Clinical Approach to Respiratory SystemCHAPTER 1

In respiratory system, history taking (the questionnaire part) is the most important part of clinical approach. It is often more helpful than clinical examination. Without proper history taking, clinical examination will be fruit less. As for example, uncomplicated pulmonary tuberculosis may not have any physical finding. Similarly a lung pathology surrounded by normal lung parenchyma like lung abscess, lung mass, etc. may not have any sign. Physical examination findings and investigation results should be interpreted on the basis of history. Clinical examination may suggest pleural effusion or high-resolution computed tomography (HRCT) findings may suggest ILD but that means nothing. Proper history taking will help you in reaching a final complete diagnosis.

Patient may have many complaints or may have no complaint (patient may come with an abnormal chest X-ray done for routine check-up). Chief complaints are one or two (rarely three) important complaints among them and those will be determined by doctor not by patient. As for example, many elderly patients will complain of constipation and that cannot be their chief complaint. But in intestinal obstruction, constipation is the chief complaint.

Onset of disease: History should start with how the disease has been started, the onset. Diseases may have insidious onset (when patient cannot point out when the disease has been started) and that indicates a chronic diseases like tuberculosis (TB), chronic obstructive pulmonary disease (COPD), interstitial lung disease (ILD), etc. Acute onset (patient can say when the disease has started) indicates acute disease occurring over days as for example, fever for 10 days. Sudden onset means patient can pin point the exact onset by time or by event (while reading newspaper I develop chest pain). Sudden onset means before a particular moment he was healthy. Sudden onset diseases are mainly vascular diseases like acute myocardial infarction, stroke, pulmonary thromboembolism (PTE), and pneumothorax, foreign body inhalation, etc.

Progression: Secondly, history should include the progress of illness like disease progressed to reach a plateau and then decreases in severity (closed pneumothorax, collapse); continuous deterioration of disease (COPD, ILD), intermittent or episodic with intervening symptoms-free period (asthma), having sudden deterioration (acute exacerbation of COPD, ILD), or change in character of previous symptoms or addition of symptoms (bronchogenic carcinoma over COPD).

Sequence of events: Thirdly, the sequence of events should be clearly noted even they are of same duration. Sudden onset pleuritic chest pain after a bout of cough and that is followed by dyspnea indicates pneumothorax.

Duration of illness: Chronic diseases may persist for months or years (usually more than 6 weeks) like COPD, asthma, some ILD. Acute diseases usually last for days to weeks. In our country, TB should be suspected in all patients with cough for more than 2 weeks. Duration of illness more than 1 year usually excludes lung cancer except bronchioloalveolar cell carcinoma.

Analysis of symptoms: There are six respiratory symptoms (cough, expectoration, hemoptysis, dyspnea, wheeze and chest pain) and few general3 symptoms (fever, swelling, weight loss, weakness, etc.) those are important in respiratory medicine. Permutation and combination of those six respiratory symptoms will give an idea about the disease. Dyspnea with wheeze usually indicates airway disease but sometimes the combination may be found in left ventricular failure and even in interstitial lung disease.

Cough: Cough is the most common respiratory symptom. Cough may indicate infection, irritation, inflammation of airways, lung parenchyma, upper airways and pleura. Cough is a reflex with receptors present in the respiratory tract from pharynx to smaller bronchi and pleura. Center is in the medulla. During coughing respiratory muscles constrict vigorously with closed glottis; as a result intrathoracic pressure is increased; then glottis is suddenly opened up; and there is sudden expulsion of content of airways. Cough arising from larynx is harsh, barking and may be painful. Tracheal cough is harsh, dry and painful. Cough arising from airways (bronchitis) is usually associated with wheeze. It is important to know the onset, progression of cough, diurnal and seasonal variation of cough, and whether cough is associated with expectoration. Children, elderly, sick patients and often female patients cannot expectorate; then it is important to note the sound of cough to be sure whether it is actually dry cough.

Expectoration: When expectoration is present then the amount (scanty, copious); color (whitish, pinkish, gray, yellow or green), character (serous, mucoid, mucopurulent or purulent), and odor (foul smelling) are to be noted. It is also important to know whether expectoration has a postural relation or diurnal variation. Macroscopic examination of expectoration often gives important clues: mucoid/mucopurulent sputum in COPD, bronchiectasis, lung abscess; scanty, blackish tenacious sputum in asthma, pink frothy sputum in left ventricular function (LVF), rusty sputum in pneumococcal pneumonia, etc.

