Pneumonia Flashcards
Who does pneumonia most commonly affect
- Young children
- Elderly
- Immunocompromised
Which bacteria cause pneumonia
- Most commonly streptococcus pneumoniae
- Haemophilus influenzae
- Mycoplasma pneumoniae
- RSV,influenza,staphyloccous aureus, klebsiella pneumoniae, pneumocystis jirovecii
-The following cause atypical/walking pneumonia chlamydophilia pneumoniae,legionella pneumonia
How is pneumonia spread?
- Nasopharyngeal aspiration
- droplet spread
- Inhalation of airborne microorganisms
- Haematogenous spread
Describe the components of the respiratory immune system
- ) Mucociliary clearance: entrapment in mucus, ciliary escalator
- )Alveolar macrophages: phagocytosis, inflammation
- ) Neutrophils: phagocytosis
- )Complement&antibodies: opsonisation, agglutination
- )Lymphocytes: inflammation, activation of other immune cells
Describe the pathophysiology of pneumonia
- Alveoli with pus
- Impaired gas exchange
- SIRS
- Bacteraemia
What makes up the pus that fills the alveoli?
- Pathogen
- Congestion: vascular engorgement, intra-alveolar fluid
- Red hepatisation: exudation of RBCs, neutrophils, fibrin
- Grey hepatisation-Disintegration of RBC,persisting inflammatory cells
- Resolution
What is red hepatisation?
-Red cells,neutrophils &fibrin present in the alveoli
What is grey hepatisation?
- Follows red hepatisation
- The red cells have been broken down leaving a fibrinosuppurative exudate
How does the lung appear in pneumonia?
-Large & heavy
What are the symptoms of infection?
- Dyspnoea
- Cough
- Sputum+/- purulence
- Fever
What are the clinical signs of infection?
- Tachypnoea
- Tachycardia
- Hypotension
- Pyrexia
- Crackles
- Whispering pectoriloquy,increased tactile fremitus and vocal resonance
- Cental cyanosis
- Altered mental status
What investigations can we use when trying to diagnose pneumonia?
- Arterial blood gas( ABG)
- Chest X ray (CXR)
- Full blood count (FBG)
- U&E, CRP, liver function test (LFT)
- Blood & sputum cultures
- Viral PCR
- Atypical serology
- Urine Ag for Legionella & S.pneumoniae
What is systemic inflammatory response syndrome?
- Serious condition related to systemic inflmmation, organ dysfunction and organ failure
- Subset of cytokine storm in which there’s abnormal regulation of various cytokines
- Closely related to sepsis, in which patients satisfy criteria for SIRS and have a suspected or proven infection
What are the 4 SIRS criteria?
- Tachycardia(HR>90bpm)
- Tachypnea(RR>20 Breaths/min)
- Fever
- Hypothermia (temp>38 or <36)
3 additional criteria…
- Leukocytosis
- Leukopenia
- Bandemia
What are the 4 stages of pneumonia?
1.) Congestion days 1-2
2.)Red hepatisation dqays 3-4
3.) grey hepatisation days 5-7
4.)Resolution day 8-3 weeks
NB hepatisation refers to the lung taking on a lung like appearance