INTRODUCTION TO PULMONARY MEDICINE

Maryellen Antonetti

Clinical Medicine & Surgery II

OBJECTIVES

Review & recall the basic pulmonary anatomy

Apply the mechanics of inspiration & expiration to disease processes

Utilize the concepts of pulmonary physiology in relation to disease

Recognize the basic elements of PFT

Describe the procedure for PFT

Define the procedure & purpose of Pulse Oximetry

Determine the 5 main symptomatic manifestations of pulmonary disease

Compare & contrast lung sounds

Identify & implement the principles of prevention for pulmonary disease

AIRWAY ANATOMY

A distinctive feature of the cartilaginous bronchi is the presence of bronchial gland cells, or submucosal glands, situated deep within the mucosa and connected to the lumenal surface by ducts

The Membranous Airways: Bronchioles

The bronchioles are lined with ciliated cells, but have fewer Goblet cells. The Goblet cells tend to disappear distally and are replaced by the secretory Clara cells. Clara cells may destroy inhaled toxins.

Gas Exchange Airway: Respiratory Bronchioles, Alveolar Ducts and Sacs

The distinguishing feature

of TRU (terminal respiratory

unit) is the presence of

alveoli.

LOBAR ANATOMY

The right upper lobe (RUL) occupies the upper 1/3 of the right lung. Posteriorly, the RUL is adjacent to the first three to five ribs. Anteriorly, the RUL extends inferiorly as far as the 4th right anterior rib.

LOBAR ANATOMY

The right middle lobe is typically the smallest of the three, and appears triangular in shape, being narrowest near the hilum

LOBAR ANATOMY

The right lower lobe (RLL) is the largest of all three lobes, separated from the others by the major fissure. RLL extend as far superiorly as the 6th thoracic vertebral body, and extends inferiorly to the diaphragm

LOBAR ANATOMY

The minor fissure separates the RUL from the RML, and thus represents the visceral pleural surfaces of both of these lobes

The right major fissure is more expansive in size than the minor fissure, separating the right upper and middle lobes from the larger right lower lobe.

LOBAR ANATOMY

The lobar architecture of the left lung is slightly different than the right. Because there is no defined left minor fissure, there are only two lobes on the left; left upper and lower

LOBAR ANATOMY

These two lobes are separated by a major fissure, identical to that seen on the right side, although often slightly more inferior in location

LOBAR ANATOMY

In general, fissures are not readily identifiable on plain films, with only small portions typically visualized at best. This is because fissures which are composed of only two layers of visceral pleura, may not present a significant radiographic interface and will not produce a shadow. However, if there is fluid within the pleural space or if the visceral pleura is thickened, fissures may be seen in their entirety.

BRONCHIAL ANATOMY

The trachea begins at the level of the cricoid cartilage which generally is at the level of the sixth cervical vertebra.

The intrathoracic trachea is readily seen on computed tomography appearing as an air-filled tubular structure

Terminates distally at the carina which represents the origins of the left and right mainstem bronchi.

BRONCHIAL ANATOMY

BRONCHIAL ANATOMY

The left mainstem bronchus (LMSB) measures approximately 4.5 cm in length compared to the right (RMSB) which measures approximately 2.5 cm in length.

The right mainstem bronchus (RMSB) gives rise to the right upper lobe bronchus

Note the difference in angles!!

What is the significance???

Bronchi Anatomy

The right mainstem bronchus (RMSB) gives rise to the right upper lobe bronchus which typically is directed superiorly and slightly laterally, having an almost 90o angle of incidence with the RMSB.

The trunk then gives rise to the segmental bronchi, B1, B2, and B3.

B1-apical segment

B2-posterior segment

B3-anterior segment

BRONCHIAL ANATOMY

The origin of the middle lobe bronchus marks the point of origin of the right lower lobe bronchus.

