Objective To investigate the causes of chronic cough in Chongqing City and assess the efficacy of specific therapy. Methods A total of 233 consecutively non-selected referred patients ( 136 females) whose cough duration more than eight weeks were studied. Their age[ median ( range) ] was 44. 5( 15-78) yrs and cough duration was 2. 6 ( 0. 2-30) yrs. They were diagnosed using a diagnostic protocol based on the Guideline on Diagnosis and Treatment of Chronic Cough established by China Medical Association and American College of Chest Physicians. The etiological diagnosis was made according to clinical manifestations, lab examinations, and response to specific therapy. The effects was assessed four weeks after the drug withdraw. Results The cause of chronic cough was confirmed in 216 patients ( 92. 7% ) . Seventeen patients( 7. 3% ) had not been definitely diagnosed. Cough due to a single cause was found in 163 patients ( 75. 45% ) , and due to multiple causes in 53 patients ( 24. 53% ) . The causes included upper airway cough syndrome ( UACS) in 127 patients( 44. 4% ) , cough variant asthma ( CVA) in 73 patients( 25. 5% ) , gastro-esophageal reflux cough ( GERC) in 26 patients( 9. 1%) , postinfectious cough and angiotensin converting enzyme ( ACE) inhibitor-induced cough in 6 patients( 2. 1% ) , atopic cough in 5 patients( 1. 7% ) , chronic bronchitis in 3 patients ( 1. 0% ) , respectively. After specific therapy based on diagnosis, cough cured in 59 patients ( 25. 3% ) , and alleviated in 114 patients ( 49. 3% ) , no response in 40 patients( 17. 1% ) . Conclusion The causes of chronic cough in different areas maybe variant. UACS, CVA and GREC are the main causes of chronic cough in Chongqing City. Specific therapy is effective in majority of patients with chronic cough.
临床上通常将以咳嗽为唯一症状或主要症状、时间超过 8周、胸部x检查无明显异常者称为不明原因慢性咳嗽，简称慢性咳嗽 。慢性咳嗽是内科门诊患者最常见的病症，与典型支气管哮喘、肺部感染、肺纤维化和支气管肺癌等疾病不同，由于缺乏典型的相关症状，胸片检查无异常，一些临床医生习惯性地给病人戴上“支气管炎或慢性支气管炎”(简称“慢支”)的帽子，给予止咳祛痰或反复使用多种抗生素治疗，当然临床疗效并不理想。我们进行的流行病学调查结果显示，72％的慢性咳嗽患者被诊断为“支气管炎、慢支或慢性咽喉炎”，而病因诊断显示其中慢性支气管炎仅占4％(该资料尚未发表)。 慢性咳嗽的病因非常复杂，但并非毫无规律可循。只要掌握正确的诊断方法，按照慢性咳嗽病因诊断程序，大部分患者实际上可以获得明确的病因诊断，根据病因进行特异性治疗能够取得良好的治疗效果。在诊断慢性咳嗽时主要应注意以下几个问题。
Objective To explore the effect of lower airway inflammation on the pathogenesis of upper airway cough syndrome( UACS) . Methods Ten cases of UACS and 10 cases of chronic rhinitis or sinusitis without cough were enrolled as group A and group B, respectively. And 10 healthy volunteers were included as controls( group C) . The cough threshold C2 and C5 to inhaled capsaicin, defined as the lowest concentration of capsaicin required to induce ≥2 and ≥5 coughs, was measured. The total and differential cell counts was determined in induced sputum, and the levels of histamine and prostaglandin E2 were analyzed in supernatant of sputum. Results Cough threshold was significantly lower in group A than group B [ C2: ( 0.65 ±0. 08) μmol / L vs ( 3.90 ±1. 37) μmol / L; C5: ( 1.59 ±0. 28) μmol / L vs ( 33.46 ±23. 71) μmol / L, P lt;0. 05] and comparable between group B and group C( P gt; 0. 05) . Group A, similar to group B( P gt; 0. 05 ) , contained more inflammatory cells, with decreased percentage of macrophages and increased percentage of neutrophils in induced sputum than group C( P lt; 0. 05) . Furthermore, the levels of histamine[ ( 9. 55 ±1. 89) ng/mL vs ( 2. 37 ±0. 25) ng/mL, P lt; 0. 05] and prostaglandin E2 [ ( 361. 71 ±39. 38) pg/mL vs ( 144. 34 ±15. 69) pg/mL, P lt; 0. 05] were higher in supernatant of induced sputum from group A than group B, while the latter was not different from group C( P gt; 0. 05) . Conclusion Increased cough sensitivity caused by airway inflammation may be important for the pathogenesis of UACS, and the activation of mast cells in mucosa of lower airway might be an important factor.
