the age of 40 MAC relatively unaffected by gender, duration of anesthesia, comorbidities
59
The additive effect
0.5 MAC of nitrous oxide + 0.5 MAC of isoflurane= 1 MAC sevoflurane the idea that giving nitrous can decrease the MAC requirement of another gas but make it as effective as 1 MAC of another agent
60
Vaporizers are
calibrated for specific agents
61
The vaporizer facilitates the movement of anesthetic from the machine to the patient through
fresh gas flow, pressure, and temperature
62
What is the chemical structure of isoflurane?
halogenated methyl ethyl ether
63
Isoflurane is the most ____ of the volatile agents
potent | slower onset and recovery from anesthesia
64
Isoflurane affects CV by
minimal cardiac depression, preserves carotid baroreceptors | dilates coronary arteries; concern for 'reverse-Robin-Hood'
65
Isoflurane respiratory effects
pungent, not used for inhalational induction | tachypnea less pronounced
66
Desflurane is the ____ _____ of the volatile agents
least potent quicker induction and emergence potential to boil at room temperature
67
The cardiovascular effects of desflurane are
rapid increases in desflurane lead to increases in HR & BP | attenuated with fentanyl, esmolol, clonidine
68
The respiratory effects of desflurane are
very pungent; can cause airway irritation, increased salivation, breath holding, coughing, laryngospasm avoid in patients with reactive airway disease
69
The chemical structure of sevoflurane
fluorinated methyl isopropyl ether
70
Sevoflurane has moderate
potency and has rapid induction and emergence
71
Sevoflurane is the preferred volatile for
inhalational induction because it is non-pungent
72
Sevoflurane has the following CV effects:
may prolong QT interval | CO is less maintained than other volatile agents- HR not increased
73
Sevoflurane is metabolized
in the liver | increases in inorganic fluoride ions but never shown to result in nephrotoxicity
74
Soda lime can degrade sevoflurane
into Compound A increased gas temperature, low flow anesthesia, high sevoflurane concentrations and prolonged surgeries (nephrotoxic in rats, not humans) For safety: calcium hydroxide absorbent, flows 2 lpm, avoid in patients with renal dysfunction
75
Nitrous oxide is
not a volatile anesthetic | it is colorless and odorless
76
Nitrous oxide acts on
NMDA receptor antagonist which may lower risk for chronic pain after surgery
77
A safety consideration of nitrous oxide is
it is nonexplosive and nonflammable however it does support combustion like oxygen
78
Nitrous oxide has decreased in popularity because
chronic exposure can lead to inactivation of vitamin B12 cofactor for enzyme synthesis, disrupting DNA synthesis leading to teratogenic bone marrow and immunosuppression effects (don't use on pregnant women in first two trimesters)
79
Nitrous oxide has effects on the respiratory system including
increasing respiratory rate | decreasing hypoxic drive
80
Nitrous oxide has effects on the cerebral system including
increases CMRO2 and CBF
81
Nitrous oxide increases the risk of
PONV
82
Nitrous oxide stimulates the
SNS, BP, HR, CO unchanged or slightly elevated
83
Absolute contraindications to using nitrous oxide include
expansion of gas-filled space | methionine synthase pathway deficiency
84
Relative contraindications of nitrous oxide include
PONV, first trimester of pregnancy, increased ICP, pulmonary HTN, prolonged surgery >6 hours
85
Xenon is a
noble gas with known anesthetic properties
86
Xenon works
through NMDA and glycine receptor binding sites
87
Xenon has minimal
CV, hepatic, or renal effects and has no effect on the ozone layer
88
Xenon violates the principle of ideal gases because
it is expensive and has limited availability (hard to extract)
89
The BP, VP, blood:gas, oil:gas, MAC for sevoflurane
BP: 59, VP: 157, Blood gas: 0.65, Oil:gas 47, MAC 2.0
90
The BP, VP, blood:gas, oil:gas, MAC for desflurane
BP: 24, VP: 669, Blood gas: 0.42, Oil:gas 19, MAC: 6.0
91
The BP, VP, blood:gas, oil:gas, MAC for isoflurane
BP: 49, VP: 238, Blood:gas 1.46, Oil:gas 91, MAC 1.2
92
The BP, VP, blood: gas, oil:gas, MAC for nitrous oxide
BP: -88, VP: 38,770, Blood gas: 0.42, oil:gas 1.4, MAC 104
93
Malignant hyperthermia can be triggered by
volatile anesthetics, succinylcholine, and stress
94
Malignant hyperthermia is due to
ryanodine receptor gene mutation (chromosome 19)
95
Signs and symptoms of malignant hyperthermia include
increase in CO2 production, muscle rigidity, metabolic acidosis, high temperature (late sign) also may see dark urine color, tachycardia, tachypnea
96
The treatment for malignant hyperthermia is
dantrolene sodium- muscle relaxant 1 mg/kg (supplied in 70 mL vials containing 20 mg of Dantrolene, 3000 mg of Mannitol and sodium hydroxide) administer until symptoms subside up to 10 mg/kg
97
Ryanodex is
a new IV formulation of dantrolene for the prevention and treatment of MH shorter half-life requires supplementation of mannitol requires fewer dials and less reconstitution
98
Anesthesia in pregnant patients
most common appendectomy, cholecystectomy, ovarian, or trauma
99
For pregnant patients
elective surgery should be delayed until after delivery | Nonurgent surgery should be performed in the second trimester

Pharmacology Sem 1 (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions