Acute bronchitis/flu/asthma Flashcards
Acute bronchitis
General and RF
Acute inflammation of the large airways of the lower respiratory tract, commonly accompanied by an upper respiratory tract infection
Among the top 10 conditions for which patients seek medical attention
Most commonly caused by a viral infection
More frequent during late fall and the winter months
♀=♂
Children/adolescents > adults
Risk factors:
Chronic lung disease (COPD, asthma)
Smoking
Chronic exposure to air pollution
acute bronchitis
patho
A virus or bacterium causes infection and inflammation of the cells of the tissue lining the bronchi
Irritation and inflammation cause:
Impaired ciliary function
Hyperemia and edema in the mucous membrane
Decreased bronchial mucociliary function
Increased mucus production → characteristic cough of acute bronchitis
Acute bronchitis
S/Sx
Cough(predominant symptom)
Productive with clear, yellow, or purulent sputum; may contain streaks of blood
Purulent sputum isNOTspecific to bacterial causes
Chest discomfort (frequent coughing)
Wheezing
Rhonchi (clears with coughing)
Subjective dyspnea
Malaise
Fever:
Uncommon, but possible
Often low grade if present
Should raise concern possible pneumonia or bacterial superinfection
Findings that are more consistent with pneumonia than acute bronchitis
Fever
Tachypnea
Rales
Dullness to percussion
Egophony: E → A
Tactile fremitus: ↑ in areas of increased lung density (consolidation)
acute bronchitis
Diagnosis
Made clinically based on history and physical examination
Suspected in patients with an acute onset of cough, which often follows a URI without findings to suggest pneumonia
Additional work-up can include:
Chest x-ray
Microbiologic testing
Rarely indicated because results do not normally change management
Indicated during suspected outbreaks
acute bronchitis
Chest X-ray indications
Obtained to rule out serious illness or pneumonia
Indications:
Signs of consolidation on exam:
Dullness to percussion
Egophony
Tactile fremitus
Abnormal vital signs:
Fever
Tachycardia
Tachypnea
↓ Oxygen saturation
Mental status or behavioral changes in the elderly (> 75 years of age)
Immunocompromised patients
Findings:
Usually normal in acute bronchitis
May show thickening of the bronchial walls in the lower lobes
Infiltrates/consolidation indicate pneumonia
acute bronchitis
Tx
Self-limiting condition
Usually requires only supportive care
Patient education
Explain why antibiotics areNOTindicated
Symptoms resolve spontaneously within 1‒3 weeks
Treatment of symptom reduction:
For cough
Nonpharmacological therapies
Hot tea, throat lozenges, honey
Antitussive agents
Given if cough is distressing or interfering with sleep
Dextromethorphan (Robitussin)
Guaifenesin (Mucinex)
Codeine → generally avoided due to addictive potential
acute bronchitis
Tx For malaise, myalgias, and fever
Analgesic antipyretics:
NSAIDs
Acetaminophen
Acute bronchitis
Tx For wheezing/ pts with asthma or COPD
For wheezing
beta-agonists (Albuterol)
For patients with underlying lung disease (COPD, asthma):
Prednisone
Consider antimicrobials in cases of known or suspected bacterial infections
Lifestyle modifications
Smoking cessation
Avoidance of allergens/pollutants
Influenza, Covid-19, and pneumonia vaccines according to standard guidelines
Influenza
Antigenic drift
Mutations accumulate in the viral genes that code for viral surface proteins resulting in new antigenic sites (HA or NA spikes); changes are generally minor
Epidemic
Antigenic shift
Two or more different strains of a virus combine to form a new subtype that is radically different; limited or no prior immunity
pandemic
flu
Transmission and Viral shedding
Transmission:
Airborne respiratory droplets
Person-to-person contact
Contact with contaminated items
Incubation period: 1–4 days
Viral shedding:
Begins with or just before the onset of symptoms (0–24 hours)
Lasts 5–10 days
Children and immunocompromised individuals tend to shed virus longer
flu
Clinical Presentation
Prodrome (3–24 hours)
Myalgia, malaise, headache, anorexia
Disease (7–10 days)
Fever
Range 37.8–40.0°C (100–104°F)
Lasts 1–5 days
Chills
Myalgias
Headache
Nonpurulent conjunctivitis
Nasal congestion or rhinorrhea
Sore throat
Mild cervical lymphadenopathy
Nonproductive/dry cough
