Serious Infections Flashcards
What is the most common cause of bacterial endocarditis?
Staph aureus
Which patients should get a TOE to investigate endocarditis?
All patients except those with a negative TTE and a low clinical suspicion of endocarditis
What percentage of patients with a bacterial endocarditis will have a negative echocardiogram?
15% - so if negative repeat in 7-10 days
What is the mechanism of action of beta lactams?
Binds to the penicillin binding protein which prevents transpeptidation for bacterial cell wall synthesis
What is the treatment for enterococcus faecalis endocarditis?
Amoxicillin and ceftriaxone for 6 weeks
Should all patients with staph aureus bacteraemia have an echocardiogram?
Yes
What is the recommended duration of treatment for staph aureus bacteraemia?
2 weeks if uncomplicated (no endocarditis, no prosthesis, negative cultures after 2-4 days)
4-6 weeks if complicated
What are the most common pathogens in meningitis?
Streptococcus pneumonia (most common)
Neisseria meningitides (more common under 60)
Listeria monocytogenes (more common over 60)
Haemophilis influenza
Strep agalactiae
What are risk factors for pneumococcal meningitis?
Otitis media, sinusitis, mastoiditis, CSF leak, cochlear implants, asplenia, HIV/AIDS, immunosuppression
Which patients should you consider listeria meningitis in?
Age > 50, long term glucocorticoids/immunosuppression, diabtes, alcoholism, cirrhosis, ESRF, malignancy, HIV/AIDS, organ transplantation
Which patients should you suspect meningococcal meningitis in?
Young adults without comorbidities
Which patients should have a CT prior to LP in suspected meningitis?
Decreased consciousness, focal neurological deficit, papilloedema, new onset seizures, immunocompromised, known phx of mass lesion/stroke
(however these indications are controversial)
What are the CSF findings for bacterial meningitis?
Opening pressure >20, positive gram stain, protein > 1g/L, low glucose, white cell count >1000 with >50% PMNs
What is the benefit of a PCR panel on CSF sample?
Has good sensitivity even when sample taken post antibiotic treatment
What are the clinical benefits of dexamethasone in pneumococcal meningitis?
Reduced mortality, reduced hearing loss/other neurologic sequelae
When and how should dexamethasone be given for pneumococcal meninigits?
Start with or before first dose antibiotics, given 10mg IV Q6H for 4/7
Is there a role for dexamethasone in meningococcal meningitis?
No – can be stopped once diagnosed
What is the empiric therapy for meningitis?
Dexamethasone
Ceftriaxone 2g IV Q12H
+/- vancomycin
+/- benzylpenicillin
What is the alternative to ceftriaxone if there is severe allergy?
Moxifloxacin
Which patients should receive vancomycin?
If gram positive diplococci on gram stain, pneumococcal antigen assay positive or known/suspected otitis media/sinusitis (e.g. if suspected ceftriaxone resistant strep pneumoniae)
Which patients should receive benzylpenicillin?
Age > 50, immunocompromised, pregnant, alcohol abuse (e.g. suspected listeria monocytogenes)
Who should get post exposure prophylaxis for meningococcal meningitis?
Household contacts or health care workers who have performed airway management without a mask
Which patients should get vaccinated for meningitis in adulthood?
Asplenia, CSF leak, cochlear implants, complement deficiency, HIV/AIDS, transplant recipients
What is seen on peripheral blood film for patients post splenectomy?
Howell-Joly bodies
