Week 10 - Gas Exchange Introduction

Question 1

Alveoli diagram

Answer 1

Question 2

How oxygen moves and how we breathe pathway*

Answer 2

Question 3

What is ventilation?

Answer 3

• The process of inhaling oxygen into lungs and exhaling carbon dioxide from lungs

Question 4

What is impaired ventilation? (3, 6)

Answer 4

1. Inadequate bone/muscle/nerve function to move air into lungs
   - rib fracture, spinal cord injury
2. Narrowed airways
   - Asthma
3. Poor gas diffusion
   - pneumonia

Question 5

What is perfusion?

Answer 5

• the ability of blood to transport oxygen containing Hgb to cells, and return CO2 containing Hgb to the alveoli

Question 6

What occurs with impaired perfusion? (2)

Answer 6

• decreased cardiac output
• Thrombi, emboli, blood loss

Question 7

What occurs in transport?

Answer 7

• availability of Hgb and its ability to carry oxygen from alveoli to cells for metabolism, and carry CO2 produced by cellular metabolism from cells to alveoli to be eliminated

Question 8

What occurs in impaired transport? (2)

Answer 8

• Insufficient RBCs to carry oxygen
• Low Hgb (anemia)

Question 9

What are the clinical manifestations of mild gas exchange impairment? (3)

Answer 9

• fatigue
• HR increase
• RR increase

Question 10

What are the clinical manifestations of moderate gas exchange impairment? (2, 4)

Answer 10

1. Respiratory acidosis
   - ventilation problem
2. Metabolism acidosis
   - Transport or perfusion problem

Question 11

What are the clinical manifestations of severe gas exchange impairment? (3)

Answer 11

• cellular ischemia
• necrosis
• death

Question 12

Which populations are at risk for impaired gas exchange? (3)

Answer 12

• infants
• young children
• Older adults

Question 13

Which individuals are at risk for impaired gas exchange? (6)

Answer 13

1. Nonmodifiable
2. Tobacco use
3. Altered LOC
   - note cough reflex not good, high risk for aspiration pneumonia
4. Bed rest/prolonged immobility
   - note collapsing alveoli and not opening airway (risk of pneumonia)
5. Chronic Diseases
6. Immunosuppression

Question 14

What laboratory diagnostic tests can you do for impaired gas exchange? (5)

Answer 14

1. ABGs (resp. acidosis or alkalosis)
2. CBC (RBC, WBC, Hgb, Hct)
3. Sputum examination (C&S)
4. Skin tests (mantoux)
5. Pathologic analysis (tissue from lungs)

Question 15

What radiologic diagnostic tests can you do for impaired gas exchange? (4)

Answer 15

1. Chest xray (TB, tumours, edema, etc)
2. CT scan (computed tomography)
3. VQ scan (Ventilation-Perfusion)
4. PET scan (Positron Emission tomography)

Question 16

In lecture. what is hypoxemia? (2)

Answer 16

• partial pressure of arterial O2 is below normal
• spleen makes RBC, and hypoxemic pt have a lot

Question 17

In lecture, what is hypoxia?

Answer 17

insufficient O2 at tissue level

Question 18

What can we do for primary clinical management of impaired gas exchange? (4)

Answer 18

• infection control
• smoking cessation
• immunizations
• postoperative

Question 19

What can we do for secondary management of impaired gas exchange? (4, 10)

Answer 19

1. Pharmacotherapy
   - drugs that affect upper airways
   - lower airway bronchodilators
   - Agents to help cough up mucus (codeine)
   - Cough suppressants
   - Antimicrobials
   - Agents to aid smoking cessation
2. Oxygen therapy
3. Nutrition
4. Positioning