41. Respiratory monitoring

Question 1

What measures SvO2

Answer 1

Saturation of blood in the pulmonry artery

Question 2

DO2 formula

Answer 2

C.O. x CartO2

Question 3

SvO2 formula

Answer 3

SaO2 - VO2 /(1.34 x Hb x C.O.)

Question 4

SvO2 normal values

Answer 4

65 - 80
Close to 40 tissue hypoxia

Question 5

Bilirubin level that causes falsely low pulse oximetry

Answer 5

30 mg/dl

Question 6

Methylglobinemia

Answer 6

PO2 normal
Cyanosis doesn’t respond at O2
Tx. methylene blue

Question 7

CO poisoning

Answer 7

Reduces delivery of O2 from hemoglobin
No reduce PaO2

Question 8

Haldene effect

Answer 8

Oxygenation of blood in the lungs displaces carbon dioxide from hemoglobin which increases the removal of carbon dioxide. This property is the Haldane effect. Consequently, oxygenated blood has a reduced affinity for carbon dioxide

Question 9

FRC decrease and increase

Answer 9

Increase in Age and height
Decrease in woman and obese

Question 10

Extraction ratio of O2

Answer 10

1 - SvO2

Question 11

Transpulmonary pressure characteristics

Answer 11

Higher in the apex
Ptp = Paw - Ppl

Question 12

Closing capacity and age

Answer 12

In younger individuals close to RV
In elderly earlier, at or above FRC

Question 13

Most important factor to develop atelectasis in patients under general anesthesia

Answer 13

BMI

Question 14

Pulse oximetry waves range

Answer 14

from 660 nm to 940 nm (the best)

Question 15

Pleth variability index

Answer 15

6 - 8
Lower, less variability to fluids
Higher more likely to respond to fluids

Question 16

Hemoglobin types

Answer 16

F fetal
H Thalassemia alpha
K Uncommon mutation. No effect in SaO2 but yes in SpO2
S sickle cell

Question 17

A a gradient

Answer 17

PAO2 - PaO2
Normal range 10

Question 18

Driving pressure

Answer 18

Plateau pressure - PEEP

Question 19

V/Q

Answer 19

Emphysema > Chronic bronchitis, PE, Asthma

Question 20

Shunt

Answer 20

ARDS > pneumonia/ atelectasis / pul. edema

Question 21

Auto PEEP

Answer 21

Positive pressure and end of expiration
Common in COPD
IN ARDS, increase resistance, decrease lung responsiveness