Lrti And Pneumonia Flashcards
What are the microbial flora of the upper resp tract
Common
Viridans streptococci Neisseria spp Anaerobes Candida sp
Less common Streptococcus pneumoniae Streptococcus pyogenes Haemophillus influenzae
Other
Pseudomonas, Escherichia coli
What are the defences of the respiratory tract
• Muco-ciliary clearance mechanisms nasal hairs, ciliated columnar epithelium of the respiratory tract
• Cough & the sneezing reflex
• Respiratory mucosal immune system
Lymphoid follicles of the pharynx and tonsils, alveolar macrophages, secretary IgA and IgG
How can registry defences be compromised
Poor swallow (CVA, muscle weakness, alcohol) - Anything that affects epiglottis - anything that weakens muscles - affect tone of larynx and upper airways -aspirate secretions - flora from the mouth can go to lungs Abnormal ciliary function (smoking, viral infection) Abnormal mucus (cystic fibrosis) Dilated airways: bronchiectasis Defects in host immunity HIV, Immunosuppression
What are some upper rts=is
Ss
What are some lower rtsi
Bronchitis, pneumonia, bronchiolitis, emphysema, bronchiectasis, 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 • Organisms: – viruses – S. pneumoniae – H. influenzae – M. catarrhalis • Bronchodilation; Physiotherapy; +/- Antibiotics- remove music from chest
What is chronic bronchitis
NOT primarily infective. Exacerbations have been associated with many organisms, but the role of infection remains controversial
Conglomerates with cost. At higher risk of infection. ??
What is pneumonia
• Inflammation of the lung alveoli • Patients are unwell 20-40% admitted to hospital mortality 5-10% • Presentation – Fever – Cough – Pleuritic chest pain – Shortness of breath • Often localising signs and abnormal CXR Associated effusion?
Describe the classification of pneumonia
• By clinical setting (e.g. Community acquired, Hospitals acquired)
• By presentation (acute and chronic)
• By organism (Bacterial, Viral, fungal)
• By lung pathology (lobar pneumonia, bronchopneumonia, interstitial pneumonia)
Pneumonitis: non infective inflammatory disease
Describe teh appareance of the lung sin pneumonia
Ss
What is CAP and which organisms are associated with it
Community acquired pneumonia (CAP) • No microbiological ID made in most cases. Main organisms: – Streptococcus pneumoniae – Haemophilus influenzae – Moraxella catarrhalis – Staphylococcus aureus – Klebsiella pneumoniae
What are the causes o CAP
- Typical Organisms / Manifestations (85%)
- S. pneumoniae
- H. influenzae
- Atypical manifestations of cap / Manifestations (15%) - Atypical -most lack a cell wall - teh antibiotics aimed at gram +ves with a cell wall DO NOt work on these bc they have no cell wall
- Legionella – contaminated water sources
- Mycoplasma- epidemics 4-6 yrs
- Coxiella burnetii (Q fever)-worldwide, farm animals, hepatitis
- Chlamydia psittaci (Psittacosis) exposure to birds, splenomegaly, rash, haemolytic anaemia
What are the symptoms of pneumonia
• Shortness of breath • Cough +/- sputum (yellow, rusty, current
jelly) • Fever • Rigors • Pleuritic chest pain • Malaise, nausea & vomiting
What is seen upon examination of pneumonia
• Pyrexia
• Tachycardia • Tachypnoea • Cyanosis • Dullness to percussion, tactile vocal
fremitus • Bronchial breathing • Crackles
What are the investigations for pneumonia
• Full Blood Count, • Urea & Electrolytes • C Reactive Protein • Arterial Blood Gases • Chest X Ray
Describe teh investigations of new Monica in terms of microbiological instigation
• Sputum / Induced sputum
• Blood culture
• Broncho Alveolar Lavage fluid (BAL) - Wash out lungs with fluid, wash it away, sam plefluid
• Nose & Throat swabs or NPAs (viruses)
• Urine (antigen test for legionella /
pneumococcus)
• Serum (antibody test) acute & convalescent sera (usually collected at presentation and 10-14 days later)
