Downloaded 334 times
Uploaded byIndramani Prakash
INVESTIGATION IN RESPIRATORY SYSTEM
Investigation modalities in respiratory disorders include laboratory tests, histological and cytological examination, respiratory function tests, imaging techniques, and tests of cardiopulmonary function. Key laboratory tests include D-dimer for pulmonary embolism and alpha-1 antitrypsin for emphysema. Histological examination plays a central role in diagnosing lung cancers and infections. Spirometry is the most important respiratory function test and can identify obstructive and restrictive lung diseases. Imaging with chest X-ray, CT, and MRI provides structural information. Tests such as arterial blood gas analysis and cardiopulmonary exercise testing evaluate ventilatory function and exercise capacity.
More Related Content
Similar to INVESTIGATION IN RESPIRATORY SYSTEM
INVESTIGATION IN RESPIRATORY SYSTEM
- 1. INVESTIGATION MODALITIES IN RESPIRATORYDISORDER (other than TB) Dr Indramani Prakash Jr 2 PG Deptt. Of Medicine Allahabad
- 2. MODERATOR Dr. Sujeet Verma(MD) P.G.Deptt. Of Medicine MLN Medical college Allahabad
- 3.
- 4. Laboratory methods Besidesroutine laboratory blood and urine tests, several specific blood and other tests for respiratory diseases are available..
- 5. Disease Test Pulmonary embolismD-dimer Inherited emphysema α1-antitrypsin Cystic fibrosis Specific genetic tests Lung cancer Tumour marker (e.g. CEA) Malignant mesothelioma Tumour marker (mesothelin, osteopontin, fibulin) Pneumonia Procalcitonin (Latent) tuberculosis infection Tuberculin skin test, interferon-gamma release assay Unexplained breathlessness NT-proBNP (increased in heart failure) Sarcoidosis Angiotensin-converting enzyme (ACE) Extrinsic allergic alveolitis (hypersensitivity pneumonitis) Specific precipitating antibodies Asthma Total and specific immunoglobulin E, skin testing with allergens Eosinophilic diseases Eosinophils Connective tissue disorders Immunological tests such as rheumatoid factor Pleural effusion Total protein, LDH, glucose, cholesterol and others in pleural fluid Table 1 – Specific laboratory tests for some respiratory diseases. NT-proBNP: N- terminal pro-brain natriuretic
- 6. Histological and cytological examination Histologyand cytology play a central role in the diagnosis of many malignant and benign respiratory diseases, including infections. Conventional histopathological techniques are often supplemented by 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. Respiratory function tests Themain clinical roles of respiratory function tests include diagnosis, assessment of severity, monitoring,treatment and evaluation of prognosis.
- 8. Spirometry Spirometry is themost important function test – it measures vital capacity (VC) and forced expiratory volume in 1 second (FEV1). This permits differentiation between restrictive and obstructive respiratory diseases. If expired volume is measured by electrical integration of airflow (using a pneumotachograph), maximum flow–volume curves can also be registered. These tests are used to measure the effect of bronchodilating drugs on reversibility of obstruction as well as to determine responsiveness to bronchial provocation tests. Simple instruments for patient home use include peak flow
- 9. a) Patient performingsirometry. b) Interpretation of spirometric curves.
- 11.
- 12. Obstructive Lung Disease FEV1/FVC < 0.70 defines obstruction FEV1 usually decreased FVC may be decreased ◦ e.g. if expiration incomplete due to air trapping If FEV 25-75% decreased and all of the above are normal – “Minimal airways obstruction”
- 13. Restrictive Lung Disease FVC Decreased FEV1 often decreased proportionate to FVC FEV1/FVC Normal or Increased Can have simultaneous obstruction and restriction May need lung volume measurements (RV, FRC, TLC) to confirm.
- 14. (A) Normal. Inspiratorylimb of loop is symmetric and convex. Expiratory limb is linear. Flow rates at the midpoint of the inspiratory and expiratory capacity are often measured. Maximal inspiratory flow at 50% of forced vital capacity (MIF 50%FVC) is greater than maximal expiratory flow at 50% FVC (MEF 50%FVC) because dynamic compression of the airways occurs during exhalation.
- 15. (B) Obstructive disease(eg, emphysema, asthma). Although all flow rates are diminished, expiratory prolongation predominates, and MEF < MIF. Peak expiratory flow is sometimes used to estimate degree of airway obstruction but is dependent on patient effort.
- 16. (C) Restrictive disease(eg, interstitial lung disease, kyphoscoliosis). The loop is narrowed because of diminished lung volumes, but the shape is generally the same as in normal volume. Flow rates are greater than normal at comparable lung volumes because the increased elastic recoil of lungs holds the airways open.