Giving rise to the B4 and B5

segmental bronchi

B6 is the first branch off the lower

lobe bronchus, then B7,B8,B9

B10

BRONCHIAL ANATOMY

SEGEMENTAL ANATOMY

Next, the lungs are divided into segments, labeled as S1, S2, etc. from the upper lobe to the lower. RUL has three segments

RML has two

RLL has five

Left:Two

MECHANICS OF INSPIRATION

Diaphragm contracts, abd. Contents pushed down

Ribs move up and out

This allows for a larger intrathoracic volume, but LOWER pressure and starts the flow of air into the lungs

External intercostals and accessory muscles may be used for vigorous inspiration

MECHANICS OF EXPIRATION

Expiration is a passive process

Air is driven out by the reverse pressure gradient between lungs and atmosphere, until the system reaches equilibrium again,based upon compliance vs. elasticity

During exercise, abdominal muscles compress the abd. cavity & push diaphragm up & internal intercostal muscles pull ribs down and inward

LUNG COMPLIANCE

Compliance describes the distensibility

A measure of how lung volume changes as a result of pressure

Inversely correlated to elastance

Think of a thick/thin rubber band: the greater the amt. of elastic tissue the greater the recoil but the lower the compliance(Barrel chest in COPD)

A decrease in compliance can lead to easier collapse( fibrosis)

SURFACE TENSION OF AVEOLI

Lined with a film of fluid and is a very small area, so fluid molecules attract & create a surface tension, that can collapse the aveoli

A larger aveoli would have less pressure & less tendency to collapse, so needs only minimal pressure to keep it open

Surfactant keep aveoli open under high collapsing pressures

THE ROLE OF SURFACTANT

Decreases surfaces tension, so decreases the collapsing pressure for a given radius

Without surfactant get complete atelectasis; inability to expand aveoli

Surfactant increases lung compliance which reduces the work of lung expansion

Premature infants and role of surfactant

INNERVATION OF AIRWAY REVIEW

Bronchial smooth muscle is innervated by parasympathetic cholinergic fibers & sympathetic adrenergic fiber

Parasympathetic produces constriction so increases airway resistance (asthma)

Sympathetic stim produces relaxation of bronchial smooth muscle via B2 receptor stim, thus increase airway diameter & decreased resistance.

Pulmonary Function Testing (PFT’S)

Normal values for lung function are based on age, gender, and height. Ie) FEV1 decreases by 20-30ml/yr

Purpose is to determine whether the individual patient has normal or abnormal lung function.

Objective measurement of function

Spirometric exam is most common & is a measure of air movement during controlled maneuvers

Spirometric Exam

Primary spirometric parameters are:

Forced expiratory volume in 1 sec. (FEV1)

Forced vital capacity (FVC):Max volume of air that can be forcefully exhaled at start of TLC

Ratio of both as a %

CO diffusing capacity (DLCO)

ABG

Detect & quantify airway obstruction

SPIROMETRY & EXPIRATORY FLOW

Most useful when pt. has symptoms, risk factors or PE findings. Correlates well with exercise tolerance

Used to define basic class of lung disorder, severity, or progression

Spirograms allow measurement of vital capacity and FEV1.

FEV1 of 2-3L/sec mild exercise impairment; <1 sec is severe

Lung Volumes

Functional residual capacity (FRC) is gas in the lung at rest. Independent of patient effort

Total lung capacity (TLC) is gas volume after maximal inspiration

Usually reported as abnormal if below 80% of predicted normal

Blebs or bullae can cause low lung volumes, WHY??

SIGNIFICANCE OF FEV1 and VC

Normal FEV1/VC is 0.8; 80% of VC is expired in 1 second.

In restrictive dx, fibrosis, both are reduced but the ratio may not change

In obstructive dx, asthma, FEV1 is reduced more than VC and the ratio becomes decreased

PEAK FLOW METER

Peak flow meters are inexpensive, hand-held devices used to

monitor pulmonary function in patients. The peak

flow roughly correlates with the FEV1.

1.Ask the patient to take a deep breath.

2.Then ask them to exhale as fast as they can through

the peak flow meter.

