Cough: Make It Easy. Kreetha Thammakumpee Respiratory and Respiratory Critical Care Medicine Faculty of Medicine, Prince of Songkla University

Transcription

1 Cough: Make It Easy Kreetha Thammakumpee Respiratory and Respiratory Critical Care Medicine Faculty of Medicine, Prince of Songkla University

2 Cough: definition Acute < 3 wk Subacute 3-8 wk Chronic cough > 8 wk, Female > Male

3 Cough reflex arc Location of cough Receptors* Larynx and supralaryngeal area Trachea and bronchi Ear canals and eardrums Pleura, pericardium and diaphragm Esophagus and stomach Nerve Vagus CNS cortical modulation Cough center (medulla, nucleus tractus solitarius) Nerve Spinal motor Phrenic Vagus Effector Expiratory muscles, Including pelvic sphincters Diaphragm Larynx Trachea Bronchi

4 Common causes of acute cough Infection Acute exacerbation of chronic pulmonary disease Pneumonia Pulmonary embolism

5 Common associations with chronic cough Gastroesophageal reflux Rhinosinusitis (UACS/postnasal drip) Asthma Eosinophilic bronchitis Upper respiratory tract infection Obstructive sleep apnea Chronic tonsillar enlargement Chronic snoring ACEI

6 Upper Airway Cough Syndrome: UACS Allergic, infection, vasomotor etiologies are most common Stimulation of cough receptors within the laryngeal mucosa Nasal discharge, a sensation of liquid dripping into the back of the throat, and frequent throat clearing

7 Upper Airway Cough Syndrome: UACS May also be "silent Clues on physical examination are a cobblestone appearance and the presence of secretions in the nasopharynx Lack of a diagnostic test A trial of Rx is usually the first line of investigation

8 Postnasal drip and chronic cough? Postnasal drips not always associated with cough No unique features in history, examination, or investigations that identify UACS as a cause of cough Rx nasal corticosteroids and /or antihistamines

9 Silent postnasal drip or unexplained chronic cough? Patients with chronic cough & no symptoms of rhinosinusitis but respond to upper-airway specific Rx Irwin RS. 2006; 129(1.suppl):1s-23s. The prevalence of silent postnasal drip range from zero to significant numbers The improvement in cough with antihistamines - Action on the central and peripheral cough reflex rater than an effect on rhinosinusitis

10 Asthma 2 nd leading cause in adult and most common cause in children Typical asthma VS. cough variant asthma Reversible airflow obstruction or positive bronchoprovocation test does not necessarily prove that the cough is secondary to asthma

11 Asthma and Cough One study evaluated the utility of spirometry pre-and post-bronchodilator in predicting that asthma was responsible for cough. - Spirometry was falsely positive in 33% - Methacholine challenge test was falsely positive in 22%. Irwin RS. Am Rev Respir Dis 1990; 141:640. Dx by appropriate therapeutic trial

12 Cough variant asthma PEFR monitoring and bronchodilator responsiveness - Poor diagnostic sensitivity and specificity Methacholine challenge test - High negative predictive value - Poor positive predictive value Sputum eosinophil cell count and exhaled nitric oxide measurement - High sensitive and specific predictive value - Predictive of response to corticosteroid therapy

13 Eosinophilic Bronchitis Eosinophilic airway inflammation Absence of airway hyperresponsiveness ICS is the first line Rx and effective

14 GERD associated chronic cough The second or third most common cause of persistent cough Pathogenesis - Stimulation of receptors in the upper respiratory tract - Aspiration of gastric contents - An esophageal-tracheobronchial cough reflex induced by reflux of acid into the distal esophagus.

15 Are tests for GERD necessary? Symptoms can vary and are not always present GERD +ve in patients with cough due to other conditions Esophageal ph monitoring is poor predictive value in determining the response to Rx for GERD 28% of patients with chronic cough + esophageal ph test +ve response to PPIs Rx Patterson et al. Eur Respir J 2004; 24: At present, the routine use of objective investigation of GERD cannot be recommended

16 Are PPIs effective in chronic cough? Several randomized controlled trials of PPIs in chronic cough have not confirmed the success of earlier uncontrolled studies RCT - 56 patients with chronic cough - Esomepraxole 20 mg bid VS. placebo Chang AB. BMJ 2006; 332: Cough related-quality of life was not significantly different Fathi H. Thorax 2008;63:s47

17 Does laryngopharyngeal reflux cause cough? Reflux of gastric contents into the laryngopharynx Overlap with GERD cough PPIs are recommended for LPR

18 Respiratory tract infection Organisms - Mycoplasma pneumonia - Chlamydophila pneumonia - Bordetella pertussis Several possibly interrelated mechanisms - Secretions from a postnasal drip - Enhanced sensitivity of airway nerves - Airway inflammation following acute viral respiratory infections

19 ACE inhibitors Hypothesized that accumulation of bradykinin Usually begins within one week of Rx, but the onset can be delayed up to six months. Often presents with a tickling, scratchy, or itchy sensation in the throat Typically resolves within one to four days of discontinuing therapy, but can take up to four weeks.

