Respiratory System Evaluation


  1. Mediastinal position
  2. Chest expansion
  3. Lung resonance
  4. Breath sounds
  5. Adventitious sounds
  6. Voice transmission
  7. Effort of ventilation
  8. Clubbing
  9. Assessment of functional accomplishment
  10. General observation



Position of mediastinum gives important clues to the nature of process in each hemithorax. Trachea is the index of upper mediastinum and heart of the lower mediastinum.

Method of Exam: Examine the position of mediastinum by standing in front of the patient. Make certain that the patient is seated straight or preferable standing erect.

  1. Inspect for the symmetry of clavicular insertion of both sternomastoids:
  2. Tracheal Position: Assess and compare the space between the trachea and sternomastoid on either side. Keep the tips of your index and ring fingers over the medial end of the clavicles. Then, with middle finger, assess the space between the trachea and sternomastoid.
  3. Position of Heart: Identify the location of apex of the heart by inspection and palpation. Caution: Make sure that the heart is not enlarged.

Normal: The right sternomastoid is slightly prominent normally. The trachea is slanted to the right. The apex of the heart is located on the 5th left IC space just internal to the midclavicular line.

Abnormal: Any deviation of the mediastinum is abnormal.

The mediastinum can be either pulled or pushed away from the lesion.

  1. Pull: Loss of lung volume (atelectasis, fibrosis, agenesis, surgical resection, pleural fibrosis)
  2. Push: Space occupying lesions (pleural effusionm pneumothoras, large mass lesions)
  3. Mediastinal mass and thyroid tumors
  4. Scoliosis


Assessment of chest expansion with deep inspiration helps identify the side of abnormality.

  1. Overall Chest Expansion: Take a tape and encircle chest around the level of nipple. Take measurements at the end of deep inspiration and expiration.

    Normally, 2-5 inches of chest expansion can be observed. Any lung or pleural disease give rise to a decrease in overall chest expansion. It is typically low in patients with COPD. These patients have very high FRC and have limited capability to expand the chest from this position.

  2. Symmetry of Chest Expansion: Have patient seated erect or stand with arms on the side. Stand behind patient. Grab the hemithorax on either side of axilla and gently bring your thumbs to the midline. Have patient slowly take a deep breath and expire. Watch the symmetry of movement of the hemithorax. Simultaneously, feel the chest expansion. Next, stand in front and lay your hand over both apices of the lung and anterior chest and assess chest expansion.

    Chest expansion symmetrical. Both sides take off at the same time to the same extent. Asymmetrical chest expansion is abnormal. The abnormal side expands less and lags behind the normal side. Any form of unilateral lung or pleural disease can cause asymmetry of chest expansion.

    Caution: 1) apply different amounts of pressure and note the effect
                 2) have the patient sit crouched up and note its effect on the symmetry of chest expansion.



The lung is filled with air (99% of lung is air), hence percussion of it gives a resonance. This step helps identify areas of lung devoid of air.

Keep the middle finger firmly over the chest wall along intercostal space and tap chest over it using middle finger of opposite hand. The movement of tapping should come from the wrist. Tap 2-3 times in a row. Listen and feel the resonance. Percuss the chest all around. Stand back, have patient cross arms to shoulder. This maneuver will wing the scapula and expose the posterior thorax. Percuss starting from top to bottom of thorax on either side. Compare the resonance by percussing the corresponding spaces alternately. Stand on one side of the patient and with the flat of your hand, tap the chest from top to bottom and from side to side to compare. Then, have the patient keep their hands over head and percuss axilla. Then move to the front and percuss anterior chest, clavicles and supraclavicular space.

Normal: Appreciate the dullness of the left anterior chest die to heart and right lower chest due to liver. Note the hyper-resonance of the left lower anterior chest due to air filled stomach. Normally, the rest of the lung fields are resonant.

Abnormal: Decreased or increased resonance is abnormal. Increased resonances can be noted either due to lung distention as seen in asthma, emphysema, pneumothorax or bullous disease.

Decrease resonances are noted with pleural effusion and all other lung diseases. Experienced physicians are able to discriminate between dullness of pleural effusion from a consolidation or a mass lesion of lung. The dullness is fatal and the finger percussion is painful with pleural effusion.



Auscultation of lungs help determine the airway and alveolar integrity, ventilation, and presence of abnormality.

There are two normal breath sounds, bronchial and vesicular. Breath sound heard over the tracheobronchial trees are close to the chest wall without surrounding lung tissue are trachea, right sternoclavicular joints and posterior right interscapular space. These are the sites where bronchial breathing can be normally heard. In all other places there is lung tissue and vesiculate breathing heard.

