Auscultation of the lungs. Semiotics of the respiratory

system diseases. The respiratory distress syndromes

of and respiratory failure, general clinical symptoms

Respiratory System:

Primary function is to obtain oxygen for use by body's cells & eliminate carbon dioxide that cells produce

Includes respiratory airways leading into (& out of) lungs plus the lungs themselves

Pathway of air: nasal cavities (or oral cavity) > pharynx > trachea > primary bronchi (right & left) > secondary bronchi > tertiary bronchi > bronchioles > alveoli (site of gas exchange)

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• The excha nge of gases (O2 & CO2) between the alveoli & the blood occurs by simple diffusion: O2 diffusing from the alveoli into the blood & CO2 from the blood into the alveoli. Diffusion requires a concentration gradient. So, the concentration (or pressure) of O2 in the alveoli must be kept at a higher level than in the blood & the concentration (or pressure) of CO2 in the alveoli must be kept at a lower lever than in the blood. We do this, of course, by breathing - continuously bringing fresh air (with lots of O2 & little CO2) into the lungs & the alveoli.

• Breathing is an active process - requiring the contraction of skeletal muscles. The primary muscles of respiration include the external intercostal muscles (located between the ribs) and the diaphragm (a sheet of muscle located between the thoracic & abdominal cavities).

The external intercostals plus the diaphragm contract

to bring about inspiration:

• Contraction of external intercostal muscles > elevation of ribs & sternum > increased front- to-back dimension of thoracic cavity > lowers air pressure in lungs > air moves into lungs

• Contrcnion of diaphragm:

• diaphragm moves downward > increases vertical dimension of thoracic cavity > lowers air pressure in lungs > air moves into lungs:

The mecanizm of breathing

The mecanizm of breathing

The considerable differences in respiratory physiology between

infants and adults explain why infants and young children have a

higher susceptibility to more severe manifestations of respiratory

diseases, and why respiratory failure is common problem in

neonatal and pediatric intensive care units. The appreciation of the

peculiarities of pediatric respiratory physiology is not only essential

for correct assessment of any ill child, but also for correct

interpretation of any pulmonary function test performed in this

population.

Physiologicoanatomical peculiarities of the respiratory

systemThe peculiarities of the nose at the neonatea) The nose consists particular by of cartilage,b) The nasal meatuses are narrow,c) There are not inferior nasal meatuses (until 4 years),d) Undeveloped submucosal membrane (until 8-9 years).

The peculiarities of sinuses in children

a) The maxillary sinus is usually present at birth,b) The frontal sinuses begin to develop in early infancy,c) The ethmoid and sphenoid sinuses develop later in childhood.

The peculiarities of the pharynx at the neonate

a) The pharynx is relatively small and

narrow,

b) The auditory tubes are small, wide,

straight and horizontal

The peculiarities of the larynx at the neonate

• a) The larynx is funnel-shaped (in the adult it is relatively round),

• b) It is relatively long,

• c) The cricoid’s cartilage descendents

The peculiarities of the trachea at the neonate

• a) The length of the trachea is relatively larger (about 4 cm (in the adult -7)) and wide,

• b) It is composed of 15-17 cartilage rings (the amount does not increase),

• c) The bifurcation of the trachea lies opposite the third thoracic vertebra in infant and descends to a position opposite the fourth vertebra in the adult,

• d) Mucus membrane is soft, well-blood supplied, but sometime dry,

• f) It can collapse easily.

The peculiarities of the bronchi at the neonate

• a) In young children the bronchi are relatively wide,

• b) The right bronchus is a straight continuation of the trachea,

• c) The muscle and elastic fibers are undeveloped,

• d) The bronchi are well blood supplied,• e) The lobules and segmental bronchus are

narrow.

The functions of the bronchus

• a) The ciliated of mucus membrane “sweeps” out dust particles,

• b) Transfer the gases into the lungs,

• c) Immunologic function

The functions of the lung are

• a) The main function of the lungs is the exchange of oxygen and carbon dioxide,

• b) To produce surfactant

The peculiarities of the lungs at the neonate

• a) Size of alveoli is smaller than in the adult;

• b) Quantity of alveoli is relatively less than in the adult.

Physiological reasons for theincreased susceptibility of infants for

respiratory compromise in comparisonto adults

Metabolism ^---------------------------------------Risk of apnoea ^----------------------------------Airway resistance ^• Upper airway resistance ^-----------------

• Lower airway resistance ^-----------------

Lung volume v-------------------------------------

Efficiency of respiratory muscles v-----------

Endurance of respiratory muscles v---------

O2 consumption ^Immaturity of control of breathing

Nose breathing; Large tongue ;Airway size v;Collapsibility ^;Pharyngeal muscle tone v;

Compliance of upper airway structures ^Airway size v; Collapsibility ^; Airway wall

compliance ^; Elastic recoil vNumbers of alveoli v; Lack of collateral

ventilationEfficiency of diaphragm v; Rib cage

compliance ^; Horizontal insertion at the rib cage; Efficiency of intercostal muscles v; Horizontal ribs

Respiratory rate ^; Fatigue-resistant type I muscle fibres v

An average respiratory rate at rest of the child of different age is:

• newborn 40-35 per minute,

• infant at 6 months 35-30 per minute,

• at 1 year 30 per minute,

• 5 years 25 per minute,

• 10 years 20 per minute,

• 12-18 years 16-20 per minute.