- 17. Lung capacity andairway 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.
- 18.
- 20. Pulmonary volumes and capacities 1)Tidal volume – is the volume of air inspired or expired with each normal breath = 500ml in young adult man. 2) Inspiratory reserve volume – is the extra volume of air that can be inspired over and beyond the normal tidal volume = 3000ml. 3) Expiratory reserve volume – is the extra amount of air that can be expired by forceful expiration after the end of a normal tidal expiration ~ 1100ml. 4) Residual volume – is the extra volume of air that still remain in the lungs after the most forceful expiration ~ 1200ml.
- 21. The pulmonary capacities Inspiratorycapacity – is the volume of air inspired by a maximal inspiratory effort after normal expiration = 3500ml = inspiratory reserve volume + tidal volume. The functional residual capacity – is the volume of air remaining in the lungs after normal expiration = 2300ml = expiratory reserve volume + residual volume. The vital capacity – is the volume of air expired by a maximal expiratory effort after maximal inspiration ~ 4600ml = inspiratory reserve volume + tidal volume + expiratory reserve volume. Total lung capacity – is the maximum volume of air that can be accommodated in the lungs ~ 5800ml = vital capacity + residual volume. Minute respiratory volume – is the volume of air breathed in or out of the lungs each minute = respiratory rate x tidal volume = 12 X 500ml = 6000ml/min. All lung volume and capacity are about 20 to 25% less in women than in men and are greater in athletic persons than in small and asthenic persons.
- 22. Diffusing capacity The diffusingcapacity 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.
- 23. Single breath CarbonMonoxide Diffusing Capacity (DlCO) Simple/automated Standardized normal values available 10 second breath hold Inspire mixture of CO, He and O2 Measure change in volume of CO between inspiration and expiration adjusted for dilution effect with He
- 24. Blood gas analysis Arterialblood gas (ABG) measurement to determine the arterial oxygen tension (PaO2) and arterial carbon dioxide tension (PaCO2) is one of the most useful diagnostic tests: blood can be sampled directly from an artery, or an estimate can be obtained from capillary blood from, for instance, a warmed earlobe. ABG measurement allows the diagnosis of hypoxaemia (decreased PaO2) with or without hypercapnia (increased PaCO2), a
- 25. Arterial oxygen saturation(SaO2) represents the percentage of binding sites on the haemoglobin molecule occupied by oxygen and offers a noninvasive method of estimating arterial blood oxygenation; it is measured directly by an oximeter with a probe attached to either the finger or the earlobe. PaCO2 can also be estimated noninvasively, using a transcutaneous electrode but such devices are not yet as widely used as oximeters. ABG measurement also allows evaluation of acid–base disorders.
- 26. Cardiopulmonary exercise testing Cardiopulmonaryexercise 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.
- 27. Respiratory muscle function measurement Respiratorymuscle function is commonly assessed by measuring maximal pressures generated at the mouth during maximal inspiratory and expiratory efforts against an occluded airway.
- 28. Control of ventilation Testsof ventilatory control include the hyperoxic rebreathing method and the hypoxia withdrawal method. Simpler, but less specific, is the measurement of the mouth occlusion pressure.
- 29. Diagnosis of sleepbreathing disorders The diagnosis of sleep-related respiratory disorders requires special tests. The gold standard is polysomnography, but simpler tests are available for screening purposes (‘respiratory polysomnography).
- 30. Right heart catheterisation Rightheart catheterisation is used in the differential diagnosis of pulmonary hypertension.
- 31.
- 32. - Plain CXR Xrayfilm provides information on the lung fields , heart ,mediastinum , vascular structures and the thorathic cage. additional information can be obtained from a lateral film.
- 33. Normal Chest X-ray Cardiac Structures ◦ Position More central in younger infants and children More on the L side in older infants and teens ◦ Size CARDIO-THORACIC RATIO! Cardiac diameter : normal individuals < 15.5 cm in males; <14.5 cm in females. A change in diameter of greater than 1.5 cm is significant.
- 34. Normal Chest X-ray 1. Soft tissue structures ◦ Shadows, most commonly, breast 2. Bony structures ◦ Count the ribs ◦ 8 – 10 ribs should be visible on inspiration ◦ Clavicle placement at 2-3 intercostal space (if not, may be rotated)
- 35. Normal Chest X-ray 3. Diaphragm ◦ Contour ◦ Rounded with sharp pointed costophrenic and costocardiac angles ◦ Right diaphragm is usually 1-2 cm higher
- 36. Normal Chest X-ray 4. Lungs ◦ Start at the top and compare the R and L ◦ Trachea should be midline over the thoracic vertebrae and air filled ◦ Lung parenchyma becomes lighter as you we down the lung. If not, it may indicate a lower lobe or pleural effusion
- 37.