3.Repeat the measurement 3 times and report the

average. Readings less than 80% of "best"

may indicate a need for additional therapy.

Readings less than 50% may indicate an

emergency situation. (This is used in

patients with asthma and COPD exacerbation.)

Diffusing Capacity

Measures lung volume using single-breath carbon monoxide method

Is a test of the integrity of the gas exchange function

The lung’s ability to absorb gas

Effected by:Aveolar surfaces, the test gas to cross, red cell mass to bind gas

Can have normal lung volumes and abnormal diffusions

What changes the Diffusing Capacity????

Edema decreases alveolar surface

Anemia decreases capillary bed exchange

Emboli or vasculitis decreases cap. Blood flow

Loss of lung tissue:surgery or emphysema

Most common cause COPD & asthma

Mitral stenosis or heart failure

Results vary widely and is most useful when using same lab for results

PFT and DISEASE

Use obstructive lung disease as an example: emphysema, asthma, cystic fibrosis, etc.

Characterized by decreased flows on forced expiratory testing

There is increased airway resistance, decreased exp. flows, & air trapping

Air trapping results in increased Tidal volume, functional residual capacity and residual volume

LUNG VOLUMES

LUNG VOLUMES

A lung volume refers to a basic volume of the lung, whereas lung capacities, also a volume measurement, are the sum of two or more basic lung volumes.

VENTILATION EQUATIONS

To assess the effectiveness of ventilation,certain lung volumes are measured over time. A volume measured over time (usually a minute) is

designated by a V with a dot over it (). It is assumed that the total volume of air inspired is equal to the total volume of air expired per minute. The

volume of air inspired or expired per minute is called minute volume. It is abbreviated as I if inspired volume is measured, or E for the expired volume. Minute volume is calculated by multiplying the average tidal volume (VT) by the number of breaths per minute, or frequency of breaths per minute (f), as shown is equation 1. Alveolar ventilation (A) is the volume of air that actually reaches the alveoli each minute. A is calculated by subtracting dead space volume (VD)

Terms, Symbols, Definition

Tidal Volume (VT): volume of gas inspired or expired during a normal spontaneous breath.

Inspiratory Reserve Volume (IRV): volume of gas that can be inspired at the end of a spontaneous inspiration.

Expiratory Reserve Volume (ERV): volume of gas that can be expired at the end of a spontaneous VT.

Residual Volume (RV): volume of air in lungs that cannot be forcefully expired or the volume of air in lung at end of a vital capacity.

Vital Capacity (VC): maximum volume of gas that can be expired after a maximal inspiration or IRV + VT + ERV.

Inspiratory Capacity (IC): the maximal volume of air that can be inspired from normal end-expiration or VT + IRV

Functional Residual Capacity (FRC): total volume of air in the lung at end of normal end-expiration or ERV + RV.

Total Lung Capacity (TLC): total volume of gas in lung at maximal end- inspiration or VC +RV or IRV + VT + ERV + RV. Tidal volume V₁ The volume of air inhaled or exhaled with each breath during quiet breathing

PROCEDURE FOR PFT’S

The patient can be either seated or standing for testing, position should be noted. Nose clips are recommended. Testing begins with the patient taking normal tidal volume breaths. At end-expiration, the patient performs a maximal inspiration (inspiratory capacity) to TLC. The patient then exhales as hard and fast as possible until "all the air is out." This volume is FVC, and the remaining volume of air in the lungs is RV. A slow vital capacity (VC) maneuver also may be performed, especially if FVC is decreased compared to the predicted value. The subject should perform a minimum of three and a maximum of eight FVC maneuvers until at least two acceptable curves are obtained.

What is Pulse Oximetry

Noninvasive, continuous measurement

Use fingertip or ear lobe; toes in peds

Measures oxyhemoglobin & total hemoglobin which estimates oxygen saturation (Sa O2), not Pa O2!!! Ie) SaO2 of 90% is Pa O2 of 60 mmHg.