Hemoptysis: Hemoptysis may be frank hemoptysis (bronchiectasis, tuberculosis), blood streaks expectoration (tuberculosis, bronchitis), blood- stained expectoration (red currant jelly sputum in Klebsiella infection) and rusty sputum (pneumococcal pneumonia). Severity of hemoptysis is to be assessed by asking whether hemoptysis causes hemodynamic instability, demands hospitalization or blood transfusion.

Chest pain: Pain arising from pleura is sharp, pin-pricking or stabbing in character, found in the lateral side of thorax that increased with deep inspiration and coughing. Mediastinal pain is usually dull-aching, poorly localized central chest pain. Myocardial pain is compressive or oppressive in the retrosternal area that increased with exertion and decreased with rest. Pericardial pain is due to inflammation of adjacent pleura (pericardium has no pain fiber) and has same characteristic of pleural pain. Lung has no pain fiber and pain in lung diseases is due to involvement of pleura, chest wall or mediastinum. The following points should be noted for chest pain: character of pain (pleuritic, dull aching); location of pain (central, lateral or back of chest wall), pattern of pain (built over minutes or immediately, fleeting) provoking4 and alleviating factors, referred pain or radiation of pain, severity of pain, frequency or periodicity of pain, and associated symptoms.

Dyspnea: Dyspnea is an unusually uncomfortable awareness of breathing. Dyspnea may be produced by disproportionate increase in work of breathing, or stimulation of receptors (J receptor) in the lung. It is said to be arising from signals in distorted muscle spindle. It is very important to differentiating dyspnea of cardiac origin from that of respiratory origin though it is often not possible. Cardiac dyspnea may be associated with exertion, palpitation, paroxysmal nocturnal dyspnea, orthopnea, etc. Dyspnea with wheeze suggests airway disease. Dyspnea with serous, mucoid or mucopurulent, scanty tenacious expectoration usually suggests lung disease. Whereas, pinkish and frothy expectoration suggests LVF. It is important to note the onset, duration, progression, aggravating and relieving factors and associated symptoms of dyspnea.

Wheeze: Wheeze is a noisy sound occurring with respiration and usually occurs in obstructive airway diseases. It should be differentiated from stridor a predominantly inspiratory sound due to localized obstruction of upper air ways.

Fever: Maximum normal oral temperatures are 37.2°C (98.9°F) at 6 AM and 37.7°C (99.9°F) at 4PM. Temperature above that should be considered as fever. Fever is classically described as continuous, remittent and intermittent. But in today's era of antibiotics and anti-pyretic, those classical typing is rarely possible. Acute onset of high fever with cough suggests pyogenic respiratory infection. In high fever, due to liberation of exogenous pyrogens or endogenous cytokines thermal regulation center is set at a higher level; to achieve that goal body first preserves heat by peripheral vasoconstriction causing a sensation of chill, and then body produces heat by muscle constriction causing rigor. Fever with chill and rigor suggest organisms have entered bloodstream like viremia, bacteremia or parasitemia. Insidious onset of low-grade fever with cough suggests chronic infection due to tuberculosis, fungal disease. Evening rise of temperature is typically described for tuberculosis but it is not specific and it can be found in any chronic inflammation. It represents normal diurnal variation of temperature (minimum in the morning and highest in the evening). In low-grade fever, temperature crossed the threshold limit in the evening and thereby it is felt by patients. In chronic infection patient may be habituated with temperature and may not complain it. On the other hand, patient may have feverishness (sometimes an expression of weakness) not actual fever. It is always important to record temperature sublingually.

Other symptoms: Swelling of face may occur in renal diseases, hypothyroidism, corticosteroid therapy (moon face) or superior vena cava (SVC) syndrome. In renal disease swelling usually starts from face; whereas in heart failure it starts from feet. In SVC syndrome swelling is associated with congestion whereas in other conditions swelling is associated with pallor. Pedal edema may be found in malabsorption in abdominal tuberculosis. Weight loss may be indirectly evident from loosening of garments. Weight loss is found in tuberculosis, lung5 cancer, acquired immunodeficiency syndrome (AIDS), anorexia and anxiety. Weight loss with normal or increased appetite may be found in diabetes mellitus or hypothyroidism.

