Pulmonary function tests are used to evaluate the respiratory system by measuring lung volumes, gas exchange, and other functions. They have several indications, including investigating symptoms of pulmonary disease, monitoring known lung diseases, and preoperative evaluation. The tests can be categorized as measuring mechanical lung function, gas exchange, or cardiopulmonary interaction. Common tests include spirometry, lung volume measurements, diffusion capacity tests, and exercise tests.
This presentation describes the indications, contraindications, methods of performing spirometry. It explains the interpretation of spirometry with examples.
Pulmonary function tests (PFTs) are noninvasive tests that show how well the lungs are working. The tests measure lung volume, capacity, rates of flow, and gas exchange. This information can help your healthcare provider diagnose and decide the treatment of certain lung disorders.
This presentation describes the indications, contraindications, methods of performing spirometry. It explains the interpretation of spirometry with examples.
Pulmonary function tests (PFTs) are noninvasive tests that show how well the lungs are working. The tests measure lung volume, capacity, rates of flow, and gas exchange. This information can help your healthcare provider diagnose and decide the treatment of certain lung disorders.
A technique used to measure air flow in and out of the lungs.
A recording of lung volumes and capacities defined by the respiratory process. These recordings may be static (untimed) or dynamic (timed).
Assesses the integrated mechanical functions of lungs, chest wall and respiratory muscles.
The gold standard for diagnosis, assessment and monitoring of COPD.
Better than PEFR (which is effort dependent) for demonstrating airway obstruction in BA.
The most commonly used PFT
What are the pulmonary function tests used?
What are the indications?
What are the contraindications?
How to perform each and prepare patients?
How to interpret and reach a diagnosis?
How to clean and calibrate devices?
Gas exchange between the alveoli and the pulmonary capillary blood occurs by diffusion, as will be discussed in the next chapter. Diffusion of oxygen and carbon dioxide occurs passively, according to their concentration differences across the alveolar-capillary barrier. These concentration differences must be maintained by ventilation of the alveoli and perfusion of the pulmonary capillaries.
Alveolar ventilation brings oxygen into the lung and removes carbon dioxide from it. Similarly, the mixed venous blood brings carbon dioxide into the lung and takes up alveolar oxygen. The alveolar Image not available. and Image not available. are thus determined by the relationship between alveolar ventilation and pulmonary capillary perfusion. Alterations in the ratio of ventilation to perfusion, called the Image not available., will result in changes in the alveolar Image not available. and Image not available., as well as in gas delivery to or removal from the lung.
Alveolar ventilation is normally about 4 to 6 L/min and pulmonary blood flow (which is equal to cardiac output) has a similar range, and so the Image not available. for the whole lung is in the range of 0.8 to 1.2. Image not available. However, ventilation and perfusion must be matched on the alveolar-capillary level, and the Image not available. for the whole lung is really of interest only as an approximation of the situation in all the alveolar-capillary units of the lung. For instance, suppose that all 5 L/min of the cardiac output went to the left lung and all 5 L/min of alveolar ventilation went to the right lung. The whole lung Image not available. would be 1.0, but there would be no gas exchange because there could be no gas diffusion between the ventilated alveoli and the perfused pulmonary capillaries.
Oxygen is delivered to the alveolus by alveolar ventilation, is removed from the alveolus as it diffuses into the pulmonary capillary blood, and is carried away by blood flow. Similarly, carbon dioxide is delivered to the alveolus in the mixed venous blood and diffuses into the alveolus in the pulmonary capillary. The carbon dioxide is removed from the alveolus by alveolar ventilation. As will be discussed in Chapter 6, at resting cardiac outputs the diffusion of both oxygen and carbon dioxide is normally limited by pulmonary perfusion. Thus, the alveolar partial pressures of both oxygen and carbon dioxide are determined by the Image not available. If the Image not available. in an alveolar-capillary unit increases, the delivery of oxygen relative to its removal will increase, as will the removal ...
A technique used to measure air flow in and out of the lungs.
A recording of lung volumes and capacities defined by the respiratory process. These recordings may be static (untimed) or dynamic (timed).
Assesses the integrated mechanical functions of lungs, chest wall and respiratory muscles.
The gold standard for diagnosis, assessment and monitoring of COPD.
Better than PEFR (which is effort dependent) for demonstrating airway obstruction in BA.
The most commonly used PFT
What are the pulmonary function tests used?
What are the indications?
What are the contraindications?
How to perform each and prepare patients?
How to interpret and reach a diagnosis?
How to clean and calibrate devices?
