Cough (Case 9)

Chapter 15
Cough (Case 9)

Ranjit Nair MD and Sean M. Studer MD, MSc

Case: The patient is a 66-year-old man with a history of diet-controlled diabetes mellitus who works as a truck driver and has not seen a physician for more than 10 years. He presents to the emergency department from home in respiratory distress for the past 8 hours. He admits to having rhinorrhea for the past 2 weeks, a cough with rust-colored sputum for the past 3 days, and right-sided chest pain every time he takes a deep breath. He also reports some shaking chills and subjective fever. He has never been hospitalized and has no known drug allergies. He smokes cigarettes only when he is drinking alcohol on the weekends.

On physical exam, his vital signs are temperature of 102.1° F orally, pulse of 105 beats per minute (bpm), respiratory rate of 30 breaths per minute, and blood pressure of 135/80 mm Hg; pulse oximetry is 85% on room air and 96% on 4 L oxygen via nasal cannula. In general, he appears anxious. On lung exam, crackles are auscultated at the right base.

Differential Diagnosis


Acute bronchitis




Cystic fibrosis


Speaking Intelligently

Cough is one of the most common respiratory complaints. Acute cough can be a symptom of a potentially life-threatening illness (e.g., pneumonia or pulmonary embolism), although most episodes are of minor consequence. Chronic cough (i.e., persisting for more than 3 weeks) is much more common and is associated with conditions such as postnasal drip, asthma, gastroesophageal reflux, chronic bronchitis, and bronchiectasis. Medications, specifically angiotensin-converting enzyme (ACE) inhibitors, may also be associated with chronic cough. Lung cancer and aspiration are less common etiologies of chronic cough.


Clinical Thinking

• Duration may be an important clue as to etiology of cough.

• Acute cough occurs in those with upper and lower respiratory infections, inhalation of noxious gases or chemicals, and aspiration.

• Chronic cough (i.e., cough persisting for more than 3 weeks) is usually explained by a careful history and physical examination, followed by specific diagnostic tests.

• For a cough to be worrisome enough for the patient to undergo a thorough assessment, it should be present for at least 6 to 8 weeks, not just a residual effect from a preceding respiratory tract infection.


• Include associated symptoms of fever, chills, pleuritic chest pain, and dyspnea.

• If the cough is productive, the character of the sputum should be described, including whether or not blood is present.

• Medication history may detect current use of an ACE inhibitor.

• A history of cigarette smoking, including current use and pack-year history, should prompt counseling regarding smoking cessation.

• Risk factors for pulmonary tuberculosis should be sought.

• Multiple prior lung infections might suggest bronchiectasis.

• Cystic fibrosis should be considered in the right clinical setting.

Physical Examination

• Given the possibility that postnasal drip may trigger cough, a thorough examination of the nose, sinuses, pharynx, and larynx should be performed.

• Associated wheezing may suggest the diagnosis of asthma or obstructive lung disease, or perhaps congestive heart failure.

• In the patient with acute cough, dullness to percussion, increased tactile fremitus, and localized crackles are strongly suggestive of bacterial pneumonia.

Tests for Consideration

Sputum analysis (Gram stain, acid-fast bacillus [AFB] smears, cytology) and culture may suggest a specific etiology, although fiberoptic bronchoscopy may be required if the diagnosis remains elusive.


Blood cultures in patients in whom bacterial pneumonia is suspected


• Rapid testing of nasopharyngeal specimens for influenza A and B antigens in the appropriate clinical setting


Pulmonary function tests (PFTs) if airway obstruction is considered likely



→ Chest radiography is indicated, although a radiographic image rarely identifies the etiology.


→ CT imaging may be required, depending upon the likely etiology.


Clinical Entities Medical Knowledge


Pneumonia is an infection of the lung parenchyma, usually occurring after aspiration of upper airway resident flora or inhalation of aerosolized material. Bacterial pneumonia is a common cause of morbidity and mortality in older adults, especially in those with comorbidities such as diabetes or congestive heart failure. A yearly influenza vaccine is important for all patients. Immunization with the 23-valent pneumococcal polysaccharide vaccine is recommended for all patients over the age of 64 years and other adults with specific risk factors. The 13-valent pneumococcal conjugate vaccine has recently been FDA approved for use in adults 50 years of age and older. The most common pathogens associated with community-acquired bacterial pneumonia are Streptococcus pneumoniae, Mycoplasma pneumoniae, Chlamydophila pneumoniae, Legionella pneumophila, Haemophilus influenzae, and Moraxella catarrhalis.


