Community Acquired Pneumonia Flashcards
Histological appearance
-Thickened walls
-Pus and blood in air spaces
Pulmonary symptoms of CAP
-Preceding URTI common
-Cough (92%)
-Breathlessness (67%)
-New sputum production (54%)
-Haemoptysis (15%)
Extrapulmonary symptoms of CAP
-Confusion
-Abdominal pain
-Non-specific systemic
=GI upset
=myalgia
=headache
Examination findings of CAP
-Fever
-Rigors
-Tachycardia
-Hypotension
-Tachypnoea
-Coarse inspiratory crackles
-Reduced expansion
-Bronchial breathing
-Pleural rub on side of pneumonia
-Confusion
-Abdominal tenderness
Definition of CAP
-Symptoms and signs consistent with lower respiratory tract infection
-New CXR shadowing (loss of definition of heart border, consolidation, etc.,)
-No other explanation
Common CT findings in CT
-Air bronchogram
=Air in bronchi (alveolus filled with pus and blood)
Epidemiology of CAP
-Incidence between 5 and 11 per 1000 in UK and rises with age
Mortality:
-<1% in the community
-6-12% among patients hospitalised
-Over 35% in patients admitted to ITU
Commonest pathogens in CAP
-S. Pneumoniae
-Virus
-Hospitalised= legionella, mycoplasma
Multisystem complications of S.pneumoniae
-Septicaemia
-Pyopneumothorax (pus and air in pleural space)
-Pericarditis/ endocarditis
-Meningitis/ brain abscess
-Peritonitis
-Arthritis
-Herpes labialis
Multisystem complications of mycoplasma pneumoniae
-Meningoencephalitis
-Aseptic meningitis
-Guillian-Barre
-Transverse myelitis
-Cerebellar ataxia
-Ascending polyneuropathy
-Pericarditis
-Myocarditis
-Diarrhoea
-Haemolytic anaemia
-Skin rashes
-Poly arthropathy
-Hepatitis
-Pancreatitis
-Splenomegaly
-Acute glomerulonephritis
-Haemorrhagic myringes
Legionella multisystem complications
-Confusion
-Encephalomyelitis
-GB
-Cerebellar
-Pericarditis
-Hyponatraemia
-Renal failure
-Rhabdomyolysis and myositis
-Diarrhoea
-Poly arthropathy
-Jaundice, abnormal LFT
-Pancreatitis
-Thrombocytopenia
C. burnetii multisystem complications
-Optic neuritis
-Hepatitis
-Haemolytic anaemia
-Osteomyelitis
-Endocarditis with chronic infection
S. aureus multisystem complications
-Pneumatoceles (big cysts in airways) and/or pneumothorax (especially in children)
-Septicaemia
-Lung abscess
-Metastatic infection
(Common after flu-like illness)
Severity assessment in patients admitted with pneumonia
-CURB65
-Biomarker (CRP)
-Clinical progress
Describe CURB65
-Confusion (new onset), MST 8 or less
-Urea >7
-RR 30 or more
-SBP<90 or DBP <60
-Age>65
Score per criteria
Score 0-1= Low severity (0.7-2.1% mortality)
-Score 2= Moderate= 9.2%
-3-5= High= 15-40%
(Predict 30-day mortality)
Biomarkers= CRP
-CRP compared to baseline at day 3/4= assessing progress
=Falls by 50% or more (likely to make full recovery, no ventilation, less 30-day mortality, less likely to have complicated pneumonia)
Clinical response by day 3
Good clinical outcome
=Temp <37.2
=HR <100
=RR<24
=SBP>90
=Sats >90%
PLUS
-CRP <30
-PCT <0.25
Investigations for moderate pneumonia
-Blood cultures
-Sputum for routine culture and sensitivity tests for those who have not received prior antibiotics
-Pneumococcal urine antigen test
Investigations where legionella is suspected
-Urine for legionella antigen
-Sputum or other respiratory sample for legionella culture and DIP
Investigations of severe pneumonia
-Same plus
-Investigations for atypical and viral pathogens
=Sputum for direct immunofluorescence/ PCR for mycoplasma pneumoniae, chlamydia, influenzas A&B, parainfluenza 1-3, adenovirus, pneumocystis jiroveci, respiratory syncytial virus
=Initial and follow up viral and atypical pathogen serology
General principles of management
-2 or more CURB65 factors= hospital
-Bed rest
-No smoking
-Fluids
-Simple analgesia
-LMWH prophylaxis
-Oxygen to keep SaO2>93%
-Nutritional support
-Monitor clinically
Antibiotics for low severity pneumonia
-Oral Amoxicillin 500mg tds (strep pneumoniae)
-IV Amoxicillin 500mg tds if oral not possible
Antibiotics for moderate severity pneumonia
-Antibiotics within 4 hrs
-Oral Amoxicillin 500mg-1G tfs + Clarithromycin 500mg bd
-IV Amoxicillin 500mg tds/ IV Benzylpenicillin 1.2G qds + IV Clarithromycin 500mg bd if oral not possible
Antibiotics for high severity pneumonia
-Antibiotics ASAP and consider critical care review
-IV Co-amoxiclav 1.2G tds + IV Clarithromycin 500mg bd
-If Legionella suspected add in IV Levofloxacin
Indications for IV antibiotics
-Unable to swallow
-Concern re absorption from the gut
-Severe CAP
When switch IV to oral antibiotics
Good clinical improvement + apyrexial for 24hrs
Complications of pneumonia
-Lung abscess
-Pleural effusion
-Empyema (infection in pockets in pleural space)
When is chest drain considered?
-Pleural fluid acidosis
-Positive bacteriology from pleural culture
-Pus
Empyema findings
-High protein (>30)
-Very high LDH (>1000)
-Usually, loculations
-Bacteria gram stain
-Very high neutrophils
-Low pleural glucose (<2.2)
-pH <7.2
Primary bacteriology of pleural infection (empyema)
-Oral streptococci (52%) especially millen group
-Anaerobes such as cocci and Bacteroides group (20%)
-S.aureus (11%)
-Gram -ve aerobes (9%)
Secondary bacteriology of pleural infection (empyema)
-MRSA 25%
-G -ve aerobes (E Coli, Ps. aeruginosa, Klebsiella) 17%
-S. aureus 10%
-Anaerobes 8%
Management of empyema
-Fluids
-LMW Heparin
-Nutrition
-ICD (chest drain)
-Antibiotics
=Co-amoxiclav
=Metronidazole
=Cephalosporins
=No aminoglycosides
-If HAP cover MRSA + Anaerobes
-Failure to respond: refer CT surgeons, decortication and rib resection +ICD (frail)
