The cardinal symptoms of respiratory disease are dyspnea and cough (Chaps. 33 and 34). Dyspnea can result from many causes, some of which are not predominantly caused by lung pathology. The words a patient uses to describe breathlessness or shortness of breath can suggest certain etiologies of the dyspnea. Patients with obstructive lung disease often complain of “chest tightness” or “inability to get a deep breath,” whereas patients with congestive heart failure more commonly report “air hunger” or a sense of suffocation.
The tempo of onset and duration of a patient's dyspnea are helpful in determining the etiology. Acute shortness of breath is usually associated with sudden physiological changes, such as laryngeal edema, bronchospasm, myocardial infarction, pulmonary embolism, or pneumothorax. Patients with underlying lung disease commonly have progressive shortness of breath or episodic dyspnea. Patients with COPD and idiopathic pulmonary fibrosis (IPF) have a gradual progression of dyspnea on exertion, punctuated by acute exacerbations of shortness of breath. In contrast, most asthmatics have normal breathing the majority of the time and have recurrent episodes of dyspnea usually associated with specific triggers, such as an upper respiratory tract infection or exposure to allergens.
Specific questioning should focus on factors that incite the dyspnea, as well as any intervention that helps resolve the patient's shortness of breath. Of the obstructive lung diseases, asthma is most likely to have specific triggers related to sudden onset of dyspnea, although this can also be true of COPD. Many patients with lung disease report dyspnea on exertion. It is useful to determine the degree of activity that results in shortness of breath as it gives the clinician a gauge of the patient's degree of disability. Many patients adapt their level of activity to accommodate progressive limitation. For this reason it is important, particularly in older patients, to delineate the activities in which they engage and how they have changed over time. Dyspnea on exertion is often an early symptom of underlying lung or heart disease and warrants a thorough evaluation.
Cough is the other common presenting symptom that generally indicates disease of the respiratory system. The clinician should inquire about the duration of the cough, whether or not it associated with sputum production, and any specific triggers that induce it. Acute cough productive of phlegm is often a symptom of infection of the respiratory system, including processes affecting the upper airway (e.g., sinusitis, tracheitis) as well as the lower airways (e.g., bronchitis, bronchiectasis) and lung parenchyma (e.g., pneumonia). Both the quantity and quality of the sputum, including whether it is blood-streaked or frankly bloody, should be determined. Hemoptysis warrants an evaluation as delineated in Chap. 34.
Chronic cough (defined as persisting for more than 8 weeks) is commonly associated with obstructive lung diseases, particularly asthma and chronic bronchitis, as well as “nonrespiratory” diseases, such as gastroesophageal reflux (GERD) and postnasal drip. Diffuse parenchymal lung diseases, including idiopathic pulmonary fibrosis, frequently present with a persistent, nonproductive cough. As with dyspnea, all causes of cough are not respiratory in origin, and assessment should consider a broad differential, including cardiac and gastrointestinal diseases as well as psychogenic causes.
Patients with respiratory disease may complain of wheezing, which is suggestive of airways disease, particularly asthma. Hemoptysis, which must be distinguished from epistaxis or hematemesis, can be a symptom of a variety of lung diseases, including infections of the respiratory tract, bronchogenic carcinoma, and pulmonary embolism. Chest pain or discomfort is also often thought to be respiratory in origin. As the lung parenchyma is not innervated with pain fibers, pain in the chest from respiratory disorders usually results from either diseases of the parietal pleura (e.g., pneumothorax) or pulmonary vascular diseases (e.g., pulmonary hypertension). As many diseases of the lung can result in strain on the right side of the heart, patients may also present with symptoms of cor pulmonale, including abdominal bloating or distention, and pedal edema (Chap. 234).
A thorough social history is an essential component of the evaluation of patients with respiratory disease. All patients should be asked about current or previous cigarette smoking as this exposure is associated with many diseases of the respiratory system, most notably COPD and bronchogenic lung cancer but also a variety of diffuse parenchymal lung diseases [e.g., desquamative interstitial pneumonitis (DIP) and pulmonary Langerhans cell histiocytosis]. For most disorders, the duration and intensity of exposure to cigarette smoke increases the risk of disease. There is growing evidence that “second-hand smoke” is also a risk factor for respiratory tract pathology; for this reason, patients should be asked about parents, spouses, or housemates who smoke. It is becoming less common for patients to be exposed to cigarette smoke on the job, but for older patients, an occupational history should include the potential for heavy cigarette smoke exposure (e.g., flight attendants working prior to prohibition of smoking on airplanes).
Possible inhalational exposures should be explored, including those at the work place (e.g., asbestos, wood smoke) and those associated with leisure (e.g., pigeon excrement from pet birds, paint fumes) (Chap. 256). Travel predisposes to certain infections of the respiratory tract, most notably the risk of tuberculosis. Potential exposure to fungi found in specific geographic regions or climates (e.g., Histoplasma capsulatum) should be explored.
