Presentation on theme: "Cough & Expectoration Pulmonary Medicine Department Ain Shams University"— Presentation transcript:
Cough & Expectoration Pulmonary Medicine Department Ain Shams University
Definition Cough is a sudden and explosive forcing of air through the glottis to expel mucus or other material from the tracheobronchial tree. It is the most pathognomonic of all respiratory symptoms as it is an expression of disease in the upper respiratory passages, the bronchi or lungs.
A cough consists of the following steps: 1. An inspiration. 2. Closure of the glottis with relaxation of the diaphragm. 3. Forced expiration: Contraction of the expiratory muscles (abdominal and thoracic) to develop high intrathoracic pressure (up to 300 mmHg) that leads to pressure gradients between the bronchi and the atmosphere, then 4. Sudden opening of the glottis and expulsion of a burst of air through airways that were narrowed by the high intrathoracic pressure.
Cough may be either: A voluntary act (impulses from the cerebral cortex) or, A reflex response to irritation of the respiratory mucosa, mediated through a center in the medulla.
Stimuli reaching cough center arise from: Receptors located either in the respiratory passages (mechanoreceptors or chemoreceptors between the larynx and second order bronchi especially at bronchial bifurcations) Other organs outside the respiratory system (e.g. ear or diaphragm)
The cough reflex consists of: Afferent : Vagus and Glossopharyngeal nerves. Center : Cough Center in the Medulla. Efferent : Phrenic nerves, spinal nerves intercostals nerves and vagi recurrent laryngeal nerves.
Etiology (a)Inflammatory stimuli : acute viral laryngotracheal bronchitis, chronic bronchitis, pneumonias …..Etc (b) Chemical stimuli : inhalation of irritant gases e.g., cigarette smoke. (c) Thermal stimuli: inhalation of very hot or cold air. (d) Mechanical stimuli: from compression of the airways secondary to tumor, mediastinal tumor, or aortic aneurysm. Inhalation of foreign body. Postnasal drip is a common but often unrecognized form of mechanical stimulation leading to coughing.
DURATION OF COUGH Estimating the duration of cough is the first step in narrowing the list of possible diagnoses. There is controversy about how best to define chronic cough. We propose that cough be divided into three categories: Acute: defined as lasting less than three weeks; Subacute: lasting three to eight weeks; and Chronic: lasting more than eight weeks. Since all types of cough are acute at the outset, it is the duration of the cough at the time of presentation that determines the spectrum of likely causes.
Most Common Causes Of Cough In Adults Most Common Causes Of Acute Cough In Adults Common cold Allergic rhinitis Acute bacterial sinusitis Exacerbation of chronic obstructive pulmonary disease Bordetella pertussis infection
Most Common Causes Of Subacute Cough In Adults Postinfection B. Pertussis infection Subacute bacterial sinusitis Asthma
Most Common Causes Of Chronic Cough In Adults Postnasal-drip syndromes Nonallergic rhinitis Allergic rhinitis Vasomotor rhinitis Chronic bacterial sinusitis Asthma Gastroesophageal reflux disease Chronic bronchitis Angiotensin-converting– enzyme inhibitors Eosinophilic bronchitis
Complications of Cough Cardiovascular: Arterial hypotension Loss of consciousness Rupture of subconjunctival, nasal, and anal veins Dislodgement/malfunctioning of intravascular catheters
Neurologic: Cough syncope Headache Cerebral air embolism CSF fluid rhinorrhea Malfunctioning ventriculoatrial shunts Stroke due to vertebral artery dissection
Relation to posture: Related: Localized bronchial disease. On lying in one side Leaning forward Lying supine Not related: Generalized bronchial disease.
Treatment Drugs used in the treatment of cough are: 1. Drugs acting on CNS to depress the cough center: Opiates and Nonopiates antitussives. 2. Drugs acting on the afferent side of cough reflex: peripheral antitussives (depressing pulmonary receptors) & bronchodilators. 3. Drugs acting on efferent side of cough reflex: expectorants as alkaline, nauseant and stimulant expectorant e.g. Iodides 4. Mucolytics: drugs that reduce mucus viscosity as bromohexine, iodides, acetyl cysteine, trypsin, chemotrypsin 5. Postural drainage also helps expectoration.
Brassy Cough Intrathoracic tumours, especially aneurysm, compressing on the trachea cause cough with a metallic hard quality described as “brassy cough”. Back
Bovine Cough The non-explosive cough (a cough that lost its expulsive character) associated with recurrent laryngeal nerve paralysis. Back
Croup The paroxysms of coughing followed by a prolonged stridulous inspiration characteristic of pertussis. Back
A Bubbly Cough Indicates sputum in the larger airways and the likelihood of expectoration. Back
BHR Paroxysms of cough without sputum production occur in people with increased airway reactivity. They often follow upper respiratory viral infections and persist for some months as the reactive airways dysfunction syndrome. Back