The patient with community-acquired bacterial pneumonia typically has fever, rigors, pleuritic chest pain, and cough productive of purulent sputum. In patients with atypical pneumonia the fever may be low grade, and patients may have nonproductive cough and no chest pain. However, there is variation in the initial symptoms and signs such that these presentations cannot reliably distinguish the specific infectious cause of the pneumonia. On physical exam there may be signs of consolidation, which can include the presence of localized dullness to percussion, increased tactile fremitus, and crackles. Examples of these sounds can be heard at this website:


Chest radiographs (PA and lateral) reveal parenchymal opacities, which will establish the diagnosis in the appropriate clinical setting (i.e., leukocytosis, fever, sputum production). A CBC with differential may help determine if there is a bacterial infection, and specifically, a differential will indicate a “left shift,” or increased numbers of bands, which suggests that a bacterial etiology is likely. An ABG measurement may help determine the severity of hypoxemia and inpatient disposition (i.e., whether admission to the ICU is necessary).

Pathogen identification should be attempted before antimicrobial therapy is initiated; this is especially important whenever the result is likely to change the approach to management, especially in patients in whom drug-resistant pathogens are eventually isolated. Pretreatment blood cultures should be drawn. Sputum Gram stain and culture should be obtained in hospitalized patients, because sensitivities can help guide therapy and help tailor antibiotics toward a specific organism. Patients with severe community-acquired pneumonia should also have urinary antigen tests sent for L. pneumophila and S. pneumoniae, although the Legionella urinary antigen is positive only in cases caused by L. pneumophila serogroup I. CT of the chest is usually not necessary to establish the diagnosis but should be considered if a complicated infection is considered (e.g., post-obstructive pneumonia or empyema). HIV testing should be considered in patients who have risk factors associated with this disease. A diagnosis of HIV would be important to know so as to also consider infection caused by certain opportunistic organisms (e.g., Pneumocystis jirovecii or Mycobacterium tuberculosis).


The decision concerning disposition of patients with community-acquired pneumonia is sometimes difficult; there have been a few proposed criteria to determine inpatient vs. outpatient therapy. One proposed severity of illness criterion that may help predict a complicated course is CURB-65. Scoring 1 point for each criterion, patients with a score of 0–1 can be managed as outpatients, those with a score of 2 should be admitted to a hospital ward, and those with scores of 3 or higher often require ICU care. Another model (the pneumonia severity index [PSI] from the Pneumonia Patient Outcomes Research Team) stratifies patients into five mortality risk classes. Although use of these objective criteria may decrease the number of hospitalized patients with community-acquired pneumonia, subjective factors (such as the ability of the patient to safely and reliably take oral medications) must be considered. Admission to an ICU is required for patients with community-acquired pneumonia who develop septic shock requiring vasopressors or have acute respiratory failure requiring intubation and mechanical ventilation.

Specific antimicrobial recommendations for patients with community-acquired pneumonia depend on resistance of pathogens to commonly used antimicrobial agents and local susceptibility patterns. In previously healthy outpatients with community-acquired pneumonia and no history of antimicrobial use within the past 3 months, therapy should be a macrolide (e.g., azithromycin or clarithromycin) or doxycycline. Recommended empiric antimicrobial therapy for a hospitalized non-ICU patient includes a respiratory fluoroquinolone (e.g., levofloxacin, gemifloxacin, or moxifloxacin) or a macrolide combined with a β-lactam (e.g., ceftriaxone or cefuroxime). For patients admitted to the ICU, a β-lactam plus either azithromycin or a respiratory fluoroquinolone should be used. For patients in whom infection caused by methicillin-resistant Staphylococcus aureus (MRSA) is also possible, vancomycin or linezolid should be added. See Cecil Essentials 22, 99.


Acute Bronchitis

Bronchitis is inflammation of the respiratory system, which includes the nasal passages down to the trachea and bronchi but does not include the lung parenchyma, so the chest radiograph is clear. Acute bronchitis is most commonly a result of a viral infection that may last up to 2 weeks but occasionally may be caused by bacterial pathogens similar to those that cause community-acquired pneumonia.


