Intro to O2 therapy

Question 1

Too much O2 will damage what? Physiological damage

Answer 1

• increased free radical leading to oxidative damage to vital organs
• mucosal inflammation
• cillia inactivation
• hemolysis
• desctruction of Type I pneumocytes
• increased production of Type II pnuemocytes

Question 2

O2 Toxicity occurs at what levels?

Answer 2

375mmHg with FiO2~0.50 over 14hrs

Question 3

O2 therapy precautions

Answer 3

• affects lungs at clinical PO2 levels- patchy infiltrates on x-ray in lower lung
  CNS- hyperbaric pressures

Question 4

pathophysiology; too much O2?

Answer 4

• damage capillary endothelium
• interstitial edema
• AC memberane thickiening
• changes in levels of type I and type II pneumocytes
• shunting–> hypoxemia

Question 5

Increased metabolism by O2

Answer 5

• increased cellular byproducts than antioxidants can clean up
• recruit neutrophils (WBC)–> more inflammation and free radicals

Question 6

Absorption Atelactasis

Answer 6

• nitrogen washout
• no non- diffusing gas remain in the lungs
• when O2 leaves, the alveoli will be vacant and collapsed

Question 7

O2 hazards

Answer 7

• increased risk for fire

- cautious when using electronic equipment, scalpels, cardioconversion, cardio shock

Question 8

Nasal Cath

Answer 8

FiO2: 0.24-0.44 with flow of 1-6LPM. 4% increases forver 1LPM inrease
- for babies

Question 9

Nasal Canula

Answer 9

FiO2: 0.24-0.44 with flow of 1-6LPM. 4% increases forver 1LPM inrease

Question 10

Simple mask

Answer 10

5-8LPM; FiO2 .40-.60

Question 11

High flow NC

Answer 11

1-15LPM replaces PRBM

Question 12

PRBM

Answer 12

6-15LPM (usually start at 10LPM); FiO2 0.60-0.80 and up

Question 13

NRBM

Answer 13

8-15LPM; FiO2>0.80

Question 14

Trans Tracheal Cathter

Answer 14

for difficult airways

placed through cricoid cartliage or between second and third tracheal ring

Question 15

Oxymask

Answer 15

1-15LPM;FiO2 0.24-0.90

Question 16

Low flow O2 devices

Answer 16

• Variable FiO2

- does not meet total inspiratory demands of patients

Question 17

Percent O2 in atmosphere

Answer 17

21%

Question 18

What is O2 used for

Answer 18

ATP production, angiogenesis, vasodilation/ vasoconstriction, suppress anaerobic bacteria

Question 19

Hypoxia

Answer 19

inadequate O2 for cellular metabolism

Question 20

hypoxemia

Answer 20

low blood O2 levels

Question 21

causes of hypoxemia

Answer 21

decreased alveolar oxygen tension, increased altitude, inadequate ventilation (hypopnea, apnea)

Question 22

Hypoxemia by shunt

Answer 22

perfusion no ventilation

Question 23

hypoxemia via deapspace

Answer 23

ventilation without perfusion

Question 24

response to hypoxemia

Answer 24

Increased MV, increased Cardiac output, Increased production of RBCs

Question 25

signs and symptoms of hypoxemia

Answer 25

cyanosis, arrythmia, disorientation, polycythemia (high Hb - more chronic), lethargy

Question 26

4 types of Hypoxia

Answer 26

hypoxic, anemic, ciruculatory, histotoxic

Question 27

hypoxic hypoxia

Answer 27

not enough O2 in cells

responds to O2 therapy

Question 28

circulatory hypoxia

Answer 28

normal blood O2 levels but not enough blood reaching the tissues
NO response to O2 therapy

Question 29

histotoxiic hypoxia

Answer 29

Sufficient blood O2 levels and O2 delivered but inability of the tissues to use O2. e.g. CN poisoning
NO respose to O2 therapy

Question 30

anemic hypoxia

Answer 30

not enough RBC to deliver O2 to tissues. Either due to RBC deformity, CO poisoning.
May respond to O2 therapy