LRTI And Pneumonia Flashcards
What are some common microbial flora of the upper respiratory tract?
Viridans streptococci
Neisseria
Anaerobes
Candidia
How does our body stop bacteria invading and causing infections?
Muco-ciliary clearance mechanisms, nasal hairs and ciliated columnar epithelium of the respiratory tract.
Respiratory mucosal immune system. Lymphoid follicles of the pharynx and tonsils, alveolar macrophages, secretory IgA and IgG.
Cough and sneezing reflex
How can you compromise respiratory defences?
Poor swallow (muscle weakness, alcohol)
Abnormal ciliary function (smoking, viral infection)
Abnormal mucus (CF)
Dilated airways (bronchiectasis)
Defects in host immunity - immunosuppression, HIV
What can severe otitis media cause?
Mastoiditis, meningitis and brain abscesses. Don’t miss it!
What are some lower respiratory tract infections?
Bronchitis Pneumonia Bronchiolitis Bronchiectasis Empyema Lung abscess
What is acute bronchitis?
Inflammation of medium sized airways
Mainly in smokers
Cough, fever, increased sputum production, increased shortness of breath
CXR: normal
Organsisms:
Steptococcus pneumoniae
Haemophilius influenzae
Moraxella catarrhalis
Bronchodilation using physiotherapy and (maybe) antibiotics.
What is chronic bronchitis?
NOT primarily infective
Exacerbations have been associated with many organisms, but the role of infections remains controversial
What is pneumonia?
Inflammation of the lung alveoli
Patients are unwell - 20-40% admitted to hospital and mortality is 5-10%
Presentation: Fever Cough Pleuritic chest pain Shortness of breath
Localising signs and abnormal CXR
How can you classify pneumonia?
Clinical setting -Community acquired, hospital acquired
Presentation -acute vs chronic
Organism -bacterial, viral, fungal
Lung pathology -lobar pneumonia, bronchopneumonia, interstitial pneumonia
What organisms more commonly cause communit acquired pneuma>
Strep pneumoniae (common) Haemophilus influenzae (common) Moraxella catarrhalis Staph aureus Klebsiella pneumoniae
What atypical organisms can cause CAP?
Legionella - water
Mycoplasma -epidemics
Coxiella burnetti (Q fever) -farm animals
Chlamydia psittaci - birds, spenomegaly, rash, haemolytic anaemia
What are he symptoms for community acquired pneumonia?
Shortness of breath Cough +/- sputum Fever Rigors Pleuritic chest pain Malaise, nausea and vomiting
What do you examine for in community acquired pneumonia?
Pyrexia Tachycardia Tachypnoea Cyanosis Dullness to percussion Bronchial breathing Crackles
What investigations do you do for community acquired pneumonia?
FBC U&E CRP ABG CXR
What microbiological samples / investigations do you do if the patient isn’t getting better?
Sputum / induced sputum Blood culture Broncho alveolar Lavage Nose and Throat swabs or NPAs (viruses) Urine Serum antibody
How do you manage pneumonia?
CURB-65 score -admit or not
Antibiotics-different depending on infection
What is the CURB-65 score?
This is a score used to predict mortality in community acquired pneumonia.
What antibiotic are used for mild-moderate pneumonia?
Amoxicillin or doxycycline /erythromycin / clarithromycin (if allergic)
What antibiotic are used for moderate-severe pneumonia?
Co-amoxiclav and clarythromycin.
This is when patients need hospital admission
What could become complications fo acute bacterial pneumonia?
Lung abscess
Bronchiectasis
Empyema
What do you think about if the patient fails to improve upon treatment?
Empyema / abscess Proximal obstruction (tumour) Resistant organism (TB) Not receiving or absorbing antibiotics Immunosuppression Other diagnosis -lung cancer
Discuss streptococcus pneumonia
Gram positive diplococci a haemolysis Causes 30-50% of CAP Acute onset: -Severe pneumonia, fever, riggers, lobar consolidation Treat with amoxicillin or IV penicillin
Why do you need different antibiotics for organisms that are atypical?
Because they don’t have a cell wall so beta lactams the work by destroying the cell wall do not work.
You need agents that work on protein synthesis
- Macrolides (erythromycin)
- Tretracyclines (doxycycline)
Also may have extra pulmonary features such as hepatitis low Na.
What is viral pneumonia?
Damage to cells lining the airways / alveoli by the virus and immune cells.
Fluid filled air paces interferes with gas exchange
Mild to severe
Severe viral pneumonia causes necrosis / haemorrhage (similar to ARDS)
Patchy or diffuse ground glass opacity on CXR
What is hospital acquired pneumonia?
Developed after 48 hours in hospital
Often previous antibiotics
+/- ventilator
Can have infectious or non–infectious causes of abnormal CXR and lung function.
Bronchial lavage is desirable to differentiate upper from lower respiratory flora
What organisms commonly cause hospital acquired pneumonia?
Staph aureus
Pseudomonas
Haemophilus influenzae
Acinetobacter baumanii
How do you treat hospital acquired pneumonia?
Co-amixiclav
If worse (ITU): Pipperacilin / tazobactam or Meropenem
What is aspiration pneumonia?
Aspiration of exogenous material or endogenous secretions into the respiratory tract.
Common in patients with neurological dysphagia (strokes), epilepsy, alcoholics, drowning
You care at risk if you live in a nursing home or have had an overdose.
Mixed infection - viridians streptococci and anaerobes
Treat with co-amoxiclav
What patients are classified as immunosuppressed and what bacteria do you worry could have infected them?
HIV: PCP, TB, atypical mycobacteria
Neutropenia: fungi e.g. aspergillus
Bone marrow transplant: cytomegalovirus
Splenectomy: encapsulated organism (S. pneumoniae, H. influenzae, N. Meningitidis)
How do you prevent pneumonia?
Immunisation -flu, pneumococcal
Chemoprophylaxis -penecillin /erythromycin
Smoking cessation advice
