Post on 05-Nov-2019
VAP Prevention: What Is Really Fundamental?
Michael S. Niederman, MD
Chairman, Department of Medicine
Winthrop-University Hospital
Mineola, NY Professor of Medicine
Vice-Chairman, Department of Medicine
SUNY at Stony Brook
Prevention of VAP
• How Much of VAP Is preventable?
• Methods for VAP Prevention
– Recommended Strategies
• What are The Implications of The Zero VAP
Movement ?
Prevention of VAP
• How Much of VAP Is preventable?
• Methods for VAP Prevention
– Recommended Strategies
• What are The Implications of The Zero VAP
Movement ?
What Percent of Nosocomial Infection is Really
Preventable?
• 25 studies identified
• Global intervention vs. all types of NI led to a risk reduction of 11-55%
• Studies looking at specific infections found a reduction of 14-71%
– Greatest effect in catheter associated blood stream infections.
• Mean reduction rate of 56%, but up to 70%
– Reduction of VAP and surgical site infection rates was less
– Harbarth S, et al. J Hosp Infect 2003; 54: 258-266.
• To estimate the preventability of HAI in the US, used published
studies on prevention published in the last 10 years, and rated as
“good” quality by AHRQ
– 65-70% CAUTI and CABSI preventable
– 55% VAP and SSTI preventable. Only 2 good and 3 moderate quality studies
to evaluate. Feel that VAP reduction may be an OVERESTIMATE.
– Umscheid CA, et al. ICHE 2011; 32: 101-114.
Could We Do Even Better and Prevent ALL
VAP? IHI says “YES”
• From the IHI (Institute for Healthcare Improvement) Website
– No VAPs – It CAN Be Done!
Advocate Health Care; Oak Brook, Illinois, USA
– Reducing Ventilator-Associated Pneumonia: Changing Culture
Lee Memorial Health System, Cape Coral Hospital; Fort Myers, Florida, USA
• Absence of VAP for 200 days with implementation of a bundle. “ We celebrate each month that passes without a VAP”
• No mortality data.
• Berriel-Cass et al. Jt Comm Journal on Qual and Pat Safety 2006, 32: 612.
Can Prevention Efforts Really Lead to Zero
VAP?
• Compare incidence of VAP
(quantitative culture dx) in 45
month baseline period (n=856)
to 30 month multi-modality
intervention period (n=835). All
MV > 48 hours
• VAP rates reduced by 43%
(22.6 to 13.1 episodes /1000
vent days) BUT even with high
compliance to prevention , did
not drop to zero
• Bouadma L, et al. Clin Infect
Dis 2010; 51:1115-22
Interventions: HOB elevation, hand
hygeine, ETT cuff pressure > 20 cm
water, OG tube, oral chlorhexidine,
minimal tracheal suctioning
The Ventilator Bundle: Prevention ? Not
Elimination
• “Evidence-based” interventions
– Peptic ulcer disease prophylaxis
– Deep vein thrombosis prophylaxis
– Elevation of the head of the bed
– Awaken to follow commands
– Assess readiness to wean
• Applied in 112 ICU’s for 30 months and reported a 71% drop in VAP, with a correlation between compliance and VAP rates, but no measurement of secondary benefits – Used CDC VAP definition, applied by
infection preventionists
• Berenholtz SM et al. ICHE 2011; 32: 305-314.
Prevention of VAP
• How Much of VAP Is preventable?
• Methods for VAP Prevention
– Recommended Strategies
• What are The Implications of The Zero VAP
Movement ?
Recommended Prevention Strategies
• Systematic review of all randomized, controlled trials and reviews on prevention of VAP from 1980-2006.
• Recommended: – Orotracheal intubation
– Circuit changes if soiled or damaged, but not by schedule
– Change HME every 5-7 days, or as necessary
– Closed suction system (vs. open system)
– Subglottic secretion drainage
– HOB elevation of 45 degrees (questioned in some newer studies)
– CONSIDER: rotating beds, oral antiseptic rinse
• NOT recommended: in –line bacterial filters, iseganan
• NO recommendation: type of airway humidification, search for sinusitis, timing of tracheostomy, prone prosition, aerosol antibiotics, intranasal mupirocin, topical or IV preventive antibiotics – Muscedere J, et al: J Crit Care 2008; 23: 126-137.