Disorders of the respiratory rate

• Tachypnea is the increase of the respiratory rate.

• Bradypnea is the decrease of the respiratory rate.

• Dyspnea is the distress during breathing.

• Apnea is the cessation of breathing

Factors involved in increasing respiratory rate

• Chemoreceptors - located in aorta & carotid arteries (peripheral chemoreceptors) & in the medulla (central chemoreceptors)

• Chemoreceptors (stimulated more by increased CO2 levels than by decreased O2 levels) > stimulate Rhythmicity Area > Result = increased rate of respiration

Heavy exercise ==> greatly increases respiratory rate

Mechanism?

1. NOT increased CO2

2. Possible factors:

– reflexes originating from body movements (proprioceptors)

– increase in body temperature

– epinephrine release (during exercise)

3. impulses from the cerebral cortex (may simultaneously stimulate rhythmicity area & motor neurons)

Form of thoraxNormostenic type

Disorders of the respiratory depth

• Hyperpnea is an increased depth.

• Hypoventilation is a decreased depth and irregular rhythm.

• Hyperventilation is an increased rate and depth.

Pathological respiration

• Seesaw (paradoxic) respirations: the chest falls on inspiration and rises on expiration. It is usually observed in respiratory failure of third degree;

• Kussmau’sl breathing is hyperventilation, gasping and labored respiration, usually seen in diabetic coma or other states of respiratory acidosis:

Decreased vocal fremitus in the upper airway may indicate

• a) the obstruction of a major bronchus,

• b) pneumo-, hydro-, haemothorax,

• c) emphysema of lungs,

• d) adiposity can also be the cause of decreased vocal fremitus.

The voice of fremitus is increased

• a) in pneumonia,

• b) in abscess,

• b) in atelectasis,

• c) in cavern.

The pathological dullness is heard in cause of

• pneumonia,

• hydro-, haemothorax,

• pulmonary edema,

• lung or mediastinal tumor

The bandbox is heard in cause of

• emphysema of lungs,• cavern of lung,• abscess of lung, • pneumothorax,• bronchial asthma, • asthmatic bronchitis.• In topographic percussion the chest, the doctor

looks for the lungs’ borders.

Auscultation

Vesicular breath sounds are normally heard over the entire surface of the lungs, with the exception of the upper intrascapular area and the area beneath the manubrium. Inspiration is louder, longer, and higher-pitched than expiration. Sometimes the expiratory phase seems nearly absent in comparison to the long inspiratory phase. The sound is a soft, swishing noise.

Bronchovesicular breath sounds

Bronchovesicular breath sounds are normally heard over the manubrium and in the upper intrascapular regions where there are bifurcations of large airways, such as the trachea and bronchi. Inspiration is louder and higher in pitch than that heard in vesicular breathing

Puerile breath sounds

Puerile breath sounds are one of normal types of breathing in children by three years old. Puerile breath sounds have shot inspiration and louder, a hollow expiratory phase, blowing character

Bronchial breath sounds

They are almost the reverse of vesicular sounds; the inspiratory phase is short and the expiratory phase is longer, louder, and of higher pitch. They are usually louder than any of the normal breath sounds and have a hollow, blowing character.

Rough breath sounds

Have shot inspiration and louder expiratory phase. Rough breath has hollow and blowing character.

Absent or diminished breath sounds

are always an abnormal finding warranting investigation. Fluid, air, or solid masses in the pleural space all interfere with the conduction of breath sounds (pneumonia, pneumo-, hydro-, haemothorax, tumor of lung or mediastinal, emphysema of lungs, atelectasis, airways obstruction, a foreing body in the bronchus).

Voice sounds

Voice sounds are also part of auscultation of the lungs. Normally voice sounds or vocal resonance is heard, but the syllables are indistinct. They are elicited in the same manner as vocal fremitus, except that the doctor listens with the stethoscope

Whispered pectoriloquy,

• Whispered pectoriloquy, in which the child whispers words and the nurse, hears the syllables

Bronchophony,

Bronchophony, in which the child speaks words that are not distinguishable but the vocal resonance is increased in intensity and clarity

Egophony

Egophony, in which the child says "ee," which is heard as the nasal sound "ay" through the stethoscope

Method of percussion

Rales

Rales result from the passage of air through fluid or moisture. They are more pronounced when the child takes a deep breath. Even though the sound may seem continuous, it is actually composed of several discrete sounds, each originating from the rupture of a small bubble. The type of rales is determined by the size of the passageway and the type of exudate the air passes through. They are roughly divided into three categories: fine, medium, and coarse