Use the diaphragm of the stethoscope. Listen to the chest posteriorly, in axilla, and front of chest similar to the way lungs were percussed. Follow the same routine, listen to alternating corresponding sites. Listen to at least one complete respiratory cycle at each site. First listen with quiet respiration. If breath sounds are inaudible, then have him take deep breaths.

Note the intensity of breath sounds, symmetry, length of inspiration and expiration. Listen for the pause between inspiration, expiration, and the quality of pitch or the sound. Note the presence or absence of adventitious sounds.

Normal: The bronchial breath sounds over the trachea has a higher pitch, louder, inspiration and expiration are equal and there is a pause between inspiration and expiration. The vesicular breathing is heard over the thorax, lower pitched and softer than bronchial breathing. Expiration is shorter and there is no pause between inspiration and expiration. The breath sounds are symmetrical and louder in intensity in based compared to apices in erect position. No adventitious sounds are heard.

Abnormal: Intensity of breath sounds , in general, is a good index of ventilation to the underlying lung. If the intensity increased there is more ventilation and vice versa. Breath sounds are markedly decreased in emphysema.

Symmetry: If there is asymmetry in intensity, the side where there is decreased intensity is abnormal.

Any form of pleural of pulmonary disease can give rise to decreased intensity.

Bronchial breathing anywhere other than over the trachea, right clavicle or right interscapular space is abnormal. Presence of bronchial breathing would suggest:

  1. Consolidation
  2. Cavitation
  3. Complete alveolar atelectasis with patient airways
  4. Mass interposed between chest wall and large airways

In all these conditions, there are no ventilation into alveoli and the sound that is heard originates from bronchi and is transmitted to the chest wall.

Experienced physicians could discriminate between consolidation and cavitation by noting the quality of bronchial breathing. In consolidation, the bronchial breathing is low pitched and sticky (tubular type of bronchial breathing). In cavitary disease, it is high pitched and hollow (cavernous breathing). You can simulate this sound by blowing over an empty coke bottle.


A: Make sure you warm the stethoscope before placing on the patient's chest. Rub the metallic part of the stethoscope and warm it up.

B: Don't make the patient hyperventilate by making them take deep breaths too many times. Give a rest in between. Instruct the patient to take a deep breath only when you have your stethoscope on their chest.



There are three adventitious sounds:


  1. Rhonchi
  2. Rales or crackles
  3. Presence of adventitious sounds indicate an abnormality.

Pleural Rub: Normal pleural surfaces glide smoothly during respiration. If the surface is roughened due to any form of pleurisy, a scratching, grating sound, obviously related to respiration is heard. You can hear the sound by compressing harder with the stethoscope and making the patient take deep breaths. It is very localized and can be palpable.

Rhonchi: Long continuous sounds, generated by obstruction to airways. When detected, note whether it is generalized or localized, during inspiration or expiration, and pitch.

Diffused rhonchi: Would suggest asthma or COPD

Localized rhonchi: Localized obstruction of any etiology, tumor, tuberculosis or mucous. Mucous secretions will disappear with coughing.

Inspiratory rhonchi: In general, implies large airway obstruction. Asthmatics will have inspiratory rhonchi while it is uncommon in COPD.

Loud audible:

inspiratory rhonchi: Is called a stridor.

High pitched rhonchi: Called sibilant rhonchi.

Low pitched rhonchi: Sonorous rhonchi.

Positional: Wheezing in general will get worse in supine position. The airways get smaller in supine position; hence, the narrowing gets worse. Note the changes in intensity of localized wheezes in the decubitus position.

Rales Crackles: Discontinuous or interrupted sounds are called crackles. Make a notation about timing, intensity, effect with respiration position and coughing. Typically, early inspiratory crackles are associated with congestive heart failure while pan-inspiratory or late inspiratory crackles are associated with diffuse interstitial pulmonary fibrosis.



You can assess voice transmission by palpation (tactile fremitus) and auscultation (vocal resonance).

Have patient repeat 1, 2, 3. Listen and feel the chest for tactile fremitus and vocal resonance. Note the intensity, symmetry and quality of pitch.

Normal: The sounds are sharp and distinct over the bronchi. Over the lung fields, the words become indistinct and muffled. The sound generated in the larynx is transmitted along the tracheobronchial tree and gets muffled in the alveoli.

Abnormal: Any situation where bronchial breathing is heard the sounds become loud, sharp, and distinct (bronchophony). In extreme situations, the whispered words come clearly and distinctly (whispering, pectoriloquy). A qualitative alteration of voice transmission is noted over consolidation and along the upper margin of pleural effusion (egophony). The sound is like a nasal twang or goat bleating. A quantitative decrease in voice transmission could be die to any other form of lung or pleural disease. Asymmetrical voice transmission points to a disease on one side, abnormal voice transmission.



