LRTI

Question 1

pathophysiology of pneumonia

Answer 1

inhale aerosolised droplets + susceptible host -> pneumonia

Question 2

risk factors for pneumonia

Answer 2

1) smoking

2) COPD, lung cancer, asthma

3) immune suppression

Question 3

clinical presentation of pneumonia - systemic

Answer 3

fever, chill, malaise, change in mental status (elderly), tachycardia, hypotension

Question 4

clinical presentation of pneumoniae - locaslied

Answer 4

cough, chest pain (pruritic chest pain: pain from coughing), SOB, tachypnoea, hypoxia, increased sputum production

Question 5

pneumonia diagnosis - physical examination

Answer 5

• diminished chest sound over affected area
• inspiratory cackles during lung expansion

Question 6

pneumonia diagnosis - radiographic finding

Answer 6

• require evidence of new infiltrates/dense consolidations (unilateral white patches)

Question 7

pneumoniae diagnosis - lab findings

Answer 7

1) general (WBC, CRP, procalcitonin)

• X specific to pneumonia

2) urinary antigen test

• test for strep pneumoniae, legionella pneumophilla
• can remain positive for days-wks despite treatment
• recommend for severe CAP or hopistalised pt
• X for outpatient

Question 8

where to obtain culture for gram stain for pneumonia

Answer 8

1) sputum

• hypotonic saline to induce pt to cough out sputum
• low yield cuz prone to contamination by oropharyngeal secretion

2) LRTI samples

• invasive sampling, less contamination

Question 9

why take blood culture for diagnosis of pneumonia?

Answer 9

rule out bacteriaemia

Question 10

ISDP guidelines for who needs pre-treatment culture & gramstain

Answer 10

1) Severe CAP
2) risk factors for drug resistant pathogens (MRSA, pseudo)

• empirically treated for either
• either infection in last 1 yr
• hospitalised/IV Abx within last 90 days

Question 11

definition of community acquired pneumonia

Answer 11

onset in community or < 48 hr after hospital admission

Question 12

risk factors for community acquired pneumonia

Answer 12

• history of pneumonia
• normal pneumonia risk factors (Recite them.)

Question 13

prevention of community acquired pneumonia

Answer 13

1) smoking cessation
2) immunisation (influenza, pneumococcal)

Question 14

CAP: CURB-65: criteria

Answer 14

(each criteria 1 point)

1) new onset confusion
2) urea > 7 mmol/L
3) RR ≥ 30 breaths/min
4) BP (SBP > 90 or DBP ≤ 60)
5) age ≥ 65 yo

Question 15

CAP: CURB-65: total score vs location of treatment

Answer 15

• 0/1: outpatient
• 2: inpatient
• ≥ 3: inpatient (ICU)

Question 16

classification of severe CAP

Answer 16

(≥ 1 major or ≥ 3 minor criterion)

major:
1) mechanical ventilation
2) septic shock requiring vasoactive medications to keep BP going

minor
1) RR ≥ 30 breaths/min
2) PaO2/FiO2 ≤ 250
3) multilobar infiltrates
4) confusion/disorientation
5) uraemia (urea > 7 mmol/L)
6) leukopenia (WBC < 4 x 10^9 /L)
7) hypothermia (< 36)
8) hypotension requiring aggressive fluid resuscitation -> vasopressors

Question 17

types of pathogen causing outpatient CAP wo comorbidities

Answer 17

strep pneumoniae

Question 18

empiric therapy for outpatient CAP wo comorbidities

Answer 18

1) beta lactam (amoxicillin)
2) respiratory fluoroquinolone

Question 19

pathogen for outpatient CAP w comorbidities

Answer 19

1) Strep pneumoniae
2) haemophilus influenzae
3) atypical (mycoplasma, legionella, chlamydia)

Question 20

empiric for outpatient CAP w comorbidities

Answer 20

1) beta lactam (augmentin) + macrolide (clarithro)
2) respi fluroquinolone

Question 21

what are considered comorbidities for outpatient CAP

Answer 21

chronic heart/lung/liver/renal disease, DM, alcoholism, malignancy, asplenia

Question 22

type of pathogens for non severe inpatient CAP

Answer 22

1) strep pneumoniae
2) haemophilus influenzae
3) atypicals

Question 23

empiric therapy for non severe inpatient CAP

Answer 23

1) beta lactam (augmentin) + macrolide (clarithro)

2) respi fluroquinolone

Question 24

what are some MRSA risk factors CAP

Answer 24

1) respiratory isolation in MRSA in last 1 year
2) hospitalisation/parenteral Abx in past 90 days + MRSA PCR screen +ve (need to swab to see if colonised by MRSA)

Question 25

empiric therapy for non severe inpatient CAP w MRSA risk factor

Answer 25

add MRSA coverage to normal empiric - IV vanco/linezolid

Question 26

pseudomonas risk factors for non severe inpatient CAP

Answer 26

respiratory isolation of pseudomonas in last 1 year

Question 27

empiric therapy for non severe inpatient CAP w pseudomonas risk

Answer 27

modify for pseudomonas coverage - beta lactam: piperacillin/tazo or ceftazidime - macrolide: levofloxacin

