Infectious Diseases Flashcards
which classes of antibiotic have a beta-lactam ring?
- penicillins
- carbapenems
- cephalosporins
stepwise approach to picking ABx in hospital?
- start empirically with amoxicillin (covers streptococcus, listeria and enterococcus)
- switch to co-amoxiclav (all of above plus staphylococcus, haemophilus and e. coli)
- switch to tazocin (plus pseudomonas)
- switch to meropenem (plus ESBLs)
- add on teicoplanin / vancomycin (covers MRSA)
- add clarithromycin / doxycycline (covers atypical bacteria)
pathophysiology of sepsis?
- cytokines trigger a huge immune response
- nitrous oxide gives vasodilation
- coagulation system gets activated, causes DIC
- hypoxia occurs, causing anaerobic respiration and blood lactate rises
what are the 2 ways in which septic shock can be defined?
either of these:
- systolic BP <90 despite fluid resus
- lactate >4 mmol/l
management of septic shock?
- aggressive fluid resus
- ICU admission
- inotropes (noradrenalin)
features of severe sepsis?
- hypoxaemia
- oliguria
- AKI
- thrombocytopenia
- coagulation dysfunction
- hypotension
- lactate >2 mmol/l
risk factors for sepsis?
- extremes of age
- chronic disease (e.g. COPD, DM)
- surgery
- recent trauma / burns
- pregnancy / peripartum
- indwelling catheter / central line
which signs make up the NEWS?
- temp
- HR
- RR
- O2
- BP
- GCS
signs O/E in sepsis?
- signs of source of infection (cellulitis, wound discharge, cough, dysuria)
- non-blanching rash
- reduced UO
- mottled skin
- cyanosis
- arrhythmias (e.g. new AF)
what is often the first sign of sepsis?
high RR (tachypnoea)
how might elderly patients present with sepsis?
- confused
- drowsy
- “off legs”
which pts might have normal obs even if they are severely septic?
- neutropenic pts
- immunosuppressed pts
investigations for sepsis?
a bunch of bloods:
- FBC
- UEs
- LFTs
- CRP
- clotting (DIC)
- blood cultures
- blood gas (lactate)
which additional, non-blood test investigations can be helpful in sepsis?
- urine dip and culture
- CXR
- CT (look for source of infection)
- LP (if meningitis / encephalitis)
management of sepsis?
- follow local protocol
- assess and treat within 1 hour
- do sepsis 6 / BUFALO
- O2
- empirical broad-spec ABx
- IV fluids
what does BUFALO stand for?
- blood cultures (take)
- urine output (take)
- fluids (give)
- ABx (give)
- lactate (take)
- O2 (give)
define neutropenic sepsis
sepsis in a pt with a neutrophil count less than 1 * 10^9 /L
drugs which cause neutropenia? give an indication for each of them
- chemotherapy (Ca)
- clozapine (schizophrenia)
- hydroxychloroquine (RA)
- methotrexate (RA)
- sulfasalazine (RA)
- carbimazole (hyperthyroidism)
- quinine (malaria)
- infliximab (immunosuppression)
- rituximab (immunosuppression)
when should you suspect neutropenic sepsis?
- have a high index of suspicion
- any fever >38C is neutropenic sepsis until proven otherwise
ABx of choice in neutropenic sepsis?
tazocin (piperacillin with tazobactam)
what is the difference between meningitis and meningococcal septicaemia?
- meningitis is inflammation of the meninges
- meningococcal septicaemia is when the meningococcus bacteria is in the blood stream
unique feature of meningococcal septicaemia? what causes this?
- non-blanching rash
- it is the result of DIC and subcut haemorrhages
what are the most common causative organisms of bacterial meningitis in non-neonates?
- n. meningitidis (meningococcus)
- strep. pneumoniae (pneumococcus)
what is the most common causative organism in neonatal bacterial meningitis?
group B streptococcus (GBS)
presentation of meningitis?
- fever
- neck stiffness
- vomiting
- headache
- photophobia
- altered consciousness
- seizures
