Acute cough Flashcards
what is acute cough
- caused by many resp diseases, aim is to protect resp tract
- voluntary or involintarily activated reflex arc
- triggered by chemical or mechanical stimuli
how is cough stimulated
- receptors in head, neck and chest are stimulated
- information transmitted to cough centre in medulla via afferent limb of vagus nerve
- get increased neural activity in efferent pathway to moth repsiratory musculature and airway
what are the 3 categories of acute cough
acute (lasting <3 weeks)
subacute (lasting 3–8 weeks)
chronic (lasting >8 weeks)
what is the most common cause of acute cough
viral ifnections of upper respiratory tract
*coughs can persist after infection (postinfectious)
what causes a cough in viral infections
arises from stimulation of cough relfex in upper resp tract caused by postnasal drip, cleaing or throat or both
what is an indication of a Bordetella pertussis or B. parapertussis infection
patients with subacute or chronic cough
or when the cough is paroxysmal or accompanied by vomiting
*refer
when to refer for acute cough
if breathing is compromised
high fever
seizures
frequent vomiting episodes
or the patient becomes dehydrated.
what are common causes of cough
Asthma
Chronic obstructive pulmonary disease
Drugs, e.g., ACE inhibitors, beta-blockers, ASA or NSAIDs in sensitive individuals
Environmental/occupational irritants, e.g., air pollution, cigarette smoke, asbestos
Foreign body
Gastroesophageal reflux disease
Heart failure
Pulmonary embolism
Rhinitis: allergic, nonallergic
Sinusitis
Upper airway cough syndrome (formerly postnasal drip syndrome)
Upper/lower respiratory tract infection (viral or bacterial): acute or postinfectious
what are less common causes of cough
Bronchiectasis
Cystic fibrosis
Interstitial lung disease
Lung cancer
Psychogenic cough
Unexplained cough (idiopathic)
Zenker diverticulum (esophageal pouch)
what are the goals of therapy for treatment of acute cough
Alleviate symptoms
Diagnose and treat underlying cause, when possible
Prevent complications
non pharmacologic therapy for treatment of acute cough
- not sufficient evidence but hydration w/ oralliquids and humidification of room air can be beneficial
* Room humidifiers used as preventive measures should be well cleaned to avoid aerosolizing mould
- nasa saline irrigation may help to relieve symptoms of nasal congestion
*Avoid exposure to inhaled irritants such as smoke, dust, pollutants and allergens.
treatment for viral respiratory infection
- no cure
- despite lack of evidence many use nonspecific treatments like nonprescription antitussives and protussives (expectorant) depending on mucus
- do not recommend tho bc lack of evidence
evidence for non prescription cough medication
lac of evidence for or against
- probably mostly placebo
antihistamines for treatment of acute cough
- First generation
- small effect on cough caused by upper respiratroy tract infections
- anticholinergic properties can reduce postnasal drop (mechanism resposibe for cough in common cold)
- effect is modest
- side effect” drowsiness, dry mouth and confusion
- NOT recommended until more evidence comes out
- Second generation
- lack significant anticholinergic efects
- not effective for acute cough treatment unless secondary to allergic rhinitis
antitussive for treatment of acute cough
- act centrally to supress cough
exact mechanism not known -> thought to involve brainstem
- not recommended when cough performs a useful function, then are retaining mucus you dont want to be
Dextromethorphan and codeine for treatment of acute cough
- commonly used to treat cough related to upper respiratory tract infections
*little evidence for efficacy
- some studies show no more effective than placebo
*extromethorphan has been abused for its euphoric properties, while codeine carries a risk of dependence and addiction
* not recommend centrally acting cough suppressants for cough secondary to upper respiratory tract infections.
- effective for cough due to COPD, supressing cough counts be 40-60%, can use for short term relief
example of expectorant for treatment of acute coughGuaifenesin
Guaifenesin
use of expectorants to treat acute cough
- protussive agents act peripherally
- ex: Guaifenesin (shown to enhance cough effectiveness by clearing airway secretions), guaiacol and ammonium chloride (efficacy & safety not established
- act by reduce sputum viscosity, permitting more effective removal of secretions from the respiratory tract
- lack of evidence to support efficacy -> do not thin sputum nor increase sputum volume
- Adequate hydration with oral liquids and inhalation of humidified air is perhaps the best protussive or “expectorant” measure.
Honey for treatment of acute cough
- can be effecive cough supressant in children
- no studies in adults available
*Cochrane review concluded that honey administered before sleep is probably better than no treatment, placebo or diphenhydramine, and no different from dextromethorphan, at relieving cough symptoms.
- has demulcent, antioxidant and antibacterial effects
- > demulcent effect may act to decrease cough
* risk of botulism, only give to immunocompetent children >1 year of age
zinc lozenges for treatment of acute cough
- used to alleviate cough due to the common cold
- studies show conflicitng results, overall insufficient evidence to recomend sin preparations
* zing can also be associated with unpleasant taste, mouth irritation and nausea.
anesthetics for treatment of acute cough
ex benzocaine, phenol and menthol
- may reduce sensitivity of peripheral nociceptors
- have been used as antitussives but evidence for efficacy is poor
NSAIDs for treatment of acute cough
Inflammatory pathways have been largely investigated to play a role in the pathophysiology of cough
hNSAIDs were found to have no effect on cough symptoms.
prescription therapy for cough
salbutamol or formotero
onky recommended for cough due to obstructive lung disease like asthma or COPD.
*Following a respiratory infection, patients sometimes develop a cough for which inhaled corticosteroids could be beneficial; the potential benefit of inhaled corticosteroids requires confirmation through further studies before making recommendations for their routine use.
cough can be secondary to another medical condiiton, treat unerlying cause:
Allergic Rhinitis and Viral Rhinitis, Influenza, Sinusitis and Pharyngitis, Acute Bronchitis
