Pneumonia (CAP, HAP, VAP)

Question 1

Risk stratification of CAP

Answer 1

Severe CAP: >= 1 major/ >= 3 minor

Major:

• Mechanical ventilation
• Septic shock requiring vasoactive medications

Minor:

• RR >= 30 breaths/min
• PaO2/FiO2 <= 250 (hypoxia)
• WBC < 4 x 10^9/L
• Urea > 7mmol/L
• Multilobar infiltrates
• Confusion
• Hypothermia (T < 36C)
• Hypot/s requiring aggressive fluid resuscitation

Question 2

Microbiology of CAP

Answer 2

Outpatient:

i) Strep pneumoniae
ii) Haemophilus influenzae
iii) Atypical (Mycoplasma, Chlamydophila)

Inpatient (Non-severe):

i) Strep pneumoniae
ii) Haemophilus influenzae
iii) Atypical (Mycoplasma, Chlamydophila, Legionella)

Inpatient (Severe):

i) Strep pneumoniae
ii) Haemophilus influenzae
iii) Atypical (Mycoplasma, Chlamydophila, Legionella)
iv) Staph aureus
v) Other Gram -ve (eg. Klebsiella, burkholderia pseudomallei)

Question 3

Standard antibiotic regimen for OUTPATIENT CAP

Answer 3

Generally healthy:
1) Amoxicillin: 1g PO TDS* OR
Levofloxacin: 750mg PO OD* (or Moxifloxacin)

Chronic heart/lung/liver/renal disease, diabetes, asplenia, malignancy, alcoholism:
1) Augmentin 625mg PO TDS/2g PO BD or Cefuroxime 500mg PO BD* +
Azithromycin 500mg PO OD or Clarithromycin 500mg PO BD or Doxycycline 100mg PO BD

2) Levofloxacin: 750mg PO OD* (or Moxifloxacin)

Question 4

Standard antibiotic regimen for NON-SEVERE INPATIENT CAP

Answer 4

1) Augmentin 1.2g IV Q8h* or Ceftriaxone 1-2g IV Q24h
+
Azithromycin 500mg PO OD or Clarithromycin 500mg PO BD or Doxycycline 100mg PO BD

2) Levofloxacin 750mg IV Q24h* (or Moxifloxacin)

IV beta-lactam/ FQ KIV to step down later

Question 5

Standard antibiotic regimen for SEVERE INPATIENT CAP

Answer 5

1) Augmentin 1.2g IV Q8h* + Ceftazidime 2g IV Q8h*
+
Azithromycin 500mg PO OD or Clarithromycin 500mg PO BD or Doxycycline 100mg PO BD

2) Levofloxacin 750mg IV Q24h* (or Moxifloxacin)
+ Ceftazidime 2g IV Q8h*

Note: If patient has severe penicillin allergy, no choice just got to omit Ceftazidime

Question 6

Indication for MRSA COVERAGE in CAP & antibiotics

Answer 6

Indication (any):

• Prior respiratory isolation of MRSA in last 1 year
• Severe CAP only: Hospitalisation & received IV antibiotics within last 90 days

To add:

1) Vancomycin IV
2) Linezolid IV/PO

Question 7

Indication for PSEUDOMONAL COVERAGE in CAP & antibiotics

Answer 7

Indication (any):
- Prior respiratory isolation of P. aeruginosa in last 1 year

MODIFY standard regimen to include any ONE of these in place of Augmentin/ Ceftriaxone:
- Pip/tazo IV
- Ceftazidime IV
- Cefepime IV
- Meropenem IV
- Levofloxacin PO/IV
(Note: Moxifloxacin doesn’t cover Pseudomonas)

Question 8

Why are respiratory FQs not 1st line for CAP?

Answer 8

• Increased risk of adverse effects
• Development of resistance with overuse
• Preserve activity of other Gram -ve
• Delay diagnosis of TB

Question 9

Why is adjunctive corticosteroid therapy considered for CAP?

Answer 9

• Decrease inflammation in lungs
• May decrease length of stay & time to clinical stability

HOWEVER,
not routinely recommended bc impact is small & likely outweighed by increased hyperglycemia

Question 10

Monitoring of CAP therapy

Answer 10

Clinical improvements: ~48-72hrs

• Should not escalate therapy in 1st 72hrs
• Radiographic resolution lags behind, up to 4-6weeks for resolution (Repeat only if clinical detoriation)

Monitor for adverse effects, renal function

Question 11

When can empiric coverage for MRSA/Pseudomonas be stopped?

