Investigative procedures used in patients with pulmonary diseases

1. INVESTIGATIVE PROCEDURES USED IN PATIENTS WITH
PULMONARY DISEASES
JAMIA MILLIA ISLAMIA
CENTRE FOR PHYSIOTHERAPY AND REHABILITATION SCIENCES
NAFISA SARFARAZ
BPT 4TH YEAR

2. Introduction
• Airway injury or dysfunction results in obstructive lung diseases, including asthma and chronic obstructive pulmonary
disease (COPD). Injury to the pulmonary parenchyma can produce restrictive lung diseases, such as idiopathic pulmonary
fibrosis, acute respiratory distress syndrome, and pulmonary vascular disease.
• obstructive lung disease have shortness of breath due to difficulty exhaling all the air from the lungs. Because of damage to
the lungs or narrowing of the airways inside the lungs, exhaled air comes out more slowly than normal. At the end of a full
exhalation, an abnormally high amount of air may still linger in the lungs.
• COPD, asthma, bronchiectasis, cystic fibrosis
• Restrictive lung disease most often results from a condition causing stiffness in the lungs themselves. In other cases,
stiffness of the chest wall, weak muscles, or damaged nerves may cause the restriction in lung expansion.
• Some conditions causing restrictive lung disease
• Interstitial lung disease such as idiopathic pulmonary fibrosis, Nueromascular disorder, sarcoidosis, obesity including
obesity hypoventilation syndrome.

3. Investigative procedures
• Clinical history
• Physical examination
• Laboratory method
• Pulmonary function test
• Imaging techniques
• Exercise testing

4. Clinical history
• Specific respiratory symptoms include dyspnoea, abnormal breath sounds (such as wheezing or stridor), hoarseness, cough
with or without sputum production, haemoptysis, snoring and chest pain.
• Each may be of different onset (acute or chronic) or severity, isolated or combined, and sometimes accompanied by general
symptoms of disease such as fever, weight loss, oedema, night sweats, nocturia.
Physical examination
Physical examination classically follows a sequence:
• Inspection, palpation (feeling with the hands), percussion and auscultation (listening with a stethoscope).
• Inspection may show important physical signs such as cyanosis, abnormal breathing patterns, finger clubbing, chest wall
deformities, oedema, superior vena cava syndrome or Horner’s syndrome.
• Palpation may detect, for instance, enlarged lymph nodes, subcutaneous emphysema or points of tenderness.
• Percussion may reveal areas of dullness (e.g. pleural effusion) or hyperresonance (e.g. pneumothorax) and auscultation may
detect abnormal breath sounds, such as wheezes, crackles, or a pleural friction rub, signs that are characteristic of particular
respiratory diseases.

5. Laboratory method
Microbiological tests
• Microbiological tests have an essential role in the investigation of infectious respiratory diseases caused by
viruses, bacteria, fungi or parasites.
• They include examination of expectorated (or induced) sputum.
• The standard bacteriological techniques of microscopy and culture are often supplemented by molecular
biological techniques (PCR) for detecting the DNA (or RNA) of the organism.
• Serological tests for confirming particular infections include identification of the relevant bacteriological or
virological antigens and measurement of specific antibodies, in particular the demonstration of a rise in
antibody titre. Urinary antigen detection may permit the rapid diagnosis of pneumococcal and Legionella
infections.
• Respiratory viruses may be cultured from different materials, most easily from nose or throat swabs.
Serological tests in general provide only a retrospective assessment; specific immunoglobulin M may be of
greater diagnostic value.
• The laboratory diagnosis of pulmonary fungal infections is usually based on isolation of the organism from
cultures, histological examination and serological tests, but also on direct microscopy after special staining
(e.g. Pneumocystis jirovecii ).
• Parasitic lung infections may be detected by microscopy of certain materials (e.g. stool, blood), serological
tests or histological tests.

6. Histological and cytological test
• immunohistochemistry using specific markers for the differentiation of several neoplasms, such as small cell
neuroendocrine carcinoma and malignant lymphoma.
• Cytopathological examination is used mainly in the diagnosis of malignancies (e.g. malignant effusion).
• In bronchoalveolar lavage fluid, it may be helpful in the diagnosis of some interstitial lung diseases, such as extrinsic
allergic alveolitis (hypersensitivity pneumonitis), eosinophilic pneumonia, alveolar proteinosis or asbestosis.

