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Bronchial provocation testing: s performed to evaluate how "reactive" or "responsive" your lungs are. The test starts with a very small dose of methacholine and, depending on your response, the doses will be increased until either you experience a 20 percent drop in breathing ability, or you reach a maximum dose with no change in your lung function.

narrowing your bronchial airways.

Cardiopulmonary exercise testing: provides assessment of the integrative exercise responses involving the pulmonary, cardiovascular, haematopoietic, neuropsychological, and skeletal muscle systems, which are not adequately reflected through the measurement of individual organ system function.

Exhaled nitric oxide: can help diagnose and manage asthma. It measures the amount of nitric oxide that is exhaled from a breath. Increased levels of nitric oxide are associated with swelling of lung airways.

Intercostal drain placement: inserting a plastic tube into the pleural cavity to drain air or fluid.

Nocturnal polygraph: used to study the way your body functions when you sleep and to diagnose potential, sleep-related breathing disorders such as sleep apnoea, snoring, upper respiratory tract congestion, or restless leg syndrome.

Pleural aspiration:  a small needle or tube is inserted into the pleural space to remove fluid that has accumulated around the lung.

Skin-prick tests: checks for immediate allergic reactions to as many as 50 different substances at once.

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Medical techniques for obtaining biological specimens 

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Medical techniques for obtaining biological specimens 

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Collection of blood and serum

Collection of sputum

Percutaneous needle aspiration: done to collect cells or a tissue sample for testing. Needle on chest to lungs.

Thoracentesis: drain extra fluid from around the lungs (pleural space) with a needle.

Bronchoscopy: technique used to look at your air passages with a small camera that is located at the end of a flexible tube. This connects to a video screen for the doctors to view and take photos of your air passages.

Flexible fiberoptic bronchoscopy: more appropriate procedure to explore the distal airway, whereas rigid bronchoscopy allows more complete visualization of the proximal airway

Transbronchial needle aspiration: procedure to obtain cellular material using a needle that is passed through the bronchial wall.

Endobronchial ultrasound-transbronchial needle aspiration: look into your lungs (similar to a bronchoscopy) but them to take samples of the glands in the center of your chest (mediastinum) using the aid of an ultrasound scan, these glands lie outside the normal breathing tubes (bronchi).

A flexible tube (bronchoscope) with a camera

A small ultrasound probe

on the end of the camera allows the doctor to see the glands in the center of the chest (mediastinum) and take samples under direct vision.

Emerging bronchoscopy techniques

Pleural biopsy: takes a sample of the pleura using a special needle. If a chest X-ray or other test suggests you have: a build-up of fluid in your pleural cavity or space. thickening of the pleura.

Medical thoracoscopy: to look at an abnormal area seen on an imaging test (such as a chest x-ray or CT scan). It also can be used to take biopsy samples of lymph nodes, abnormal lung tissue, the chest wall, or the lining of the lung (pleura).

Surgical techniques for obtaining biologic specimens

Mediastinoscopy: direct visual examination of the area inside the mediastinum through a mediastinoscope.

Mediastinotomy: surgical opening of the mediastinum.

Video-assisted thoracoscopic surgery: minimally invasive. tiny camera and surgical tools are inserted into the chest through one or more small cuts in the chest wall.

Thoracotomy: surgical procedure in which a cut is made between the ribs to see and reach the lungs or other organs in the chest or thorax

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Routine radiography:  using radiation to provide images

Chest X-ray: an imaging test that uses X-rays to look at the structures and organs in your chest

Computed tomography: a narrow beam of x-rays is aimed at a patient and quickly rotated around the body, producing signals that are processed by the machine's computer to generate cross-sectional images, or “slices.”

Magnetic resonance imaging with electrocardiography: recording of the electrocardiogram (ECG) during magnetic resonance imaging (MRI); aneurisms, lung cancer, vascular structi

Nuclear medicine techniques: administration of a radiolabeled chemical called a radiopharmaceutical. This radiopharmaceutical is administered internally, via injection, swallowing or inhalation.

Positron emission tomography-computed tomography: produce small particles called positrons. A positron is a particle with roughly the same mass as an electron but oppositely charged.: tumors

measures metabolic activity of the cells of body tissues.

it can find abnormal activity and it can be more sensitive than other imaging tests.

Pulmonary angiography or yntygraphy: test to see how blood flows through the lung. Uses x ray and dyes to see inside of arteries: inject something to dye and inhale somethingç. imaging

Scintigraphic imaging: creates images of the body's internal organs and tissues using gamma rays emitted by radioactive isotopes

Ultrasound: uses high-frequency sound waves to view inside the body. Because ultrasound images are captured in real-time, they can also show movement of the body's internal organs as well as blood flowing through the blood vessels.

Virtual bronchoscopy: a novel computed tomography (CT)-based technique that allows a noninvasive intraluminal evaluation of the tracheobronchial tree.