Gas exchange between the alveoli and the pulmonary capillary blood occurs by diffusion, as will be discussed in the next chapter. Diffusion of oxygen and carbon dioxide occurs passively, according to their concentration differences across the alveolar-capillary barrier. These concentration differences must be maintained by ventilation of the alveoli and perfusion of the pulmonary capillaries.
Alveolar ventilation brings oxygen into the lung and removes carbon dioxide from it. Similarly, the mixed venous blood brings carbon dioxide into the lung and takes up alveolar oxygen. The alveolar Image not available. and Image not available. are thus determined by the relationship between alveolar ventilation and pulmonary capillary perfusion. Alterations in the ratio of ventilation to perfusion, called the Image not available., will result in changes in the alveolar Image not available. and Image not available., as well as in gas delivery to or removal from the lung.
Alveolar ventilation is normally about 4 to 6 L/min and pulmonary blood flow (which is equal to cardiac output) has a similar range, and so the Image not available. for the whole lung is in the range of 0.8 to 1.2. Image not available. However, ventilation and perfusion must be matched on the alveolar-capillary level, and the Image not available. for the whole lung is really of interest only as an approximation of the situation in all the alveolar-capillary units of the lung. For instance, suppose that all 5 L/min of the cardiac output went to the left lung and all 5 L/min of alveolar ventilation went to the right lung. The whole lung Image not available. would be 1.0, but there would be no gas exchange because there could be no gas diffusion between the ventilated alveoli and the perfused pulmonary capillaries.
Oxygen is delivered to the alveolus by alveolar ventilation, is removed from the alveolus as it diffuses into the pulmonary capillary blood, and is carried away by blood flow. Similarly, carbon dioxide is delivered to the alveolus in the mixed venous blood and diffuses into the alveolus in the pulmonary capillary. The carbon dioxide is removed from the alveolus by alveolar ventilation. As will be discussed in Chapter 6, at resting cardiac outputs the diffusion of both oxygen and carbon dioxide is normally limited by pulmonary perfusion. Thus, the alveolar partial pressures of both oxygen and carbon dioxide are determined by the Image not available. If the Image not available. in an alveolar-capillary unit increases, the delivery of oxygen relative to its removal will increase, as will the removal ...
This is an amazing article giving brief clinical application of PFT.
Bedside PFT are best explained here.
Bedside PFT references most of times are incomplete and inadequate
COURTSEY -DEPARTMENT OF ANESTHESIA, MAMC and LOK NAYAK HOSPITAL, NEW DELHI
PULMONARY FUNCTION TESTS - LAB DATA INTERPRETATIONLincyAsha
PULMONARY FUNCTION TESTS
LAB DATA INTERPRETATION
CLINICAL PHARMACY PRACTICE
M.PHARMACY
PHARMACY PRACTICE
1ST YEAR
Pulmonary function tests are a series of tests performed to examine a patient’s respiratory system and identify the severity of pulmonary impairment.
These tests are performed to measure a patient’s lung volume, capacity, flow rate and gas exchange.
This allows medical professionals to obtain an accurate diagnosis and determine the best course of medical intervention for the patient.
In general there are two types of lung disorders that these tests can be used to assess
Obstructive lung diseases
Restrictive lung diseases
1.OBSTRUCTIVE LUNG DISEASES
It include conditions that make it difficult to exhale air out of the lungs
This results in shortness of breath that occurs from narrowing and constriction of the airways and causes the patient to have decreased flow rates. Eg. COPD, Asthma
2.RESTRICTIVE LUNG DISEASES
It include conditions that make it difficult to fully fill the lungs with air during inhalation.
When the lungs aren’t fully able to expand it causes the patient to have decreased lung volumes. Eg. Pulmonary fibrosis, interstitial lung disease
Pulmonary function tests would be indicated for the following:
On healthy patients as part of a routine physical exam
Evaluate signs and symptoms of lung disease
Diagnosis of certain medical conditions
Measure current stage of disease and evaluate its progress
Assess how a patient is responding to different treatments
Determine patient’s condition before surgery to assess the risk of respiratory complications
Screen people who are at risk of pulmonary disease
Determine how much a patient’s airways have narrowed due to disorders
In certain types of work environments to assess the health of employees.
Additionally PFTs may be indicated for the following
Chronic lung conditions
Restrictive airway problems
Asthma
COPD
Shortness of breath
Impairment or disability
Early morning wheezing
Chest muscle weakness
Lung cancer
Respiratory infections
STATIC LUNG VOLUMES
Lung volume is the amount of air breathed by an individual under a specific condition.
1.Tidal Volume (TV)
It is the volume of air inspired or expired during normal breathing at rest.
