Pulmonology is a medical specialty that deals with diseases involving the respiratory tract. Pulmonology is synonymous with pneumology, respirology and respiratory medicine. In some countries it is also known as chest medicine.
Main diagnostic activities include a physical examination and some laboratory tests and instrumental procedures.
The physical examination is divided in 3 different phases.
The initial part of the visit begins with a thorough review of the patient’s medical history and pulmonary symptoms.
Symptoms data are collected using standard questionnaires (such as MRC and CECA) in order to eventually link some specific symptoms to the presence of a chronic disease, evaluate the level of physical functional limitation (MCR dyspnea scale) and quality of life (CAT, COPD Assessment Test).
The second phase of the visit consists in the objective structured clinical examination, while the third phase takes into consideration – if the patient agrees – some instrumental examinations, from the simplest and minimally invasive to the most sophisticated, when needed.
Main instrumental examination in pulmonology:
Saturimetry: it determines the oxygen saturation percentage in the patient’s blood. It is a painless and well tolerated examination that is carried out with pulse oximeters: a sensor device is placed on a thin part of the patient’s body, usually a fingertip. The device passes two wavelengths of light through the body part to a photodetector. It measures the changing absorbance at each of the wavelengths, allowing it to determine the absorbances due to the pulsing arterial blood alone. The device can work over a limited span of time as well as for the whole day.
Spirometry (meaning the measuring of breath) is the most common of the pulmonary function tests, measuring lung function, specifically the amount (volume) and/or speed (flow) of air that can be inhaled and exhaled. The spirometry test is performed using a device called a spirometer, which displays some graphs, called spirograms, such as a volume-time curve or a flow-volume loop.
Salbutamol reversibility test: this test is needed in case of obstructive lung disease (with a FEV1/FVC ratio <70. A spirometry is carried out 20 minutes after the patient has inhaled a testing dose of salbutamol (200-400 mcg. The test is to be considered positive if the value of FEV1 has increased > 12% and/or ≥ 200ml as absolute value. This test is useful for the differential diagnosis between COPD and asthma, to evaluate the reversibility of COPD and to monitor the effectiveness of bronchodilators treatment.
The six-minute walk test (6MWT) measures the distance an individual is able to walk over a total of six minutes on a hard, flat surface. The goal is for the individual to walk as far as possible in six minutes. The individual is allowed to self-pace and rest as needed as they traverse back and forth along a marked walkway. The original purpose of the six minute walk was to test exercise tolerance in chronic respiratory disease and heart failure. The test has since been used as a performance-based measure of functional everyday exercise capacity even in healthy older adults. Every 60 seconds heart rate and oxygen saturation are measured, as well as the number of meters walked during the test.
Arterial hemogasanalysis is a blood test carried out on a blood sample taken from the radial artery (at the wrist) or rarely from the brachial artery (at the inner part of the elbow) or from the femoral artery (inguinal). Arterial hemogasanalysis is carried out to measure the amount of oxygen and carbon dioxide present in the blood, as well as the blood pH. This kind of tests is required to verify the presence or the importance of already diagnosed respiratory failure and pulmonary ventilation disorders (hypo- and hyperventilation, changes in ventilation during sleep, etc…). It can also be carried out to evaluate the effectiveness of a therapy, in particular in case of oxygen therapy.
To be able to evaluate each patient’s case properly, the lung specialist should be able to take advantage of a 2 projections chest x-rays that will make available all relevant info about the size of the heart and all other major blood vessels (pulmonary artery, ascending aorta, aortic arch), lungs, rib cage and diaphragm.
The clinical evaluation and the results of instrumental tests may guide towards the diagnosis of some of the most common obstructive diseases (chronic bronchitis, asthma, emphysema, bronchiectasis), infective diseases (pneumonia) or more rare interstitial and infiltrative pulmonary diseases or lung cancer. Patients affected by COPD (chronic bronchitis, emphysema), suffering from dyspnea and with reduced exercise tolerance may be guided through a program of breathing rehabilitation. Currently the exercise training is considered as the main feature of a personalized rehabilitation program that can help the patient recover autonomy, physical performance and social activities. Breathing rehabilitation can reduce symptoms, increase working capacity and improve the quality of life in all those patients suffering from chronic respiratory failure even in presence of structural irreversible alterations.
In case of interstitiopathy and when suspecting bronchiectasis a morphological study of the lung through a HRCT (high resolution computed tomography without contrast agents) will be sufficient to make a diagnosis.
Multidetector spiral computed tomography, with low dosage protocols, is actually the treatment of choice for the early diagnosis of pulmonary neoplasm.
Last but not least, the coronary computed tomography angiography is the best available method to evaluate pulmonary blood circulation problems and in particular to diagnose pulmonary embolism. CT Angiography is a radiological examination that by means of a contrast agent allows the visualization of blood vessels progress.