It can visualize areas inaccessible to the flexible bronchoscope.

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Primary Pulmonary Hypertension →  blood vessels in the lungs narrow (constrict) and the pressure in the pulmonary artery rises far above normal levels.

Cor pulmonale

Chronic Thromboembolic Disease → high blood pressure in the small blood vessels of your lungs.

It is caused by blood clots and scarring

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Simple and cheap

Dependent on flow rate of larger airways → may be falsely reassuring in patients with moderate airflow limitation

Used to

Diagnosing asthma

Monitor

Exacerbations of asthma

Response to treatment

1. Full inspiration to TLC

2. Blow out forcefully into the peak flow meter

3. The best of 3 attempts is recorded

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Diagnosing Restrictive Lung Disease

Measures

TLC → by inhaling air containing a known concentration of He and measuring its dilution in the exhaled air

RV → by subtracting the vital capacity from the TLC

TLC measurements using this technique are inaccurate if there are large cystic spaces in the lung because helium cannot diffuse into them.

Under these circumstances the thoracic gas volume can be measured more accurately using a body plethysmograph

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Examples obstructive and restrictive spirometer 

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Examples obstructive and restrictive spirometer 

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Examples obstructive and restrictive spirometer 

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Examples obstructive and restrictive spirometer 

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Standard PFTs

Spirometry

Obstructive

Lung volumes

Restrictive

Diffusing capacity of carbon monoxide (DLCO)

Suggesting possibility of pulmonary vascular disease

Specialized PFTs

Arterial blood gas

Exercise oximetry

6 minute walk test

walk as far as possible in 6 min. Helps prognosis

Peak flow

maximum oxygen outflow in 1 breath

Maximum inspiratory and expiratory pressures

rough estimate of diaphragmatic strength and muscular disease

respiratory failure

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Diagnosis of symptomatic disease (chronic dyspnoea or cough)

Screening for early, asymptomatic disease

Prognostication of known disease

Monitor response to treatment

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Arterial Blood Gasses → measures O2 and CO2 content in blood
6 Minute Walk Test → used to monitor response to treatments for heart, lung + other health problems
Peak Flow → to measure max expiratory air flow
Maximum Inspiratory and Expiratory Pressures → to estimate of diaphragmatic strengths

Exercise oximetry

→ Measuring someone’s pulse oximetry (= Oxygen saturation level w/o needles or blood → Saturation of RBCs with oxygen) at rest and with modest activity

Fast

Cheap

Diagnosing Mild Subclinical Lung Disease

Using ear or finger probes

6 minute walk test

Patient asked → Walk as far as possible for 6 min

Record

Oxygen saturation

Pulse rate

Distance

NO diagnosing specific disease

YES

Prognosis

Response to treatment

Maximum inspiratory and expiratory pressures

Provides a rough estimate of Diaphragmatic Strength in Neuromuscular Disease

Including predicting risk of Respiratory Failure during Exacerbations such as an Impending Myasthenic Crisis

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Values from PFTs are reported as a % of that predicted, given the patients age, gender, height.
Normal: within 80-120% or between 5th and 95th percentile

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Reference values are derived from large groups of nonsmoking, normal subjects. Prediction variables include height, sex, age, certain races (african american and asian), & size (which is estimated with body height).
Differences in these variables = changes in Lung Capacities (i.e Taller subject: = bigger lung/airways = maximal flows are higher).

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Depends on:
1. age
2. sex
3. ethnicity
4. height

Data collection
- Researchers gather data from patients who are not suffering form pulmonary distress (are healthy). This will then be used as a reference for those who are suffering.

Statistical analysis
- Statistics are utilised to analyse the data. The patterns and relationship between the lung function parameters are clearly indicated by the statistics.

Equation development
- Based on the analysis a representative equation is produced which will help form the predicted values

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Restrictive Diseases → Reduction in lung volume → difficulty taking air in → due to stiffness of lung tissue or chest wall cavity

a reduced expansion of the lungs and decreased total lung capacity.
- the amount of lung is lowered —> fibrosis

Eg. Fibrosis in general is a restrictive disease, but not systic fibrosis

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Obstruction (inflammation and excess mucus due to conditions) → Reduction in airflow → Difficulty in exhaling air → air will remain in lung after full expiration

Obstruction, inflammation caused the dysfunction of lungs
Eg, asthma, chronic bronchitis (one of the COPD), system fibrosis (problem with producing the mucus, too many mucus in the lungs)

Patients can breath in, but can hardly breath out.