2.Inspiratory Reserve Volume (IRV)
It is the volume of air inspired with maximum effort over and above the normal tidal volume.
3.Expiratory Reserve Volume (ERV)
It is the volume of air expired forcefully after a normal respiration.
4.Residual Volume (RV)
It is the volume of air remaining in the lungs after a forceful expiration
STATIC LUNG CAPACITIES
1.Inspiratory capacity (IC)
It is the amount of air a person can inspire forcefully after a normal respiration.
IC = TV+IRV
2.Functional Residual Capacity (FRC)
It is the amount of air that remains in the lungs at the end of normal respiration.
FRC = ERV+RV
3.Vital Capacity (VC)
It is the maximum volume of air exhaled forcefully from the lungs after a maximum inspiration.
4.Total Lung Capacity
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It is a walnut-sized gland that forms part of the male reproductive system and is located in front of the rectum and just below the urinary bladder
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Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
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Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
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Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
Lung Cancer: Artificial Intelligence, Synergetics, Complex System Analysis, S...Oleg Kshivets
RESULTS: Overall life span (LS) was 2252.1±1742.5 days and cumulative 5-year survival (5YS) reached 73.2%, 10 years – 64.8%, 20 years – 42.5%. 513 LCP lived more than 5 years (LS=3124.6±1525.6 days), 148 LCP – more than 10 years (LS=5054.4±1504.1 days).199 LCP died because of LC (LS=562.7±374.5 days). 5YS of LCP after bi/lobectomies was significantly superior in comparison with LCP after pneumonectomies (78.1% vs.63.7%, P=0.00001 by log-rank test). AT significantly improved 5YS (66.3% vs. 34.8%) (P=0.00000 by log-rank test) only for LCP with N1-2. Cox modeling displayed that 5YS of LCP significantly depended on: phase transition (PT) early-invasive LC in terms of synergetics, PT N0—N12, cell ratio factors (ratio between cancer cells- CC and blood cells subpopulations), G1-3, histology, glucose, AT, blood cell circuit, prothrombin index, heparin tolerance, recalcification time (P=0.000-0.038). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and PT early-invasive LC (rank=1), PT N0—N12 (rank=2), thrombocytes/CC (3), erythrocytes/CC (4), eosinophils/CC (5), healthy cells/CC (6), lymphocytes/CC (7), segmented neutrophils/CC (8), stick neutrophils/CC (9), monocytes/CC (10); leucocytes/CC (11). Correct prediction of 5YS was 100% by neural networks computing (area under ROC curve=1.0; error=0.0).
CONCLUSIONS: 5YS of LCP after radical procedures significantly depended on: 1) PT early-invasive cancer; 2) PT N0--N12; 3) cell ratio factors; 4) blood cell circuit; 5) biochemical factors; 6) hemostasis system; 7) AT; 8) LC characteristics; 9) LC cell dynamics; 10) surgery type: lobectomy/pneumonectomy; 11) anthropometric data. Optimal diagnosis and treatment strategies for LC are: 1) screening and early detection of LC; 2) availability of experienced thoracic surgeons because of complexity of radical procedures; 3) aggressive en block surgery and adequate lymph node dissection for completeness; 4) precise prediction; 5) adjuvant chemoimmunoradiotherapy for LCP with unfavorable prognosis.
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TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
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Pulmonary Thromboembolism - etilogy, types, medical- Surgical and nursing man...VarunMahajani
Disruption of blood supply to lung alveoli due to blockage of one or more pulmonary blood vessels is called as Pulmonary thromboembolism. In this presentation we will discuss its causes, types and its management in depth.
2. INTRODUCTION
Pulmonary function tests is a generic term used to indicate
a battery of studies or maneuvers that may be performed
using standardized equipment to measure lung function.
Evaluate one or more aspects of the respiratory system
Respiratory mechanics
Lung parenchymal function/ Gas exchange
Cardiopulmonary interaction
3. INDICATIONS
1. Investigation of patients with symptoms/signs/
investigations that suggest pulmonary disease e.g.
• (Cough/Wheeze/Breathlessness/Crackles)
2. Monitoring patients with known pulmonary disease
for progression and response to treatment e.g.
• Interstitial fibrosis
• COPD
• Asthma
• Pulmonary vascular disease
4. 3. Investigation of patients with disease that may have a
respiratory complications e.g.
• Connective tissue disorders
• Neuromuscular diseases
4. Preoperative evaluation prior to e.g.
• Lung resection
• Abdominal surgery
• Cardiothoracic surgery
5. 5. Evaluation patients a risk of lung diseases e.g.