Relatively accurate, reliability goes down as clinical situation deteriorates (perfusion)

Types of Pulseoximetry

SUMMARY OF PFT

Lung volume

TLC Total lung capacity

FRC Functional residual capacity

ERV Expiratory reserve volume

RV Residual volume

Expiratory flow

FEV₁ Forced expiratory volume (in 1 second)

FVC Forced vital capacity

FEV₁ % FEV₁ /FVC ratio (expressed as %)

Diffusing capacity

DL _CO Diffusing capacity for carbon monoxide

Arterial blood gases

SYMPTOMATIC MANIFESTATIONS OF PULMONARY DISEASE

Although a wide array of pathologic factors can produce respiratory symptoms and signs, the five most common manifestations of pulmonary disease that require evaluation are (1) cough, (2) shortness of breath or dyspnea, (3) chest pain, (4) hemoptysis, and (5) a solitary pulmonary nodule.

COUGH

Cough may be a transient or persistent symptom. Common causes of transient cough are inflammatory reactions on the surface of the trachea or bronchial branches, usually from bacterial or viral infections. Occasionally, noxious vapors in the atmosphere can induce cough (e.g., tobacco smoke, volatile chemical compounds, and vehicular exhaust). For persistent cough, one of the most prominent causes is an allergic inflammatory reaction of the bronchi associated with asthma; cough may be the earliest presenting manifestation.

COUGH

Another common cause of tracheobronchial irritation is regurgitation of acidic gastric contents into the tracheobronchial tree during sleep. Such regurgitation and aspiration result from failure of gastric emptying

Many individuals regurgitate gastric and esophageal contents during sleep and are totally unaware of this phenomenon.

COUGH

An important cause of persistent cough is a tumor in the tracheobronchial tree that leads to distortions of the bronchial wall and increases stimuli to the cough center.

the possibility of a bronchial carcinoma or adenoma must be considered.

Extrabronchial lesions that cause cough include a mediastinal or esophageal tumor, an aortic aneurysm that compresses a bronchus, or an enlarged left atrium compressing the left main bronchus. Sinusitis with persistent nasal secretions into the pharynx and upper airway is a frequent cause of therapy-resistant chronic cough.

COUGH

The presence, type, and amount of sputum can be useful in differential diagnosis. (DOCUMENT IT)

Acute onset of sputum with cough suggests acute pulmonary infection or sinusitis

Long-standing sputum production, usually in the morning, is characteristic of chronic bronchitis from smoking

Sputum throughout the day are characteristic of bronchiectasis or lung abscess. Foul-smelling sputum suggests anaerobic infection associated with lung abscess.

Yellow or green sputum, due to the release of enzymes by leukocytes, is usually a sign of infection.

SOB, that is Shortness of Breath

"Shortness of breath," "a feeling of not being able to get enough air," and "labored breathing" are all terms used by patients to describe the symptom of dyspnea

The cause of dyspnea may be pulmonary disease, circulatory disease, or both.

Most consistent correlate of the symptom of dyspnea is increased mechanical work of breathing, usually brought on by increased airway resistance as occurs in asthma, or

Decreased distensibility of the lungs as occurs in interstitial fibrotic reactions; increased effort is required to produce a higher negative pressure in the pleural space to inflate the lungs.

SOB Stimulated by CO2

An increased drive to ventilate may also cause dyspnea. Such stimuli include hypoxia, usually when arterial oxygen tensions are less than 60 mm Hg, and stimuli from inflamed lung parenchyma, as in bacterial pneumonia or alveolitis that drive the respiratory centers of the brain, often lower the resting carbon dioxide pressure (P CO₂ ) to less than the normal level of 40 mm Hg and cause dyspnea, especially on mild exertion.

Pulmonary emboli may present with shortness of breath and a normal chest roentgenogram. However, the inefficiency of the embolized lung for gas exchange requires abnormally high ventilatory rates to maintain a normal arterial P CO₂

SOB in Cardiac Disorders

Because of the high prevalence of heart disease and heart failure in the general population, many patients with dyspnea have cardiac abnormalities.