7. Pulmonary function test
Pulmonary Function Tests:
• Spirometry
• Lung Volumes
• Diffusion Capacity
• Maximal Voluntary Ventilation (MVV)
• Maximal Inspiratory Pressure (Pi max)
• Maximal Expiratory Pressure (Pe max)
• Arterial Blood Gas (ABG)
• Walking Oxymetry
• Bronchochallenge Tests

8. INDICATIONS:
Pulmonary Evaluation:
• Presence of impairment
• Type of Pulmonary dysfunction
• Quantification of impairment in known disease
• Monitor the progression of known disease
• Monitor the treatment response of known disease
Preoperative Assessment:
• Estimate the risk for postoperative
• complications (operability)
• Tolerance for lung resection (resectability)
Disability Evaluation

9. Spirometry:
Measures the lung volume change during forced breathing maneuvers:
• Forced vital capacity (FVC)
• Forced expiratory volume in the first second (FEV-1)
TECHNIQUE
• Before performing the forced expiration, tidal (normal) breaths can
be taken first, then a deep breath taken in while still using the mouthpiece,
followed by a further quick, full inspiration.
• Alternatively, a deep breath can be taken in then the mouth placed
tightly around the mouthpiece before a full expiration is performed.
• The patient can be asked to completely empty their
lungs then take in a quick full inspiration, followed by a full expiration.

10. Obstructive Lung Diseases:
• Emphysema & Chronic Bronchitis
• Cystic Fibrosis
• Asthma
• Bronchiectasis
• Some Interstitial Lung Disease: (combined)
Restrictive Lung Diseases:

11. INTERPRETATION

12. The features of an obstructive disease are
• The height of the PEF is less than predicted
• descending limb is concave (“scooped”) with the concavity being more pronounced as the severity of the
obstruction increases.
• descending slope represents maximum mid expiratory flow and FEFs, which are
reduced due to air flow limitation at low lung

14. Lung capacity and airway resistance
• The total lung capacity can be determined using either gas dilution techniques or body plethysmography. The latter
method also allows the measurement of airway resistance. The forced oscillation technique, which measures the
resistance of the total respiratory system, has the advantage that the patient does not need to perform specific
breathing manoeuvres.
Diffusing capacity
• The diffusing capacity of the lung for carbon monoxide (also known as transfer factor), which is usually performed
as a single-breath test, measures the overall gas-exchange function of the lung.

15. Walking Oxymetry:
Goal: detects the hidden diffusion defect.
Technique: check O2 saturation at rest, 4 mins and 6 mins walk.
• Walking Oxygen Desaturation:
1. Diffusion defect.
2. V/Q mismatch
3. Shunt
• Criteria for Oxygen Supplementation (Home Oxygen):
1. PO2 <55 or Oxygen Saturation <88%
2. PO2 <59 with:Pulmonary Hypertension or Polycythemia
Maximal Voluntary Ventilation (MVV):
Measures the ventilatory reserve
The subject breaths as hard and fast as possible for 10-15 sec, and then adjust it to 1 min.
MVV = FEV-1 times 35-40
Decreases:
•Poor effort
•Neuromuscular diseases
•Obstructive & restrictive lung diseases
•Heart diseases
•Obesity

16. Maximal Inspiratory Pressure (Pi max) & Maximal Expiratory Pressure (Pe max):
Goal: To measure the strength of the respiratory muscles.
Technique: the amount of pressure the subject can generate in:
Deep inspiration (inspiratory muscles): (Pimax)
Deep expiration (expiratory muscles): Pemax
Normal value: Pimax (-60) & Pemax (+120) cm H2O
Indications:
• Neuromuscular diseases
• Unexplained decrease in VC & MVV
Weaning (Pimax > -30)
Arterial Blood Gas:
• Oxygenation (PO2 and FiO2) & Ventilation (PCO2 and PH)
• Acid – Base balance (PCO2, HCO2, and PH)
Bronchochallenge Tests:
Goal: evaluate the airway hyperresponsivness (asthma).
Technique: Methacholine, Histamine, Cold, Exercise…etc.
Criteria: 20% decrease in baseline FEV-1

18. Imaging techniques
• Chest radiography
• Computed tomography
• MRI
• Ultrasonography
• Bronchoscopy

21. Interpretation of the CXR.
• Correct patient (name and date of birth)
• Date of CXR
• Correct labelling of right and left side
• Symmetry: medial ends of both clavicles and thoracic spines
• Adequate exposure: vertebral bodies visible
• Shape and bony structures of the chest wall
• Position of trachea
• Mediastinal contours
• Hila
• Size of lungs
• Lung markings
• Position and clarity of diaphragm
• Ribs and clavicle
• Soft tissue
• Heart size and cardiac silhouette
• Area behind the heart
• Lung apices
• First costochondral junctions
• Costophrenic angles

