Epidemiology of Ventilator Associated Pneumonia in an

Adult ICUImperial College Healthcare NHS Trust, St Mary's

Campus, London

Kingston H, Sange M, Rey V, Jepson A, Stotz M

IntroductionVentilator Associated Pneumonia (VAP)

Pneumonia following 48h invasive ventilationIncidence 8‐28%*Mortality 24‐50%*Interventions reduce riskCostlyBSAC HAP (including VAP) guidelines, 2008†

*Chastre J et al. AJRCCM; 2002:165, 867-903†Masterton RG et al. JAC; 2008:62, 5-34

BackgroundAims of our project (audit)

Review incidence of VAP on St. Mary’s ICUOrganisms and susceptibilitiesCalculate cost of antibioticsAudit the diagnosis of VAP

St Mary’s adult ICUA 13 bed closed general ICUElectronic records

Suspicion of VAP

Patients with suspected VAP started on antibiotics

Vancomycin + piperacillin/tazobactam standard first lineVancomycin discontinued 48h if no MRSAPiperacillin/tazobactam 5 days initially

Bronchoalveolar lavage (BAL) taken firstNon‐directed unless formal bronchoscopy indicated

Definition of VAPBacteriological criteria

BAL with ≥ 104 potentially pathogenic organisms

Clinical criteriaImaging:

New or progressive infiltratesAnd 2 of:

WCC > 12 x 109/L or < 4 x 109/LTemperature > 38˚CPurulent sputum

AJRCCM; 2005:171, 388-416

ResultsNumber of

patients%

Patients admitted over 6 month

period260

No pre‐existing chest infection 209

Ventilated ≥48h 69 100%One or more

significant BAL 22 31.9%

Significant BAL and clinical VAP 8 11.6%

Cost of VAP ‐ antibiotics

Mean cost in antibiotics per patient ventilated >48h = £87.97

Number of episodes

Mean cost per episode

Mean duration of treatment,

Days(SD)No clinical

VAP but significant

BAL

21 £189.28 7.1 (5.7)

Clinical VAP and

significant BAL

8 £261.90 7.9 (3.4)

Organisms isolated from BAL

Organism BAL ≥104 + clinical VAP BAL ≥104 + no clinical VAP

N % N %

LF 4 50 6 28.6

“NLF” 2 25 5 23.8

H.influenzae 1 12.5

S.maltophilia 1 12.5 2 9.5

Pseudomonas spp. 7 33.3

Enterococcus spp. 1 4.8

Total 8 21

Organisms isolated in BAL

Resistance rates (Gram –ve)

Clinical features presentDiagnosis Features present Number %

VAP CXR + ≥2 of 3 clinical features 8 27.6%

?Clinical VAT2 of 3 clinical features inc secretions

5 17.2%

No VAP/VAT

CXR + 1 of 3 clinical features 6 20.7%

CXR alone 1 3.4%

2 of 3 clinical features not inc

secretions2 6.9%

1 clinical feature 6 20.7%

None 1 3.4%

Recording of DiagnosisIn none of the 8 cases was a diagnosis of VAP found anywhere within the electronic notesIn 3 of the 8 cases a lower respiratory tract infection of some kind was coded for.Implies lack of consideration of pneumonia as a noteworthy entity

perhaps due to continuum ‘no pneumonia – VAT –VAP’Uncertainty when to diagnose itDiagnosis made days after treatment started

ConclusionIncidence of VAP low

Only microbiologically confirmed VAPInsensitive clinical criteriaNot all patients may get BAL doneFalse negative BAL

ExpensiveLocal variation in pathogensVariation in pathogens isolated from BAL depending on if clinical criteria metSignificant BAL in absence of clinical VAP

PerspectivesRaise VAP awarenessInterventions to implement?

?Anaesthetic hygieneVentilator Care BundleKinetic bedsSpecial ET tubes

Subglottic suctioningSilver coated

All patients with clinical criteria need BALRe‐Audit