Antibiotics in Cardio-Respiatory Infections Flashcards
Infections of the respiratory tract
- sinusitis
- tonsillitis
- pharyngitis
- tracheitis
- laryngitis
- pleurisy
- bronchioloitis
- bronchitis
- pneumonia
Types of organisms in the URT
- normal flora
- temporary colonisers
- pathogens
Examples of organisms in the URT
- strep pneumonie
- viridians streptococci
- staph aureus
- candida
- Corynebacterium diptheria
- haemophilus influenzae
- Group A Strep
Example of normal flora in URT
Viridans Streptococci
Example of temporary colonisers in URT
Staph aureus
Candida
Example of pathogens in URT
- group A strep
- Corynebacterium diptheria
URTI Bacteria Common
Strep pyogenes = group A
Strep pneumonia
Haemophilus influenzae
Uncommon causes of URTI
Cornebacterium diphtheriae
Nesisseria meningitidis
URTI Viruses Common
Rhinovirus Influenza/parainfluenza Coronavirus Adenovirus RSV Coxsackie Enterovirus
Influenza Presentation
Fever Headache Malaise Myalgia Arthralgia GI Symptoms Coryza
Treatment for uncomplicated influenza
- if previously healthy = none
- if at risk = oseltamivir 75mg PO within 48 hours of onset
Treatment for complicated influenza
- oseltamivir PO/NG 1st line, zanamivir INH, NEB or IV 2nd line
Define complicated influenza
Requires hospital admission AND OR
- pneumonia/hypoxaemia
- CNS = meningitis
- co-morbidity exacerbation
Investigation for influenza
- nasophargyngeal swab for flu PCR in 2ndry care
- none in primary
Prevention of influenza
Vaccination
HCW
Common pharyngitis viruses
Rhinovirus Influenza/parainfluenza Coronavirus Adenovirus RSV Coxsackie Enterovirus EBV CMV HSC Measles HIV
Common pharyngitis bacteriae
Group a,b,c streptococci
Mycoplasma pneumoniae
Neisseria gonorrhoea
Corynebacterium diptheriae
Pharyngitis presentation
Sore throat Fever Felt ill Tonsillar exudate Tender cervical nodes Scarlet fever
Treatment for pharyngitis
Penicillin V for 10 days
Investigations for pharyngitis
Throat swab
Moderate group of Group A Strep sensitive to penicillin and erythromycin
Centor criteria
- aid diagnosis of Group A Strep Point - tonsillar exudate = 1 - tender cervical LN = 1 - absence of cough = 1 - history of fever = 1
1-2 points = 20% chance = no treatment
3-4 points = 50% chance = treatment advised
Pharyngitis treatment if penicillin allergy
Erythromycin
Pencillin treatment for pharyngitis dose
Penicillin V 500mg QDS
OR
1g BD for 5-10 days
Clarithromycin Treatment for pharyngitis dose
500mg BD for 5 days
Complications of pharyngitis
Rheumatic fever
Glomerulonephritis
Why shouldn’t you give amoxicillin if sore throat in pharyngitis?
- causes rash if patient has EBV = infectious mononucleosis
- not an allergy to amoxicillin
Advantages of amoxicillin
- better absorbed than pen V and clarithromycin
- easier to take
- BUT STILL DON’T GIVE IN EBV
Viruses causing acute otitis media
Rhinovirus Influenza/parainfluenza Coronavirus Adenovirus RSV Coxsackie Enterovirus
Bacteria causing acute otitis media
Strep pneumoniae Haem influenza Moraxella catarrhalis Mycoplasma pneumonia Streptococus pyogenes
What do the 7 main URTI viruses most commonly cause?
Rhinitis
Sinusitis
Otitis media
Pharyngitis
Treatment or otitis media in children?
- no AB usually
- if need to = amoxicillin 5-7 days OR clarithromycin 5-7 days
Indications for AB in acute otitis media children?
- <2 years
- symptoms >48 hours
- high fevers
- bilateral
- otorrhea
Treatment for acute otitis media adults?
- amoxicillin or co-amoxiclav
- OR clarithromycin
Complications of otitis media in adults
Decreased hearing
Mastoiditis
Brain abscess
Organisms causing sinusitis
- 7 common viruses
- strep pneumoniae
- haemo influenza
- Moraxella catarrhalis
Treatment for sinusitis
- pen V or clarithromycin
- co-amoxiclav if systemically unwell
LRTIs
- bronchiolitis
- pleurisy
- bronchitis
- pneumonia
- bronchiectasis and CF
- empyema
Types of pneumonia
- CAP = typical and atypical
- HAP
- Aspiration
Organisms causing typical CAP
- strep pneumoniae
- Haem Inf
- staph aureus
- M TB
Organisms causing atypical CAP
- mycoplasma pneumoiae
- legionella
- chlamydia pneumoniae
- chlamydia psittaci
RF for pneumococcal pneumonia
- influenza
- alcohol
- smoking/COPD
- HIV
First line treatment for Strep Pneumonia?
Antibiotic resistance increasing
- first = amoxicillin
- doxycycline
- levofloxacin
Some strains amxocillin resistant = take travel history!