The basis of the dyspnea is usually a high filling pressure of the left ventricle, which causes high left atrial pressures and high pulmonary capillary and pulmonary arterial pressures, which in turn increase the pulmonary blood volume and reduce lung compliance

CHEST PAIN

Chest pain is also a common presenting symptom of lung disease. Pleuritic pain is sharp and severe, magnified by breathing, and may be associated with a pleural friction rub. Pericarditis causes chest pain that may not be related to breathing and often is relieved by leaning forward; pericardial friction rubs may be audible in synchrony with the heartbeat.

Chest pain of an MI from coronary artery disease should be discernible on the basis of its relation to physical exertion and its characteristic radiation to the left shoulder or arm, neck, and jaw

The chest pain of PE may also be characterized by anterior chest pressure, which may persist for hours and be related to pulmonary hypertension

HEMOPTYSIS

The most common cause of hemoptysis is pneumonia or pulmonary infection, including bronchiectasis

Bloody streaking of purulent sputum occurs during pneumonia or severe bronchitis and subsides as the infection is treated.

The sudden appearance of hemoptysis without other cause must be considered a possible manifestation of lung tumor, either benign or malignant.

A pulmonary embolism that leads to pulmonary infarction almost always results in hemoptysis

Pulmonary tuberculosis, especially with cavity formation, is a prominent cause of hemoptysis, especially in patients with HIV infection. Hemoptysis is not uncommon in cystic fibrosis

HEMOPTYSIS

A certain proportion of patients have sudden and usually mild hemoptysis for which no cause can be found; such episodes may result from a ruptured blood vessel or varix in the bronchial mucosa, and clotting parameters should be checked.

Mild hemoptysis also results from coughing stimulated by blood from the oropharynx; comprehensive oropharyngeal evaluation is diagnostic.

Bronchopulmonary aspergillosis or an aspergilloma can cause persistent hemoptysis, while an A-V malformation can cause sudden, life-threatening hemoptysis.

SOLITARY PULMONARY NODULE

A solitary pulmonary nodule on a chest radiograph, especially if it is new, poses the possibility of a malignancy and requires immediate diagnostic evaluation.

The presence of calcification in at least 10 to 20% of the nodule near its center is the most reliable indicator of a benign lesion. However calcification of a solitary nodule is not specific for benign disease, as a cancer can develop within a scar or granuloma.

SOLITARY NODULE

This chest X-ray shows adenocarcinoma of the lung. There is a rounded light spot in the right upper lung (left side of the picture) at the level of the second rib. The light spot has irregular and poorly defined borders and is not uniform in density.

Diseases that may cause this type of X-ray result would be tuberculous or fungal granuloma, and malignant or benign tumors.

SOLITARY NODULE

PREVENTING INFLUENZA

Persons aged 50 years or older;

Residents of nursing homes and other chronic-care facilities that house persons of any age who have chronic medical conditions;

Adults and children who have chronic disorders of the pulmonary or cardiovascular systems, including asthma;

Adults and children who have required regular medical follow-up or hospitalization during the preceding year because of chronic metabolic diseases (including diabetes mellitus), renal dysfunction, hemoglobinopathies, or immunosuppression (including immunosuppression caused by medications);

Children and teenagers (aged 6 months to 18 years) who are receiving long-term aspirin therapy and therefore might be at risk for developing Reye syndrome after influenza; and

Women who will be in the second or third trimester of pregnancy during the influenza season.

Employees of nursing homes and chronic-care facilities who have contact with patients or residents; persons who provide home care to persons in high-risk groups; and household members (including children) of persons in high-risk groups.

