quiz 5

Question 1

4 Phases of uptake and distribution

Answer 1

1. inspired (alveolar concentration)
2. alveolar (alveolar concentration)
3. blood (alveolar concentration)
4. Distribution from the blood to the tissue

Question 2

Using ______ of delivery gases (O2, N2O/O2) in the _______ range, can precisely control the partial pressure of an anesthetic agent inspired and accomplish what is called a _______ .

Answer 2

high flows

5-10L/min

wash in

Question 3

When High concentrations of inspired gases are rapidly removed from the lungs by the blood. This tends to encourage increased inspired volumes of fresh gases at a high concentration, increasing minute ventilation as a result.

Answer 3

Concentration Effect

Question 4

The rate at which the alveolar partial pressure of the anesthetic rises is determined by 2 factors:

Answer 4

• inspired concentration

- alveolar ventilation

Question 5

When first gas (N2O) is used, it is picked up rapidly from the alveoli by the blood. This rapid crossing of N2O into the blood tends to pull the second gas (e.g., isoflurane) along with it, so that the arterial partial pressure of the second gas rises more rapidly than it would if it were alone in the alveoli.Called?

Answer 5

Second Gas Effect

(Means that after n20 leaves alveoli quickly to blood, alveolar size has shrunk, increasing gas concentration allowing quicker exchange to blood)

Question 6

Three (3) factors determine how rapidly anesthetics pass from the inspired gases to the blood:

Answer 6

Solubility of the agent
Rate of blood flow through the lungs (CO)
Partial pressure of the agents in the arterial/venous blood (Pa)

Question 7

When Increased inspired volumes promotes an increase in alveolar partial pressure (PA) and helps to offset the decrease in partial pressure of the gases brought on by pulmonary capillary uptake, which in turn promotes the rapid induction of anesthesia.

Answer 7

Concentration Effect

Question 8

SOLUBILITY OF AGENT IN BLOOD =

Answer 8

ANESTHETIC BLOOD CONCENTRATION/ANESTHETIC ALVEOLAR CONCENTRATION

Question 9

Blood gas solubility: The ______ the number the _______ it takes to anesthetize patient.

Answer 9

higher

longer

Question 10

PARTIAL PRESSURE OF ARTERIAL/MIXED VENOUS BLOOD:

Answer 10

Initially as the venous blood returns to the lung, the partial pressure of the agent will be very low as most was delivered to the tissue which also had very low to no partial pressure

As the venous partial pressure rises there is less picked up from the alveoli and uptake decreases

(Increased cardiac output, blood moving passed alveoli too quickly to pick up as much gas, so slower uptake and vice/versa for low CO)

Question 11

When the agent is delivered to the tissues by the arterial blood, the partial pressure in the tissues begins to rise and approach the partial pressure of the blood. The rate at which this occurs depends upon several factors:

Answer 11

• Solubility of the gas in tissues

- Tissue blood flow

Question 12

Partial pressure in arterial blood/tissues

Answer 12

Higher gradient in beginning, once gradient decreases, uptake slows

Question 13

Stage 1

Answer 13

start of gas, breathing increases – faster rate, shallower breath

It begins with the administration of anesthesia and ends with the loss of consciousness.

Question 14

stage 2

Answer 14

breathing erratic, ocular irregularities aka move independently, secretion of tears increased, tense struggling, swallowing, retching, vomiting.

This stage extends from the loss of consciousness to the beginning of surgical anesthesia

Question 15

stage 3

Answer 15

more reg breathing, ocular movements back to normal, block more reflexes, laryngeal reflexes and deep glottic reflexes decreased, and shouldn’t respond much to incision

Question 16

Stage 4

Answer 16

most all reflexes inhibited, pupils blown, tend to stay away from stage 4

Question 17

which stages do pupils not react to light?

Answer 17

3 and 4

Question 18

which stage is bp high?

Answer 18

2

Question 19

which stages have irregular pulse?

