Pulmonary Edema and ARDS Overview

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Questions and Answers

What process leads to the creation of a novel influenza virus due to the interaction of two different strains?

Genetic recombination

Antigenic shift (correct)

Antigenic drift

Viral mutation

Which pathogen is most commonly associated with secondary bacterial pneumonia following influenza infection?

Escherichia coli

Staphylococcus aureus (correct)

Streptococcus pneumoniae

Haemophilus influenzae

What is the recommended age to start receiving the inactivated influenza vaccine?

2 years

1 year

6 months (correct)

3 months

Which type of vaccine is NOT suitable for pregnant women?

Live-attenuated vaccine Signup and view all the answers

What was the virus that caused the global pandemic in 2019?

SARS-CoV-2 Signup and view all the answers

What protein on the COVID-19 virus is responsible for binding to host cells?

Spike protein Signup and view all the answers

Which statement about the origin of SARS-CoV-2 is considered controversial?

It originated from a laboratory leak in Wuhan. Signup and view all the answers

What characteristic appearance do coronaviruses have under electron microscopy?

Crown-like spikes Signup and view all the answers

What are some of the rare adverse effects associated with both live viral infections and vaccinations?

Bell's palsy and myocarditis Signup and view all the answers

What was a significant source of debate related to vaccinations?

Vaccination mandates and their political implications Signup and view all the answers

Which age group is recommended to start the PCV15 vaccine?

Children starting at 6 months Signup and view all the answers

What are the recommended vaccinations for an individual age 65 and older?

PCV20 once OR PCV15 followed by PPSV23 a year later Signup and view all the answers

Which condition requires an extra dose of PCV15 followed by PPSV23?

Asplenia or surgical splenectomy Signup and view all the answers

What is a characteristic presentation of Tracheoesophageal fistula (TEF) in neonates?

Coughing up milk during initial feedings Signup and view all the answers

How is the diagnosis of Tracheoesophageal fistula typically made?

By insertion of a nasogastric tube Signup and view all the answers

Which vaccine is safe to give during pregnancy?

IM killed vaccine Signup and view all the answers

Which treatment is commonly used for chronic sinusitis?

Amoxicillin/clavulanate Signup and view all the answers

What presents as recurrent sinopulmonary infections in patients with IgA deficiency?

Sinusitis Signup and view all the answers

Which segment of the influenza virus is responsible for mediating viral attachment to host cells?

Hemagglutinin Signup and view all the answers

What is the primary function of neuraminidase in the influenza virus?

Cleaving sialic acid residues Signup and view all the answers

Which of the following drugs acts as a neuraminidase inhibitor?

Zanamivir Signup and view all the answers

What result can occur from antigenic drift in the influenza virus?

Seasonal epidemics Signup and view all the answers

Which symptom is commonly associated with influenza according to USMLE guidelines?

Myalgias Signup and view all the answers

When is a CT scan typically indicated in the context of sinusitis?

When chronic sinusitis exceeds 12 weeks Signup and view all the answers

What is the most likely diagnosis for a 2-year-old who awakens with severe ear pain after a viral infection and has dried blood on the ear lobe?

Tympanic membrane perforation Signup and view all the answers

Which condition is characterized by inflammation of the mastoid bone often due to untreated otitis media?

Mastoiditis Signup and view all the answers

What is the appropriate imaging method to diagnose mastoiditis in a child?

CT scan of the temporal bone Signup and view all the answers

Which infection is characterized by bullous formation and often caused by bacteria like Strep pneumoniae or Mycoplasma?

Myringitis Signup and view all the answers

What is a classic cause of necrotizing otitis externa, especially in populations with specific skin traits?

Pseudomonas infection Signup and view all the answers

What is the first-line topical treatment for a child diagnosed with otitis externa?

Topical ciprofloxacin-hydrocortisone drops Signup and view all the answers

Which symptom is commonly associated with sinusitis following an upper respiratory tract infection?

Lingering fever for more than 10 days Signup and view all the answers

What is considered a notable characteristic of otitis externa in swimmers?

Necrotizing infections due to prolonged exposure to water Signup and view all the answers

What is the primary mechanism by which pulmonary edema occurs due to left heart failure?

Transudation of fluid into the alveolar spaces Signup and view all the answers

Which of the following conditions is NOT typically associated with pulmonary edema for USMLE purposes?

Hypertensive emergency Signup and view all the answers

What does 'cephalization of pulmonary vessels' indicate in the context of pulmonary edema?

Increased blood flow to the upper lobes Signup and view all the answers

In the context of ARDS, what is the significance of a PaO2/FiO2 ratio?

It indicates the severity of hypoxemia Signup and view all the answers

Following a near-drowning episode, what condition is a patient most likely to develop?

Acute respiratory distress syndrome (ARDS) Signup and view all the answers

Which of the following is a typical cause of dyspnea in a patient with myocardial infarction?

