Acute_Bronchitis_Flashcards
Definition
Acute bronchitis is inflammation of the bronchial airways, most commonly caused by a chest infection. It is typically self-limiting, meaning it resolves on its own. As a lower respiratory tract infection, it can cause cough, sputum production, wheezing, and chest pain.
Pathophysiology
Acute bronchitis is most commonly caused by infection, though other factors like smoke inhalation can also trigger inflammation.
When viruses or bacteria enter the lungs, they cause inflammation throughout the bronchial tree from the trachea to the alveoli. This inflammation leads to increased mucus secretion and airway narrowing, resulting in symptoms.
The condition involves inflammation of the trachea and major bronchi, causing swollen airways and sputum production. While most cases resolve within 3 weeks, 25% of patients experience a persistent cough beyond this period. Though the exact proportion of different pathogens is debated, viral infection is the primary cause. About 80% of cases occur during autumn or winter.
Cause: Inflammation of the bronchial wall due to viral or bacterial infection.
Mechanism: Leads to increased mucus production and bronchial edema.
Symptoms: Productive cough lasting >2 weeks in 50% of cases, potentially lasting >4 weeks in 25%.
Repair Process: Post-infection, bronchial repair can take weeks.
Epidemiology
Acute bronchitis is very common in general practice.
Viral infections are the predominant cause.
Incidence:
- 100 million ambulatory visits annually in the US.
- 300–400 consultations per 1,000 patients annually in the UK.
Seasonality: Higher incidence in autumn and winter.
History
Classical symptoms include cough, shortness of breath (SOB), and sputum production.
Bronchitis typically begins with a dry cough that develops into a productive cough over 3-4 days, usually resolving within 3 weeks.
Patients commonly present with a cough producing white, clear, or discolored sputum, often accompanied by shortness of breath.
Patients typically present with an acute onset of:
- cough (either dry or productive)
- sore throat
- rhinorrhea
- wheeze
Note: Symptoms are subjective experiences, while signs are objective findings.
When assessing shortness of breath, evaluate its impact on daily activities.
Consider the onset of shortness of breath—sudden onset may indicate pulmonary embolism, pneumothorax, or pneumonia.
Watch for red flags: cough lasting longer than 3 weeks, weight loss, hemoptysis, significant chest pain, severe breathlessness, and risk factors like smoking.
Consider the context, timing, and associated symptoms.
Note that acute bronchitis is distinct from chronic bronchitis.
Acute bronchitis, typically caused by viral infection, is common in general practice. It is self-limiting, lasting from a few days to just over a week, with complete resolution and return to normal lung function.
- Presentation: Acute cough (often productive), dyspnea, wheezing, and no history of chronic respiratory illness.
- Exclusions: Rule out asthma, pneumonia, or other systemic diseases.
Examination
Most patients have a normal chest examination, though some may present with:
- Low-grade fever
- Wheeze/rhonchi
On examination, patients typically have a mild bilateral wheeze with no other findings. Some may have a low-grade fever.
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Findings:
- Signs of upper respiratory tract infection (e.g., nasal congestion)
- Wheezing or prolonged expiration
- Absence of signs pointing to pneumonia (e.g., no rales)
Investigations - Bedside
Clinical Diagnosis: Based on history and physical findings.
Investigations - Bloods
Acute bronchitis is typically a clinical diagnosis however, if CRP testing is available this may be used to guide whether antibiotic therapy is indicated
C-reactive Protein (CRP): <20 mg/L: No antibiotics. 20–100 mg/L: Delayed antibiotics. >100 mg/L: Immediate antibiotics.
Investigations - Imaging
if prolonged for longer than 2/3 weeks and bringing up green phlegm and breathlessness - consider chest X-ray - rule out pneumonia or other underlying lung pathology - patch on the lung which differentiates from acute bronchitis
Investigations - Special Tests
Procalcitonin: Emerging biomarker for bacterial infections.
Management - Conservative
Advise the person on self-care strategiessuch as adequate fluid intake, and the use of paracetamol or ibuprofen for symptomatic relief.
