Pneumonia Flashcards
What is pneumonia?
Inflammation of the lung parenchyma caused by a lower respiratory tract infection. Often occurs after a viral infection in the upper respiratory tract. Uncertain how the bacteria reach the lower respiratory tract after attaching to disaccharide receptors on pharyngeal epithelial cells.
What are the (debatable) methods of invasion of pathogens in pneumonia?
Inhibition of IgA.
Pneumolysins, which inhibit ciliary beating.
Damage of the epithelial cells by prior infection.
Hijacking the platelet aggregating factor receptor pathway to reach the alveoli.
What are the symptoms of pneumonia?
Fever.
Cough with purulent sputum.
Dyspnoea.
Pleuritic pain.
What are the signs of pneumonia?
Percussion: dull.
Auscultation: crackles, bronchial breathing.
Respiratory failure: cyanosis tachypnoea.
Septicaemia: rigors.
What is the treatment of pneumonia?
Breathing: maintain oxygen saturation levels.
Antibiotics: treat the underlying cause (check hospital guidelines).
Pain: give analgesics.
Pneumococcal vaccines for those at risk, e.g. diabetics, immunosuppressed and over 65s.
What are the complications of pneumonia?
Respiratory failure: by causing acute respiratory distress syndrome (ARDS).
Septic shock: the causative agent enters the patient’s bloodstream, releasing cytokines.
Pleural effusion.
Empyema.
Lung abscess.
Hypotension: sepsis or dehydration is usually the underlying cause.
What investigations should be performed for suspected pneumonia?
CXR: look for infiltrates.
Identify the causative organism by assessing a sputum sample.
Monitor oxygen saturation.
Bloods: look for raised WCC and raised inflammatory markers.
Urinary antigen test: for pneumococcal or Legionella antigen.
Arterial blood gas (ABG).
How is the severity of pneumonia assessed?
CURB-65. Confusion Urea >7mmol/L Respiratory rate >30/min BP <90/<60mmHg >65 years old Each section is worth 1 point. 1 = outpatient care, 2 = admission, >3 = requires ICU admission.
What are the causative organisms of pneumonia in children?
Viruses.
Pneumococcus.
Mycoplasma.
What are the causative organisms of community acquired pneumonia?
Streptococcus pneumoniae. Haemophilus influenzae. Moraxella catarrhalis. Chlamydia pneumoniae (atypical). Mycoplasma pneumoniae (atypical). Legionella pneumophila (atypical). Viruses.
What are the causative organisms of hospital acquired pneumonia?
Gram-negative bacteria. Staphylococcus aureus. Streptococcus pneumoniae. Anaerobes. Fungi. Legionella pneumophila.
What are the causative organisms of pneumonia in HIV patients or immunocompromised patients?
Pneumocystis jirovecii. Cytomegalovirus. Adenovirus. Herpes simplex virus. Mycobacterium tuberculosis. Bacterial infection, e.g. Staphylococcus aureus.