Endotracheal Tube and Airway Interventions
• Biofilm on the inside of the ETT may add to VAP , and the mucus shaver has
been developed to remove it
– Studied in 6 sheep, 2 controls (routine suction), q 6 H
• Kolobow T, et al. Anesthesiology. 2005 ; 102:1063-5.
• Can remove biofilm/mucus layer, but will it prevent VAP?
• Endotracheal tube cuff modifications
– Intermittent subglottic secretion drainage.
– Cuff material and shape modifications (Polyurethane vs. PVC), shape (tapered). Lorente et al. Am J Respir Crit Care Med 2010; 182: 870-876.
• Ultrathin polyurethane HVLP (high volume, low pressure) cuffs reduce channel folds to prevent oral secretions reaching the lung
– Continuous adjustment of cuff pressure to 25 cm water pressure . Nseir et al. Am J Respir Crit Care Med 2011; 184: 1041-1047.
• Silver coated endotracheal tube: reduced VAP with no change in duration MV, ICU LOS or mortality. Kollef et al. JAMA 2008; 300: 805-813.
– Anti-bacterial peptide coated endotracheal tube: Cerashield
• NIV to promote early extubation, but may not prevent VAP. Girault C, et al. Am J Respir Crit Care Med 2011; 184: 672-679.
• Saline instillation prior to suctioning . Beneficial, but could also be harmful
Use of the “Mucus Shaver” To Prevent VAP
0.35 g mucus removed per use, led to lower
peak airway pressure on vent
Scanning EM ( TOP = shaver, MIDDLE=
New tube, BOTTOM= suction
The IHI Ventilator Bundle
• “Evidence-based” interventions to improve outcomes in ventilated patients, as part of the “Save 100,000 Lives Campaign”
– Peptic ulcer disease prophylaxis
– Deep vein thrombosis prophylaxis
– Elevation of the head of the bed
– Sedation vacation
– Daily weaning trial
• Applied in 35 ICU’s and reported a 44.5% drop in VAP, a correlation between compliance and VAP rates, and concluded that the “observations seem sufficiently robust” to support implementation
• Resar et al. Jt Comm Journal Qual Patient Safety 2005; 31: 243
Adherence With Ventilator Bundles Reduces
VAP Rates
• Found a correlation between compliance with bundles and VAP rates, BUT
– No dissection of the impact of each element
– No standardized, independently verified definition of VAP.
– Methods of defining adherence unclear
– No reported impact on other secondary endpoints: LOS, antibiotic use, mortality
• Resar et al. Jt Comm Journal Qual Patient Safety 2005; 31: 243
• How to best implement a bundle?
– Probably need a daily checklist
– Can enhance adherence to recommended processes of care in ICU
• Weiss et al. Am J Respir Crit Care Med 2011; 184: 680-686
•
Education Can Improve Nursing Knowledge of
VAP Prevention Tools
• European ICU nurses given a test on evidence-based
guidelines for VAP prevention
• 3329 questionnaires collected.
– Average score 45%
– 55% knew preference for oral intubation (vs. nasal)
– 35% knew to change vent circuit for each new patient
– 51% knew of subglottic secretion drainage
– 85% knew of semi-recumbent position to prevent VAP
• Better scores with seniority and larger ICU
– Labeau S, et al. J Hosp Infect 2008; 70: 180-185
Should We Be Using SDD?