20 ACE inhibitors Generally recurs with rechallenge More common complication in women than in men Does not occur more frequently in asthmatics than in non-asthmatics. Generally not accompanied by airflow obstruction

21 Rare Causes Swallowing dysfunction may lead to recurrent aspiration Lesions that compress the upper airway Chronic tonsillar enlargement Irritation of the external auditory canal Premature ventricular contractions (PVCs) Holmes-Adie syndrome due to autonomic dysfunction Psychogenic

22 Unexplained chronic cough Distinct condition or inadequate therapy? Inadequate Rx - poor compliance with therapy - ineffective therapy Idiopathic chronic cough (cough hypersensitivity syndrome) - Female, middle-aged, onset of cough around menopause - viral illness at onset of cough - association with airway infection with Bordetella pertussis and basidiomycetous fungi - High level of anxiety or depression

23 DIAGNOSTIC APPROACH

24 An Algorithmic Approach to Chronic Cough Melvin R. Pratter. Ann Intem Med. 1993;119: Objectives: To evaluate a stepwise approach to chronic cough that emphasized initial treatment of all patients with an antihistamine-decongestant for postnasal drip and to determine the value of routine bronchoprovocation challenge in the evaluation of chronic cough. Design: Prospective trial using an algorithm for chronic cough in immunocompetent nonsmoking outpatients. Patients: Forty-five patients met the inclusion criteria. The mean duration of cough was 140 weeks (range, 3 to 2080 weeks)

25 Step 0: Hx + PE. + Spirometry + Methacholine Step 1: Azatadine + Pseudoephredine Yes Improvement no Cont. Rx + nasal corticosteroid Go to step 2 Resolved or no further improvement no Sinusitis X-ray Yes Cont.Rx Rx sinusitis

26 Step 2: Bronchoprovacation test +ve -ve Inhaled beta2- agonist Step 3 CXR Add Prednisolone 1mg/Kg/day Abnormal Normal Evaluation Go to step 4

27 Step 4: Symptom of GERD + ve Ranitidine + antireflux measure - ve + ve Cont. Rx Response - ve 24 hr esophageal probe monitoring + ve Omiprazole 20 mg/day 8 wk - ve Go to step 5

28 Step 5: Bronchoscopy -ve +ve Rx Asthma Rx Etiology Not improved Psychogenic cough was consider

29 An Algorithmic Approach to Chronic Cough Melvin R. Pratter. Ann Intem Med. 1993;119: Results - Marked improvement and resolution (mean, 3.1 and 7.1 weeks, respectively), with resolution in 96% of patients. - Antihistamine-decongestant therapy was beneficial in 39 of 45 patients and was the only therapy needed for 16 patients. - Bronchoprovocation challenge had a negative predictive value of 100% and a positive predictive value of 74% for cough caused by asthma.

30 RECOMMENDATION for DIAGNOSTIC APPROACH

31 Cough > 3 week History, physical exam suggest post-nasal drip, asthma or GERD History, physical exam do not strongly suggest cause or do suggest pulmonary parenchymal disease Purulent sputum OR Smoker OR ACE inhibitor treatment OR Immunocompromised host Treat accordingly Evaluate and treat accordingly (eg,antibiotics; smoking cessation; stop ACE inhibitor) Cough resolved Cough persists Chest radiograph Cough persists Cough resolved

32 Chest radiograph Normal Abnormal Sequentially treat (or evaluate): UACS, Asthma, Non-asthmatic eosinophilic bronchilic, GERD Evaluate based on the nature of The radiographic abnormality Treat accordingly Treat accordingly Cough resolved Cough persists Evaluate for less common conditions Treat accordingly Cough persists Cough resolved Cough resolved Cough persists Always reconsider adequacy of treatment regimens Before considering cough to be psychogenic

33 TREATMENT

34 Upper airway cough syndrome Allergic rhinitis - intranasal glucorticosteroids - oral and nasal antihistamines - oral decongestants - oral leukotriene receptor antagonists Non-allergic rhinitis - oral first generation antihistamine - or a combined antihistamine-decongestant 1 ST gen. antihistamines are preferred over 2 nd gen. due to the stronger anticholinergic effect - intranasal administration of one of the following: azelastine, glucocorticoid, and ipratropium bromide

35 GERD Lifestyle modifications Proton pump inhibitor Prokinetic

36 NONSPECIFIC TREATMENT Centrally acting antitussive agents - Dextromethorphan - Codeine - Morphine - Gabapentin Peripherally acting antitussive agents - Benzonatate - Thalidomide - Nebulized lidocaine

37 Thank you for your attention