Lower Respiratory Tract Infections Flashcards
What is pneumonia?
Strictly speaking it means any inflammatory condition affecting the alveoli of the lungs
But usually relates to a bacterial infection
What is the commonest type of organism that causes pneumonia?
Bacterial
What other types of organisms can cause pneumonia?
Viruses
Fungi
What are symptoms of pneumonia?
Cough Sputum (purulent, rusty) SoB Chest pain (pleuritic) Fever Malaise
What are signs of pneumonia?
Pyrexia, tachycardia Tachypnoea Reduced oxygen saturations Dullness to percuss affected lobe Bronchial breathing Inspiratory creps Increased vocal resonance
What is the classical CXR finding in pneumonia?
Consolidation
What bloods would you do for someone with pneumonia?
FBC - usually seen neutrophilia in bacterial infections
UE
CRP - raised in response to infections
May do ABG if low oxygen sats/pre-existing lung disease, e.g. COPD
Aside from CXR/bloods, what other investigation might you do in pneumonia?
Sputum microscopy + culture
Blood culture
Urinary legionella anigen
Throat swab (for atypical pathogens)
What organism most commonly causes pneumonia?
Strep pneumoniae
What severity scoring system is used to determine best treatment course in pneumonia?
CURB 65 C = confusion U = urea >7 Resp rate >=30/min B = BP, systolic <=90 +/or diastolic <=60mmHg
65 - aged >=65
How is a CURB score of 0 managed?
In the community
How is a CURB score of 1 managed?
Have SaO2 assessed if >92% –> do CXR and manage in community
If CXR shows bilateral/multinodal shadowing hospital admission advised
How is a CURB score of 2+ managed?
In hospital (as it represents severe CAP)
What does the CURB correlate with?
Risk of mortality at 30 days
What are the basics of treating pneumonia?
Antibiotics
Supportive care - oxygen, IV fluids etc.
What is idiopathic interstitial pneumonia?
A group of non-infective causes of pneumonia, e.g. COP
What is COP a complication of?
RA or amiodarone therapy
What scoring system for pneumonia should be used in the primary care setting?
CRB65 Confusion (abbreviated mental test score <=8/10) Resp rate >=30/min BP systolic <=90, diastolic <=60 Aged >=65
How should a CRB65 score of 0 be managed?
At home
All other scores in hospital
What other method may be used to decide if patients need antibiotics for pneumonia in primary care?
Point of care CRP testing
CRP <20 - do not give antibiotics
20-100 - consider delayed prescription
>100 - offer antibiotics
For what CURB65 score should ITU be considered?
3+
What investigations should be done for suspected pneumonia?
CXR
Intermediate/high risk patients - blood + sputum cultures, pneumococcal and legionella urinary antigen tests
CRP monitoring
How is low-severity CAP managed?
1st line: amoxicillin (if allergic - tetracycline/macrolide) 5 day course
How is moderate/high-severity CAP managed?
Dual antibiotic therapy - amoxicillin + macrolide 7-10 day course
Consider co-amoxiclav/ceftriaxone/piperacillin with tazobactam + macrolife in high severity CAP
NICE recommend pneumonia patients are not routinely discharged in the last 24 hours if they have 2 or more of:
Temp >37.5C RR >=24 HR >100bpm Systolic BP 90mmHg or less O2 <90% on air Abnormal mental status Inability to eat without assistance
Describe how pneumonia gradually gets better
1 week - fever resolved
4 weeks - chest pain + sputum production substantially redued
6 weeks - cough and SoB should be substantially reduced
3 months - most symptoms resolved but fatigue may be present
6 months - should feel normal
What are complications of pneumonia?
Septicaemia AKI Empyema Lung abscess Haemolytic anaemia (mycoplasma) ARDS
What are differentials for pneumonia?
TB Lung cancer Cardiac failure PE Pulmonary vasculitis (e.g. Wegener's)
What is an empyema?
Pus in the pleural space
What is pleuritic chest pain?
Chest pain on inspiration due to inflammation of the parietal pleura
What do the majority of empyemas follow?
A pneumonia
What organism most commonly causes an empyema?
Strep
What are symptoms/signs of an empyema?
Consitutional symptoms - malaise, anorexia etc.
Pyrexia, rigors
Dullness to percussion
Reduced breath sounds and reduced vocal resonance
Productive cough
Pleuritic chest pain
SoB
What investigations should be ordered for suspected empyema?
Blood cultures CRP WCC CXR Thoracentesis - pleural fluid appearance, odour, pH, total protein concentration etc.
NB aspiration of frank pus is diagnostic (no futher Ix req)
Pleural fluid pH <7.2 also diagnostic
How is empyema managed?
IV antibiotics
Chest tube drainage
Supportive care
Intrapleural fibrinolytics and surgery may be recommended for some patients
What organisms are more likely to result in a cavitating pneumonia and hence predispose to lung abscess formation?
S. aureus
Pseudomonas
Anaerobes
What are symptoms of lung abscesses?
Fever, productive cough, wt loss etc.
What investigations are used to investigate a suspected lung abscess?
CXR
Sputum gram stain, culture
How is lung abscess managed?
Antibiotics
Chest physio/postural drainage
May require drainage via bronchoscopy or percutaneous drainage