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DLCO (Diffusing Capacity of Carbon Monoxide)

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DLCO (Diffusing Capacity of Carbon Monoxide)

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Measures how much volume of CO diffuses per min per unit of P across the alveolar capillary membrane

The test suggests restrictive and vascular pulmonary lung disease

Units used
-  mlCO / min / mmHg (rate of absorption)

Steps

1. A rubber bag is filled with a standard single-breath DLCO gas mixture (usually 0.3% CO, 10% He, 21% O2, balance N2).

2. The volume of the bag is adjusted to the subject so that it empties at end-inhalation with every breath.

3. At the end of an exhalation the subject is switched into the bag who then hyperventilates at a rate of approximately 30 breaths per minute.

4. During the first several breaths, CO and He undergo dilution and equilibration with the patient’s FRC.

5. An initial carbon monoxide reading is taken at this time and used as a baseline.

6. The test usually continues for another 30 seconds or so after the baseline measurements are taken and the subject is then switched out of the breathing circuit

Conditions that alter DLCO

Low DLCO

Low membrane surface area → Ex. Emphysema / Fibrosis

High membrane thickness → Ex. ILD

Pulmonary hypertension

Heart failure

Anemia

High DLCO

Exercise prior to test → increases Cardiac Output

Supine position → changes distribution of pulmonary blood flow & ventilation

Asthma → due to increased perfusion of the lung apices in asthmatics

pulmonary hemorrhage → since there is blood out → CO can bind to hemoglobin without diffusing

Polycythemia → opposite of anemia

Mild left heart failure → increased left-sided pressures with preservation of cardiac output → increased pulmonary blood volume

Diagnostic information

Determines the cause of restrictive lung disease

DLCO low → likely to have Interstitial Lung Disease

DLCO normal → Extra torathic cause of restriction

A chest wall disorder

Neuromuscular disease

Obesity

Differentiate within obstructive LD

DLCO low → emphysema type of COPD

DLCO normal → pure chronic bronchitis type of COPD

patients with asthma usually have normal, but can be higher

Among patients with normal lung mechanics → Differentiate between

DLCO low → Pulmonary Vascular Disease

DLCO normal → normal PTF

*It is particularly useful in detecting and monitoring diseases affecting the lung parenchyma

KCO is raised duing hemorrage

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Pb = barometric pressure

T = length of the re-breathing period, in minutes

FACO1 = fractional CO at beginning of re-breathing period (after initial equilibration between lungs and bag)

FACO2 = fractional CO at end of re-breathing period

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Inspiratory capacity

Inspiratory reserve volume + Tidal volume

Functional reserve capacity

Expiratory reserve volume + Residual volume

Vital capacity

Inspiratory reserve volume + Tidal volume + Expiratory reserve volume

Total lung capacity

Inspiratory reserve volume + Tidal volume + Expiratory reserve volume + Residual volume

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Spirometry indicators of obstructive and restrictive 

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Spirometry indicators of obstructive and restrictive 

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Obstructive LD

FEV1

Can be normal

Almost always decreased → airways obstructed → longer to push air

FVC

Normal in mild or moderate obstruction

Severe obstruction → Decrease

FEV1 / FVC ratio

Since FEV1 decreases more than FVC → ratio (= Tiffaneau Index) → ratio is decreased under 70% (normal value)

Restrictive LD

FEV1

Normal or

Decreased

FVC → Decreased

FEV1 / FVC ratio

Since FVC decreases to similar or greater degree than FEV1

→ Ratio is either

Normal (= 70%)

Increased (> 70%)

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The patient takes a maximum inspiration followed by a forced expiration (for as long as possible) into the spirometer. The spirometer measures the one second forced expiratory volume (FEV1) and the total volume of exhaled gas (forced vital capacity, FVC). Both FEV1 and FVC are related to height, age and sex

In airflow limitation, the FEV1 is reduced as a percentage of FVC. In normal health the FEV1/FVC ratio is around 75%. With increasing airflow limitation FEV1 falls proportionately more than FVC, so the FEV1/FVC ratio is reduced. With restrictive lung disease FEV1 and FVC are reduced propor- tionately and the FEV1/FVC ratio remains normal or may even increase because of enhanced elastic recoil.

Response to bronchodilators

for Obstructive LD

an increase greater than 12 to 15% in FEV1 → significant

still provide them if not

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PFT show evidence of airflow limitation. The FEV1: FVC ratio is reduced and the PEFR is low. In many patients the airflow limitation is partly reversible (usually a change in FEV1 of <15%), and it can be difficult to distinguish between COPD and asthma. Lung volumes may
be normal or increased; carbon monoxide gas transfer factor is low when significant emphysema is present.

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In advanced pulmonary hypotension the P wave is tall (P pulmonale) and there may be right bundle branch block and evidence of right ventricular hypertrophy

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Can be useful, particularly when the plain chest X-ray is normal

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A chest X-ray is often normal, even when the disease is advanced. The classic features are overinflation
of the lungs with low, flattened diaphragms, and sometimes the presence of large bullae. Blood vessels may be ‘pruned’ with large proximal vessels and relatively little blood visible in the peripheral lung fields.