28. • Computed tomography
• Computed tomography (CT) of the chest is the second most important radiological modality in respiratory medicine,
allowing much more detailed visualisation of thoracic structures than radiography. It is often performed with intravenous
contrast enhancement (in suspected pulmonary embolism cases, for example). CT is also helpful for guiding needle
aspiration of peripheral lung lesions. High-resolution CT (HRCT) has improved the diagnosis of diffuse interstitial lung
disease considerably. Low-dose CT is used in follow-up and serial early lung cancer detection. CT can be used for virtual
bronchoscopy or angiography, but this has not become routine. CT is applied in combination with positron emission
tomography (PET) mainly for staging lung cancer and other malignancies, and in the differential diagnosis between
benign and malignant lung lesionslesions.
• Magnetic resonance imaging
• MRI has the advantage that radiation is avoided. Its main indications are visualisation of the great vessels and the heart,
but it is also useful with suspected tumour invasion of the mediastinum and the chest wall.
• Ultrasonography
• Ultrasonography has become an important imaging technique. Its advantages are lack of radiation, low cost and mobility.
It is mainly used in the investigation of pleural effusions (in which it also has a role in guiding thoracentesis) but also in
pleural thickening, chest wall abnormalities, for the diagnosis of pneumothorax and for biopsies of lesions adjacent to the
chest wall. A special application is endobronchial ultrasound (EBUS), which can be used for visualisation of mediastinal
lymph nodes as well as pulmonary parenchymal lesions
• Endoscopy and biopsy techniques are essential tools in many respiratory diseases when simpler clinical and laboratory
methods of investigation have failed to yield a diagnosis. The results of biopsies are heavily dependent upon the quality
of the pathological and microbiological examinations.
• Bronchoscopy
• The most important endoscopic method in respiratory medicine is bronchoscopy; for diagnostic purposes, this is almost
exclusively performed with a flexible bronchoscope using video-assisted imaging, usually under local anaesthetic .
Bronchoscopy is associated with very few complications. The procedure not only allows inspection and sampling of the
airways, but also facilitates transbronchial needle aspiration (TBNA) from the lymph nodes, sampling material from
peripheral lesions with special catheters and brushes, or transbronchial lung biopsy (TBLB) by forceps, often under
guidance of EBUS or fluoroscopy. A more elaborate technique to guide the bronchoscopist to small lesions is
electromagnetic navigation.

29. Exercise testing
• Exercise (walking) tests are used to determine the severity, response to treatment, and prognosis in patients with chronic
respiratory diseases, including COPD, pulmonary hypertension, diffuse parenchymal lung diseases, and in chronic heart failure.
The procedure must be standardised, with Clear instructions to each patient.
• Exercise tests are an important part of the assessment of functional status and required in those who are being considered
for lung transplantation, heart and lung transplantation, or lung volume reduction surgery.
• These measurements are often the primary end‐point in trials looking at the efficacy of treatments in these conditions.
Exercise testing is contraindicated in those who have had a recent myocardial infarction, those with severe angina, and
those with uncontrolled hypertension.
• The six‐minute walk test (SMWT) is easy to do, safe and well tolerated, even in patients who have limited exercise tolerance.
The patient is asked to walk along a straight line on a hard surface, on his/her own and the distance walked in six minutes is
measured. The oxygen saturation and extent of breathlessness should be determined. The SMWT correlates well with pulmonary
function tests, quality of life measures, and mortality.
• The shuttle walk test (SWT) requires the patient to walk back and forth between two markers set 10metres apart in response to a
pre‐set timer. The timer beeps to indicate when the patient should have reached the marker. The interval between beeps will
gradually decrease until the patient is unable to keep up. Both the SWT and the SMWT will improve with inhaled therapy for
COPD and with pulmonary rehabilitation. Oxygen saturation should be measured at rest and during the SMWT and the SWT.
The oxygen saturation correlates with disease severity and can be used to monitor the progression of the disease and any
improvement with treatment.
• Cardiopulmonary exercise testing
Cardiopulmonary exercise testing (CPET), with determination of minute ventilation, cardiac and respiratory frequency, oxygen
uptake and carbon dioxide output, is an objective measure of exercise capacity (spiroergometry). Simpler tests use capillary oxygen
partial pressure measurements during exercise on an ergometer or symptom-limited walking tests, such as the 6-min shuttle walk
test, with measurement of SaO2 using an oximeter.

30. References
• EUROPEAN LUNG white book
• Pulmonary function test by American thoracic society
• Principles of respiratory investigation
• Essential Respiratory Medicine ,Shanthi Paramothayan ,Consultant Respiratory Physician UK
• Interpreting pulmonary function tests: Recognize the pattern, and the diagnosis will follow
November 2003 Cleveland Clinic Journal of Medicine 70(10):866, 868, 871-3, passim DOI: 10.3949/ccjm.70.10.866 Source PubMed