When present illness is not associated with or is a sequel of previous illness, the previous illness should be put in past history. When present illness is same or a continuation of previous illness then previous illness should be put in present history.

Personal history should include the following things:

Family history includes contact history with cases of tuberculosis; history of atopy or allergic diathesis in family; liver diseases for suspected alpha1 anti-trypsine deficiency.

In general survey, some points are more important for respiratory medicine and they need special emphasis.6

General look, signs of dyspnea, gross deformity: When patient enters your chamber the first look is very important. Following points are to be noted like patient coming walking without support, with support, by wheel-chair or by stretcher. Patient's level of consciousness and orientation should be assessed while taking history. Signs of dyspnea should be looked for and those include tachypnea, activity of accessory muscles of respiration, suprasternal suction and intercostal suction. Any gross deformity and abnormalities should be noted. As for example, an amputation of limb may be due to osteosarcoma and present lung problem may be secondary to that.

Facies, decubitus, built, nutrition, body mass index (BMI): Anxious facies is the usual presentation. A toxic and seek look indicates serious illness. Swelling of face and neck may be suggestive of SVC syndrome. Patient may be orthopnic or prefers lying down in bed or prefers a particular lateral decubitus position. It is always important to note why he preferred that particular position. It is important to calculate BMI (weight × height²) measured in Kg/m². Normal BMI is between 19 to 26 and more than 30 is obesity. Nutrition is generally assessed by measuring BMI, muscle bulk by mid-arm circumference, subcutaneous fat by skin fold thickness over triceps or below the scapula and by looking for signs of vitamin deficiencies.

Blood pressure (BP), pulse, respiratory rate, temperature: BP is important to assess whether patient is hypertensive (note history of antihypertensive medications) or hypotension (systolic <90 and diastolic <60 mm of Hg). Hypotension is a measurement for shock. Pulse for assessing tachycardia (>100/min) or bradycardia (<60/min). Respiratory rate to assess tachypnea. Temperature is for assessing fever or hypothermia.

Neck vein and peripheral lymph nodes: Neck veins are generally examined, though not mandatory, at 45° angle. Among waves prominence of ‘a’ wave suggest increased right atrial/ventricular pressure in cor pulmonale. Absence of pulses wave is important and it indicates SVC obstruction. Engorgement of neck veins may be found in right ventricular failure (with presence of venous pulses to be confirmed by hepato/abdomino-jugular reflux); and engorged vein without pulsation is suggestive of SVC syndrome.

Pallor, polycythemia, cyanosis, clubbing, jaundice, edema: Both pallor and polycythemia may be associated with COPD. Any chronic respiratory disease and malignancy may cause pallor as a result of anemia of chronic disease. Anemia due to hemoptysis is not common but it can be seen in diffuse alveolar hemorrhage. Polycythemia is not an uncommon finding and it is usually related to chronic hypoxia of respiratory disease. Cyanosis is usually central and due to hypoxia. Peripheral cyanosis may be found in cor pulmonale with right heart failure. Clubbing may be present in any chronic suppurative condition of thorax and bronchogenic carcinoma. Jaundice is usually drug-induced (mainly ATDs), due to liver metastasis and sometimes with severe pneumonia. Pedal edema may be found in cor pulmonale with right ventricular failure, malnutrition and abdominal tuberculosis. Unilateral or unequal edema may suggest deep vein thrombosis. Looking for calf muscle tenderness may be dangerous and should not be attempted.

Examination of respiratory system is divided into two parts: examination of upper respiratory tract and examination of lower respiratory tract.

Examination of respiratory system must start from examination of upper respiratory tract. Upper respiratory tract is the part of airway starting from external nares to the junction of larynx with trachea. Examination of upper respiratory system includes nasal cavity, nasopharynx, nasal sinuses and oropharynx. A large part of upper respiratory tract is not visible without instrumentation, and in some situation help of ENT surgeon may be necessary. Examination of upper respiratory tract is important as it is a part of airway tree. As for example, allergic rhinitis is associated with asthma. Sarcoidosis, Wegener's granulomatosis, tuberculosis can affect upper respiratory tract. In addition, oral cavity (buccal cavity, teeth and gum) should be included in the examination of upper respiratory tract as unhealthy teeth and gum may lead to infection of lung by aspiration. Aspiration may be macroaspiration evident clearly from history and microaspiration, small amount of aspiration of upper airway secretion occurs during sleep.

