Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Anesthesia Exam 1 > Anesthesia and the Respiratory System > Flashcards

Anesthesia and the Respiratory System Flashcards

(53 cards)

Start Studying
1
Q

DO2 = CO x ____

A

DO2 = CO x Oxygen Content

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is normal CaO2? (arterial oxygen content)

A

approx 20mL/dL

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

how much O2 travels dissolved in the blood?

A

1-2%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

T/F: 98-99% of O2 travels with Hb

A

true
1-2% of O2 travels dissolved in blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what PO2 values correlate with 90-95% saturation?

A

PO2 of 60 or 80mmgHg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is the definition of mild hypoxemia?

A

PaO2 < 80 mmHg OR
SaO2 < 95% OR
CaO2 < 19 mL/dL

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is the definition of severe hypoxemia?

A

PaO2 < 60 mmHg. OR
SaO2 <90% OR
CaO2 < 18mL/dL

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

T/F: hypoxemia and anemia are equivalent as both cause low CaO2

A

false- hypoxia is not anemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

T/F: both hypoxemia and anemia cause low CaO2

A

true! both they are not the same thing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

CaO2 equation

A

CaO2 = (Hb x % saturation x 1.36) + (PaO2 x 0.003)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

a bulldog presents with difficult breathing and you are suspecting there are airway issues. what are your differentials for hypoxemia

A
  1. low inspired O2 (low FiO2)- could be low tension or partial pressure O2 from altitude
  2. hypoventilation (high CO2)
  3. ventilation/perfusion mismatch (V/Q mismatch)
  4. anatomic shunts
  5. diffusion impairment
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

low FiO2 means

A

there is low inspired O2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

T/F: low inspired Oxygen (low FiO2) won’t affect the A-a gradient

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is room air FiO2?

A

21%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is 100% FiO2

A

100% FiO2 O2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

why might you put a patient on 100% O2?

A

if they are stressed their tissues are consuming more O2; this will help patient breathe and buys you time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

T/F: low PAO2 has no force for O2 molecules to cross membranes

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is the PAO2 of fort collins compared to sea level?

A

FOCO: 75mmgHg
sea level: 100mgHg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

why does fort collins have lower PAO2?

A

because the barometric pressure is 640 compared to at sea level where barometric pressure is 760mmHg and PAO2 is

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

how does hypoventilation work?

A

increase of PACO2 will occupy the alveoli and decrease PAO2, then decreasing PaO2

PaCO2 will remain high and in equilibrium with the alveoli PACO2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what is the difference between increased and decreased V/Q? (ventilation/perfusion)

A

increased V/Q = inflated alveoli but not perfused
decreased V/Q = perfused alveoli but not inflated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what type of A-a gradient do you see with V/Q mismatch?

Study These Flashcards
A

very large A-a gradient

22
Q

does hypoventilation affect the A-a gradient?

Study These Flashcards
A

no, it is normal

23
Q

what is the most common cause of hypoxemia in horses?

Study These Flashcards
A

V/Q mismatch: PAO2 will be normal but the PaO2 will be low, creating a large PA-a gradient

meaning oxygen isn’t diffusing from alveoli into the blood

24
anatomic shunts
blood that doesn't cross the alveoli for gas exchange ex: thebesian vessels from the myocardium and bronchial vessels from the lung: never went thru alveoli and aren't picking up O2
25
pathologic shunts
ex: patent ductus arteriosus (PDA) with right to left shunt, ventricular septal defect (VSD) with right to left shunt, etc usually congenital or young age
26
diffusion impairment
diffusion of O2 impairment due to alveolar wall or vasculature injury ex: pulmonary fibrosis, vasculitis, O2 toxicity
27
what causes of hypoxemia cause a large A-a gradient?
1. V/Q mismatch 2. anatomical shunt R-->L 3. diffusion impairment (alveoli)
28
pulmonary fibrosis, vasculitis and O2 toxicity are all examples of
diffusion impairment (causes large A-a gradient)
29
what is venous admixture?
V/Q mismatch, anatomic shunts, diffusion impairment all venous admixture will have large A-a gradient and low P-F ratio
30
T/F: all venous admixture will have large A-a gradient
true
31
how do you assess lung function?
1. PA-a gradient 2. O2 index or P-F ratio: normal >500 (PaO2/FiO2)
32
what is a normal A-a gradient?
less than 10mmHg for 21% O2 less than 100mmHg for 100% O2
33
what is PaO2?
O2 measured in arterial blood
34
what is FiO2?
inspired fraction (%) measured O2 from alveolia
35
what is PAO2?
calculated for the alveoli
36
why is PaO2 the best lung function test?
allows to assess O2 exchange at the alveoli 1. PA-a gradient 2. Pa:Fi ratio or O2 index
37
what is the importance of PaO2?
1) Assess patient oxygenation status and aerobic metabolism (eg. hypoxemia or not) 2) Best lung function test because allows to assess O2 exchange at the alveoli - PA-a gradient - Pa:Fi ratio or O2 index
38
CO2 determines
ventilation
39
T/F: CO2 is a potent respiratory stimulant and stimulates the CV system
true: CO2 stimulates chemoreceptors
40
T/F: CO2 influences pH
true- CO2 is an acid and will thus lower pH
41
T/F: hypercapnia increases ICP and IOP
true: CO2 above normal range to stimulate CO2 and blood
42
what is the value to diagnose hypercapnia? what will this cause
Hypercapnia: PaCO2 > 45mmHg severe cases may cause vasodilation, CNS depression and hypoxemia
43
how is CO2 distributed in the blood?
90% travels as HCO3 2% travels in RBC 3% travels as PV CO2 5% travels bound to other molecules
44
what parameters are used to measure CO2 and ventilation?
Tidal Volume (VT) Minute Ventilation
45
what are normal tidal volume values?
anesthesia: 10-20mL/kg critical care: 5-10mL/kg (more trauma and inflammation)
46
what is the normal range for minute ventilation?
100-200mL/kg
47
how do you calculate minute ventilation (VE)?
VE = VT (tidal volume) x respiratory rate per minute
48
causes for hypercapnia?
Reduced Ventilation (decreased CO2 elimination) - VT Increased Dead Space (decreased CO2 elimination) Exercise (increased CO2 production) Hyperthermia (increased CO2 production) pH imbalance (increased CO2 production or decreased CO2 elimination) Disease (increased CO2 production) - Malignant hyperthermia, seizures, etc
49
CNS Depressing Drugs
Opioids, 2 agonists, benzodiazepines, barbiturates, propofol, ketamine, etomidate, inhalants
50
Muscle Relaxing Drugs
benzodiazepines, guaifenesin, metocarbamol, neuro-muscular blockers (atracurium), some antibiotics (aminoglycosides)
51
secondary Respiratory Pathologies of Consideration
Myasthemia Gravis Hypothyroid Addison / Cushing Right to left cardiac shunts Pulmonary artery hypertension Heart failure Acute renal disease Sepsis other
52

Anesthesia Exam 1 (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions