Cardio-Resp Infections Flashcards
Normal flora in URT
Viridans streptococci
Temporary colonisers in URT
Staph aureus
Candida
Pathogens in URT
Strep Pneumonia
Corynebacterium diptheria
Haemophilus Influenzae
Group A Strep
Common URTI viruses
rhinovirus influenza coronavirus adenovirus RSV coxsackie enterovirus
Common URTI bacteria
Strep pyogenes- group A
Strep pneumoniae
Haemophilus influenzae
Influenza symptoms
Fever
Coryza
systemic symptoms- headache, malaise, myalgia, arthralgia
+/- GI symptoms
Influenza investigation
Primary care- not needed
Secondary care- nasopharyngeal swab for flu PCR
Influenza treatment
Within 48 hrs of start of symptoms
Oseltamivir 75mg bd oral/NG for 5 days
Pharyngitis- viruses
7 common URTI viruses
EBV
CMV
HSV
Pharyngitis- bacteria
Group A, B, C Streptococci
Mycoplasma pneumoniae
Neisseria gonorrhoea
Corynebacterium diptheriae
Pharyngitis symptoms
Sore throat
Fever
Tonsillar exudate
Tender cervical nodes
Pharyngitis centor criteria
Tonsillar exudate Tender cervical LN Absence of cough h/o fever --> if 3/4- 50% chance
Pharyngitis antibiotic sensitivity
All are penicillin sensitive
Majority erythromycin sensitive (for penicillin allergic people)
Pharyngitis Treatment
Penicillin V 500mg QDS or 1g BD for 5-10 days
OR clarithromycin 500mg BD for 5 days
Pharyngitis complications
Rheumatic fever
Glomerulonephritis
Amoxicillin + EBV
Often causes rashes
–> doesn’t mean they have allergy
Amoxicillin and sore throat
DO NOT GIVE
Acute Otitis media viruses
Common URTI viruses
Acute Otitis media bacteria
Streptococcus pneumoniae Haemophilus influenzae Moraxella catarrhalis Mycoplasma pneumoniae Streptococcus pyogenes
Acute otitis media- children
No antibiotics unless:
- <2 years
- symptoms persist >48 hours
- high fevers
- bilateral
- otorrhea
Acute otitis media antibiotics
Amoxicillin 5-7 days (or co-amoxiclav)
OR clarithromycin 5-7 days
Acute otitis media complications
Decreased hearing
Mastoiditis
Brain abscess
Sinusitis viral
Common URTI viruses
Sinusitis bacterial
Streptococcus pneumoniae
Haemophilus influenzae
Moraxella catarrhalis
Sinusitis treatment
Treatment usually not necessary
Consider penicillin V or clarithromycin
Co-amoxiclav is systemically unwell
LRTI
Pneumonia - community acquired (typical or atypical), hospital acquired, aspiration
Exacerbations of chronic bronchitis
Bronchiectasis + cystic fibrosis
Empyema
Community Acquired Pneumonia- typical
Strep pneumoniae
Haemophilus influenzae
Staph aureus
M tuberculosis
Community Acquired Pneumonia- Atypical
Mycoplasma pneumoniae
Legionella
Chlamydia pneumoniae
Chlamydia psittaci
Pneumococcal pneumonia RFs
Influenza
Alcohol
Smoking/COPD
HIV
Pneumococcal pneumonia- resistance
Antibiotic resistance increasing
Always take a travel history- lots of country have resistant strains against amoxicillin
Atypical pneumonia
Mycoplasma pneumoniae
Legionella species
Mycoplasma
Smallest
No cell wall
Not affected by cell wall antibiotics
M pneumoniae
Autumn-winter Epidemics Dry cough \+/- pharyngitis, rhinorrhea, otalgia \+/- hepatitis, meningitis
M pneumoniae antibiotics
Macrolides (e.g. clarithromycin)
Quinolones (e.g. levofloxacin)
Tetracyclines (e.g. doxycycline)
Legionella spp microbiology
> 50 species
Gram -ve rods
Slow growth (3-5 days)
Legionella spp antibiotics
Cell wall antibiotics not effective
Quinolones>macrolides>tetracyclines effective
S aureus pneumonia with abscess RFs
Colonisation of URT
Viral URTI
S aureus pneumonia with abscess- PVL toxin strains causes
Severe disease
Necrotising/abscess formation
CURB-65
Confusion Urea > 7mmol/l Respiratory rate >30/min BP (systolic <90 or diastolic< 60) Age> or =65
CURB-65 Score 0-1
Low severity
Risk of death <3%
Outpatient
CURB-65 Score 2
Moderate severity Risk of death 9% Admit Microbiological investigations IV Rx
CURB-65 Score 3-5
High severity
Risk of death 15-40%
Urgent admission
CURB-65 0-1 treatment
Oral amoxicillin 500mg TDS OR doxycycline 100mg OD
CURB-65 2 treatment
IV benzylpenicillin 1.2g QDS & doxycycline 100mg BD
CURB-65 >2 treatment
IV co-amoxiclav 1.2g TDS & doxycycline 100mg BD
OR
IV ceftriaxone 2g OD & doxycycline 100mg BD
CAP Summary
Mild- po amoxicillin
Moderate- IV benzylpenicillin + doxycycline
Severe- IV co-amoxiclav + doxycycline
h/o travel- IV ceftriaxone & doxycycline
Hospital Acquired Pneumonia
> 48 hrs after admission or within 2 weeks of admission
Hospital Acquired Pneumonia predisposing factors
Abnormal conscious state/intubation & ventilation
Immunosuppression
HAP microbiology
as for CAP + gram negative organisms (e. coli, klebsiella, pseudomonas)
