Pulmonary Diagnostic Procedures

Question 1

What are 4 common diagnostic pulmonary procedures?

Answer 1

1. Chest imaging
2. Bronchoscopy
3. Blood gas analysis
4. Ventilation/Perfusion (V/Q) scan

Question 2

Which procedure is considered the predominant diagnostic test to determine anatomic abnormalities and pathological processes within the chest?

Answer 2

Chest Radiographs - Always performed first!

Question 3

What structures should you be able to visualize on radiograph?

Answer 3

Bones, soft tissue, hemidiaphragms, mediastinum, trachea, heart
Pulmonary specific: Hilum, lung fields, lesions, silhouette sign

Question 4

A pulmonary radiograph shows a partially or completely obliterated line of demarcation

Answer 4

Silhouette sign

Question 5

What technique is primarily used for diagnosis of tumors vs calcifications or nodules?

Answer 5

Computed tomography (CT) – Also known as digital chest radiography

Question 6

Disadvantages of CT Scan

Answer 6

Risk of transporting patient out of ICU
Significant increase in radiation
Risk of intravenous contract

Question 7

Technique used for tissue biopsy, secretion sampling/removal, and bronchial lavage for tissue identification

Answer 7

Bronchoscopy

Question 8

What is the purpose of bronchoscopy?

Answer 8

Allows direct access & visualization of previously inaccessible areas inside the tracheobronchial tree

Question 9

What information is gained in an Arterial Blood Gas (ABG) analysis?

Answer 9

pH, Oxygen, Carbon Dioxide, & Bicarbonate

Question 10

Normal = 7.35-7.45

Answer 10

pH

Question 11

pH < 7.35

Answer 11

Acidosis

Question 12

pH > 7.45

Answer 12

Alkalosis

Question 13

Normal = 80-100 mmHg
Abnormal < 80 mmHg

Answer 13

PaO2 - Partial pressure of oxygen in blood (bound to hemoglobin)

Question 14

Normal = >90-95%

Answer 14

SpO2 - Peripheral O2 saturation

Question 15

Mild Hypoxemia Level

Answer 15

60-80 mmHg

Question 16

Moderate Hypoxemia Level

Answer 16

40-60 mmHg

Question 17

Severe Hypoxemia Level

Answer 17

< 40 mmHg

Question 18

Normal = 35-45 mmHg

Answer 18

PaCO2 - Partial pressure of CO2 in blood (reflecting alveolar ventilation)

Question 19

PaCO2 < 35 mmHg

Answer 19

Hyperventilation

Question 20

PaCO2 > 45 mmHg

Answer 20

Hypoventilation

Question 21

For every ___ mmHg increase in PaCO2 the pH should fall ___ units

Answer 21

10 mmHg, 0.07 units

Increase CO2 drives pH DOWN (more acidic)

Question 22

Normal = 22-26 mEq/L

Answer 22

Bicarbonate HCO3 – Determines acid balance vs imbalance

Question 23

Low HCO3

Answer 23

Metabolic Acidosis
Eliminating bicarbonate will decrease pH - Acidosis

Question 24

High PaCO2 (hypercapnia - hypoventilation)

Answer 24

Respiratory Acidosis

Question 25

High HCO3

Answer 25

Metabolic Alkalosis Retaining bicarbonate will increase pH - Alkalosis

Question 26

Low PaCO2 (hypocapnia - hyperventilation)

Answer 26

Respiratory Alkalosis

Question 27

Respiratory Acidosis

Answer 27

INCREASE in PaCO2 + DECREASE in pH *Inverse* Compensation: RETAIN bicarbonate to increase pH

Question 28

Respiratory Alkalosis

Answer 28

DECREASE in PaCO2 + INCREASE in pH *Inverse* Compensation: EXCRETE bicarbonate to decrease pH

Question 29

Metabolic Acidosis

Answer 29

DECREASE in HCO3 = LOW pH *Both decrease* Compensation: Hyperventilation (decreasing CO2) to increase pH

Question 30

Metabolic Alkalosis

Answer 30

INCREASE in HCO3 = HIGH pH *Both increase* Compensation: Hypoventilation (increasing CO2) to decrease pH

Question 31

Inverse relationship exists between which two variables?

Answer 31

pH & CO2

Question 32

If inverse relationship remains between pH & CO2...

Answer 32

Respiratory

Question 33

If inverse relationship does NOT remain between pH & CO2...

Answer 33

Metabolic

Question 34

Process of reading ABG values

Answer 34

1. Assess pH (acidosis vs alkalosis) 2. Classify pH vs CO2 relationship (R vs M)... look at HCO3 as needed for metabolic 3. Determine adequacy of alveolar ventilation (PaCO2)

Question 35

Alveolar Ventilation at <30 mmHg

Answer 35

Hyperventilation to increase PaCO2

Question 36

Alveolar Ventilation at 30-50 mmHg

Answer 36

Adequate as is

Question 37

Alveolar Ventilation at >50 mmHg

Answer 37

Ventilatory failure (too much PaCO2)

Question 38

Technique that uses inhaled and injected radioactive material to measure ventilation and perfusion within the lungs. Perfusion involves radioactive albumin and ventilation involves inhalation of radioactive gas

Answer 38

Ventilation/Perfusion Scan (V/Q Scan)

Question 39

Decreased uptake of radioisotope during perfusion scan

Answer 39

Problem with blood flow!

Question 40

Decreased uptake of radioisotope during ventilation scan

Answer 40

Reduced breathing & ventilation! Potential airway obstruction