Respiratory Infections Flashcards
(22 cards)
What are the differences between the upper and lower respiratory tracts in terms of normal flora?
The upper respiratory tract contains normal flora such as S. Aureus, S. Pneumoniae and Haemophilus
The lower respiratory tract is sterile and doesnt contain bacteria normally
What defence do the alveoli themselves have to pathogens?
They contain IgA antibodies, complement and macrophages for killing pathogens
What are some of the common pathogens in the different regions of URT infections?
Nasopharynx - Rhinovirus (common cause of cold)
Oropharynx - Group A steptococcus
Epiglottis - H.Influenzae
Larynx - S.Aureus
What are the main differences between a common cold and influenza?
Influenza commonly has headache and temperature whereas cold does not
Influenza can also have general aches and pains and fatigue whereas this is less likely in cold
Influenza has exhaustion whereas cold does not
What are the types of influenza and which commonly cause disease?
The common types are A, B and C and A and B cause the majority of disease
How is a diagnosis of Influenza made?
Through throat swab
What is the most common cause of bacterial pharangitis?
Streptococcus pyogenes
What are the three common causes of otitis media?
Viruses, s. pneumoniae and s. aureus
What is the cause of whooping cough?
Bordatella pertussis bacteria
What factors predispose people to lower respiratory tract infections?
Alcoholism
COPD
Cystic fibrosis
Mechanical ventilation
What are the two different types of pneumonia?
Acute pneumonia is either community or hospital aquired
Chronic pneumonia is either fungal or due to TB
What are the signs and symptoms for typical pneumonia and atypical pneumonia?
Typical pneumonia: -Fever -Chest pain -Purulent sputum -CXR shows lobar consolidation Atypical pneumonia: -dyspnea -cough -systemic upset -little sputum -cxr shows diffuse shadowing
What is the most common cause of community aquired pneumonia?
Streptococcus pneumoiae
Microinspiration of droplets whilst sleeping
What are the four stages of classical lobular pneumonia?
Acute congestion capillary enlargement and neutrophil recruitment
Red hepatisation - red blood cells move into alveoli
Grey hepatisation - red cells broken down leaving exudate
Resolution
What are typical organisms that cause COPD exacerbations?
H.Influenzae and S.Pneumoniae
What are the common causes of atypical pneumonias and how are they treated?
Commonly caused by mycoplasma pneumoniae, also legionella pneumoniae
Can be from faulty air con
Can be treated with tetracyclines
What are the clinical findings in atypical pneumonia?
Insidious onset with low grade fever Non productive cough Chest pain Flu like symptoms No signs of consolidation
What is CURB65 and what score is severe?
C - Confusion new onset U-Urea greater than 7mmol/L R - resp rate of greater than 30 B - Blood pressure less than 90 systolic Over 65 Scoring over 3 is severe
What are the treamtent options for mild and severe pneumonia?
In mild pneumonia it is usually treated with amoxicillin or clarithromycin
In severe it is treated with benzylpenicillin or clarithromycin
How do you treat early and late onset hospital aquired pneumonia?
Early onset (>5 days since hosp admission) you give co - amoxiclav Late onset is treated with piperacillin
What is the pathogenesis of TB?
Mycobacterium tuberculosis is inhaled
This is ingested by phagocytes but prevents the lysosome binding
This can remain dormant and then becomes reactivated and causes secondary TB
Release of cytokines from memory T cells cause cavitating lesions
What is the treatment for TB?
triple therapy of isoniazid, pyrazinamide and rimfampicin
