LRTI (HAP/VAP)

Question 1

Define HAP and VAP

What is nosocomial pneumonia?

Answer 1

HAP: Onset ≥ 48h after hospital admission

VAP: Onset ≥ 48h after mechanical ventilation

Nosocomial pneumonia includes both HAP and VAP

Question 2

Risk factors for HAP/ VAP?
(Patient-related (8), infection-control (2) and healthcare-related factors (5))

Answer 2

Patient-related:
- Elderly
- Smoking
- COPD
- Cancer
- Immunosuppression
- Prolonged hospitalisation
- Coma, impaired consciousness
- Malnutrition

Infection control-related:
- Lack hand hygiene
- Contaminated respiratory care devices

Healthcare-related:
- Prior abx use
- Sedatives
- Opioid analgesics
- Mechanical ventilation
- Supine position

Question 3

What do you need for diagnosis of HAP/ VAP? (3)

Answer 3

Need chest XR + systemic s/sx + localised s/sx for diagnosis

Question 4

Key pathogens to cover for HAP/ VAP?

Answer 4

• P. aeruginosa
• MSSA
• Other GNR
  (Enterobacter spp, Klebsiella spp, E. coli)

If MRSA risk factors: cover MRSA

Question 5

MRSA risk factors for HAP/ VAP?

Answer 5

• Prior IV abx use within last 90 days
• Isolation of MRSA in last year
• Hospitalisation in a unit where > 20% of Staph. aureus are MRSA
• Prevalence of MRSA in hospital not known but pt at high risk for mortality (eg need for ventilatory support due to HAP and septic shock)

Question 6

When do we need to use double antipseudomonal abx from different classes? (3)

Answer 6

• Risk factor for antimicrobial resistance (prior IV abx use in last 90d, acute renal replacement therapy prior to VAP, isolation of P. aeruginosa in last year)
• Hospitalisation in a unit where > 10% Pseudomonas isolates are resistant to an agent considered for monoTx
• Pt at high risk for mortality (ie ventilatory support due to HAP, septic shock)

Question 7

Tx for HAP/ VAP?

Without MRSA risk factors

Answer 7

Anti-pseudomonal β-lactam:
- IV piperacillin-tazobactam 4.5g tds-qds
- IV cefepime 2g tds
- IV meropenem 1g tds/ IV imipenem 500mg qds

AND/OR

Anti-pseudomonal FQ:
- IV levofloxacin 750mg od/ IV ciprofloxacin 400mg bd-tds
OR
Aminoglycoside:
- IV amikacin 15-20mg/kg od

Question 8

Which abx should we avoid using if we don’t have to cover for MRSA?

Answer 8

Ciprofloxacin

Question 9

Tx to include if we want to cover for MRSA?

Answer 9

First-line:
- IV vancomycin 25-40mg/kg loading dose then 15mg/kg bd-tds

Alternative:
- IV/PO linezolid 600mg bd

Question 10

What are some abx we DO NOT use for MRSA cover for HAP/VAP? Why?

Answer 10

Do not use:
- Clindamycin
- Doxycycline
- Co-trimoxazole

They are more for CAP, not reliable for HA-MRSA

Question 11

What must we take note of when using AGs for HAP/VAP?

Answer 11

Avoid use of AGs as sole antipseudomonal agent

Question 12

When should we de-escalate Tx for HAP/VAP? (3)

Answer 12

When pt is:
- Hemodynamically stable (labs, vital signs)
- Improving clinically
- Able to ingest PO

Question 13

How should we de-escalate HAP/VAP with a positive culture?

Answer 13

• Use AST to guide selection of lower spectrum/ PO abx
• P. aeruginosa use a single antipseudomonal agent

Question 14

How should we de-escalate HAP/VAP with no positive culture?

Answer 14

• De-escalate according to local antibiogram; if not available just maintain coverage for P. aeruginosa, enteric GNR and MSSA
• May not be possible for pts with significant MDRO
• IV-to-PO if possible

Question 15

How long will it take for most pts to achieve clinical stability?

How about elderly?

Answer 15

Within first 48 - 72h (hence do not escalate abx Tx in first 72h unless culture-directed or significant clinical deterioration)

Elderly/ pts with multiple co-morbs may take longer