week 3 Flashcards
what is the difference between primary and secondary immunodeficiencies
primary ones are genetically inherited
secondary immunodeficiencies are acquired later in life
when are most primary immunodeficiencies diagnosed
in early childhood
what is the definition of neutropenia
neutrophils < 0.5 x 10^9/L
what is the diagnostic critera for neutropenic sepsis
patient with neutropenia
fever of >38C
or other signs of sepsis
who are at high risk of neutropenic sepsis
cancer patients receiving chemotherapy
what is the general guidance for antimicrobial agent in neutropenic sepsis
IV broad spectrum
give an example of a recommended antimicrobial agent for use in treating neutropenic sepsis
tazocin
other than antibiotics, what are measures should be taken in someone with neutropenic sepsis
barrier nursing
IV fluids
avoid regular paracetamol
why is regular paracetamol avoided in neutropenic sepsis?
can mask fever
what are transplant patients at risk of infections
immunosuppresive drugs
what bacteria are common in transplant patient infections
ps aeruginosa
staph epidermis
what viruses and fungi are common in transplant patient infections
aspergilosis, cryptococcus, candida
hsv, cmv, vzv, ebv
what kind of infections are asplenic patients more susceptible to
bacterial infections with encapsulated bacteria
why is the common pattern of infection in asplenic patients
short prodrome with sudden deterioration (DIC, septic shock, seizures, coma)
common bacterial causes of meningitis
Neiserria meningitis strep pneumonia staph aureus GBS listeria monocytogenes e coli mycobacterium TB
common viral causes of meningitis
enteroviruses
HSV 1 and 2
varicella zoster virus
EBV
most common bacterial cause of meningitis in newborns
GBS
what is the triad of features found in bacterial meningitis
headache
neckstiffness
photophobia
what are the clinical features of bacterial meningitis
fever headache neckstiffness photophobia altered mental state seizure \+ve kernigs and brudzinskis vomiting
what clinical feature can also be found in viral meningism, but not in bacterial
coryzal prodrome
what are signs of meningococcal septicaemia
non-blanching purpuric rash
sepsis
investigations for meningitis
blood cultures LP blood glucose bloods head imaging coagulation ABG
why is blood glucose important to do at the same time as an LP
to compare CSF glucose with blood
CSF picture in bacterial meningitis
appearance lymphocytes polymorphs protein glucose
cloudy low lymphocytes high polymorphs high protein low glucose
CSF picture in viral meningitis
appearance lymphocytes polymorphs protein glucose
clear high lymphocytes low polymorphs mildly raise protein normal glucose
CSF picture in TB meningitis
appearance lymphocytes polymorphs protein glucose
cloudy delayed increase in lymphocytes high polymorphs high protein low glucose
in suspected meningitis, fastest way to check for raised ICP?
fundoscopy - papiloedema
3 possible sequelae of meningitis
deafness
neurological defects
amputation
treatment for meningitis
3rd gen cephalosporin
dexamethosone
treat sepsis
common viral causes of encephalitis
HSV 1 and 2
VZV
coxsackie virus
difference between bacterial meningitis and viral encephalitis in clinical features
viral encephalitis often have neurological defects and decreased consciousness
investigations done in encephalitis
LP - PCR for viral dna
brain imaging
EEG
blood serology
treatment for HSV encephalitis
IV aciclovir for 2-3 weeks
what bacteria species are asplenics particularly susceptible to
encapsulated e.g.
strep pneumoniae
HiB
N. Menigitides
E. Coli
salmonella
Klebsiella
strep Group b
why are splenic patients more susceptible to encapsulated bacteria?
because encapsulated bacteria cannot be phagocytosed and require opsonisation and cell-mediated antibody production. without a spleen, patients cannot respond appropriately to such bacteria