Second Line treatment for Strep Pneumonia
- ceftriaxone
- teicoplanin
- vancomycin
Atypical pneumonia species
Mycoplasma pneumoniae
Legionella species
Mycoplasma features
- no cell wall
- small
- gram stain not visible
- cell AB don’t affect them
M pneumonia features
- dry cough
- epidemics
- winter
- with pharnygitis, rhinorrhea, otalgia, hepatitis, meningitis
Treatment for mycoplasma pneumonia
- macrolides = clarithromycin
- quinolones = levofloxacin
- tetracyclines = doxycycline
Legionella features
- gram negative rods
- growth needs special media
- slow growth 3-5 days
Treatment for legionella
- cell wall AB not effective
- quinolones>macrolides>tetracyclines
RF of S aureus pneumonia
- viral URTI
- colonisation of URTI
What can S aureus pneumonia cause?
- necrotising/abscess formation
- severe disease
CAP Diagnosis
CURB65 Confusion Urea>7mmol/l RR>30min BP = systolic <90 or diastolic <60 Age >65
0-1 = low severity, outpatient 2 = moderate, admit, Ix microbiology, IV Tx 3-5 = high, urgent admission
Treatment for 0-1 score of CURB65
Oral amoxicillin 500mg TDS
OR
Doxycycline 100mg OD
Treatment for 2 score CURB65
IV benzylpnecillin 1.2g QDS AND Doxycycline 100mg BD
> 2 treatment score CURB65
IV co-amoxiclav 1.2g TDS AND doxycycline 100mg BD
OR
IV ceftriaxone 2g OD AND doxycycline 100mg BD if history of travel
HAP define
> 48 hour after admission or within 2 weeks of admission
Predisposing factors to HAP
- abnormal conscious state/intubation and ventilation
- immunosuppression
Organisms causing HAP
- same as CAP
- also E coli, klebsiella, pseudomonas
Treatment for mild/moderate HAP
doxycycline
Treatment for severe HAP
early onset <5 days = coamoxiclav
late onset >5 days = piperacillin-tazobactam
Cause of aspiration pneumonia
- bacteria from URT/stomach
Treatment for aspiration pneumonia
1 = amoxicillin and metronidazole 2 = levofloxacin and metronidazole 3 = co-amoxiclav 4 = piperacillin-tazobactam
triggers for COPD exacerbation
- virus
- bacteria
- pollution
- CCF
- VTE
- aspiration
When are AB effective in COPD exacerbation?
- increased dyspnoea
- increased sputum purulence
- increased sputum volume
Treatment for COPD exacerbation
- doxycycline or clarithromycin
- guided by sputum results
- 5 day treatment
- if recurrence within 3 months = use alternative agent
- if consolidation on CXR = treat as CAP/HAP
Features of bronchiectasis
- abnormal dilatation of major bronchi and bronchioles
- chronic daily cough with sputum
- CT = bronchial wall thickening and luminal dilatation
CF features
- congenital
- abnormal secretions = chronic infections and bronchiectasis
treatment for bronchiectasis and CF
- guided by sputum culture
- if no pseudomonas = clarithromycin or doxy or co-amoxiclav
- if psueodmonas = ciprofloxacin or IV pip0taz
Prophylaxis of bronchiectasis and CF
- chest physio
- postural drainage
- oral azithromycin
- inhaled AB = nebulised gentamicin, tobramycin, colistin
Define empyema
- complicated parapneumonic effusion
- effusion into pleural space adjacent to bacterial pneumonia
- treat pneumonia to treat normally unless complicated
treatment of empyema
- drainage
- AB 2-4 weeks until CXR resolution
Prevention of resp infections
VACCINES
- influenza
- pneumococca
- haemo influenzae
- pertussis
- diptheria
RF of infective endocarditis
- iatrogenic = infected cannulae
- IVDA = right sided often
- staph aureus, strep pneum, yeast infection
Causes of abnormal valve
- rheumatic fever
- Degen calcific disease
- congenital defects
- mitral valve prolapse!!
Antibiotic sensitivity testing
- disc diffusion tests (qualitiative - sensitive or resistant)
- MIC tests (E-test) (quantitiative, how sensitive/resistant)
Define MIC
Minimum Inhibitory concentration
Lowest conc of an antimicrobial that will inhibit the visible growth of a micro-organism after overnight incubation
Define MBC
Minimum bactericidal concentration
Lowest conc of antimicrobial that will prevent the growth of an organism after subculture on to antibiotic-free media
Empirical Therapy for endocarditis when?
- only if severe sepsis
Native valve infective endocarditis therapy
- vanco and genta
- OR
- vanco and meropenem (gram negative risk)
Prosthetic valve infective endocarditis therapy
vanco and genta and rifampicin
6 weeks
- rifampicin treats biofilm
Directed therapy infective endocarditis for staphylococcous
Staphylococcus – flucloxacillin 4 hourly MRSA – vancomycin
Directed therapy infective endocarditis for streptococci
Streptococci – benzyl penicillin 4 hourly Penicillin resistance – vancomycin & gentamicin
Directed therapy infective endocarditis for enterococci
Enterococci – amoxicillin 4 hourly & gentamicin
Define biofilm
cluster of bacteria in extracellular matrix attached to surface
What is required in directed therapy for infective endocarditis
- guidance of microbiology/infectious diseases team