HAP mild/moderate
doxycycline
HAP severe
early onset (<5 days)- co-amoxiclav) late onset (>5 days)- piperacillin-tazobactam
Aspiration pneumonia aetiology
Bacteria from URT/stomach
Low virulence
Polymicrobial (aerobic streptococci + anaerobes)
Aspiration pneumonia treatment options
Amoxicillin + metronidazole
Levofloxacin + metronidazole
Co-amoxiclav
Piperacillin-tazobactam
Exacerbation of COPD
Acute- due to inflammation in airways
Worsening of symptoms- SOB, Cough, Sputum
Possible triggers for ECOPD
Viruses COPD Bacteria Pollution CCF VTE Aspiration
Infective ECOPD- bacteria
Haemophilus influenzae Moraxella catarrhalis Streptococcus pneumoniae
Pseudomonas aeruginosa Chlamydia pneumoniae
Infective ECOPD- viral
Rhinovirus Influenza/parainfluenza Adenovirus RSV Metapneumovirus Coronavirus
IECOPD Antibiotics
Effective if h/o >2 of:
- increased dyspnoea
- increased sputum purulence
- increased sputum volume
IECOPD Empirical treatment
Doxycycline or clarithromycin
IECOPD Specific treatment
Duration- 5 days
If relapse within 3 months, alternative agent
If consolidation on CXR then treat as CAP/HAP
Bronchiectasis
Abnormal dilatation of major bronchi + bronchioles
Chronic daily cough with viscid sputum production
CT- bronchial wall thickening + luminal dilatation
Cystic fibrosis
Congenital
Abnormal secretions resulting in chronic infections + bronchiectasis
Bronchiectasis + CF Treatment
Guided by sputum culture
If no pseudomonas- clarithromycin of doxycycline or co-amoxiclav
If pseudomonas- po ciprofloxacin or IV pip-taz
Bronchiectasis + CF prophylaxis
Chest physio/postural drainage Oral azithromycin (for recurrent only) Inhaled abx (nebulised gentamicin, tobramycin, colistin
Empyema
Complicated parapneumonic effusion (effusion into pleural space adjacent to bacterial pneumonia)
Usually small
Usually resolve with pneumonia treatment
Complicated parapneumonic effusion
Bacteria involve pleural space
Empyema develops
Empyema treatment
Drainage
Antibiotics until XR resolution (2-4 weeks)
Prevention of Resp Infections
VACCINATIONS
Influenza
Pneumococcal Haemophilus influenzae Pertussis
Diptheria
Infective Endocarditis RF
Iatrogenic- infected cannula
IVDA (often leads to right side endocarditis)
Infective endocarditis pathogens
High pathogenicity organisms
Staphylococcus aureus Strep pneumoniae
yeast
Infective endocarditis- abnormal native valve
rheumatic fever
degenerative (calcific) disease
congenital defects (especially turbulent flow)
mitral valve prolapse (5-10 x risk)
Infective endocarditis- abnormal valve bacteria
Often low virulence
oral (viridans) streptococci Enterococcus spp.
HACEK group of organisms
Occasionally …Coxiella burnetii, Chlamydia spp, Mycoplasma spp., Bartonella spp.
Infective endocarditis- prosthetic valve
1st year after surgery- risk approx. 1-2%
Commonly- staph aureus, coagulase negative staph
After 1 year post-surgery- risk <0.5%
Commonly- oral streptococci, enterococcus spp.
Infective Endocarditis treatment principles
Vegetation impenetrable by phagocytes Surgical backup essential Synergistic combination often required Intravenous therapy essential – duration? Duration? - 4 weeks native valve IE - 6 weeks prosthetic valve IE Need to know aetiology of infection - MIC of organism guides therapy
Infective endocarditis antibiotic sensitivity testing
Disc diffusion tests MIC tests (E test)
Infective endocarditis antibiotic sensitivity testing- MIC
Minimum inhibitory concentration = lowest concentration of an antimicrobial that will inhibit the visible growth of a microorganism after overnight incubation
Infective endocarditis antibiotic sensitivity testing- MBC
minimum bactericidal concentration = lowest concentration of antimicrobial that will prevent the growth of an organism after subculture on to antibiotic-free media.
Empirical therapy for endocarditis
Only if severe endocarditis
Native valve- vancomycin + gentamicin OR vancomycin + meropenem
Prosthetic valve- Vancomycin + gentamicin + rifampicin
IE directed therapy
Staphylococcus- flucloxacillin 4 hourly (MRSA- vancomycin)
Streptococci- benzyl penicillin 4 hourly (penicillin resistance- vancomycin + gentamycin)
Enterococci- amoxicillin 4 hourly + gentamicin
Prosthetic valve IE course
6 weeks
Poor prognosis
Add oral rifampicin to treat biofilm
Endocarditis summary
uncommon but may high morbidity & mortality
difficult to diagnose
4-6 weeks of IV antibiotic therapy
surgery occasionally needed
valve replacement carries risks of new infection
Antimicrobial prophylaxis is generally no longer indicated but this is controversial