• Exposure to pulmonary toxins such a radiation/
medication/environmental/occupational exposure
6. Surveillance following lung transplantation to assess
for
• Acute rejection
• Infection
• Obliterative bronchiolitis
6. Contraindications
Myocardial infarction within the last month
Unstable angina
Recent thoraco-abdominal surgery
Recent ophthalmic surgery
Thoracic or abdominal aneurysm
Current pneumothorax
7. INDEX
1. CATEGORIZATION OF PFT’S
2. Bedside pulmonary function tests
3. Static lung volumes and capacities
4. Measurement of FRC, RV
5. Dynamic lung volumes/forced spirometry
6. Flow volume loops and detection of airway obstruction
7. Flow volume loop and lung diseases
8. Tests of gas exchange function
9. Tests for cardiopulmonary reserve
10. Preoperative assessment of thoracotomy patients
8. CATEGORIZATION OF PFT
MECHANICAL VENTILATORY
FUNCTIONS OF LUNG / CHEST
WALL:
• BED SIDE PULMONARY FUNCTION TESTS
• STATIC LUNG VOLUMES & CAPACITIES –
VC, IC, IRV,ERV,RV, FRC.
• DYNAMIC LUNG VOLUMES –FVC, FEV1,
FEF 25-75%, PEFR, MVV, RESP. MUSCLE
STRENGTH
9. GAS- EXCHANGE TESTS
:
• A)Alveolar-arterial po2 gradient
• B) Diffusion capacity
• C) Gas distribution tests 1)Single breath N2 test
2)Multiple Breath N2 test
3) Helium dilution method
4) Radio Xe scinitigram.
10. • Qualitative tests:
1) History , examination
2) ABG
• Quantitative tests
1)6 min walk test
2)Stair climbing test
3)Shuttle walk
4) CPET(cardiopulmonary exercise testing)
CARDIOPULMONARY
INTERACTION:
11. INDEX
1. Bedside pulmonary function tests
2. Static lung volumes and capacities
3. Measurement of FRC, RV
4. Dynamic lung volumes/forced spirometry
5. Flow volume loops and detection of airway obstruction
6. Flow volume loop and lung diseases
7. Tests of gas function
8. Tests for cardiopulmonary reserve
9. Preoperative assessment of thoracotomy patients
12. Bed side pulmonary function tests
1) SABRASEZ BREATH HOLDING TEST:
Ask the patient to take a full but not too deep breath &
hold it as long as possible.
>25 SEC.-NORMAL Cardiopulmonary Reserve
(CPR)
15-25 SEC- LIMITED CPR
<15 SEC- VERYPOOR CPR (Contraindication
for elective surgery)
13. 25-30 SEC - 3500 ml VC
20 -25 SEC - 3000 ml VC
15 -20 SEC - 2500 ml VC
10 -15 SEC - 2000 ml VC
5-10 SEC - 1500 ml VC
14. Bed side pulmonary function tests
2) SCHNEIDER’S MATCH BLOWING TEST:
MEASURES Maximum Breathing Capacity.
Ask to blow a match stick from a distance of 6” (15
cms) with-
Mouth wide open
Chin rested/supported
No purse lipping
No head movement
No air movement in the room
Mouth and match at the same level
15. Bed side pulmonary function tests
Can not blow out a match
MBC < 60 L/min
FEV1 < 1.6L
Able to blow out a match
MBC > 60 L/min
FEV1 > 1.6L
Modified match test:
DISTANCE
9”
6”
3”
MBC
>150 L/MIN.
>60 L/MIN.
> 40 L/MIN
16. Bed side pulmonary function tests
3)COUGH TEST: DEEP BREATH F/By COUGH
ABILITY TO COUGH
STRENGTH
EFFECTIVENESS
INADEQUATE COUGH IF: FVC<20 ML/KG
FEV1 < 15 ML/KG
PEFR < 200 L/MIN.
VC ~ 3 TIMES TV FOR EFFECTIVE COUGH.
17. Bed side pulmonary function tests
4)FORCED EXPIRATORY TIME:
After deep breath, exhale maximally and forcefully &
keep stethoscope over trachea & listen.
N FET – 3-5 SECS.
OBS.LUNG DIS. - > 6 SEC
RES. LUNG DIS.- < 3 SEC
5) SINGLE BREATH COUNT:
After deep breath, hold it and start counting till the next
breath.
N- 30-40 COUNT
Indicates vital capacity
18. Bed side pulmonary function tests
6)WRIGHT PEAK FLOW METER: MeasuresPEFR
(Peak Expiratory Flow Rate)
N – MALES- 450-700 L/MIN.
