Ex2 IA System Effects

Question 1

Effect on MAP

Answer 1

IAs:
Dose-dependent decrease (increasing concentrations)
N2O: no change or increase
N2O + Iso = less of a decrease in BP

Question 2

Effect on HR

Answer 2

Iso/Des: dose dependent increase

Sevo at <1.5 MAC: decrease; >2 = normal

Question 3

Effect on rhythm

Answer 3

Prolonged QT

Sevo should be avoided in prolonged QT

Question 4

Effect on ventilation

Answer 4

Dose dependent depression of ventilation (Dec. response to increased CO2/decreasedO2)
Shallow breathing, increased rate, Bronchodilation
Inhibit HPV (esp > 1-2 MAC)

Question 5

HPV

Answer 5

Hypoxic Pulmonary Vasoconstriction

Question 6

Effect on chest wall

Answer 6

Decreased FRC, atelectasis in dependent areas

Question 7

Effect on CNS

Answer 7

N2O: increased CBF, modest increase in CMRO2
IAs: decreased CMRO2, increased CBF

Question 8

All volatiles cause a cerebral ______ in a dose dependent manner

Answer 8

dilation

Question 9

All volatiles _______ ICP at concentrations exceeding _____ MAC

Answer 9

increase; 1 MAC

Question 10

What is impaired at concentrations > 1 MAC?

Answer 10

Autoregulation

Question 11

Cerebrovascular response to ______ is maintained

Answer 11

PaCO2

Question 12

Which type of procedure would avoid IAs?

Answer 12

Spinal

Question 13

CNS Effects

Answer 13

Dose dependent depression of amplitude/increase latency of SSEPs (& AEPs)

Question 14

EPs may be abolished at _____ MAC

Answer 14

1

Question 15

At what concentration do volatiles reduce the reliability of MEPs?

Answer 15

Low concentrations

Question 16

Effect on EEG

Answer 16

Increased amplitude, burst suppression > MAC 1.5

Question 17

Which IAs are epileptogenic?

Answer 17

Enf > Sevo

Question 18

Volatiles ____ NDMRs (and DMR)

Answer 18

potentiate

Question 19

Which volatiles trigger MH?

Answer 19

All

NOT N2O

Question 20

Effect on Liver

Answer 20

Dose dependent reductions in hepatic blood flow, mild LFT elevations

Question 21

Severe liver injury may occur with _____

Answer 21

Iso, Des

Question 22

Effect of VAs on CO result in

Answer 22

Positive feedback —> VAs depress CO, decreased CO = more Pa; excessive depth of anesthesia may occur

Question 23

Anesthetic preconditioning

Answer 23

All VAs produce biphasic preconditioning on myocardium that rivals ischemic preconditioning (myocardial injury is limited after insult, fxn is preserved)

Question 23

Which IAs are pungent?

Answer 23

ISO, Des

Question 24

Pungency of an IA causes

Answer 24

Bronchoconstriction, airway irritation

Question 25

How to avoid effects of pungency

Answer 25

Small doses of opioids attenuate this effect

Question 26

Which VA potentiates roc most?

Answer 26

Des

Question 27

Liver effect from VAs is a result of

Answer 27

CYP450 metabolism results in trifluoroacetate — binds covalently to hepatocytes which triggers an immune response **hepatic necrosis***

Question 28

Do VAs effect the renal system?

Answer 28

Yes - Dose dependent decrease in renal blood flow, GFR, UO | d/t dec. BP/CO

Question 29

Nephrotoxicity is characterized by

Answer 29

Polyuria, hypernatremia, hyperosmolality, increased serum creat., poorly concentrated urine

Question 30

Renal Toxin _____ at levels _____

Answer 30

Inorganic F > 50 mmol/L

Question 31

Which VA may concern anesthetist with renal toxicity?

Answer 31

Sevo — metabolized to inorganic F

Question 32

Prolonged Sevo anesthesia ______ impair renal function

Answer 32

Does not

Question 33

How is compound A formed?

Answer 33

CO2 absorbents (K/Na hydroxide) react with Sevo

Question 34

Compound A

Answer 34

Nephrotoxin — proximal renal tubular injury

Question 35

Dose at which Compound A causes nephrotoxicity

Answer 35

50 ppm

Question 36

How do VAs effect skeletal muscles

Answer 36

Relaxation | N2O = rigidity at high concentration s

Question 37

When does MH manifest?

Answer 37

Not always immediate - Des: 3 hours post VA

Question 38

Effect of VAs on OB

Answer 38

Dose dependent decrease in uterine contractility/blood flow

Question 39

Effect of VAs on OB - modest vs substantial

Answer 39

Modest: 0.5 MAC Substantial: >1 MAC

Question 40

Effect of VAs on Immune system

Answer 40

``` Depressed PMLs inhibited (inflammation) ```

Question 41

N2O effect on genetics

Answer 41

Teratogenic d/t inhibition of DNA synthesis (avoid in pregnancy; esp 1st trimester)

Question 42

Effects on Bone marrow function

Answer 42

N2O causes megaloblastic changes/agranulocytosis | D/t effects on Vit B — production of DNA/erythrocytes

Question 43

Chronic administration of N2O can lead to

Answer 43

Peripheral neuropathy - d/t vitamin B12 enzyme dysfunction, peripheral/spinal cord nerve degeneration (prolonged administration 15 days); and symptoms of pernicious anemia

Question 44

Effects of IAs on systemic O2 requirements

Answer 44

Decreased

Question 45

Des > ISO produces?

Answer 45

Carbon monoxide from degradation by CO2 absorbants

Question 46

Cost considerations of IAs

Answer 46

- vapor pressure (mL vapor from each mL fluid) - potency - solubility - FGF (open or closed)