Answer 11

In 48hrs if not found in culture

Question 12

Criteria to meet for stepping down IV -> PO therapy for CAP

Answer 12

ALL to be met:

• Hemodynamically stable
• Clinically improving
• Afrebile >= 24hrs
• Normally functioning GIT
• Can ingest PO

Question 13

Treatment duration for CAP

Answer 13

Until clinical stability for at least ~5days
- Afrebile, normal vital signs, able to maintain oral intake, O2 saturation & mental status

MRSA/ Pseudomonas: 7 days
Burkholderia pseudomallei: 3-6mths

Question 14

Risk factors for HAP/VAP

Answer 14

1) Patient-related
- Elderly, smoking, COPD/Cancer/Immunosuppression, Prolonged hospitalisation, Coma/Impaired consciousness, Malnutrition

2) Infection-control
- Hand hygiene compliance, contaminated respiratory care devices

3) Healthcare-related
- Prior antibiotic use, sedatives, opoid analgesics, mechanical ventilation, supine position

Question 15

Prevention strategies of HAP/VAP

Answer 15

• Hand hygiene
• Judicious use of antibiotics & medication with sedative effects

VAP specific:

• Limit duration of mechanical ventilation
• Minimise duration & deep levels of sedation
• Elevate head by 30degrees

Question 16

Microbiology of HAP/VAP (Minimum)

Answer 16

1) MSSA
2) Pseudomonas Aeruginosa

• May need additional coverage for MRSA/Gram -ve
  (Look at hospital/ unit’s bacteria susceptibility rates (ie. antibiogram) )

Question 17

MDRO Risk Factors

Answer 17

HAP:
- Prior IV abx within 90days

VAP:

• Prior IV abx within 90days
• Septic shock at time of VAP onset
• ARDS preceding VAP onset
• > = 5days of hospitalization prior to VAP onset
• ACUTE renal replacement therapy prior to VAP

Question 18

Mortality Risk Factors

Answer 18

For HAP ONLY:

• Requiring mechanical ventilation as a result of HAP
• In septic shock

Question 19

“Backbone regimen” for HAP/VAP

Answer 19

Either:
1) Pip/Tazo: 4.5g IV Q6-8h*
2) Cefepime: 2g IV Q8h*
3) Meropenem: 1g IV Q8h*
    Imipenem: 500mg IV Q6h*
4) Levofloxacin: 750mg IV Q24h*

(Note: Ciprofloxacin cannot bc no Gram (+) coverage)

Question 20

Indication for MRSA coverage & antibiotic regimen for HAP

Answer 20

Indication:

• MDRO risk factor
• Mortality risk factor
• MRSA prevalence >= 20% or unknown

Antibiotics:

1) Vancomycin 15mg/kg IV Q8-12h*
2) Linezolid 600mg IV Q12h

Question 21

Indication for ADDITIONAL GRAM -VE coverage & antibiotic regimen for HAP

Answer 21

Indication:

• MDRO risk factor
• Mortality risk factor

Antibiotics:
1) Gentamicin: 5-7mg/kg IV Q24h*
2) Amikacin: 15mg/kg IV Q24h*
3) Tobramycin
4) Levofloxacin: 750mg IV Q24h*
5) Ciprofloxacin: 400mg IV Q8-12h*
(Note: Cipro here is okay bc for extra Gram -ve coverage)

Question 22

Indication for MRSA coverage & antibiotic regimen for VAP

Answer 22

Indication:

• MDRO risk factor
• MRSA prevalence > 10-20% or unknown

Antibiotics:

1) Vancomycin 15mg/kg IV Q8-12h*
2) Linezolid 600mg IV Q12h

Question 23

Indication for ADDITIONAL GRAM -VE coverage & antibiotic regimen for VAP

Answer 23

Indication:

• MDRO risk factor
• Single Anti-pseudomonal agent with activity < 90% or unknown

Antibiotics:
1) Gentamicin: 5-7mg/kg IV Q24h*
2) Amikacin: 15mg/kg IV Q24h*
3) Tobramycin
4) Levofloxacin: 750mg IV Q24h*
5) Ciprofloxacin: 400mg IV Q8-12h*
(Note: Cipro here is okay bc for extra Gram -ve coverage)

Question 24

Rationalre for additional Gram -ve coverage

Answer 24

Synergistic activity, prevent resistance, expand spectrum of coverage

Risks: Increase cost, adverse effects

Clinical data: No diff in mortality, length of stay & treatment failure rates BUT
- Still used empirically to broaden spectrum of Gram -ve coverage in pts who are at risk for MDRO/death

Question 25

When to de-escalate treatment for HAP/VAP?

Answer 25

• Clinically improving
• Positive cultures with documented susceptibility
• Negative blood & respiratory cultures

Question 26

How to de-escalate treatment for HAP/VAP?

Answer 26

Positive blood +/- respiratory culture:
- Maintain coverage for organisms growth

Negative blood +/- respiratory culture:
- Go back to “backbone” regimen (Coverage for MSSA + Pseudomonas)

Question 27

Monitoring of therapy for HAP/VAP

Answer 27

• Adverse effects
• Renal function
• Clinical improvements expected in ~72hrs

Question 28

Duration of therapy for HAP/VAP

Answer 28

7 days