FEMALES- 350-500 L/MIN.
19. 7)DE-BONO WHISTLE BLOWING TEST:
MEASURES PEFR.
Patient blows down a wide bore tube at the end of which is a
whistle, on the side is a hole with adjustable knob.
As subject blows → whistle blows, leak hole is
gradually increased till the intensity of whistle
disappears.
At the last position at which the whistle can be blown , the
PEFR can be read off the scale.
20. 8) WRIGHT RESPIROMETER : measures TV,MV
Instrument- compact, light and portable.
Can be connected to endotracheal tube or face mask
MV- instrument record for 1 min. And read directly
TV-calculated and dividing MV by counting Respiratory
Rate.
Disadvantage: It under- reads at low flow rates and over-
reads at high flow rates.
21. INDEX
1. Bedside pulmonary function tests
2. Static lung volumes and capacities
3. Measurement of FRC, RV
4. Dynamic lung volumes/forced spirometry
5. Flow volume loops and detection of airway obstruction
6. Flow volume loop and lung diseases
7. Tests of gas function
8. Tests for cardiopulmonary reserve
9. Preoperative assessment of thoracotomy patients
22.
23.
24.
25.
26. PREREQUISITES
Do not smoke for at least 1 hour before the test.
Do not drink alcohol for at least 4 hours before
the test.
Do not exercise heavily for at least 30 minutes
before the test.
Do not wear tight clothing that makes it difficult
for you to take a deep breath.
Do not eat a large meal within 2 hours before the
test.
29. Spirometry Interpretation: So what
constitutes normal?
Normal values vary and depend on:
I. Height – Directly proportional
II. Age – Inversely proportional
III. Gender
IV. Ethnicity
32. INDEX
1. Bedside pulmonary function tests
2. Static lung volumes and capacities
3. Measurement of FRC, RV
4. Dynamic lung volumes/forced spirometry
5. Flow volume loops and detection of airway obstruction
6. Flow volume loop and lung diseases
7. Tests of gas function
8. Tests for cardiopulmonary reserve
9. Preoperative assessment of thoracotomy patients
33. Measuring RV, FRC
It can be measured by
◦ Nitrogen washout technique
◦ Helium dilution method
◦ Body plethysmography
34. N2 Washout Technique
The patient breathes 100% oxygen, and all the nitrogen
in the lungs is washed out.
The exhaled volume and the nitrogen concentration in
that volume are measured.
The difference in nitrogen volume at the initial
concentration and at the final exhaled concentration
allows a calculation of intrathoracic volume, usually
FRC.
35. Helium Dilution technique
Pt breathes in and out from a reservoir with known
volume of gas containing trace of helium.
Helium gets diluted by gas previously present in
lungs.
eg: if 50 ml Helium introduced and the helium
concentration is 1% , then volume of the lung is
5L.
36. Body Plethysmography
Plethysmography (derived from greek word meaning
enlargement). Based on principle of BOYLE’S
LAW(P*V=k)
A patient is placed in a sitting position in a closed body
box with a known volume
The patient pants with an open glottis against a closed
shutter to produce changes in the box pressure
proportionate to the volume of air in the chest.
As measurements done at end of expiration, it yields
FRC
37.
38.
39. INDEX
1. Bedside pulmonary function tests
2. Static lung volumes and capacities
3. Measurement of FRC, RV
4. Dynamic lung volumes/forced spirometry
5. Flow volume loops and detection of airway obstruction
6. Flow volume loop and lung diseases
7. Tests of gas function
8. Tests for cardiopulmonary reserve
9. Preoperative assessment of thoracotomy patients
40. FORCED SPIROMETRY/TIMED
EXPIRATORY SPIROGRAM
Includes measuring:
•Pulmonary mechanics – to
assess the ability of the lung
to move large vol of air
quickly through the airways
to identify airway
obstruction
•FVC
•FEV1
•FEF [ 25-75]
•Forced inspiratory
rates(FIF’s)
•MVV
41. FORCED VITAL CAPACITY
The FVC is the maximum volume of air that can be
breathed out as forcefully and rapidly as possible
following a maximum inspiration.
Characterized by full inspiration to TLC followed by
abrupt onset of expiration to RV
Indirectly reflects flow resistance property of airways.
45. Measurements Obtained from the FVC
Curve and their significance
FEV1 – Decreased in both obstructive & restrictive lung
disorders
FEV1/FVC – Reduced in obstructive disorders.