- 38.
- 39. PA vs APviews PA view Scapula is seen in periphery of thorax Clavicles project over lung fields Posterior ribs are distinct Position of markers AP view Scapulae are over lung fields Clavicles are above the apex of lung fields Position of markers Anterior ribs are distinct
- 40. Penetration With correct exposurewe should barely see the intervertebral disc through the heart If we see them very clearly the film is overpenetrated If we do not see them it is underpenetrated
- 41.
- 42. It is superiorto CXR in determining the position and size of a pulmonary lesion and whether calcification or cavitations is present. It is now routinely used in the assessment of patients with suspected lung cancer and facilitate guided percutaneous needle biopsy. HRCT (high resolution), that uses thin section to provide a detail assessment of pulmonary parenchymal diseases ( interstitial lung disease , bronchiectasis) Computed tomography
- 44. An axial sliceof a thin-slice CT acquisition (low- dose). The yellow arrow indicates a solid pulmonary nodule.
- 45. Pulmonary and bronchial angiography Pulmonaryangiography and bronchial angiography (together with bronchial artery embolisation for the treatment of haemoptysis) are invasive techniques for imaging vessels and are only used if less invasive techniques (contrast CT/magnetic resonance imaging (MRI)) fail or need to be confirmed.
- 46. Fluoroscopy Fluoroscopy (an X-raytechnique by which respiratory movement is visualised directly) is used mainly for guidance of biopsy of peripheral lung lesions and for differential diagnosis of an elevated diaphragm.
- 47. Magnetic resonance imaging MRIhas 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.
- 48. Chest MRI findingsof a middle-aged female patient. A round-like lesion with long T1 and T2 signals at the upper posterior portion of the right mediastinum ...
- 49. Ultrasonography Ultrasonography has becomean 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. Its most important use is the sampling of mediastinal lymph nodes in the setting of endoscopic lung cancer staging, where EBUS has largely replaced
- 50. Nuclear medicine techniques Nuclearmedicine techniques include perfusion and ventilation scintigraphy, which are mainly indicated in the diagnosis of pulmonary embolism but also for regional lung function studies, e.g. for predicting post-operative lung function before lung surgery. Inhalation scintigraphy can be used to investigate mucociliary clearance.
- 51. Invasive biopsy techniques Bronchoscopy Themost 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.
- 52. Figure -a) Transbronchialneedle aspiration during flexible bronchoscopy. b) Flexible bronchoscopy showing a tumour that is almost completely obstructing the right main bronchus, indicating inoperability due to the location of the tumour.
- 53. Bronchoalveolar lavage Bronchoalveolar lavage(BAL) involves the instillation of saline via a bronchoscope in order to collect specimens for cytological or microbiological investigation. It is used mainly in interstitial lung diseases or lower respiratory tract infections, as material can easily be obtained from the periphery of the lung.
- 54. Autofluorescence and narrow- bandimaging Autofluorescence or narrowband imaging may be helpful in the detection of precancerous lesions and early cancers located in the bronchial tree.
- 55. Percutaneous needle biopsy Percutaneous(or transthoracic) needle biopsy is mainly performed to investigate peripheral lung lesions when bronchoscopy is negative. It is performed with the guidance of either fluoroscopy or, preferably, CT. When lesions are adjacent to the chest wall, ultrasound guidance can also be used.
- 56. Thoracentesis and pleuroscopy (medicalthoracoscopy) Thoracentesis (pleural fluid aspiration or ‘tap’) is a frequently performed procedure in pleural effusions, preferably used under ultrasound guidance, at least when the effusion is small. Additional biopsy procedures, such as closed-needle biopsy of the pleura or pleuroscopy (medical thoracoscopy), may be necessary to confirm or exclude malignant or tuberculous causes of an effusion.
- 57. Surgical methods Surgical investigativemethods include mediastinoscopy and the minimally invasive technique of video-assisted thoracic surgery (VATS). Mediastinoscopy is used for biopsy of mediastinal lymph nodes. VATS has almost completely replaced the use of open surgery for diagnostic purposes in intrathoracic lesions (including interstitial lung disease), in which the aetiology remains uncertain after performance of the above less invasive procedures.
- 59. NEXT SEMINAR BYDr. NIKESH CALCIUM METABOLISM AND MEDICAL BONE DISEASE MOD-PROF. SARITA BAJAJ(DM ENDO)
- 60.