- resting and waiting for symptoms to pass as self limiting
- OTC cough medications -
- Education: Self-limiting nature, resolves in 4 weeks.
- Smoking Cessation: Preventive measure.
- analgesia
- good fluid intake
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Symptom Management:
- Antipyretics (e.g., paracetamol).
- Short-acting beta-agonists (e.g., salbutamol) for wheezing. -
- Do not offer an oral or inhaled bronchodilator (for example salbutamol) or an oral or inhaled corticosteroidto a person with an acute cough associated with acute bronchitis unless they have an underlying airway disease such as asthma.
- Do not offer a mucolytic(for example acetylcysteine or carbocisteine) to treat an acute cough associated with acute bronchitis.
- Antitussives (e.g., dextromethorphan) for severe cough.
- Offer written advice, such as NHS information onChest infection, available atwww.nhs.uk.
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Some people may wish to try the following self-care treatments:
- Honey.
- Pelargonium (a herbal medicine).
- Over-the-counter cough medicines containing guaifenesin (an expectorant).
- Over-the-counter cough medicines containing cough suppressants (except codeine) if the person does not have a persistent cough or excessive secretions.
Management - Medical
if prolonged for longer than 2/3 weeks and bringing up green phlegm and breathlessness - consider antibiotics (most commonly due to viruses but can get secondary bacterial infections)
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Antibiotics: Reserved for high-risk patients or systemic symptoms.
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Do not routinely offer an antibiotic totreat an acute cough associated with acute bronchitis in people who are not systemically very unwell or at higher risk of complications.Inform the person that:
- Acute bronchitis is usually a self-limiting illness and the cough usually lasts about three to four weeks.
- Antibiotics do not make a large difference to the duration of symptoms, only shortening cough duration by about half a day on average.
- Adverse effects, including diarrhoea and nausea are possible with antibiotic treatment.
- Unnecessary antibiotic prescriptions may result in antibiotic resistance.
- A pre-existing comorbid condition such asheart, lung, kidney, liver, or neuromuscular disease, immunosuppression, or cystic fibrosis.
- Older than 65 years of age with two or more of the following, or older than 80 years with one or more of the following:
- Hospital admission in the previous year.
- Type 1 or type 2 diabetes mellitus.
- History of congestive heart failure.
- Current use of oral corticosteroids.
- Reassure the person that antibiotics are not currently needed.
- Advise the person to use the delayed prescription if symptoms get worse rapidly or significantly.
- Advise the person to seek medical advice if symptoms get rapidly or significantly worse despite taking the antibiotic, or they become systemically very unwell.
- consider antibiotic therapy if patients:
- are systemically very unwell
- have pre-existingco-morbidities
- have aCRPof 20-100mg/L (offer delayed prescription) or a CRP >100mg/L (offer antibiotics immediately)
- the BNF currently recommendsdoxycyclinefirst-line: 200 mg on the first day, then 100 mg once a day for 4 days (5-day course in total).
- doxycycline cannot be used in children or pregnant women
- Alternative first choices are oral:
- Amoxicillin(preferred in pregnant women) 500 mg three times a day for 5 days.
- Clarithromycin250 mg to 500 mg twice a day for 5 days.
- Erythromycin(preferred in pregnant women) 250 mg to 500 mg four times a day or 500 mg to 1000 mg twice a day for 5 days.
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Do not routinely offer an antibiotic totreat an acute cough associated with acute bronchitis in people who are not systemically very unwell or at higher risk of complications.Inform the person that:
- Refer to hospital or seek specialist advice on further investigation and managementif a person with acute cough has any symptoms or signs suggesting a more serious condition (for example sepsis, a pulmonary embolism, or lung cancer).
Management - Surgical
Not applicable.
Risks of Treatments
Beta-agonists: Nervousness, tremor. Antibiotics: Adverse effects, antimicrobial resistance.
Benefits of Treatments
Symptomatic Relief: Reduction in cough, fever, and wheezing. Targeted Antibiotics: Address bacterial complications in select cases.
Medical and Laboratory Sciences
Procalcitonin: Differentiates bacterial from viral infections. Pulmonary Function Tests: Not recommended during acute episodes due to transient obstruction.