Fine rales

Fine rales (sometimes called crepitant rales) can be simulated by rubbing a few strands of hair between the thumb and index finger close to the ear or by slowly separating the thumb and index finger after they have been moistened with saliva. The result is a series of fine crackling sounds. Fine rales are most prominent at the end of inspiration and are not cleared by coughing. They occur in the smallest passageways, the alveoli and bronchioles

Medium rales

Medium rales are not as delicate as fine rales and can be simulated by listening to the "fizz" from recently opened carbonated drinks or by rolling a dry cigar between the fingers. They are prominent earlier during inspiration and occur in the larger passages of the bronchioles and small bronchi.

Coarse rales

Coarse rales are relatively loud, coarse, bubbling, gurgling sounds that occur in the large airways of the trachea, bronchi, and smaller bronchi. Often they clear partially during coughing. They are frequently heard in dying patients because the cough reflex is depressed, allowing thick secretions to accumulate in the trachea and major bronchi. Because they are so common when death is imminent, coarse rales are often called "the death rattle."

Rhonchi

Rhonchi are sounds produced as air passes through narrowed passageways, regardless of the cause, such as exudate, inflammation, spasm, or tumor. Rhonchi are continuous, since sound is produced as long as air is being forced past an obstruction. Although they are often more prominent during expiration, they are usually present during both phases of respiration. Rhonchi are classified according to pitch as sibilant or sonorous

Sibilant rhonchi

Sibilant rhonchi are high pitched, musical, wheezing, or squeaking in character. The wheezing quality is often more pronounced on forced expiration. Sibilant rhonchi are produced in the smaller bronchi and bronchioles

Sonorous rhonchi

Sonorous rhonchi are low pitched and often snoring or moaning in character. They are produced in the large passages of the trachea and bronchi. Like coarse rales, they can be partly cleared by coughing

Respiratory system disorder syndromes

• Syndrome of consolidation or compression of the lung tissue.• Syndrome of bronhoobstruction.• Syndrome of respiratory failure.• Syndrome of respiratory distress.• Syndrome of atelectasis.• Syndrome of pneumothorax.• Syndrome of liquid in the plural cavity. • Syndrome of laryngotracheitis.• Syndrome of bronchitis.• Syndrome of congenital stridor.• Syndrome of cough.

Croup Syndromes

1 Acute laryngotracheitis.Laryngotracheobronchitis.2.Spasmodic croup (more abrupt onset, milder course).Etiology. Viral coup syndrome is caused by a viral infection in the subglottic area of

the larynx transmitted. Most cases involve children age 3 months to 3 years. Peak incidence of the disease is in late autumn, early winter.

Clinical FindingsOften occurring at nigh.Croupy (barky) cough. Inspiratory dyspnea.Hoarseness Coryza (catarrh).Fever.Intercostal, suprasternal, infrasternal retractions.Respiratory rate slightly increased

Croup Syndromes

Croup Syndromes

Croup Syndromes

Croup Syndromes

Acute Epiglottitis

Epiglottitis is an infection of the epiglottis and supraglottic structures.The child may also show intercostal retractions and perioral cyanosis and sounds stridorous

Acute Epiglottitis

Do not attempt direct visualization of the epiglottis by depressing the tongue as this may cause reflex laryngospasm and obstruction, which may lead to respiratory arrest

Foreign body aspiration

Foreign body aspiration is occurred of aspiration of small objects (seeds, nuts, toy parts, buttons, pebbles) into laryngotracheal are or main stem bronchus. Aspiration is frequent in children between 7 months and 4 years.

Clinical FindingsSigns and symptoms depend on degree of obstruction and nature of the foreign body. The parents describe in history of disease that child was swallowing or playing with a

small object followed by sudden onset of cough, choking or gagging or wheezing. There may be a period of no symptoms following initial episode. Foreign body aspiration clinic depends on the level of obstruction. Laryngeal foreign

bodies may completely obstruct airways and may elicit stridor, high pitched wheezing, cough or aphonia and cyanosis.

Tracheal foreign bodies usually elicit cough, some stridor or wheezing and may produce "slap" sound

Bronchial foreign bodies usually cause wheezing or coughing and are frequently misdiagnosed as asthma; may present with decreased vocal fremitis, impaired or hyperresonant percussion note, and diminishes breath sounds distal to foreign body.

Diagnostic tests

• Upper airway foreign bodies may be visualized on standard roentgenography.

• Bronchoscopy is usually required for definitive diagnosis of foreign bodies in the larynx and trachea.

Treatment1. Establish airway if child is in obvious distress.2. Back blows, Heimlich maneuver.3. Removed by means of direct laryngoscopy or

bronchoscopy.4. Prevention is most important aspect; age appropriate

anticipatory guidance, including siblings.

Thank you for attention