Interpretation of FEV1 % predicted:
>80%
50%-80%
30-50%
<30%
Normal
Mild obstruction
Moderate obstruction
Severe obstruction
48. Volume,liters
Time, seconds
Restrictive and mixed obstructive-restrictive are difficult to diagnose by
spirometry alone; full respiratory function tests are usually required
(e.g., body plethysmography, etc)
FEV1 = 0.5L
FVC = 1.5L
FEV1/FVC = 0.30
Normal
Obstructive - Restrictive
6/30/2014 47
49. Forced midexpiratory flow 25-75%
(FEF25-75)
Max. Flow rate during the
mid-expiratory part of FVC
maneuver.
Measured in L/sec
May reflect effort
independent expiration and
the status of the small
airways
Highly variable
Depends heavily on FVC
N value – 4.5-5 l/sec. Or 300
l/min.
50. Forced midexpiratory flow 25-75%
(FEF25-75)
Interpretation of % predicted:
>60%
40-60%
20-40%
<10%
Normal
Mild obstruction
Moderate obstruction
Severe obstruction
51. Peak expiratory flow rates
Maximum flow rate during an FVC maneuver occurs in
initial 0.1 sec
After a maximal inspiration, the patient expires as
forcefully and quickly as he can and the maximum flow
rate of air is measured.
It gives a crude estimate of lung function, reflecting
larger airway function.
Effort dependent but is highly reproducible.
52. Peak expiratory flow rates
It is measured by a peak flow meter,
which measures how much air (litres
per minute)is being blown out or by
spirometry
The peak flow rate in normal adults
varies depending on age and height.
Normal : 450 - 700 l/min in males
300-500 l/min in females
Clinical significance - values of
<200L/min- impaired coughing &
hence likelihood of post-op
complication
53. Maximum Voluntary Ventilation (MVV) or
maximum breathing capacity (MBC)
Measures - speed and efficiency of filling & emptying of
the lungs during increased respiratory effort
Maximum volume of air that can be breathed in and out
of the lungs in 1 minute by maximum voluntary effort
It reflects peak ventilation in physiological demands
Normal : 150 -175 l/min.
<80% - gross impairment
54. Maximum Voluntary Ventilation (MVV) or
maximum breathing capacity (MBC)
The subject is asked to
breathe as quickly and as
deeply as possible for 12
secs and the measured
volume is extrapolated to
1min.
MVV is markedly decreased
in patients with
A. Emphysema
B. Airway obstruction
C. Poor respiratory muscle
strength
55. INDEX
1. Bedside pulmonary function tests
2. Static lung volumes and capacities
3. Measurement of FRC, RV
4. Dynamic lung volumes/forced spirometry
5. Flow volume loops and detection of airway obstruction
6. Flow volume loop and lung diseases
7. Tests of gas function
8. Tests for cardiopulmonary reserve
9. Preoperative assessment of thoracotomy patients
56. FLOW VOLUME LOOPS
“Spirogram” Graphic analysis of flow at various lung
volumes
Tracing obtained when a maximal forced expiration from
TLC to RV is followed by maximal forced inspiration
back to TLC
Measures forced inspiratory and expiratory flow rate
Augments spirometry results
Principal advantage of flow volume loops vs. typical
standard spirometric descriptions - identifies the probable
obstructive flow anatomical location.
57. FLOW VOLUME LOOPS
First 1/3rd of expiratory flow is effort
dependent and the final 2/3rd near the
RVis effort independent
Inspiratory curve is entirely effort
dependent
Ratio of
◦ maximal expiratory flow(MEF)
/maximal inspiratory flow(MIF)
◦ mid VC ratio and is normally 1
58. FLOW VOLUME LOOPS and DETECTION
OF UPPER AIRWAYOBSTRUCTION
Flow-volume loops
provide information on
upper airway obstruction:
Fixed obstruction: constant
airflow limitation on
inspiration and
expiration—such as
1. Benign stricture
2. Goiter
3. Endotracheal neoplasms
4. Bronchial stenosis
59. FLOWVOLUME LOOPS and DETECTION
OF UPPER AIRWAYOBSTRUCTION
Variable intrathoracic obstruction: flattening of
expiratory limb.
1.Tracheomalacia
2. Polychondritis
3. Tumors of trachea or main bronchus
During forced expiration – high pleural
pressure – increased intrathoracic pressure -
decreases airway diameter. The flow volume
loop shows a greater reduction in the
expiratory phase
During inspiration – lower pleural pressure
around airway tends to decrease obstruction
60. FLOW VOLUME LOOPS and DETECTION
OF UPPER AIRWAYOBSTRUCTION
Variable extrathoracic obstruction:
1.Bilateral and unilateral vocal cord paralysis
2. Vocal cord constriction
3. Chronic neuromuscular disorders
4. Airway burns
5. OSA
Forced inspiration- negative transmural
pressure inside airway tends to collapse it
Expiration – positive pressure in airway
decreases obstruction
inspiratory flow is reduced to a greater extent
than expiratory flow
61.
