Infectious Diseases

Question 1

which classes of antibiotic have a beta-lactam ring?

Answer 1

• penicillins
• carbapenems
• cephalosporins

Question 2

stepwise approach to picking ABx in hospital?

Answer 2

• 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)

Question 3

pathophysiology of sepsis?

Answer 3

• 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

Question 4

what are the 2 ways in which septic shock can be defined?

Answer 4

either of these:

• systolic BP <90 despite fluid resus
• lactate >4 mmol/l

Question 5

management of septic shock?

Answer 5

• aggressive fluid resus
• ICU admission
• inotropes (noradrenalin)

Question 6

features of severe sepsis?

Answer 6

• hypoxaemia
• oliguria
• AKI
• thrombocytopenia
• coagulation dysfunction
• hypotension
• lactate >2 mmol/l

Question 7

risk factors for sepsis?

Answer 7

• extremes of age
• chronic disease (e.g. COPD, DM)
• surgery
• recent trauma / burns
• pregnancy / peripartum
• indwelling catheter / central line

Question 8

which signs make up the NEWS?

Answer 8

• temp
• HR
• RR
• O2
• BP
• GCS

Question 9

signs O/E in sepsis?

Answer 9

• signs of source of infection (cellulitis, wound discharge, cough, dysuria)
• non-blanching rash
• reduced UO
• mottled skin
• cyanosis
• arrhythmias (e.g. new AF)

Question 10

what is often the first sign of sepsis?

Answer 10

high RR (tachypnoea)

Question 11

how might elderly patients present with sepsis?

Answer 11

• confused
• drowsy
• “off legs”

Question 12

which pts might have normal obs even if they are severely septic?

Answer 12

• neutropenic pts

- immunosuppressed pts

Question 13

investigations for sepsis?

Answer 13

a bunch of bloods:

• FBC
• UEs
• LFTs
• CRP
• clotting (DIC)
• blood cultures
• blood gas (lactate)

Question 14

which additional, non-blood test investigations can be helpful in sepsis?

Answer 14

• urine dip and culture
• CXR
• CT (look for source of infection)
• LP (if meningitis / encephalitis)

Question 15

management of sepsis?

Answer 15

• follow local protocol
• assess and treat within 1 hour
• do sepsis 6 / BUFALO
• O2
• empirical broad-spec ABx
• IV fluids

Question 16

what does BUFALO stand for?

Answer 16

• blood cultures (take)
• urine output (take)
• fluids (give)
• ABx (give)
• lactate (take)
• O2 (give)

Question 17

define neutropenic sepsis

Answer 17

sepsis in a pt with a neutrophil count less than 1 * 10^9 /L

Question 18

drugs which cause neutropenia? give an indication for each of them

Answer 18

• chemotherapy (Ca)
• clozapine (schizophrenia)
• hydroxychloroquine (RA)
• methotrexate (RA)
• sulfasalazine (RA)
• carbimazole (hyperthyroidism)
• quinine (malaria)
• infliximab (immunosuppression)
• rituximab (immunosuppression)

Question 19

when should you suspect neutropenic sepsis?

Answer 19

• have a high index of suspicion

- any fever >38C is neutropenic sepsis until proven otherwise

Question 20

ABx of choice in neutropenic sepsis?

Answer 20

tazocin (piperacillin with tazobactam)

Question 21

what is the difference between meningitis and meningococcal septicaemia?

Answer 21

• meningitis is inflammation of the meninges

- meningococcal septicaemia is when the meningococcus bacteria is in the blood stream

Question 22

unique feature of meningococcal septicaemia? what causes this?

Answer 22

• non-blanching rash

- it is the result of DIC and subcut haemorrhages

Question 23

what are the most common causative organisms of bacterial meningitis in non-neonates?

Answer 23

• n. meningitidis (meningococcus)

- strep. pneumoniae (pneumococcus)

Question 24

what is the most common causative organism in neonatal bacterial meningitis?

Answer 24

group B streptococcus (GBS)

Question 25

presentation of meningitis?

Answer 25

• fever
• neck stiffness
• vomiting
• headache
• photophobia
• altered consciousness
• seizures