Increased alveolar-arteriolar oxygen gradient Signup and view all the answers

What should never be done if a PPD test is positive?

Repeat the PPD test Signup and view all the answers

In cases of pulmonary edema caused by left heart failure, which of the following findings would you expect?

Elevated pulmonary capillary wedge pressure (PCWP) Signup and view all the answers

What is a characteristic feature of otitis media?

Red, immobile tympanic membrane Signup and view all the answers

Which of the following treatments is commonly used for recurrent otitis media?

Amoxicillin with clavulanate Signup and view all the answers

What is the appropriate management for serous otitis media?

Observation Signup and view all the answers

Cryptogenic organizing pneumonia was formerly known as what?

Bronchiolitis obliterans organizing pneumonia Signup and view all the answers

What is a typical presentation of Byssinosis?

Common in textile workers Signup and view all the answers

What symptom might indicate otitis media in children?

Tugging at the ear Signup and view all the answers

Which statement is true regarding the resolution of fevers associated with certain infections?

Self-resolves within 48 hours Signup and view all the answers

What indicates the need for a tympanostomy tube in children?

More than four occurrences of OM in a year Signup and view all the answers

Study Notes

Pulmonary Edema

Pulmonary edema is fluid buildup in the alveoli, often due to left heart failure.
Key factors include increased pulmonary capillary hydrostatic pressure.
Non-cardiac causes include ARDS, TRALI.
Symptoms include shortness of breath, crackles, and low oxygen saturation.
Key diagnostic tools on USMLE are PCWP and LAP (increased).
Conditions where bilateral, exudative chest infiltrates are present include pancreatitis, aspiration (vomitus, water), NG tube insertion, toxic shock, general trauma, and sepsis.
Acute respiratory distress syndrome (ARDS) is a likely cause of death in toxic shock syndrome patients.

Acute Respiratory Distress Syndrome (ARDS)

ARDS is a severe lung injury.
PaO2/FiO2 ratio <300 is a technical definition, but not typically assessed on USMLE.
Bilateral lung involvement is crucial.
It's associated with near-drowning, toxic shock syndrome, and pancreatitis.
Mechanical ventilation strategies include prone positioning, low tidal volume, and permissive hypercapnia.
Increased surfactant protein D is a marker of lung injury and is elevated in ARDS patients.

Transfusion-Associated Lung Injury (TRALI)

Non-cardiogenic pulmonary edema.
It is a type of lung injury that can occur within 6 hours of a blood transfusion.
The mechanism involves abnormal neutrophil activation in the lungs, reacting to cytokines within transfused blood products.

Transfusion-Associated Circulatory Overload (TACO)

Cardiogenic pulmonary edema that arises from the left heart struggling to handle increased hydrostatic pressure from extra blood volume.
It occurs after 6 hours of a transfusion and can affect patients with a history of heart failure or MI.
Often a blood transfusion is combined with crystalloid solutions.

Pneumonia

Lobar pneumonia (Strep pneumoniae): USMLE often links to right lower lobe consolidation, dullness to percussion.
Bilateral Interstitial pneumonia (atypical pneumonia): Mycoplasma in immunocompetent patients.
Mycoplasma may be indicated by interstitial markings and absence of strep pneumo, especially in bilateral cases.
Pneumonia in AIDS patients: PCP (Pneumocystis jirovecii).
Post-influenza bacterial pneumonia: S. aureus.
Pneumonia with hyponatremia or diarrhea: Legionella.
Neonatal pneumonia: Group B Strep (Strep agalactiae), or Listeria (if gram + rod), E. coli (if gram- rod)
Pneumonia linked to certain exposures:
- Chlamydia psittaci (bird-keepers).
- Chlamydia trachomatis (infancy, conjunctivitis).
- Coccidioides (southwest US, earthquake dust).
- Francisella (rabbits).
- Pseudomonas or S. aureus (CF).
- S. epidermidis (central venous catheter, right upper lobe lesion).
Key features for USMLE in pneumonia include adventitious or bronchial breath sounds, and increased tactile fremitus.
Empiric treatment for community-acquired pneumonia (CAP) is often azithromycin.
Severe pneumonia resulting in sepsis may lead to a ceftriaxone prescription.

Bronchiolitis

Caused by respiratory syncytial virus (RSV) in children under 18 months
Presents with bilateral wheezes and low-grade fever
Treatment is supportive care.

Laryngotracheal Bronchitis (Croup)

Caused by parainfluenza virus
Characterized by a hoarse, barking, or seal-like cough in school-aged children
Symptom relief may occur in cool air
Diagnosis with neck x-ray showing a steeple sign (sub-glottic narrowing)
Treatment is supportive, but racemic epinephrine may be indicated

Epiglottitis

Caused by Haemophilus influenzae type B
A medical emergency requiring prompt intubation.
Key symptoms include difficulty breathing, drooling, and tripod positioning.
Treatment involves antibiotics (third-generation cephalosporin), and possible supportive care.
Close contacts should also receive rifampin prophylaxis.

