Quiz 3 Study Guide

Topics Overview:

• Upper Respiratory Tract Pathology:
  • Symptoms: Conditions affecting the upper respiratory tract often result in noisy breathing, snoring, stridor, and musical or wheezing tracheal breath sounds. These sounds may sometimes be referred from the lower respiratory tract or other regions of the respiratory system.
• Lower Respiratory Tract Pathology:
  • Symptoms: Pathologies in the lower respiratory tract typically present with fine crackles, coarse crackles, rhonchus, pleural friction rub, wheezing, and bronchial breath sounds. These sounds are indicative of conditions that may affect the lungs or pleural spaces.

1. Respiratory Infections:

• Sinusitis:
  • Overview: Inflammation of the sinuses often secondary to a viral upper respiratory infection but can become bacterial.
  • Symptoms: Facial pain, headache, nasal congestion, purulent nasal discharge, fever, and cough.
  • Management: Typically involves symptomatic treatment, decongestants, and, in bacterial cases, antibiotics.
• Pneumonia:
  • Overview: Infection of the lung parenchyma, commonly bacterial or viral.
  • Symptoms: Cough, fever, pleuritic chest pain, dyspnea, and sputum production.
  • Management: Based on the causative agent; may include antibiotics, antiviral medications, supportive care, and hospitalization for severe cases.
• Bronchitis:
  • Overview: Inflammation of the bronchial tubes, usually viral.
  • Symptoms: Persistent cough, mucus production, wheezing, shortness of breath, and chest discomfort.
  • Management: Typically includes symptomatic treatment with bronchodilators, hydration, and rest. Antibiotics are usually not indicated unless bacterial infection is suspected.
• Croup:
  • Overview: Viral infection leading to inflammation and swelling of the larynx, trachea, and bronchi, commonly caused by parainfluenza virus.
  • Symptoms: Barking cough, stridor, hoarseness, and respiratory distress, particularly in young children.
  • Management: Includes corticosteroids, nebulized epinephrine for severe cases, and supportive care.
• Respiratory Syncytial Virus (RSV):
  • Overview: A common viral infection in infants and young children, often leading to bronchiolitis or pneumonia.
  • Symptoms: Runny nose, decreased appetite, coughing, sneezing, fever, and wheezing. Severe cases may result in respiratory distress.
  • Management: Supportive care, oxygen therapy if needed, and in severe cases, hospitalization.
• Diphtheria:
  • Overview: A rare but serious bacterial infection caused by toxigenic strains of Corynebacterium diphtheriae.
  • Transmission: Spread through respiratory droplets, contact with skin lesions, and possibly fomites. Raw milk and dairy products can also transmit the bacteria. Asymptomatic carriers can spread the infection.
  • Incubation Period: Typically 2 to 7 days, but it can be longer.
  • Symptoms:
    • Early Signs: Low-grade fever, gradual onset of symptoms, sore throat, and mild respiratory symptoms.
    • Characteristic Features: Grayish, adherent pseudomembrane in the nasopharynx, pharynx, or trachea; bloody nasal discharge in membranous pharyngitis; serosanguineous or seropurulent nasal discharge; hoarseness; and cough.
    • Severe Cases: Extensive neck swelling (bull neck), airway obstruction, myocarditis, and neurological complications like cranial nerve palsies and peripheral neuritis.
    • Cutaneous Diphtheria: Nonhealing ulcers with a dirty gray membrane or colonization of existing skin lesions (less common).
  • Diagnosis: Confirmed through a positive culture of Corynebacterium diphtheriae from the nose, throat, skin lesions, or beneath the pseudomembrane.
  • Treatment:
    • Immediate Management: Hospitalization, administration of diphtheria antitoxin, antibiotics (e.g., penicillin or erythromycin), and droplet precautions.
    • Post-Recovery: Patients should be immunized after recovery.
  • Complications: May include peripheral neuropathy, myocarditis, acute tubular necrosis, and respiratory failure.
• Pertussis (Whooping Cough):
  • Overview: Caused by Bordetella pertussis, a highly contagious gram-negative bacillus. Pertussis may present as a primary infection or as a reinfection, particularly in individuals with waning immunity.
  • Transmission: Spread through respiratory droplets.
  • Incubation Period: 7 to 10 days, but it can be longer.
  • Stages of Disease:
    • Catarrhal Stage: Mild upper respiratory symptoms such as runny nose, sneezing, and mild cough. This stage is the most contagious.
    • Paroxysmal Stage: Characterized by severe coughing fits followed by a “whooping” sound as the patient inhales. Coughing fits may be accompanied by vomiting and exhaustion.
    • Convalescent Stage: Gradual recovery with less frequent coughing spells.
  • Complications: Can include pneumonia, seizures, encephalopathy, and death, particularly in infants.
  • Management: Early antibiotic treatment (e.g., macrolides like azithromycin) can reduce the severity and spread of the infection. Supportive care may include hydration, oxygen therapy, and hospitalization in severe cases.