Respiratory Tract Infections Flashcards
What examples are there of compromise to respiratory defences?
Poor swallow- cva, muscle weakness, alcohol. Aspirating of salivary secretions
Abnormal ciliary function- smoking, viral infection, kartageners
Abnormal mucus- cf
Dilated airways- bronchiectasis
Defects in host immunity- HIV, asplenic, complement deficient
What is pneumococcus known as?
Old mans friend but actually one of the commonest caused of CAP.
Bacteraemic
Green alpha haemolysis
Bile soluble optochin sensitivity
What is s pneumonia?
Gram positive diplococci
30-50% of cap
Acute onset, severe pneumonia, fever, rigours, lobar consolidation
Almost always penicillin sensitive, know travel history
Resistance in Europe
What is pneumonia?
Inflammation of lung alveoli
Patients are sick, mortality of 5-10%
Fever, cough, pleuritic chest pain, shortness of breath
Often localising signs and abnormal cxr or normal in atypical
How is pneumonia classified?
Community acquired
Hospital acquired- ventilator associated
Pre existing lung disease, immunocompromised, geography, season, epidemics, travel, exposure to animals and contacts
What are the main organisms in cap?
S pneumonia H influenzae Moraxella catarrhalis- follows viral infection S aureus Klebsiella pneumoniae
What ages are various pathogens likely to infect people?
0-1 months- E. coli, gbs, listeria
1-6 months- chlamydia trachomatis, s aureus, Rsv
6 months-5 years- mycoplasma, influenza
16-30 years- m pneumoniae, s pneumoniae
What are the causes of cap?
Typical- s pneumonia, h influenzae
Atypical- legionella
mycoplasma (barking cough)
coxiella burnetti. (Q fever) , farm animals, hepatitis
Chlamydia psittaci- birds, splenomegaly, rash, haemolytic anaemia
What would you expect to find in examination of cap?
Pyrexia Tachycardia, tachypnoea Cyanosis, dullness to percussion, tactile vocal fremitus Bronchial breathing Crackles
What investigation would you ask for cap?
Fbc, u&e, crp
Bc, sputum and mc&S
Abg- useful in PCP, desaturate on exertion
Cxr
How do you manage cap?
CURB 65 score- confusion, urea more than 7, rr more than 30, bp less than 90 systolic, less than 60 diastolic, more than 65 years
Score 2- maybe admit
Score 2-5 manage as severe
What is bronchitis?
Inflammation of medium sized airways
Mainly in smokers
Cough, fever, increased sputum production, increased sob
Cxr is normal
Organisms- virus, s pneumonia, h influenza, m catarrhalis
Bronchodilation, physiotherapy, humidified oxygen
Which organisms can give cavitating pneumonia?
S aureus
Klebsiella
H influenza gram neg bacilli
What is h influenzae?
Gram neg coccobacillus
15-35% of cap
More common with pre existing lung disease
May produce b lactamase- augmentin plus or minus clarithromycin
What clincal signs point to legionella?
Confused Smoker Hyponatriaemic Infected water droplets Multi organ failure Special culture- buffered charcoal yeast extract Asymptomatic- Pontiac fever