The paraclinical exploration of the respiratory system 5

Question 1

The radiological exam

Radioscopy, radiography

Answer 1

Principle: X rays (Roentgen)
The normal X-ray image of the lungs is the result of the presence of air and pulmonary tissue
Air – radiotransparent – black
Absence of air – opacity – grey/white
Pneumothorax: radiotransparent – the pulmonary tissues are no longer visible
Pneumonia, lung cancer – opacity
Pleuresy – opacity

Question 2

The radiological exam (continued)

CT (cat scan)

Answer 2

Provides transversal section images with possibility for digital processing
It can be done with or without contrast substance

Question 3

MRI (magnetic resonance imaging

Answer 3

Principle: alteration of the electron spin in a powerful magnetic field

Question 4

Pulmonary scintigraphy

Answer 4

Principle: the administration of a radioactive tracer and the recording of its activity with a scintillation camera
It can be:
iv (intravenous administration of the tracer)
ventilation (administration of tracer through inhalation

Question 5

Respiratory functional PROBE

Answer 5

Allow the diagnosis, as well as the setting of the stages and evolution of the broncho-pulmonary diseases

Question 6

Normal or forced spirometry

Answer 6

The most used parameters:
Vital capacity VC = IRV + CV + ERV
CV (current volume) = the volume of air in motion at each respiratory cycle during normal breathing
IRV (inspiratory reserve volume) = the maximum inhaled volume, over the CV, in a profound inhalation
ERV (expiratory reserve volume) = the maximum exhaled volume, over the CV, in a profound exhalation

The most used parameters
MEVS = maximum expiratory volume in the first second of a forced exhalation
Vn = 80% of VC

Low vital capacity – restrictive respiratory syndrome 
Pneumonia
Lung cancer
Diffuse interstitial pneumopathies
Pleurisy
Left ventricle failure  

Low MEVS – Broncho-obstructive syndrome
COPD – chronic obstructive pulmonary disease
Asthma
Bronchiolitis
Lung cancer
Pulmonary emphysema, etc.

Question 7

Assessing the level of gases in the arterial blood

Answer 7

The partial oxygen pressure – PaO2
The partial carbon dioxide pressure – PaCO2
In respiratory failure:
PaO2 decreases 40mmHg

Question 8

Cutaneous oximetry

Answer 8

Allows the assessment of the oxygen saturation level of hemoglobin

Question 9

Bronchoscopy

Answer 9

Allows the visualizing of the airways all the way to the subsegmental bronchi, as well the taking of specimens for the histopathological and bacteriological exams
Indications:
Haemoptysis of unspecified aetiology
Lung cancer
Chronic cough of unspecified aetiology
Lung tumor formations of unspecified aetiology

Question 10

Thoracocentesis (aka thoracentesis, pleural tap

Answer 10

It can be:
Exploratory (for diagnosis)
Evacuatory (in the case of large pleural collections that cause respiratory failure, dyspnoea)
Therapeutic (insertion of medicine substances in the pleural cavity)
The obtained liquid – biochemical, bacteriological, cytological exams

According to the protein concentration the obtained liquid can be:
Transudative (>3g proteins %): heart failure, nephropathies and hepatopathies (hypoalbuminemia)
Exudative (>3g %): inflamatory diseases (pulmonary and pleural), lung cancer, pulmonary emboly
Macroscopically, the pleural liquid can be:
Serofibrinos (tuberculosis)
Purulent (pneumonia, purulent pleuresy)
Hemorrhagic (cancer, pulmonary emboly)
Chyle (tuberculosis, cancer)