Gastroenteritis symptoms:
Abdominal pain, vomiting, diarrhea
Flu
Dx
Key clinical findings
Typically madeclinically; rapid diagnostic tests if the results will influence management
Positive predictive value (80%–90%) of clinical diagnosis once the virus has been documented in the community
Key clinical findings:
Rapid onset of symptoms
Fever and symptoms of upper respiratory infection (URI)
Myalgias/headache
GI symptoms and high fever in children
flu
Virulent glycoproteins & Nucleoproteins
Hemagglutinin (HA):attaches to sialic acid-containing receptors on respiratory epithelial cells
Neuraminidase (NA):cleaves newly formed virions off the sialic acid-containing receptor, allowing the virus to exit cells
Nucleoprotein:helps distinguish between the 3 types of influenza viruses (A, B, and C)
Flu
Labs and imaging
Gold standards:
Viral culture (3–7 days)
Detects virus in nasopharyngeal or throat samples
RT-PCR (24 hours)
Identification of viral genomes
Rapid diagnostic testing:
ELISA (15–20 minutes)
Detection of antigens in throat and nasal swabs
Limited sensitivity and up to 98% specificity
Chest X-ray:
Obtained to rule out bacterial pneumonia
Should be obtained in the following cases:
Elderly
Patients at high risk due to medical comorbidities
Patients exhibiting signs/symptoms suggestive of pneumonia
Findings:
Bilateral symmetrical patch infiltrates
Ground-glass opacities
Focal infiltrates → bacterial pneumonia
flu
complications
Pneumonia
Viral
Suggested by a worsening cough, bloody sputum, dyspnea, and rales
Bacterial
Suggested by persistent or recurrence of fever and cough after the primary illness appears to be resolving:
Streptococcus pneumoniae
Staphylococcus aureus
Haemophilus influenzae
Post-influenza encephalitis
Myositis
Flu
Tx
Majority of patients require only supportive care (rest, hydration, and antipyretics as needed)
Aspirin should be avoided in patients≤ 18 years
Recover without complications in 1-2 weeks
Pharmacotherapy
Antiviral drugs
Neuraminidase inhibitors
Interfere with release of influenza virus from infected cells and thus halt spread of infection
Recommended forhigh-risk patients(including all hospitalized patients)
Given within 48 hours of symptom onset
oseltamivir (Tamiflu),zanamivir (Relenza), andperamivir(Rapivab)
flu
prevention
Transmission prevention:
Cough etiquette
Use of facemasks
Frequent handwashing
Social isolation of infected individuals
Influenza vaccination: 50%–90% efficacy
Recommendedannuallyfor all individuals ≥ 6 months of age who do not have contraindications
Modified annually to include the most prevalent strains (often 2 strains of influenza A and 1 or 2 strains of influenza B)
flu
2 basic types ofinfluenza vaccine:
Inactivated influenza vaccine (IIV) - 70% efficacy
Trivalent or quadrivalent vaccine given by IM injection
Adverse effects: mild pain at the injection site; fever and myalgias (uncommon)
Live-attenuated influenza vaccine (LAIV) - 85% efficacy
Given intranasally
Used for healthy people aged 2 to 49 years; should not be given to children who are<5 years and have reactive airway disease
Adverse effects: rhinorrhea and mild wheezing
Both vaccines - children who are < 8 years and have not been vaccinated should be given a primary dose and a booster dose 1 month apart
asthma
triggers
Inestablishedasthma, different triggers may exacerbate the symptoms
Environmental and drug-induced:
Allergens
Cold, dry air
Paints and fumes
Irritant gasses
Air pollution
Drugs
Behavioral and psychological:
Exercise
Hyperventilation
Stress
Other triggers:
Upper respiratory tract infections
Gastroesophageal reflux
asthma
Peak expiratory flow (PEF)
Used more for monitoring than for diagnosis
Maximal inhalation, then fast forceful exhalation (< 2 seconds) into peak flowmeter
A single peak flow is obtained during symptoms
Results compared with average normal values (based on height and age)
Post-bronchodilator administration (15 minutes after 2 puffs of a bronchodilator), improvement of > 20% suggests reversible airway obstruction
don’t need to memorize, know that it change
Early on in an acute episode, we will see hypocarbia (due to hyperventilation) → ↑ pH (respiratory alkalosis)
Severe asthma attack can lead to respiratory failure
way more symptoms with systemic steroids versus inhaled