ObjectiveTo evaluates the values of fractional exhaled nitric oxide (FENO) in the treatment of chronic cough prospectively.MethodsSubjects with chronic cough were recruited from the outpatient clinic of China-Japan Friendship Hospital. All the patients accepted FENO tests, sputum cell counts, pulmonary function tests, bronchial provocation tests, serum IgE, cough symptom scores and Leicester Cough Questionnaire before and after treatment of 4 weeks.ResultsThere were 29 patients with cough variant asthma (CVA), 19 patients with eosinophilic bronchitis (EB) and 39 patients with other causes. The baseline FENO level of the subjects whose coughs were relieved after inhaled corticosteroids (ICS) therapy of 4 weeks was (63±42) ppb, significantly higher than those with bad-response [(28±13) ppb, P<0.01]. The proportion of FENO decrease after ICS therapy was not only significantly related to the proportion of eosinophilic decrease (r=0.54, P<0.01), but also significantly related to the proportion of decrease of cough symptom scores (r=0.48, P<0.01). To distinguish the good responders from bad responders, the optimal baseline FENO cutoff value was 36 ppb, with sensitivity of 82%, specificity of 93%, positive predictive value of 94%, negative predictive value of 87%, accuracy of 83%.ConclusionsThere is a good relationship between the FENO decreasing levels after ICS therapy and the reliefs of cough symptoms in the CVA and EB patients. Chronic cough patients with FENO value more than 36 ppb are indicated to respond to ICS therapy.
ObjectiveTo investigate the diagnostic value of bronchial provocation test in patients with chronic cough. MethodsA total of 550 chronic cough patients were selected in the 452nd Military Hospital from March 2011 to February 2012. These patients all underwent the basic lung function test and the bronchial provocation test (BPT) to acetylcholine so as to assess the bronchial hyper-reactivity by inhaling methacholine. The diagnostic value of BPT was then evaluated. ResultsAll included patients had normal lung function. There were 267 patients (48.5%) who showed positive results in BPT, of whom, 236 BPT-positive patients were finally diagnosed as cough variant asthma. After regular treatment, the cough symptoms were well controlled. ConclusionCough variant asthma is one of the main causes of chronic cough. The BPT is an important method of aiding the diagnosis of cough variant asthma which helps early diagnosis of it.
Objective To investigate the changes of small airway function，airway resistance and responsiveness of extrathoracic airway in chronic cough patients before and after bronchial provocation test (BPT)．Methods 68 chronic cough patients were requested to conduct lung function test and BPT．The airw ay resistance were measured via forced oscillationary technology before and after BPT．Results BPT revealed airway hyperresponsiveness in 52％subjects．MEF50 and R0 before BPT were significantly different between the patients with or without airway hyperresponsiveness．Post BPT changes in MEF50(MEF50％) were correlated positively to the changes in FEV1(FEVl％)，and negatively to the changes in R0[Ro-d]． Extrathoracic airway hyperresponsivenes(EAHR)was f0und in13 patients，in which 6 patients were not revealed by routine BPT．Conclusion There is small airway function abnormalities in chronic cough patients．Extrathoracic airway responsiveness test is a valuable supplementary index to routine BPT．
Detection of the fraction of exhaled nitric oxide (FeNO) is a safe, simple and easy method to assess airway inflammation noninvasively. Thus, FeNO detection has been paid more attention to diagnosis and guide treatment of pulmonary diseases. The common feature of pneumonia, asthma, chronic obstructive pulmonary disease and chronic cough is the existence of varying degrees of airway inflammation. In this review, FeNO production and its potential pathologic and physiologic role in various pulmonary diseases were discussed.