62. INDEX
1. Bedside pulmonary function tests
2. Static lung volumes and capacities
3. Measurement of FRC, RV
4. Dynamic lung volumes/forced spirometry
5. Flow volume loops and detection of airway obstruction
6. Flow volume loop and lung diseases
7. Tests of gas function
8. Tests for cardiopulmonary reserve
9. Preoperative assessment of thoracotomy patients
64. ASTHMA
Peak expiratory flow reduced so
maximum height of the loop is
reduced
Airflow reduces rapidly with the
reduction in the lung volumes
because the airways narrow and the
loop become concave
Concavity may be the indicator of
airflow obstruction and may present
before the change in FEV1 or
FEV1/FVC
65. EMPHYSEMA
Airways may collapse during
forced expiration because of
destruction of the supporting lung
tissue causing very reduced flow at
low lung volume and a
characteristic (dog-leg) appearance
to the flow volume curve
66. REVERSIBILITY
Improvement in FEV1-- 12-15% or 200 ml
Sulbutamol 200-400 microgram or
ipratropium bromide(40-80microgram) after
15-30 minutes
Reversibility is a characterestic feature of
B.Asthma
In chronic asthma there may be only partial
reversibility of the airflow obstruction
While in COPD the airflow is irreversible
although some cases showed significant
improvement
68. RESTRICTIVE PATTERN-flow volume loop
low total lung capacity
low functional residual capacity
low residual volume.
Forced vital capacity (FVC) may be
low; however, FEV1/FVC is often
normal or greater than
Peak expiratory flow may be
preserved or even higher than
predicted leads to tall,narrow and
steep flow volume loop in
expiratory phase.
75. INDEX
1. Bedside pulmonary function tests
2. Static lung volumes and capacities
3. Measurement of FRC, RV
4. Dynamic lung volumes/forced spirometry
5. Flow volume loops and detection of airway obstruction
6. Flow volume loop and lung diseases
7. Tests for gas exchange function
8. Tests for cardiopulmonary reserve
9. Preoperative assessment of thoracotomy patients
76. Bed side pulmonary function tests
MICROSPIROMETERS – MEASURE FEV1,FVC
BED SIDE PULSE OXIMETRY.
ABG.
77. TESTS FOR GAS EXCHANGE
FUNCTION
1)ALVEOLAR-ARTERIAL O2 TENSION
GRADIENT:
A-a gradient = PAO2 - PaO2
Normal Value– 5-10 mmhg
Parameter –a) Diffusion
b)V/Q (Ventilation perfusion mismatch)
c)Right to left shunt
78.
79.
80.
81. TESTS FOR GAS EXCHANGE
FUNCTION
DIFFUSING CAPACITY
Surface area and integrity of the alveolar membrane and the
pulmonary vascular bed.
Volume of air diffused = Surface Area/Thickness *[P(A)-P(a)]
Normal- 20-30 ml/min/mm Hg
Depends on:
- thickness of alveolar—capillary membrane
- hemoglobin concentration
- cardiac output
82. It is measured by a single breath technique where 10% helium and 0.3%
carbon monoxide are rapidly inspired, held for 10 seconds and then
expired with the measurement of the remaining carbon monoxide.
85. INDEX
1. Bedside pulmonary function tests
2. Static lung volumes and capacities
3. Measurement of FRC, RV
4. Dynamic lung volumes/forced spirometry
5. Flow volume loops and detection of airway obstruction
6. Flow volume loop and lung diseases
7. Tests of gas function
8. Tests for cardiopulmonary reserve
9. Preoperative assessment of thoracotomy patients
86. CARDIOPULMONARY
INTERACTION
Stair climbing and 6-minute walk test
This is a simple test that is easy to perform with minimal
equipment with monitoring pulse rate and Oxygen
satuartion.
Each step height –0.153m
Performance VO2
max(ml/kg/min)
Interpretation
>5 flight of stairs > 20 Low mortality after
pneumonectomy, FEV1>2l
>3 flight of stairs Low mortality after lobectomy,
FEV1>1.7l
<2 flight of stairs Correlates with high mortality
<1 flight of stairs <10
6 min walk test <600 m <15
87. CARDIOPULMONARY
INTERACTION
Shuttle walk
The patient walks between cones 10 meters apart with
increasing pace.