Patients with bronchitis usually present with a several-day history of symptoms such as fever, rhinorrhea, and cough, which may be purulent in nature. Patients may suffer from sore throat due to a pharyngeal irritation secondary to cough. Patients also may have been exposed to a sick contact.


A patient with clinical presentation of an acute onset of fever, cough, and purulent sputum, but normal chest radiograph, is most likely suffering from acute bronchitis. The Gram stain, culture, and sensitivity of the sputum may reveal the infecting pathogen but are not usually part of routine management.


Management of acute bronchitis is generally directed at the symptoms. Antitussive therapy (based on the cause of the cough) is indicated if the cough is creating significant discomfort and suppressing the body’s protective mechanism for airway clearance; an antihistamine would be used to treat cough associated with allergic rhinitis; a decongestant or an antihistamine would be selected for cough associated with postnasal drainage; and a bronchodilator would be appropriate for cough associated with asthma exacerbation. Antibiotic therapy should be considered only for patients who do not respond to symptomatic treatment and a bacterial infection is suspected.


Tuberculosis (TB)

TB is an infectious disease caused by M. tuberculosis, an airborne infection that is spread through the respiratory secretions of people with active TB. Droplet nuclei travel directly to alveoli upon inspiration. Tubercle bacilli incite an inflammatory response known as granulomatous inflammation.


The typical presentation of a patient with tuberculosis is cough for several weeks associated with fever, night sweats, and weight loss. The patient will often describe waking up with the bed sheets being soaked or drenched with sweat. Patients who abuse injection drugs, are incarcerated, are indigent, or are from high-incidence locations (e.g., foreign endemic areas) are at increased risk for TB.


Diagnosis can be suggested by positive sputum smears for acid-fast bacilli. Bronchoscopy for sputum is also useful in establishing the diagnosis in some cases, if acid-fast smears of expectorated sputum are negative. If the AFB smear is positive, nucleic acid amplification tests such as polymerase chain reaction (PCR) on the sample can be performed to specifically probe for M. tuberculosis. Cultures and in vitro susceptibility testing are necessary for definitive diagnosis and to guide antituberculous chemotherapy.


The combination of isoniazid, rifampin, pyrazinamide, and ethambutol is often used for the first 2 months in the treatment of pulmonary TB until in vitro sensitivities are known. Once it is determined that the infection is not drug-resistant TB, the patient may continue with only rifampin and isoniazid for a total duration of 6 months. It is important to note that vitamin B6 should be prescribed to prevent peripheral neuropathy in patients predisposed to neurologic toxicity because of the use of higher isoniazid doses, nutritional deficiency, diabetes mellitus, HIV infection, renal failure, and alcoholism, and in pregnant or breastfeeding women. See Cecil Essentials 22, 99.



Influenza results from infection with one of three basic types of influenza virus—A, B, or C. Influenza virus infection occurs after transfer of respiratory secretions from an infected individual to a person who is immunologically susceptible. If not neutralized by secretory antibodies, the virus invades airway and respiratory tract cells. Once the virus is within host cells, cellular dysfunction and degeneration occur, along with viral replication and release of viral progeny. Systemic symptoms result from inflammatory mediators, similar to other viruses.


The incubation period of influenza ranges from 18 to 72 hours. Patients typically present with acute onset of fever, cough, chills, and myalgias. Patients will also have typical upper respiratory tract infection symptoms including sinus congestion, rhinorrhea, and sore throat.


The standard for diagnosing influenza A and B is viral culture of nasopharyngeal samples and/or throat samples. Rapid tests (enzyme immunoassays or nucleic acid detection–based assays) can document influenza A or B virus rapidly but have limited sensitivity (50–70%) in adults. Due to costs, sensitivity, and availability, however, most physicians make the diagnosis based on clinical suspicion. A chest radiograph may be useful in helping to exclude pneumonia.


Prevention is important for control of influenza. The CDC recommends influenza vaccination for all persons 6 months of age and older. People with a severe egg allergy should not get the vaccine. Recommendations and updates for use of influenza vaccines can be found at

Oseltamivir has been shown in clinical trials to reduce duration of symptoms in patients suffering from influenza if initiated within 2 days of the onset of symptoms, although some influenza viruses are now resistant to this agent. Patients severely ill with novel H1N1 influenza virus should be treated with oral oseltamivir or inhaled zanamivir. See Cecil Essentials 22, 95, 99, 110.



Bronchiectasis is irreversible dilation and destruction of large bronchi secondary to chronic infection and inflammation. This destruction is facilitated by the fact that most of the causes are related to impaired mucus clearance. The most common causes are repeated infections, cystic fibrosis, and immune defects.


A patient who has developed bronchiectasis due to persistent infections may present with cough for many years and a history of recurrent pneumonia. A patient with bronchiectasis may have a similar presentation to that of a patient with pneumonia, but the patient with bronchiectasis has many recurring episodes associated with a longer course. Eliciting a history of copious sputum production on a daily basis also points to a possible diagnosis of bronchiectasis.


A diagnosis of bronchiectasis can be made on chest radiograph, where one will find the typical tram-track appearance caused by dilated, thick-walled bronchi. High-resolution CT of the chest is the test of choice, however, for defining the extent of bronchiectasis; the test is nearly 100% sensitive and specific. The CT typically shows thickening of the airways characterized by tram-track parallel lines or ring shadows representing thickened bronchial walls when imaged in cross-section.


Treatment is based on treating the underlying cause of the bronchiectasis. It is important to treat infections with appropriate antibiotics, so cultures and sensitivities should be known. Prophylactic antibiotics are considered controversial because of their implication in promoting infection caused by resistant organisms. Chest physiotherapy and postural maneuvers have been shown to improve or facilitate mucus clearance but have never been shown to improve morbidity or mortality. In some patients, surgery to remove a localized area of bronchiectasis may be an option to reduce future morbidity. See Cecil Essentials 17.


Cystic Fibrosis (CF)

CF is a result of a defect in the gene encoding the CFTR protein. This protein is responsible for the flow of electrolytes across cell membranes. The abnormalities in salt and water transport across the cell membrane in patients with CF lead to a change in the composition of respiratory tract secretions, resulting in impaired mucociliary clearance, predisposition to infection, and airway obstruction. This eventually progresses to end-stage lung disease in many affected patients.


Patients with CF typically present with recurring episodes of pneumonia throughout their lifetime. CF has several clinical manifestations in other organ systems, especially the gastrointestinal, endocrine, and reproductive systems. The gastrointestinal manifestations include fat malabsorption due to exocrine pancreatic insufficiency and distal intestinal obstruction syndrome (DIOS) due to thick mucus blocking bowel contents. Pancreatic damage also results in reduced insulin secretion and diabetes, while infertility is common in males due to congenital absence or obstruction of the vas deferens.


The sweat chloride test, in combination with newborn screening and/or a sibling with a known diagnosis of CF, can establish the diagnosis. The sweat chloride test must be repeated twice to be considered abnormal; in adults, a level > 60 mEq/L and a typical clinical presentation are suggestive of CF. The criteria for diagnosis are elevated sweat chloride level on two occasions or identification of mutations known to cause CF in both CFTR genes or in vivo demonstration of characteristic abnormalities in ion transport across the nasal epithelium, plus one or more phenotypical features of CF, as follows: sino-pulmonary disease, characteristic nutritional or gastrointestinal disorders, obstructive azospermia, salt loss syndrome, a sibling with CF, or positive newborn screening.


Treatment is based on treating the underlying pneumonia and using techniques that will help the patient with mucociliary clearance. Because of the increased likelihood of bacterial infection caused by Pseudomonas aeruginosa and Burkholderia cepacia, antimicrobial therapy should be directed toward these pathogens. Postural techniques have been shown to improve mucus drainage but not to improve morbidity or mortality. At this time prophylactic antibiotics are not recommended, as they may increase drug resistance yet bring about no improvement in pulmonary function or rate of infection. Dornase alfa, which selectively cleaves DNA, reduces mucus viscosity and, as a result, improves airflow in the lung. Improved pulmonary function decreases the risk of bacterial infection. Supplemental oxygen may be used in patients with exercise-induced or resting hypoxemia. In patients with end-stage lung disease, transplantation may be an option. See Cecil Essentials 17.

Oct 3, 2016 | Posted by in MANUAL THERAPIST | Comments Off on Cough (Case 9)
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