Nose and sinuses: First inspect the nose for any deformity. Deformities of nose include fracture; red and enlarged nose in rhinophyma, depression of nasal breeze (saddle nose), etc. Destruction of nasal septum may be found in congenital syphilis. Deviation of nasal septum is most common than expected, and it can increase the risk of nasal obstruction and infection. The patency of each nostril should be examined by closing other nostril by pressing finger, and asking patient to close mouth and exhale through other nostril. Direct examination of nasal cavity and inferior turbinates is done preferably with the aid of a nasal speculum. Nasal polyp (pearly gray smooth surfaced) or bleeding8 points must be looked for. Paranasal sinuses can be palpated for tenderness as (i) frontal sinus—press upward beneath the medial side of supraorbital ridge; (ii) maxillary sinus—press against the anterior wall of malar prominence below the inferior orbital margin; and (iii) ethmoidal sinus—press medially against the medial wall of the orbit. Any discharge from sinuses or postnasal discharge should be looked for.

Oral cavity: Examination of oral cavity includes lips, teeth, gums, tongue, floor of mouth, cheeks, palate, tonsils and oropharynx. Those structures are carefully inspected for signs of inflammation, infection, deformity, ulcer formation and white patch (candidiasis). Pigmentation of oral cavity may suggest Addison's disease. Teeth are examined for tobacco staining, caries, discoloration, etc. Gums are examined for gum bleeding, gum hypertrophy, gingivitis, and halitosis as they may be associated with aspiration pneumonia. Tongue is examined for pallor, cyanosis, ulceration, leukoplakia and movement.

Mallampati classification: The classification is another important part of examination of oral cavity for assessing the feasibility of intubation. The assessment is performed with patient sitting up straight, mouth open and tongue proximally protruded. Mallampati classification is done as:

Larynx: Examination of larynx is done by direct or indirect laryngoscopy and is not done by general physician. Indirect evidence of laryngeal disease should be carefully looked; for example, hoarseness of voice may indicate laryngeal palsy, vocal cord nodule or laryngeal inflammation; similarly edema of lips, tongue, around eyes, front of neck may indicate angioedema.

Examination of thorax has four components; inspection, palpation, percussion and auscultation. Respiratory findings of different pathological conditions are depicted in Table 1.

Inspection part is important as some findings are only appreciated during inspection. As for example, important sign of volume loss or gain (flattening or bulging) are only assessed by inspection. Some findings like movement of upper part of chest, is better observed by inspection. Inspection of front and lateral aspect of thorax is examined with patient on supine or semi-recumbent position with chest and upper abdomen properly exposed, with proper illumination and with arms sufficiently abducted to make axillary areas clearly visible. For examination of back, patients are made to sit upright with arms folded across the chest. In inspection, following points should be noted carefully.9

During percussion three things should be noted: (i) sound/note, (ii) feeling of resistance and (iii) tenderness. Percussion is done by hammering with the right middle finger (at 90° angle and movement coming from right wrist joint) over the second phalanx of left middle finger firmly placed over the area to be percussed. Left index and ring fingers must not touch chest wall as it will decrease vibration of chest wall producing sound. Normal percussion note over chest is resonant as lungs mainly contain air. Lung note losses its resonance in pleural diseases other than pneumothorax and in consolidation, fibrosis, collapse, etc. where lung air is replaced. Percussion note over consolidation is usually impaired to dull; it is dull over solid organs (heart, liver, spleen) and it is stony dull (dull + sense of resistance) over pleural effusion. On the other hand, it is hyper-resonant in presence of excess air like pneumothorax, emphysema, large cyst, superficial cavity, etc. Bilateral hyper-resonant note is indirectly assessed by absence of normal dullness over liver and heart. Tympanitic note is found over a hollow organ like fundus of stomach, distended guts and over pneumothorax.