Cough is one of the most common symptoms in internal medicine patients. It has a complex etiology and is highly susceptible to misdiagnosis and mismanagement. In particular, chronic cough patients with no obvious abnormalities on chest imaging are particularly confusing for clinicians. With the increasing concern about cough, clinical studies on the diagnosis and treatment of cough etiology have been conducted in China in recent years, and preliminary results have been obtained. In order to further standardize the diagnosis and treatment of acute and chronic cough in China and to strengthen clinical and basic research on cough, the Asthma Group of the Chinese Medical Association’s Division of Respiratory Diseases organized relevant experts, took into account the results of domestic and foreign clinical studies on cough, and jointly developed the Draft Guidelines for the Diagnosis and Treatment of Cough in 2005.
The 2005 version of the guidelines has served as a good guide for clinical practice and has received valuable comments and suggestions from many experts over the past three years of implementation. In order to further improve this guideline and incorporate the latest research progress in the field of cough at home and abroad, the Asthma Group revised it in 2008 and will promulgate it in 2009. The main revisions are as follows: The 2009 edition of the guideline was expanded from seven topics and annexes in the 2005 edition to nine topics and annexes. Two new topics, diagnosis and treatment of subacute (3-8 weeks duration) cough and empirical treatment of chronic cough, as well as two sections on the definition of cough and expectorant treatment, have been added, and “Assessment of the extent and efficacy of cough” has been added to the annexes. The following is a brief description of these aspects.
I. Definition and classification of cough
The etiology section of the Chinese guidelines includes definition, clinical manifestations, diagnostic criteria (specific), and treatment. This aspect of pathogenesis is not included in China, considering the clinical application.
(I) Definition of cough: It is a defensive reflex of the body that facilitates the removal of respiratory secretions and harmful factors, but frequent and violent coughing causes serious effects on the patient’s work, life and social activities.
(ii) Classification of cough.
Classification by time: acute <3 weeks ; subacute 3-8 weeks ; chronic R8 weeks
In the ’09 version, in addition to chronicity becoming >8 weeks, the classification by nature has been added to facilitate clinical diagnosis and treatment: dry cough and wet cough.
Medical history and auxiliary examination
1.History and physical examination
2.Related auxiliary examinations.
(1)Induced sputum examination
(2)Imaging examination
(3)Pulmonary function test
(4)Fiberoptic bronchoscopy
(5)24h esophageal pH monitoring: non-acidic reflux cannot be detected, and non-acidic reflux needs to be monitored by intraesophageal luminal impedance or bilirubin.
(6)Cough sensitivity test
(7)Others
III. Diagnosis and treatment of acute cough
(I) Common cold
1. Diagnostic criteria for the common cold: clinical manifestations of nasal-related symptoms, such as runny nose, sneezing, nasal congestion and postnasal drip influenza, throat irritation or discomfort, with or without fever.
2, the common cold treatment principles: treatment is based on symptomatic treatment, generally without the use of antibacterial drugs.
(1) decongestants: pseudoephedrine hydrochloride (30-60mg/time, tid), etc.
(2) Antipyretic drugs: antipyretic and analgesic class.
(3) Anti-allergic drugs: the first generation of antihistamines, such as chlorpheniramine maleate (2-4mg/dose, tid), etc.
(4) Cough suppressants: for severe cough, central or peripheral cough suppressants, Chinese medicines, etc. may be used if necessary.
(B) Diagnosis and treatment of acute bronchitis in (added in the 09 revision)
1. Definition: Acute tracheobronchitis is an acute inflammation of the tracheobronchial mucosa caused by biologic or abiotic factors. Viral infection is the most common cause, but often secondary to bacterial infection, cold air, dust and irritating gases can also cause the disease.
Clinical manifestations: self-limiting, systemic symptoms may disappear within a few days, but cough and sputum usually last 2-3 weeks. x-ray examination has no obvious abnormalities or only increased lung texture. On examination, the breath sounds of both lungs are coarse, and sometimes wet or dry woven grass can be heard.
3.Diagnosis: The diagnosis is mainly based on clinical manifestations.
4.Treatment: The treatment principle is based on symptomatic treatment. For severe dry cough, cough suppressants can be applied appropriately; for cough with sputum that cannot be easily coughed out, expectorants can be used. If there is bacterial infection, such as coughing purulent sputum or increased peripheral blood leukocytes, antibacterial drugs can be selected.
IV. Diagnosis and treatment of subacute cough
In the 09 revision, the term post-infectious cough is adopted, but some introduction to post-cold cough is also provided. Clinical manifestations of post-infectious cough: Patients mostly present with an irritating dry cough or coughing up a small amount of white mucus sputum, which can last for 3 to 8 weeks or even longer. x-ray chest examination is not abnormal. However, post-cold cough is often self-limiting and usually resolves on its own. In the Chinese cough guidelines, no specific criteria are mentioned for the diagnosis of post-cold cough.
1. The Japanese cough guidelines have the following principles for the diagnosis of post-cold cough.
1) Persistent cough after the disappearance of cold symptoms.
2) No obvious abnormalities on chest radiographs.
3) Normal spirometry and one-second rate.
4) No past history of chronic respiratory disorders.
5)Exclude other causes of chronic cough.
2. Japanese cough guidelines for post-cold cough treatment.
Antibacterial drug therapy is ineffective.
For some chronic prolonged cough, short-term application of central cough suppressants, antihistamine H1 receptor antagonists, etc. can be used.
For a few patients with intractable severe post-cold cough, a short-term trial of inhaled or oral glucocorticoid therapy, such as 10-20 mg of prednisone for 3-7 d, can be used if general treatment is ineffective.
V. Etiology of common chronic cough
Table 1: Etiology of common chronic cough
05 guidelines
Revised 09 guidelines
(I) Cough variant asthma (CVA)
(I) Cough variant asthma (CVA)
(ii)Postnasal drip syndrome (PNDs)
(ii) Upper airway cough syndrome (UACS, also known as PNDS)
(iii)Eosinophilic bronchitis (EB)
(iii)Eosinophilic bronchitis (EB)
(iv)Gastroesophageal reflux cough (GERC)
(IV)Gastroesophageal reflux cough (GERC)