Lecture 9 9/12/24

Question 1

What are the primary goals of the respiratory system?

Answer 1

-provision of adequate gas exchange to allow maintenance of homeostasis
-obtain oxygen from environment for cellular resp.
-eliminate waste products

Question 2

What is functional residual capacity?

Answer 2

volume left in the lung after a normal tidal breath

Question 3

What is the function of pre-oxygenation?

Answer 3

fill the functional residual capacity

Question 4

What causes disturbances in respiratory rhythm?

Answer 4

-pharmacologic effects
-pathophysiology

Question 5

What is the adverse effect of abnormal respiratory rhythms?

Answer 5

increased respiratory effort

Question 6

What aspects of the resp. system can be assessed using auscultation or visual assessment?

Answer 6

-resp. rate
-rhythm
-effort

Question 7

What is ventilation?

Answer 7

movement of gas in and out of the alveoli via inhalation and exhalation

Question 8

What is the PaCO2 (partial pressure of CO2 in arterial blood) directly proportional to?

Answer 8

VCO2 (amount of CO2 produced)/VA (alveolar ventilation)

Question 9

What is the gold standard for ventilation evaluation?

Answer 9

PaCO2

Question 10

What is the gold standard for CO2 monitoring?

Answer 10

arterial blood gas assessment

Question 11

Why can venous blood be used to estimate PaCO2?

Answer 11

because arterial blood and mixed venous blood have similar PaCO2 levels

Question 12

What is capnometry?

Answer 12

measure of CO2 in exhaled resp. gases

Question 13

What are the four phases of the normal capnograph waveform?

Answer 13

-resp. baseline
-expiratory upstroke
-alveolar plateau
-inspiratory downstroke

Question 14

Where on the capnograph waveform is EtCO2 measured?

Answer 14

at the end of the tidal breath, where the alveolar plateau transitions into the inspiratory downstroke

Question 15

What is oxygenation?

Answer 15

process by which oxygen diffuses from one location to another

Question 16

What is the gold standard for evaluation of oxygenation?

Answer 16

PaO2

Question 17

What is hypoxemia?

Answer 17

abnormally low oxygenation, PaO2 less than 60mmHg

Question 18

Why can venous blood NOT be used to estimate PaO2?

Answer 18

arterial blood and mixed venous blood have very different levels of PaO2

Question 19

Why is oxygen saturation used to estimate PaO2?

Answer 19

there is a direct correlation between PaO2 and SaO2 because pressure dictates saturation

Question 20

Why is a small change in SpO2 important?

Answer 20

a small change in SpO2 is a large change in PaO2 due to the curve relationship

Question 21

What is the content of arterial oxygen/CaO2?

Answer 21

important determinant of delivery of oxygen that gives a composite of both forms of carried O2 in the blood

Question 22

What is important about monitoring the mucus membranes?

Answer 22

-want pink, well oxygenated and perfused membranes
-cyanosis requires 5g/dL of deoxygenated hemoglobin
-patients can be hypoxemic and not cyanotic, especially when anemic

Question 23

What evaluations are important to make when assessing respiratory status?

Answer 23

-RR
-rhythm
-mucus membranes
-SpO2
-capnograph

Question 24

How does fever differ from hyperthermia?

Answer 24

-fever is an elevation in temperature in order to fight off infection
-hyperthermia results from the inability to dissipate heat

Question 25

Which region of the brain dictates body temp.?

Answer 25

hypothalamus

Question 26

Why is temperature maintenance important under anesthesia?

Answer 26

the mechanisms that maintain body temperature have a wider window of activation under anesthesia and do no kick in until the body is much colder than normal

Question 27

What are the four methods of heat loss that happen in the body?

Answer 27

-convection: moving air removes radiated heat -evaporation: loss of heat by evaporation of water -conduction: direct transfer by contact -radiation: emission of electromagnetic radiation