The subject walks until they cannot make it from cone
to cone between the beeps.
Less than 250m or decrease SaO2 > 4% signifies high
risk.
A shuttle walk of 350m correlates with a VO2 maxof
11ml.kg-1.min-1
88. Cardiopulmonary Exercise Testing
Non invasive technique :cycling or treadmill
To test ability of subjects physiological response to cope
with metabolic demands
CPET involves the measurement of respiratory gas
exchange: oxygen uptake, carbon dioxide output,
and minute ventilation
In addition- monitor electrocardiography, blood pressure
and pulse oximetry,
89.
90. INDEX
1. Bedside pulmonary function tests
2. Static lung volumes and capacities
3. Measurement of FRC, RV
4. Dynamic lung volumes/forced spirometry
5. Flow volume loops and detection of airway obstruction
6. Flow volume loop and lung diseases
7. Tests of gas function
8. Tests for cardiopulmonary reserve
9. Preoperative assessment of thoracotomy patients
91. MISCELLANEOUS
Overnight oximetry
It is used as initially in the assessment of OSA.
Typically 10 oxygen desaturations per hour of more
than 4% would be considered to be indicative of
OSA.
Polysomnography should be performed in patients
where
there is a high clinical suspicion of OSA
92. Respiratory Muscle
Function
Inspiratory mouth pressures
Subjects generate as much inspiratory pressure
as possible against a blocked mouth piece
Normal value -- 100 cm of water
Values < 80 cm/H2O signifies inspiratory
muscle weakness
93. Expiratory mouth pressures
It is measure of expiratory respiratory muscle
function where patients generate a maximal
expiratory pressure (MEP) against a blocked
mouthpiece (a valsalva manoeuver) at TLC.
94. Assessment of lung function in
thoracotomy pts
As an Anesthesiologist our goal is to :
1)To identify pts at risk of increased post-op morbidity &
mortality
2)To identify pts who need short-term or long term post-
op ventilatory support.
Lung resection may be f/by – inadequate gas exchange,
pulm HTN & incapacitating dyspnoea.
95. Assessment of lung function in
thoracotomy pts
Calculating the predicted postoperative
FEV1 (ppoFEV1) and DLCO (ppoDLCO):
There are 5 lung lobes containing
19 segments in total with the division of each
lobe.
Ppo FEV1=preoperative FEV1 * no. of segments
left after resection
19
• Can be assessed by ventilation perfusion scan. For eg:
A 57-year-old man is booked for lung
resection. His CT chest show a large RUL
mass confirmed as carcinoma:
ppoFEV1= 50*16/19=42%
96. Assessment of lung function in
thoracotomy pts
InterpretationppoFEV1(% predicted)
> 40
< 40
< 30
No or minor respiratory complications
anticipated
Likely to require postoperative
ventilation/increased risk of
death/complication
Non surgery management should be
considered
InterpretationppoDLCO(% predicted)
> 40,ppoFEV1> 40%,SaO2>90% on air
< 40
< 40 and ppoFEV1<40%
Intermediate risk , no further investigation
needed
Increased respiratory and cardiac morbidity
High risk- require cardiopulmonary exercise
test
97. Combination tests
There is no single measure that is a ‘Gold standard ‘ in
predicting post-op complications
Three legged stool
Respiratory
mechanics
FEV1(ppo>40%)
MVV,RV/TLC,FVC
Cardiopulmonary reserve
Vo2max (>15ml/kg/min)
Stair climb > 2 flights, 6
min walk,
Exercise Spo2<4%
Lung parenchymal
function
DLCO (ppo>80%)
PaO2>60
Paco2<45
98. P
p
s
ulmonary function criteria suggesting increased risk of
ost-operative pulmonary complications for various
urgeries
Parameters Abdominal Thoracic
FVC < 70 % predicted < 2 lit. or < 70% predicted
FEV1 < 70 % predicted < 2 lit. – pneumonectomy
< 1 lit. – lobectomy
< 0.6 lit. – wedge or segmentectomy
FEV1/FVC < 65 % predicted < 50 % predicted
FEF 25-75 % < 50 % predicted < 1.6 lit. – pneumonectomy
< 0.6 lit.- lobectomy/segmentectomy
MVV/MBC < 50 % predicted < 50 % predicted
PaCO2 > 45 mm Hg > 45 mm Hg
99. TAKE HOME MESSAGE
They act only to support or exclude a diagnosis.
A combination of a thorough history and physicalexam,
as well as supporting laboratory data and imaging is
helpful in developing an aesthetic plan for patient with
pulmonary dysfunction.