Chest X-ray and Other Diagnostics

Question 1

Diagnostics in pulm include:

Answer 1

○ Pulmonary Function Testing
○ Peak Flow Testing
○ Oximetry
○ Capnography
○ Bronchoscopy
○ Chest X-ray

Question 2

Pulmonary Function Tests

Answer 2

● Pulmonary Function Tests (PFT) are obtained by using a Spirometer, a device with a mouthpiece hooked up to a small electronic machine.

Question 3

What is a Pulmonary Function Test used for?

Answer 3

● Non-invasive test that tests the lung volume, capacity, rates of flow, and several
other measurements.
● Very helpful in evaluation of Obstructive and Restrictive lung diseases.

Question 4

Values being tested with spirometry:

Answer 4

○ Forced Vital Capacity
○ Forced Expiratory Volume
○ Forced Expiratory Flow
○ FEV1/FVC Ratio

Question 5

The Peak Flow Meter is used primarily for monitoring _____

Answer 5

asthma.

Question 6

Peak Flow Testing

Answer 6

the Peak Flow Meter is used primarily for monitoring asthma.
● Measures the Peak Expiratory Flow Rate
○ In Liters per min.
● A non-invasive test patients with
asthma can do at home to monitor
their pulmonary function daily.

Question 7

Pulse Oximetry

Answer 7

● A non-invasive, quick and easy test that is utilized extensively in a wide range of locations (clinic, EMTs, OR, etc).
● Although its reading of Peripheral
Oxygen Saturation (SpO2) is not
always identical to the Arterial
Oxygen Saturation (SaO2) from an
ABG, it’s reliable enough to be used
safely and confidently.

Question 8

How does a pulse oximetry work?

Answer 8

● A clip or wrapping sticker is placed on a
thin part of the patient’s body, such as a
fingertip or earlobe.
● Different wavelengths of light are passed through the tissue and a detector on the opposite side.
● Complex algorithms then calculate the arterial hemoglobin oxygen saturation based on the amount of light absorbance.

Question 9

Capnography

Answer 9

● Non-invasive way to measure the Partial Pressure of CO2.
○ Mostly used in ICU and operating room.
● Capnographs detect the amount of CO2
being exhaled by the patient.

Question 10

How does capnography work?

Answer 10

● The capnograph can be placed into
the ventilation line and measure the
CO2 as ventilated air passes by.
● Using the End Tidal CO2 (ETCO2),
the machine indirectly calculates the
arterial PCO2

Question 11

Bronchoscopy

Answer 11

● An endoscopic technique of visualizing the inside of the bronchial tree for both diagnostic and therapeutic reasons.
○ Flexible fiberoptic Bronchoscope

Question 12

Bronchoscopy indications

Answer 12

○ Foreign body retrieval
○ Tissue biopsy
○ Tumor resection
○ To remove extensive secretions
○ Tracheal intubation of patients with difficult
airways
○ Percutaneous tracheostomy

Question 13

This procedure can trigger bronchospasm or bleeding. If a biopsy is performed, there is risk of pneumothorax.

Answer 13

Bronchoscopy

Question 14

An advantage of CXR

Answer 14

○ Quick test that can usually identify pathological processes such as pneumonia, congestive heart failure, etc.

Question 15

A disadvantage of CXR:

Answer 15

○ Not as comprehensive as a chest CT (for example, it cannot rule out processes such as pulmonary emboli)

Question 16

Limitations of chest x-ray

Answer 16

● Remember that many serious, life-threatening pulmonary or
cardiac conditions may present with a totally normal CXR.
○ Myocardial Infarction
○ Pulmonary Embolism
○ Asthma Exacerbation
○ Dissecting Aortic Aneurysm

Question 17

CXR views:

Answer 17

○ Posteroanterior (PA)
○ Anteroposterior (AP) - less preferred
○ Lateral
○ Decubitus - helpful for differentiating pleural effusions
○ Expiratory - helpful for diagnosing small pneumothorax
○ Oblique - helpful for further assessing ribs for fractures

Question 18

RIP mnemonic for assessing image quality

Answer 18

○ Rotation
● Spinous process at midline between two medial clavicles.
○ Inspiration
● Should see at least 8-9 posterior ribs above diaphragm.
○ Penetration
● Intervertebral disc spaces should be just visible behind the heart.

Question 19

Assess entire image using ABCDEF mnemonic

Answer 19

○ Airways
○ Bones
○ Cardiac
○ Diaphragm
○ Edges
○ Fields of the lungs

Question 20

The heart is enlarged if the greatest transverse width of the heart is _____

Answer 20

greater than half the width of the chest.

Question 21

Infiltration into the Airspace:

Answer 21

○ Appears more cloud-like or “fluffy”
○ Often times confluent “clouds”
○ May present as a Silhouette Sign (more coming)
○ May have Air Bronchograms
○ Usually respects lobar boundaries

Question 22

Infiltration into the Interstitium:

Answer 22

○ Discrete “particles” of disease in 3 possible patterns
■ Reticular (lines), Nodular (dots), Reticulonodular (net-like)
○ Not confluent, generally separated by visible lung
○ Usually no Air Bronchograms
○ May see Peribronchial Cuffing and/or Kerley B Lines
○ Does not usually respect lobar boundaries

Question 23

What are Air Bronchograms?

Answer 23

Visibility of air in the bronchus because of
surrounding airspace disease

Question 24

What does Pulmonary Edema look like on CXR?

Answer 24

The infiltration seen is
less cloud-like or fluffy, but more
of a reticulonodular pattern, with fluid
backing up into interstitial space
likely due to heart failure.

Question 25

_____ are a sign of interstitial
disease rather than airspace disease.

Answer 25

Kerley B Lines

Question 26

Characteristic sign of alveolar (airspace) edema in heart failure

Answer 26

“Bat wing” appearance.