Question 28

for non severe inpatient CAP

Answer 28

- start IV then step down to PO - test for influenza during season

Question 29

possible pathogen for severe inpatient CAP

Answer 29

- all non severe - staph aureus - other gram -ve (klebsiella pneumoniae, burkholderia pseudomallei)

Question 30

burkholderia pseudomallei (severe inpatient CAP)

Answer 30

- tropical countries - gram -ve rod found in soil (moist)

Question 31

empiric therapy for severe inpatient CAP

Answer 31

1) beta lactam (augmentin) + ceftazidime + macrolide (clarithromycin) 2) respiratory fluoroquinolone + ceftazidime

Question 32

empiric therapy for severe inpatient CAP w MRSA risk factors

Answer 32

normal empiric + MRSA coverage (IV vanco)

Question 33

pseudomonas risk factor for severe inpatient CAP

Answer 33

- respiratory isolation of pseudomonas in last 1 year - hospitalisation/IV Abx use in last 90 days

Question 34

empiric therapy for severe inpatient CAP w pseudomonas risk

Answer 34

same as normal empiric for wo pseudomonas risk but already covered (ceftazidime, levoflox)

Question 35

anaerobic cover for CAP

Answer 35

- if radiology report lung abscess/emphysema - add IV/PO metronidazole

Question 36

influenza management for CAP

Answer 36

- add empiric oseltamivir to Abx regimen ASAP if suspected - +ve influenza PCR **5 day course ** discontinue Abx at 48-72 hr if X evidence of bacterial pathogen

Question 37

why respiratory fluoroquinolone X used as first line for CAP

Answer 37

1) increase AE - tendonitis, tendon rupture, neuropathy, QTc prolongation, CNS disturbances, hypoglycaemia 2) development of resistance w overuse 3) preserve activity for other gram -ve infection 4) delay diagnosis of tb 5) undesirable monotherapy if tb

Question 38

adjunctive corticosteroid therapy for CAP

Answer 38

- reduce inflammation in lung - only if septic shock refractory to fluid resuscitation & vasopressor support

Question 39

when to de-escalate from IV to PO treatment for CAP

Answer 39

1) haemodynamically stable 2) improve clinically 3) can tolerate oral meds

Question 40

how to de-escalate from IV to PO

Answer 40

1) +ve culture - use AST to guide narrow spectrum 2) -ve culture - stop empiric for MRSA/pseudomonas/burkholderia pseudomallei after 48 hrs if pathogen X isolated & improving - same Abx from IV to PO or from same class

Question 41

what is nosocomial pneumonia

Answer 41

hospital acquired + ventilator associated

Question 42

definition for hospital acquired pneumonia (HAP)

Answer 42

onset ≥ 48 hrs after hospital admission

Question 43

definition for ventilator associated pneumonia (VAP)

Answer 43

onset ≥ 48 hrs after mechanical ventilation

Question 44

risk factors for nosocomial pneumonia

Answer 44

1) pt related - elderly - smoking, COPD, cancer, immunosuppresion - prolonged hospi, coma, impaired consciousness - malnutrition 2) infection control - X hand hygiene - contaminated respi care devices 3) healthcare related - prior Abx use (normal flora alr affected) - impaired deep breath & exhale (sedative, opioid analgesics, mechanical ventilation, supine position)

Question 45

prevention of nosocomial pneumonia

Answer 45

- consistent hand hygiene - judicious Abx use & meds w sedative effect - VAP specific ** limit duration of mechanical ventilation ** minimise duration & deep levels of sedation ** elevate head of bed by 30%

Question 46

types of pathogen for nosocomial pneumonia

Answer 46

1) non-fermenting gram neg: pseudomonas, acinetobacter 2) enteric gram neg: enterbacter spp, klebsiella spp, e.coli 3) staph aureus

Question 47

when to cover MRSA for nosocomial pneumonia

Answer 47

- prior IV Abx use within 90 days - hospitalisation in unit where > 90% staph aureus MRSA

Question 48

how many antipseudomonals for pseudomonas & GNR for nosocomial pnuemonia

Answer 48

- normally 1 antipseudomonal (X aminoglycoside)

Question 49

when to use double pseudomonal for nosocomial pneumonia

Answer 49

1) Risk factor for antimicrobial resistance - prior IV Abx use within 90 days - acute renal replacement therapy prior to VAP onset - isolation of pseudomonas in last 1 year 2) hospitalisation in unit where > 10% pseudomonas isolate resistant to agent considered for monotherapy 3) prevalence of pseudomonas X known

Question 50

nosocomial pneumonia pathogen vs empiric

Answer 50

1) pseudomonas, other GNR (enterobacter spp, klebsiella spp, e coli) - antipseudomonal beta lactam (pip/tazo) - +/- antipseudomonal fluoroquinolone (levo, avoid if X MRSA cover) 2) MRSA - IV vanco

Question 51

nosocomial when to de-escalate/change from IV to oral

Answer 51

1) haemodynamic stability 2) improve clinically 3) able to ingest oral

Question 52

nosocomial how to de-escalate/change from IV to oral

Answer 52

1) +ve culture - use AST to guide culture-directed narrow spectrum - double to single antipseudomonal 2) -ve culture - maintain coverage according to local antibiogram - X possible if significant for MDRO - PO if tolerate.