The trivalent influenza vaccine prepared for the 2000-2001 season will include A/Moscow/10/99 (H3N2)-like, A/New Caledonia/20/99 (H1N1)-like, and B/Beijing/184/93-like antigens. For the A/Moscow/10/99 (H3N2)-like antigen, U.S. manufacturers will use the antigenically equivalent A/Panama/2007/99 (H3N2) virus and for the B/Beijing/184/93-like antigen, they will use the antigenically equivalent B/Yamanashi/166/98 virus; these viruses will be used because of their growth properties and because they are representative of currently circulating A (H3N2) and B viruses.

Timing of Influenza Vaccination Activities

Beginning each September, influenza vaccine should be offered to persons at high risk when they are seen by health-care providers for routine care or as a result of hospitalization. The optimal time to vaccinate persons in high-risk groups is usually from October through mid-November, because influenza activity in the United States generally peaks between late December and early March.

Vaccination Administration Route

The intramuscular route is recommended for influenza vaccine. Adults and older children should be vaccinated in the deltoid muscle; a needle length of 1 inch or longer can be considered for these age groups. Infants and young children should be vaccinated in the anterolateral aspect of the thigh.

PNEUMOCOCCAL CONJUGATE VACCINE

Children Under 2 Years of Age

All healthy infants and toddlers should get 4 doses of pneumococcal conjugate vaccine:

! !! !! One dose at 2 , 4, 6 months of age, and

! !! !! One dose at 12-15 months of age.

Children who miss the first dose at 2 months should still get the vaccine.

 Children Between 2 and 5 Years of Age Recommended for children:

have sickle cell disease,have a damaged spleen or no spleen,have HIV/AIDS, or diabetes or cancer, or take medications that affect the immune system, such chemotherapy

This vaccine should also be considered for all other children between 2 and 5 years of age, but particularly are of Alaska Native, American Indian or African American descent.

PPV

The pneumococcal polysaccharide vaccine (PPV)

Protects against 23 types of pneumococcal bacteria.

Most healthy adults who get the vaccine develop protection

to most or all of these types within 2 to 3 weeks of

getting the shot.

Very old people, children under 2 years of age, and people with some long-term illnesses might not respond as well or at all.

PPV

Pneumococcal disease kills more people in the United States each year than all other vaccine-preventable diseases combined.

Some people are at greater risk from the disease. These include people 65 and older, the very young, and people with

special health problems such as alcoholism, heart or lung

disease, kidney failure, diabetes, HIV infection, or certain types of cancer.

Pneumococcal disease can lead to serious infections

pneumonia, bacteremia, and meningitis.

Pneumococcal infections more difficult. This makes

prevention more important.

• Alaskan Natives and certain Native American populations.

PPV

All adults 65 years of age or older.

• Anyone over 2 years of age who has a long-term health problem such as:

- heart disease - lung disease

- sickle cell disease - diabetes

- alcoholism - cirrhosis

- leaks of cerebrospinal fluid

• Anyone over 2 years of age who has a disease or

condition that lowers the body’s resistance to infection,

such as: Hodgkin’s disease - lymphoma, leukemia kidney failure - multiple myeloma, nephrotic syndrome - HIV infection or AIDS damaged spleen, or no spleen, ororgan transplant

• Anyone over 2 years of age who is taking any drug or

treatment that lowers the body’s resistance to infection,

such as:long-term steroids - certain cancer drugs or radiation therapy

PPV

A second dose is recommended for those people aged 65 and older who got their first dose when they were under 65, if 5 or more years have passed since that dose.

High risk populations

Less than 1% develop a fever, muscle aches, or more severe local reactions.

Severe allergic reactions have been reported very rarely.

Children 10 years old and younger may get this second dose 3 years after the first dose. Those older than 10 should get it 5 years after the first dose.

PPV & PREGNANCY

Pregnancy: The safety of PPV for pregnant women has not yet been studied.

There is no evidence that the vaccine is harmful to either the mother or the fetus, but pregnant women should consult with their doctor before being vaccinated.

Women who are at high risk of pneumococcal disease should be vaccinated before becoming pregnant, if possible.

GENERAL PREVENTION GUIDELINES

Will be researched and taught by students in small group presentations