CLINICAL EVALUATION OF RESPIRATORY DISEASE

Cough and respiratory distress are primary indicators of respiratory disease, apart from others, e.g. wheeze, stridor, etc. Important components of clinical evaluation in these cases are as follows:

A.

Most cases present with acute, recurrent or persistent- (a) cough, (b) respiratory distress, (c) wheezing and/or (d) stridor. Generally, congenital defects present at birth or in early infancy, viral infections at all ages, bacterial infections mainly in younger or immunocompromised children, and tuberculosis usually after infancy.

Ill-sustained breastfeeding and hoarse cry may be the earliest indicators of respiratory distress in young infants and newborns. Unlike adults, hemoptysis and chest pain are rare in children.

Other important and relevant histories in respiratory disease include:

• Associated complaints, e.g. fever, weight loss, ear/ nose discharge, headache and dysphagia.

• Preceding viral illness, e.g. measles, suspected aspiration or foreign body inhalation.

• Past history of similar or other respiratory illness (recurrence or complication)

• Family history of similar illness, atopic disorders or contact with tuberculosis, including sputum positivity and treatment status in the contact.

• Environmental history of overcrowding, air pollution, passive smoking or similar illnesses in community.

B. General examination must specifically aims to look for: (a) fever, (b) severity of respiratory distress including cyanosis, (c) superficial foci of infection, e.g. ENT disease, pyoderma, etc. (d) lymphadenopathy or other markers for tuberculosis, (e) signs of chronic lung disease, e.g. growth failure, clubbing, etc. and (f) cardiac or neurological problems, which may be the cause or effect of respiratory disease.

Respiratory distress (RD) is indicated by abnormalities of rate (tachypnea), depth (dyspnea) and/or regularity (irregular or periodic breathing) and presence of abnormal audible sounds.

Respiratory rate (RR) varies with age and other physio­logical stress, though RR gt;60/min below 2 months of age, gt;50#8725;min from 2-12 months and gt;40#8725;min in older children is considered as abnormal.

Tachypnea without significant dyspnea is mainly seen in non-respiratory conditions, e.g. fever, exercise, anemia, hysteria and restrictive lung disease, e.g. pleural effusion. Bradypnea with decreased RR indicates heavy sedation or narcotic poisoning.

Depth of breathing is indicated by amount of respiratory excursions. Intercostal indrawing, nasal flaring and/ or use of accessory neck muscles indicate presence and severity of dyspnea. Dyspnea disproportionately more than tachypnea, usually indicates airway obstructions, e.g. asthma or croup.

Presence of stridor indicates upper airway obstruction,

e. g. croup, while wheeze indicates obstructed lower airways, e.g. asthma or bronchiolitis. Expiratory grunt indicates severe parenchymal pathology, e.g. pneumonia.

Irregular breathing is normal in newborns (periodic breathing). Important pathological irregularities include Chenye-Stokes breathing (alternating apnea and hyperpnoea) in raised intracranial pressure, Kussmaul breathing (deep and rapid air hunger) in acidosis, and Biot's breathing (irregularly irregular) in meningitis

MS: Mediastinal shift

¹Egophony and Whispering pectoriloquy in large, dense consolidation.

²Bronchial breathing with h VR may be present in collapse with patent bronchus.

³Shifting dullness and suction splash indicates hydro/pyopneumothorax. Bronchial breathing and hVR/VF is common at air-fluid interface.

C. Respiratory system examination helps in localizing the site of lesion and probable pathology (Table 16.2), based on-inspection, palpation, percussion and auscultation of chest.

I. Inspection mainly includes: (a) shape of the chest, (b) type of breathing, (c) symmetry of chest movements, and (d) position of mediastinum on trail sign. Superficial abnormalities of chest, e.g. scar, injury marks and pulsations should also be looked for.

• Shape of the normal chest is bilaterally symmetric, with transverse diameter exceeding AP diameter.