The diaphragm and inspiratory intercostal muscles are primary muscles of respiration. Contraction of these muscles results in increased intrathoracic volume and increased pleural negative pressure. This results in air entering the lungs (inspiration). Expiration is passive and results from the elastic recoil of inflated lungs. The sternomastoid and scalene group of muscles are accessory inspiratory muscles. The abdominal muscles are accessory inspiratory muscles. The abdominal muscles and expiratory intercostal muscles are accessory expiratory muscles. The normal pattern of breathing (both upright and supine) is for the chest and abdomen to both increase in size with inspiration and decrease in size with expiration.


  1. Comfort
  2. Position of comfort or discomfort
  3. Prominent primary muscles, dominant inspiratory muscles
  4. Use of accessory muscles
  5. Active or passive expiration
  6. Negative pleural pressure
  7. Number of breaths per minute

Use of accessory muscles: Stand behind patient and place your hands behind the sternomastoid and feel the scalene muscles during quite respiration. If the muscle contraction is palpable during quiet tidal breathing, the accessory muscles are in use. It will be obvious when the sternomastoid muscles are in action.

Expiration passive or active: Observe and feel the abdominal muscles to see whether they are contracting during expiration. If they do, the patient is using active muscle contraction to expire. Note whether he is using pursed lip breathing.

Negative pleural pressure: Increased in negative pleural pressure can be recognized by intercostal retractions and downward pull of the trachea during inspiration.

Number of breaths: Count the number of breaths when patient is unaware. If the patient is conscious, there will be tachypnea. Don't count the respiratory rate until patient has settled down and is in his or her basal state. Normal respiratory rate is 10-14 breaths per minute.

Position of comfort: Count the number of breaths when patient is comfortable to breath in the supine or sitting position. A normal person is comfortable in any position.

Orthopnea: SOB in supine position

Platypnea: SOB in erect position

Normal: The diaphragm is the dominant muscle. The needed ventilation can be accomplished by 10-14 breaths per minute. The accessory muscles are not in use with quiet respiration. Patient appears comfortable and the rhythm of respiration is close to regular. The breathing is involuntary.

Abnormal: Person appears uncomfortable. Breathing seems voluntary. Accessory muscles are in use, expiratory muscles are active and expiration is not passive any more. The degree of negative pleural pressure is high. The respiratory rate is increased.


The terminal portion of fingers and toes are usually of the same size and gently taper at the tip. In certain conditions the soft tissue proliferate in the terminal portion of fingers and toes and find them in an appearance of club. When this occurs, patient is said to have clubbing.

Method of exam: View the fingers from a dorsal and lateral view. Note the width of terminal portion and compare with the proximal part. Look at the angle between the nail and skin bed. Attempt to feel the posterior edge of nail.

Normal: The terminal portion is of the same size as the proximal portion. The angle between the nail and skin is less than 180. The periungual skin is normal. There is no fluctuation of nail bed and you cannot feel the posterior edge of nail.

Clubbing: In clubbing, there is widening of the AP and lateral diameter of terminal portion of fingers and toes giving the appearance of clubbing. The angle between the nail and skin is greater than 180. The periungual skin is stretched and shiny. There is fluctuation of the nail bed and one can feel the posterior edge of the nail.

Significance: Clubbing has been observed with:

  1. Intrathoracic malignancy
  2. Suppurative lung disease
  3. Diffuse interstitial fibrosis
  4. In association with other system disorders



The most important functions of respiratory system are:

  1. To provide oxygen to the O 2 delivery system
  2. Suppurative lung disease
  3. Diffuse interstitial fibrosis
  4. To maintain pH

Failure of the system could result in hypoxemia, CO 2 retention and respiratory acidosis. Unfortunately, our physical assessment capabilities are of limited value and one should rely on blood gases for functional assessment. Physical exam can only detect extreme functional derangement. Many of the abnormalities noted could result from multi-functional problems.

For assessing hypoxia: Inspect conjunctiva and tongue for color. Evaluate blood vessels on sclera and conjunctiva.

Normal: The conjunctiva and tongue are pink in color. Appreciate the normal size of vessels.

Abnormal: Central cyanosis results from pulmonary dysfunction. IN hypoxia, the mm of conjunctiva and tongue are blush. If there was chronic hypoxemia and secondary erythrocytosis, you can detect the conjunctival and scleral vessels to be full, tortuous and blush.

Caution: There is no good way to clinically ascertain CO 2 retention and pH changes. Some of the findings reported in text books are late manifestations and unreliable. Rely on blood gases for assessment of functional accomplishments of lungs.



You, as a medical student, will be seeing a patient after an initial assessment by another physician. He would have set into motion certain actions which are clues to the patient's problem.

Medicine is an art. Learn to be like a detective in solving medical problems. Be attentive. Observe, smell, listen, and feel for clues. Let me give you a few examples: