Chronic Cough--Evaluation and Treatment

1. 1/25/2012 1 Chronic Cough--Evaluation and Treatment Bill Mariencheck

2. 1/25/2012 2 Introduction Subacute cough--- one lasting for more than three weeks; Chronic cough--- lasting more than eight weeks The fifth most common symptom seen in outpatient offices Patients often present with cough complication This discussion provides a brief review of common causes, evaluation techniques and treatment of common cough syndromes

3. 1/25/2012 3 Chronic Cough Physiology Each cough occurs through the stimulation of a complex reflex arc. Cough receptors exist not only in the epithelium of the upper and lower respiratory tracts, but also in the pericardium, esophagus, diaphragm, and stomach. Mechanical cough receptors can be stimulated by triggers such as touch or displacement. Chemical receptors are sensitive to noxious gases or fumes. Laryngeal and tracheobronchial receptors respond to both mechanical and chemical stimuli. Sex-related differences in cough reflex sensitivity explain the observation that women are more likely than men to develop chronic cough

4. 1/25/2012 4 Major causes of chronic cough 1981 1996 Post nasal drip 47% 38% Upper airway cough syndrome (UACS) Asthma 43% 14% GER 10% 40% Chronic Bronchitis 12% Bronchiectasis 0% 4% Miscellaneous 6% More than one Dx 18% 72%

5. 1/25/2012 5 Other Causes of Chronic Cough Post infectious causes-- both bacterial and viral respiratory pathogens Complications of drug therapy Airway disorders– Chronic Bronchitis due to its various causes, Bronchiectasis, Neoplasms and foreign bodies Parenchymal lung disorders– Interstitial diseases, lung abscess, chronic infections

6. 1/25/2012 6 Cough and Post Nasal Drip (UACS) Underlying reasons for postnasal drip include allergic, perennial nonallergic, and vasomotor rhinitis; acute nasopharyngitis; and sinusitis Symptoms of postnasal drip include frequent nasal discharge, a sensation of liquid dripping into the back of the throat, and frequent throat clearing Clues on physical examination are a cobblestone appearance to the nasopharyngeal mucosa and nasophryngeal secretions response to therapy secures the diagnosis

7. 1/25/2012 7 Non Pulmonary Causes of Chronic Cough (ENT Perspective) 1. Laryngopharyngeal reflux (GERD) 2. Neurogenic cough (post viral vagal neuropathy) 3. Asthma, allergy, sinusitis, PND 4. Aspiration due to glottic insufficiency 5. ACE inhibitors 6. Zenker’s diverticulum Amin MR and Koufman JA Am J of Otolaryngology 22:251-256, 2001

8. 1/25/2012 8 Post Viral Vagal Neuropathy Possibly initiated by viral upper respiratory infection resulting to injury of vagal branches Aberrant regeneration of fibers after neuropathy may result in vocal fold paresis and other motor and sensory dysfunction including pain Laryngopharyngeal reflux is often associated and contributes to cough persistence Treatment : ? amitriptyline, ? reflux Rx, gabapentin,

9. 1/25/2012 9 Cough and (Cough Variant) Asthma Suggested when the patient is atopic or has a family history of asthma Cough may be seasonal, may follow an upper respiratory tract infection, or may worsen upon exposure to triggers Airways hyperreactivity can be demonstrated by bronchoprovocation testing. However, in a patient with persistent cough, the presence of reversible airflow obstruction or a positive bronchoprovocation test does not necessarily prove that the cough is secondary to asthma the best way to confirm asthma as a cause of cough is to demonstrate improvement in the cough with appropriate therapy for asthma

10. 1/25/2012 10 Cough and Gastroesophageal Reflux Factors responsible for cough with GER Many patients complain of symptoms of gastroesophageal reflux (heartburn or a sour taste in the mouth); however, these symptoms are absent in more than 40 percent of patients in whom cough is due to reflux Aspiration of gastric fluids Stimulation of laryngeal receptors An esophageal-tracheobronchial cough reflex induced by reflux of acid into the distal esophagus esophageal pH monitoring, ideally performed with event markers to allow correlation of cough with esophageal pH, is generally considered the optimal diagnostic study, with a sensitivity exceeding 90 percent

11. 1/25/2012 11 Respiratory tract infection and chronic cough Cough following viral or other upper respiratory tract infection can persist for more than eight weeks after the acute infection Mechanisms include: Upper Respiratory secretions Enhanced sensitivity of airway nerves airway hyperresponsiveness Common bacterial organisms include Mycoplasma pneumoniae, Chlamydia pneumoniae, and Bordetella pertussis bacterial suppurative disease of the large airways, in the absence of bronchiectasis, may be a cause of chronic cough

12. 1/25/2012 12 Chronic cough due to ACE Inhibitors A nonproductive cough is a complication of treatment with angiotensin converting enzyme (ACE) inhibitors, occurring in 3 to 20 percent of patients treated with these agents ? Bradykinnin related ACE inhibitor-induced cough has the following general features : usually begins within one week of instituting therapy, but the onset can be delayed up to six months It typically resolves within one to four days of discontinuing therapy, but can take up to four weeks It generally recurs with rechallenge, either with the same or a different ACE inhibitor It is a more common complication in women than in men It does not occur more frequently in asthmatics than in non-asthmatics It is generally not accompanied by airflow obstruction

13. 1/25/2012 13 Cough and Non Asthmatic Eosinophilic Bronchitis Patients with this disorder demonstrate atopic tendencies, with elevated sputum eosinophils and active airway inflammation in the absence of airway hyperresponsiveness bronchial mucosal biopsies are required to definitively diagnose eosinophilic bronchitis a trial of therapy is usually performed without biopsy, since most patients respond well to inhaled corticosteroids One year follow-up of 367 patients with normal lung function and eosinophilic inflammation noted that: 55 percent remained symptomatic with normal lung function, 32 percent were free of symptoms 13 percent developed asthma

14. 1/25/2012 14 Cough and Lung Cancer lung cancer is the etiology in less than 2 percent of the cases of chronic cough but is deadly to the patient and to the doctor if undetected--- CT scan, when? Most cases of lung cancer that manifest with cough are due to neoplasms originating in the large central airways Bronchogenic cancer should be considered as a possible etiology of cough in any current or former smoker, and should be particularly suspected in those with: A new cough or a recent change in chronic "smoker's cough" A cough that persists more than one month following smoking cessation Hemoptysis that does not occur in the setting of an airway infection

15. 1/25/2012 15 Chronic Cough-- Treatment treatment aimed at the underlying disorder is reported to be successful in more than 95 percent of patients The role of nonspecific therapy is limited because a definitive determination of the cause of chronic cough can be made in most patients: Centrally acting antitussive agents Ipratropium bromide Inhaled corticosteroids

16. 1/25/2012 16 Chronic Cough-- Treatment Post nasal drip (UACS): Older antihistamine-decongestant combinations may work best Therapy directed at cause of the PND– including antibiotics for sinusitis Ipratroprium nasal spray Nasal corticosteroids

17. 1/25/2012 17 Cough Variant asthma-- Treatment Same general principles as standard asthma therapy: The mainstays of therapy are inhaled bronchodilators and/or inhaled corticosteroids a short (one to two week) course of oral prednisone can be given Maintenance inhaled steroids may be needed

18. 1/25/2012 18 Cough Treatment-- GER Avoidance of reflux-inducing foods (fatty foods, chocolate, excess alcohol) Cessation of smoking Eating three meals a day without snacking Avoidance of meals for two to three hours before lying down Elevation of the head of the bed An H2 antagonist or a proton pump inhibitor—average time for response 2 to 6 months– be patient Role of aggressive therapy, UGI imaging and consultation