Associated symptoms of fever and chills should raise the suspicion of infective etiologies, both pulmonary and systemic. Some systemic diseases, commonly rheumatologic or autoimmune, present with respiratory tract manifestations. Review of systems should include evaluation for symptoms that suggest undiagnosed rheumatologic disease. These may include joint pain or swelling, rashes, dry eyes, dry mouth, or constitutional symptoms. Additionally, carcinomas from a variety of primary sources commonly metastasize to the lung and cause respiratory symptoms. Finally, therapy for other conditions, including both radiation and medications, can result in diseases of the chest.
The clinician's suspicion for respiratory disease often begins with a patient's vital signs. The respiratory rate is often informative, whether elevated (tachypnea) or depressed (hypopnea). In addition, pulse oximetry should be measured as many patients with respiratory disease will have hypoxemia, either at rest or with exertion.
Simple observation of the patient is informative. Patients with respiratory disease may be in distress, often using accessory muscles of respiration to breathe. Severe kyphoscoliosis can result in restrictive pathophysiology. Inability to complete a sentence in conversation is generally a sign of severe impairment and should result in an expedited evaluation of the patient.
The majority of the manifestations of respiratory disease present with abnormalities of the chest examination. Wheezes suggest airway obstruction and are most commonly a manifestation of asthma. Peribronchial edema in the setting of congestive heart failure, often referred to as “cardiac asthma,” can also result in diffuse wheezes as can any other process that causes narrowing of small airways. For this reason, clinicians must take care not to attribute all wheezing to asthma.
Rhonchi are a manifestation of obstruction of medium-sized airways, most often with secretions. In the acute setting, this may be a sign of viral or bacterial bronchitis. Chronic rhonchi suggest bronchiectasis or COPD. Bronchiectasis, or permanent dilation and irregularity of the bronchi, often causes what is referred to as a “musical chest” with a combination of rhonchi, pops, and squeaks. Stridor or a low-pitched, focal inspiratory wheeze usually heard over the neck, is a manifestation of upper airway obstruction and should result in an expedited evaluation of the patient as it can precede complete upper airway obstruction and respiratory failure.
Crackles, or rales, are commonly a sign of alveolar disease. A variety of processes that fill the alveoli with fluid result in crackles. Pneumonia, or infection of the lower respiratory tract and air spaces, may cause crackles. Pulmonary edema, of cardiogenic or noncardiogenic cause, is associated with crackles, generally more prominent at the bases. Interestingly, diseases that result in fibrosis of the interstitium (e.g., IPF) also result in crackles often sounding like Velcro being ripped apart. Although some clinicians make a distinction between “wet” and “dry” crackles, this has not been shown to be a reliable way to differentiate among etiologies of respiratory disease.
One way to help distinguish between crackles associated with alveolar fluid and those associated with interstitial fibrosis is to assess for egophony. Egophony is the auscultation of the sound “AH” instead of “EEE” when a patient phonates “EEE.” This change in note is due to abnormal sound transmission through consolidated lung and will be present in pneumonia but not in IPF. Similarly, areas of alveolar filling have increased whispered pectoriloquy as well as transmission of larger airway sounds (i.e., bronchial breath sounds in a lung zone where vesicular breath sounds are expected).
The lack of breath sounds or diminished breath sounds can also help determine the etiology of respiratory disease. Patients with emphysema often have a quiet chest with diffusely decreased breath sounds. A pneumothorax or pleural effusion may present with an area of absent breath sounds, although this is not always the case.
Remainder of Chest Examination
In addition to auscultation, percussion of the chest helps distinguish among pathologic processes of the respiratory system. Diseases of the pleural space are often suggested by differences in percussion note. An area of dullness may suggest a pleural effusion, whereas hyperresonance, particularly at the apex, can indicate air in the pleural space (i.e., pneumothorax).
Tactile fremitus will be increased in areas of lung consolidation, such as pneumonia, and decreased with pleural effusion. Decreased diaphragmatic excursion can suggest neuromuscular weakness manifesting as respiratory disease or hyperinflation associated with COPD.
Careful attention should also be paid to the cardiac examination with particular emphasis on signs of right heart failure as it is associated with chronic hypoxemic lung disease and pulmonary vascular disease. The clinician should feel for a right ventricular heave and listen for a prominent P2 component of the second heart sound, as well as a right-sided S4.
Pedal edema, if symmetric, may suggest cor pulmonale, and if asymmetric may be due to deep venous thrombosis and associated pulmonary embolism. Jugular venous distention may also be a sign of volume overload associated with right heart failure. Pulsus paradoxus is an ominous sign in a patient with obstructive lung disease as it is associated with significant negative intrathoracic (pleural) pressures required for ventilation, and impending respiratory failure.
As stated earlier, rheumatologic disease may manifest primarily as lung disease. Owing to this association, particular attention should be paid to joint and skin examination. Clubbing can be found in many lung diseases, including cystic fibrosis, IPF, and lung cancer, although it can also be associated with inflammatory bowel disease or as a congenital finding of no clinical importance. Patients with COPD do not usually have clubbing; thus, this sign should warrant an investigation for second process, most commonly an unrecognized bronchogenic carcinoma, in these patients. Cyanosis is seen in hypoxemic respiratory disorders that result in more than 5 g/dL deoxygenated hemoglobin.