Answer 19

1 and 2

Question 20

Signs of “LIGHT” anesthesia include

Answer 20

Swallowing, coughing returns
Increase respirations
Increase BP, HR
Increase muscle tone
Tear formation (abolished at surgical stage)

Question 21

Signs of “DEEP” anesthesia include:

Answer 21

Bradycardia
Pupils become dilated, lack luster
Hypotension
Diaphragmatic breathing

Question 22

surgical anesthesia not present when?

Answer 22

reflexes present

Question 23

indication that surgical anesthesia is beginning?

Answer 23

loss of reflexes and rhythmic respirations

Question 24

MAC is measured where?

Answer 24

alveoli

Question 25

The ______ the MAC, the ______ potent the agent and the ______ the oil:gas partition coefficient

Answer 25

lower

more

higher

Question 26

Factors that decrease MAC:

Answer 26

• Hypoxia: decreased PaO2 causes narcosis itself
• Anemia: decreased PaO2, decreases MAC
• Drugs: lithium, narcotics, sedatives, calcium channel blockers, acute alcohol ingestion, etc.
• Hypotension: decreased MAP decreases MAC
• Age: elderly, decreased CBF, CMRO2
• Pregnancy: due partially to hormonal influences

Question 27

Factors that increase MAC:

Answer 27

• Hyperthermia
• Age: infants, MAC usually greatest in newborn due to BMR basic metabolic rate
• Drugs: chronic alcohol, barbiturates, narcotics, etc., chronic use

Question 28

VARIABLE EFFECT ON MAC:

Answer 28

Temperature:

• Hypothermia decrease
• Hyperthermia decrease ­ if > 42oC

Age:

• Young increase
• Elderly decrease

Question 29

What % patients dont move at mac 1.2? 1.3? What is standard deviation of MAC?

Answer 29

95%
99%
10%

Question 30

What is MAC-Awake?

Answer 30

minimum alveolar concentration at which 50% of subjects will respond to the command “open your eyes”.

(usually 1/3 MAC)

Question 31

represents the MAC necessary to block adrenergic response to skin incision?

Answer 31

MAC-BAR

Question 32

Uptake of the inhaled anesthetic into pulmonary arterial blood depend on?

Answer 32

• Solubility or “blood-gas partition coefficient”
• Alveolar to venous partial pressure difference
• Cardiac output

Question 33

induction of anesthesia is parallel to the rate of increase in? which is determined by?

Answer 33

Fa (alveolar concentration)

blood-gas partition coefficient

Question 34

Factors that effect Transfer of inhaled anesthetic from arterial blood to brain?

Answer 34

Brain-blood partition coefficient
Arterial to venous partial pressure difference
Cerebral blood flow

Question 35

what effects of hyper and hypoventilation on induction?

Answer 35

Hyperventilation increase induction*

Hypoventilation slow induction

Question 36

Example – blood-gas partition coefficient of 10. the concentration of the inhaled anesthetic is ___ in the blood and ___ in the alveolar gas when the partial pressure of that anesthetic in these two phases is identical.

Answer 36

10

1

Question 37

__________ or use of fresh gas flows ___ enough to permit rebreathing of anesthetic will lead to transfer of anesthetic back into the tissues delaying patient recovery.

Answer 37

Hypoventilation

low

Question 38

when can diffusion hypoxia occur? how to avoid?

Answer 38

when NO2 is abruptly stopped

100% O2 for 5-10 minutes after the N2O has been discontinued

Question 39

N2O still in the body rapidly diffuses across __________ membrane diluting the ____ concentration to a point where it can cause the PaO2 to drop and hypoxia develops

Answer 39

capillary/alveoli

O2

(this is diffusion Hypoxia)

Question 40

Other factors that influence the rate of emergence:

Answer 40

• Duration of procedure adipose tissue buildup
• Physical condition of the patient CO
• Obesity – may initially wake up, but then as agent is mobilized from fat stores they may reanesthetize themselves.
• Temperature of the patient*

Question 41

When can metabolism effect emergence?

Answer 41

in highly lipid soluble agents