Inhalant anesthesia 1 & 2 Flashcards Preview

My 2016 RUSVM Anesthesia > Inhalant anesthesia 1 & 2 > Flashcards

Flashcards in Inhalant anesthesia 1 & 2 Deck (25):
1

What is Dalton's law of partial pressure

total pressure of a gas mix is equal to sum of partial pressure of the individual gases

2

solubility

expressed as a partition coefficient describes capacity of a given solvent to dissolve anesthetic gas

3

What is blood-gas partition coefficient

describes amt of anesthetic in blood vs. alveolar gas at equal partial pressures

4

What is the significance of knowing the amount of alveolar gas

the anesthetic in alveolar gas represents brain concentration this is location of effect anesthetic dissolved in blood is pharmacologically inactive!

5

How to incr alveolar delivery of anesthetic gas

Incr inspired anesthetic concentration:

  1. incr vaporizer setting
  2. incr fresh gas flow

Incr alveolar ventilation:

  1. incr minute ventilation

6

how to decrease removal of anes gas from alveoli

decr blood solubility of anesthetic

7

What is Minimum Alveolar Concentration (MAC)

Minimum alveolar concentration of an anesthetic that prevents movement in 50% of pts exposed to a noxious stimulus

8

What ensures immobility in 95% of patients

1.2-1.4 x MAC

Example: 1.2MAC of iso = 1.2 x 1.3 = 1.6%

9

What are CV effects of inhalants

Decrease:

CO

BP

SVR

Contractility (inotropy)

No change or Increase:

HR (chronotropy)

10

What are respiratory effects of inhalants

Decrease ventilation

Bronchodilation

irritating odor: desflurane & iso

least irritating odor: sevo

11

What are neurologic effects of inhalants

Incr ICP @ >1 MAC (incr cerebral blood flow)

Decr cerebral metabolic rate

acts on brain & SC to produce immobility (not analgesia)

suppress seizure activity (except Enflurane)

12

What are renal effects of inhalants

Decr GFR & renal blood flow

Renal failure (methoxyflurane)

13

what is Compound A

Produced from sevoflurane breakdown in CO2 absorbent (baralyme > soda lime)

Nephrotoxic in rats

14

What are hepatic effects of inhalants

decr liver blood flow & O2 delivery (related to decr CO)

Halothane can cause hepatotoxicity 2 types:

incr liv enzymes (mild, self limiting)

Halothane hepatitis = immune mediated often fatal

15

What inhalant can cause malignant hyperthermia

What spp most affected

Whats first sign

Tx

Px

occurance rate

Halothane

Pigs

Rapid incr in EtCO2

Dantrolene (muscle relaxant)

Poor-grave despite tx

extremely rare

16

What can be a consequence of N2O use

diffusion hypoxia when N2O d/c

prevent by providing 100% O2 for 5-10 minutes after stopping N2O

17

What are 3 anesthetic related common complication of inhalants

Hypotension

Hypoventilation

Hypothermia

18

What is considered hypotension in SA

LA

what is corresponding number on Dopper BP

MAP < 60 mmHg

MAO < 70 mmHg

80 or 90 respectively

19

What is the most appropriate & effective tx for hypotension during inhalant anesthesia

#1 evaluate pt & turn down vaporizer if pt is too deep for current level of stimulation

if pt is light, add MAC sparing drug, then turn down vaporizer

20

What is considered hypventilation with inhalant anes

PaCO2 >40 mmHg OR EtCO2 >45 mmHG

21

What is appropriate tx for hypoventilation

#1 evaluate pt & turn down vaporizer if pt too dep for curren level of stimulation

#2 Perform IPPV

22

What is considered hypothermia during anesthesia

Temp < 97° F or 36° C

23

What is appropriate tx for hypothermia

Prevention is more effective than tx!

various ways:

BAIR hugger

bubble wrap feet

cover

warm water pad

etc.

24

What will a CO2 rebreathing waveform look like on capnograph

waveform does NOT return to baseline (0) between breaths

25