Wha needs to be considered when deciding management
• CURB-65 score – Confusion – Urea >7 mmol/l – Respiratory Rate >30 – Blood Pressure <90 systolic <60 diastolic – >65 years • Score 2 = ?admit • Score 2-5 = manage as severe
Desceire tha antibiotic treatment
• Depends on probable infection: – Community vs hospital acquired? – Severity of illness? – Personal risk factors – Ventilator associated? If severe Coamocyclav and doxycyclin Anaesthetic? Lost muscle tone Ventilators - higher risk of pseudomonas
Describe the empiric therapy for cap`
• Each hospital has its own guideline • Mild-moderate: – Amoxicillin – Or doxycycline or erythromycin / clarithromycin • Moderate-severe: – Needing hospital admission: co-amoxiclav AND clarithromycin / doxycycline
What are the outcomes of acute bacterial pneumonia
• Resolution
Organisation (fibrous scarring)
• Complications
Lung abscess Bronchiectasis Empyema (pus in the pleural cavity)
What could have developed if the patient is not improving upon treatment
• Empyema / abscess • Proximal obstruction (tumour) • Resistant organism (incl. Tb) • Not receiving / absorbing Abx • Immunosuppression • Other diagnosis – Lung cancer – Cryptogenic organising pneumonia Do another cxr, ct to check bronchioles
What is s pneumonia
• Gram +ve cocci (pairs – diplococci) • 30-50% of CAP • Acute onset – Severe pneumonia – Fever, rigors – Lobar consolidation • Treat with Benzyl penicillin or amoxicillin
Describe pneumonia due to atypical organisms
• Pneumonia caused by organisms without a cell wall
– Mycoplasma – Legionella – Chlamydia – Coxiella
• Cell-wall active antibiotics e.g. penicillins don’t work
• Need agents that work on protein synthesis
– Macrolides (clarithromycin / erythromycin)
– Tetracyclines (doxycycline)
• Extrapulmonary features – e.g. hepatitis; low sodium
Describe viral pneumonia
• Damage to cells lining the airways / alveoli by the virus Influenza, and mmune cells Parainfluenza,
• Fluid filled air spaces Respiratory Syncytial interferes with gas exchange virus (RSV)
• Mild to severe Adeno virus,
• Severe viral pneumonia necrosis / haemorrhage into the lung parenchyma – picture similar to adult respiratory
distress syndrome (ARDS)
• Patchy or diffuse ground glass opacity on chest X ray
Inflammation is diffuse and all around lung. Looks limiter to adult RDS
What viruses can cause pneumonia
Ss
What is hap
• > 48 hours in hospital
• Often previous antibiotics - more resistant
• +/- ventilator
• Infectious vs non-infectious causes
of abnormal CXR / lung function.
• Bronchial lavage desirable to differentiate upper respiratory from lower respiratory flora.
What can cause hap
- Staphylococcus aureus
- Enterobacteriaciae
- Pseudomonasspp
- Haemophilus influenzae
- Acinetobacter baumanii
- Fungi (Candida sp.)
- Other
What is used to treat hap
• First line: Co-amoxiclav • Second line/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
- At risk groups - nursing home residents and drug overdose
- Mixed infection - viridans streptococci & anaerobes
- Treat with Co-amoxiclav - first time
Describe immunosupression and lrt I
• HIV: PCP, TB, atypical mycobacteria
• Neutropenia: fungi e.g. Aspergillus spp
• Bone marrow transplant: CMV
• Splenectomy: encapsulated organisms
– e.g. S. pneumoniae, H. influenzae, malaria
• “Anything can do anything”
Describe teh prevention of hap
• Immunization
Flu vaccine – given annually to high risk patients
Pneumococcal vaccine – every five years
23 polyvalent polysaccharide vaccine dose
13 valent conjugate vaccine
Given to patients with co-morbities - increase risk of invasive pneumococcal disease
• Chemoprophylaxis
Oral penicillin / erythromycin to patients with
higher risk of lower respiratory tract infections
(i.e. asplenia, dysfunctional spleen,
immunodeficiency)
• Smoking advice