- Asymmetric flattening with drooping of shoulders indicates collapse or bronchiectasis, while asymmetric bulge indicates pleural effusion or pneumothorax.

- Bilateral bulging (Barrel chest) is common in asthma or recurrent chest infections.

- Abnormal chest shapes are also seen in non- respiratory conditions, e.g. rickets (rosary, pigeon­chest, Harrison sulcus) cardiomegaly (sternal/ precordial bulge) and spinal deformities.

• Type of breathing is normally thoracoabdominal in infancy and abdominothoracic in older children. Abdomen is pushed-out during inspiration due to downward movement of diaphragm to create negative intrathoracic pressure, and pulled-in during expiration to increase intrathoracic pressure. Important abnormalities include:

- Paradoxical breathing (reversal of normal abdominal movements) in diaphragmatic paralysis

- Paucity of abdominal movements in diaphragmatic paralysis, gross ascites/peritonitis and subdia- phragmatic abscess.

- Paucity of thoracic movements in intercostals para­lysis, pleurisy and inflammatory conditions of chest wall.

• Asymmetric chest movements indicate unilateral disease, with visually restricted movements always on affected site.

• Trail sign, i.e. unilateral prominence of sterno­cleidomastoid, denotes shift of trachea on the same side.

II. Palpation of chest includes: (a) assessment of mediastinal position, (b) chest movements, and (c) tactile vocal fremitus (TVF), apart from confirming inspection findings.

• Position of mediastinum is assessed by: (i) supra­sternal palpation of trachea, and (ii) location of apex beat. Normally, trachea is central or slightly on right side, while apex beat is in 4-5^th intercostal space, ~1 cm medial to left mid-clavicular line. Tracheal and apical shift is usually concordant, though normally located trachea with shifted apex beat may be seen in smaller lower lung lesions (and vice versa for upper lesions) and cardiac lesions. Mediastinum is:

- Central in consolidation and other lesions

- Pulled on same side in collapse or fibrosis

- Pushed on opposite side in effusion/pneumothorax

• Chest movements may be confirmed by placing flat palms of two hands on opposite sides at identical location.

• Tactile vocal fremitus (TVF)-the tactile perception of chest wall vibrations in response to phonation, is not a reliable sign in children due to thin chest wall and should be correlated with vocal resonance (VR) on auscultation, discussed later. TVF is:

- Increased over consolidation, as solid tissue is a better conductor of vibrations than air or fluid.

- Decreased over pleural effusion (dampening effect), pneumothorax or collapse (absence of air entry).

III. Percussion of chest includes percussion—(a) over different areas of lung, including isthmus, and (b) for cardiac contour, and (c) location of liver dullness. As percussion note is not uniform all over the chest (depends on density of underlying tissue), it should always be compared from opposite site. Percussion is unreliable in small or deep-seated lesions. Important percussion abnormalities are:

• Dull or impaired note in consolidation, collapse, fibrosis, thicken pleura and pleural effusion (stony dull).

• Hyperresonant or tympanic note in pneumothorax, emphysema and superficial cavity or cysts.

• Shifting dullness, i.e. change in percussion note after change of posture in hydropneumothorax.

• Obliterated cardiac dullness in left pneumothorax.

• Liver dullness is normally in 4-5^th ICS. It may be abnormally high in liver/subdiaphragmatic abscess, gross ascites or right lower-lung collapse; and abnor­mally low in cases with pushed down liver, e.g. in right pneumothorax or intestinal perforations (due to gas under diaphragm).

• Coin test (Bell tympany) is positive in massive pneu­mothorax or at the level of air-fluid interface in hydropneumothorax.

(Coin test: Place a coin over the affected site and tap with other coin.

IV. Auscultation is most informative and includes identification of—(a) character of breath sounds, (b) presence of adventitious sounds, (c) vocal resonance, and (d) other important signs.

• Breath sounds may be divided into—(a) vesicular, or (b) bronchial breathing.