Bacterial Tracheitis

Typically caused by Staphylococcus aureus after a viral URTI.
Key characteristics include stridor (suggesting upper airway narrowing), ability to fully open the mouth, lack of response to racemic epinephrine, and absence of a history of drooling.
Treatment is broad-spectrum antibiotics.

Pertussis

Whooping cough (succession of coughs followed by an inspiratory stridor).
Diagnosis can include hypoglycemia or post-tussive emesis (vomiting after coughing).
High WBC count with lymphocytosis is suggestive of pertussis.
Vaccination is crucial for prevention.

Pleurodynia

Viral infection (Coxsackie B).
Characterised by chest pain, typically located laterally.
It is not a lung condition.

Pulmonary Abscess

Caused by aspiration of oropharyngeal flora (often anaerobes).
Risk factors for aspiration should be present: alcoholism, dementia, stroke.
Key feature on x-ray is foul-smelling sputum and an air-fluid level within the lesion.
Treatment often involves clindamycin.

Acute Bronchopulmonary Aspergillosis (ABPA)

Asthma-like presentation in a patient with heightened sensitivity to aspergillus skin antigen.
Atypical pneumonia-like symptoms, resolving fever, may be triggered by exposure to organic dust/hay.

Hypersensitivity Pneumonitis

An occupational or environmental exposure can trigger this reaction.
Symptoms may appear hours to days following exposure.
Characterised by fever and respiratory difficulties.

Cryptogenic Organizing Pneumonia (COP)

A restrictive lung condition that is idiopathic (unknown cause) and does not respond to antibiotics.
It is a restrictive lung condition (i.e. not actual pneumonia).

Otitis Media (OM)

Inflammation of the middle ear space.
Treatment involves amoxicillin, with Augmentin recommended for recurrent cases.
Tympanostomy tube placement may be required for recurrent cases. Acute cases are often resolved with observation.
Key feature is an immobile tympanic membrane.

Mastoiditis

Infection of the mastoid bone, typically caused by untreated otitis media.
Usually diagnosed radiographically (CT or MRI).
If required, surgical care or oral antibiotics.

Myringitis

Inflammation of the tympanic membrane.
Possible causes: Strep pneumo, Mycoplasma.

Otitis Externa (OE)

Infection of the external ear canal, often due to Pseudomonas.
Risk factors include swimming, diabetes.
Initial treatment can involve topical ciprofloxacin-hydrocortisone drops.
Severe cases, especially in immunocompromised, may progress to nectirotizing OE.

Sinusitis

Infection involving the sinuses.
Diagnostic tools: X-rays, (CT if chronic).
Symptoms include a prolonged recovery (over 10 days) from a URTI and potentially sore cheek.
Treatment may involve antibiotics.

Tuberculosis (TB)

Infection with Mycobacterium tuberculosis
Presenting symptoms can include fever, night sweats, weight loss, and hemoptysis.
Diagnosis starts with PPD skin test, followed by chest X-ray
Treatment for latent TB is usually INH (isoniazid) for 9 months + vitamin B6 (important to note that INH can cause vitamin B6 deficiency- a key USMLE fact)
Active TB treatment involves RIPE regimen for a period (rifampin, isoniazid, pyrazinamide, ethambutol)
BCG vaccine is a live-attenuated vaccine - USMLE may avoid using the presence of this vaccine in the patient's history.

Hot Tub Lung

Inhalation of mycobacterium avium complex (MAC) fumes.
Usually in conjunction with hot tub use.
Characterised by bilateral chest infection.

Influenza

Viral infection
Characterized by respiratory distress, fever, myalgias.
Diagnosis is presumptive by symptoms and often involves amoxicillin/clavulanate (Augmentin).
Distinction of influenza from other viral infections can be based on presentation (e.g. severe myalgias in flu, vs. milder symptoms in other infections/rhinovirus).
Key structural components include two viral surface proteins, hemagglutinin and neuraminidase.

Coronavirus

Refer to text in the chapter about SARS-CoV-2 (COVID-19).

Pediatric Respiratory Conditions

Tracheoesophageal fistula (TEF): Proximal esophagus ends in blind pouch, distal esophagus connects to trachea. Presentation often involves initial feeding problems, with inability to completely insert a NG tube (as it will hit a pouch).
Choanal atresia: A developmental blockage or narrowing of the nasal passages. Presenting symptom is obligate mouth-breathing by the neonate.

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Description

This quiz covers the essential concepts of pulmonary edema and acute respiratory distress syndrome (ARDS). It highlights causes, symptoms, and key diagnostic tools relevant for USMLE candidates, along with treatment strategies. Test your knowledge on these critical respiratory conditions and their implications.