- Normal vesicular breathing with long inspiratory and shorter expiratory phase without intervening pause. In children, vesicular breathing is relatively harsh due to thin chest wall and bronchial character, discussed below, may be normally present over right apex and mid-scapular region.

- Abnormal Bronchial breathing with—(a) equal duration of inspiratory and expiratory phase, and (b) an intervening pause between two phases.

Bronchial breathing is usually heard over—(a) consolidation, (b) collapse with patent bronchus, (c) air-fluid level in effusion/hydropneumothorax due to collapsed lung, (d) cavity communicating with bronchus, and (e) communicating pneumothorax. Unlike adults, further differentiation of bronchial breathing into tubular (consolidation), cavernous (cavity) or amphoric (pneumothorax) types is neither easy, nor desirable in children.

- Absence or reduced breath sounds indicate underlying collapse, effusion or pneumothorax.

• Adventitious sounds on auscultation include crepitations (rales), rhonchi, conducted sounds and Friction rub.

- Crepitations are predominantly inspiratory, crackling/bubbling sounds due to presence of fluid in bronchi or alveoli. In crying children, crepitations are best audible in inter-cry phase, when baby takes a deep breath. Crepitations may be fine (crackling, due to fluid in alveoli) or coarse (bubbling, due to fluid in bronchi).

Important causes of crepitations include: (a) Bronchopneumonia (coarse), (b) Bronchiectasis, cavity, lung abscess (coarse, bubbling), (c) Pulmonary edema (fine, inspiratory and mainly at bases), (d) Bronchiolitis, asthma (fine, diffuse and expiratory), (e) Interstitial lung diseases/fibrosis (fine, inspiratory).

- Conducted sounds originate from upper airways and must be differentiated from crepitations on the basis of—(a) nearly similar character all over the chest, (b) change of character on coughing/crying,

(c) presence in both inspiration and expiration. Similar sounds may also be heard on placing the stethoscope over nose.

- Rhonchi are expiratory musical sounds, due to passage of air through narrowed airways. Rhonchi may be sonorous (low-pitched, in large airway obstruction) or sibilant (high-pitched, in smaller airway obstruction), often associated with audible wheeze. Rhonchi are common in—(a) asthma, (b) bronchiolitis, (c) pneumonia in young children, and

(d) other causes of wheezing (Ch 16.4.4).

- Pleural rub is a crackling sound due to friction of two pleural layers in pleurisy, before the appearance of fluid. Unlike crepitations, it is—(a) audible during inspiration as well as expiration, (b) accentuates on pressure from stethoscope, (c) localized usually in anterior axillary line, (d) not altered by coughing, and (e) disappears soon after collection of plural fluid. Pleural rub is frequently associated with chest pain during deep inspiration.

• Vocal resonance (VR) denotes audible laryngeal vibrations conducted via airway and lung (akin to palpatory TVF). Presence of a patent bronchus and conductive overlying media (lung tissue) is essential for VR.

Clarity of vocal sounds depends on density of conductive media and may be further classified as bronchophony (sounds clear but words not identifiable), whispering pectorilquy (words identifiable) and egophony (nasal quality of sounds).

- VR is increased in—(a) consolidation, (b) cavity communicating with bronchus (whispering pectoriloquy), (c) above the level of pleural effusion

or hydropneumothorax (egophony), (d) collapse with patent bronchus.

- VR is reduced in—(a) pleural effusion/thickened pleura, (b) pneumothorax, and (c) collapse without patent bronchus, and (d) emphysema, due to poor conductivity of hyper-inflated lung.

• Other important auscultatory signs in respiratory disease include:

- Succussion splash-a splashing-sound of fluid movements, heard over the lesion on shaking the patient, in hydropneumothorax, diaphragmatic hernia and rarely, large cavities.

- Post-tussive suction-a sucking sound after coughing, due to sudden gush of air in large cavities, communicating with bronchus.

16.4