• SDD is not a uniform intervention
• Meta-analysis supports a survival benefit of SDD to stomach and
oropharynx with 4 days of systemic antibiotics
• 4 Recent Prospective studies support mortality benefit to SDD
– BUT
• Benefits apply to only selected populations (trauma and surgical)
• Patients with very mild or very severe illness may not benefit
• Need to apply to ALL in ICU and this promotes the emergence of
resistance
• Increases rate of HAI after leaving ICU
• Increase in resistance after stopping SDD
• Maybe SOD or oral disinfection is just as beneficial (lower risk)
• With the advent of ventilator bundles, may get a reduction in VAP
that cannot be further reduced with SDD
Why SDD Should Not Be Used Routinely In All
ICU’s and ICU Patients
Brar NK, Niederman MS. Curr Resp Med Rev 2010; 6: 45-51
Key Points For Preventing VAP
• Identify key factors for prevention in your hospital and implement
in the form of a bundle
– Head of bed elevation may NOT be important (maybe head down to
promote secretion drainage)
• Focus prevention on: early weaning, daily interruption of sedation,
attention to the endotracheal tube and airway interventions
• Oral chlorhexidine and bundle may be as valuable as SDD
• Consider: prophylactic antibiotics for emergent intubation, early
tracheostomy if long-term intubation likely ( trend to benefit, but
not significant; Terrragni et al. JAMA 2010; 303: 1483-1489) ,
non-invasive ventilation to facilitate early weaning
• To implement a bundle, need education program, daily checklist,
monitoring of adherence and VAP rates
Prevention of VAP
• How Much of VAP Is preventable?
• Methods for VAP Prevention
– Recommended Strategies
• What are The Implications of The Zero VAP
Movement ?
VAP Rates as a Quality Indicator
• Arguments in Favor
– VAP adds to morbidity , mortality and cost and thus reducing
rates could have value
– VAP is largely preventable
– Prevention requires a team approach and requires alterations in
processes of care that are an indirect reflection of quality.
Therefore reduced rates= improved quality
– In the US, VAP may be considered a medical error, and possibly
not reimbursed
• This presumes that ALL VAP is preventable
• The advent of IHI and ventilator bundles has reinforced the
idea that VAP rates should be able to be reduced to ZERO in
good patient care centers
VAP Rates as a Quality Indicator
• Arguments against
– To use rates as a quality indicator requires a uniformly
accepted , reproducible and accurate definition of VAP
• The widely used NNIS definition does not fit these criteria
– Case mix varies from hospital to hospital ,and thus VAP rates
vary independent of quality
– Not all VAP is preventable: patient factors are not controllable,
we can only impact processes of care
– Reduction in VAP rates with current strategies has usually not
led to other secondary benefits
– Maybe better to target processes of care or measureable
outcomes (mortality, LOS, duration MV, antibiotic use)
Problems With Public Reporting of VAP Rates
• Pressure of public reporting promotes under-reporting of VAP rates
– May be reluctant to test aggressively for VAP
– Hospitals with (falsely) low rates may be lulled into thinking things are fine
– Hospitals with (falsely) high rates may get penalized in “pay for performance” atmosphere, and end up with fewer resources to help patients.
– Klompas M, Platt R. Ann Intern Med 2007; 147: 803-805.
VENTILATOR BUNDLES: THE NEW
EMPEROR??
How Can Ventilator Bundles Lead to Zero VAP
With All These Problems?
• Ventilator Bundle elements are not always logical
– Why DVT and GI bleed prophylaxis?
– Is all the benefit due to wakening and weaning?
• HOB elevation may not be worthwhile
– Many proven prevention strategies not included
• Why not oral care?
– Conflicting elements: daily awakening may promote self extubation , reintubation and add to risk
• VAP may not always be preventable
– Case mix problem
• The Reduced VAP rates reported with bundles may not be believable
– Inaccurate clinical definition, pressure of public reporting
– Surveillance itself may change reported rates
– Reduced rates NOT confirmed by secondary endpoints: antibiotic use, duration MV, LOS, cost, mortality
Influence of Diagnostic Method on The
Incidence of VAP
• Compare Dx of VAP in 53
patients with clinical
suspicion of VAP using
ET and BAL • Aspirate over dx VAP : 89%
vs. 21% with clinical VAP
• Model the potential effect
of VAP incidence and
antibiotic use with dx by
ETA or BAL
– Predicted that use of BAL
would reduce VAP by 76%
and antibiotic use by 30%
•
Morris AC, et al. Thorax 2009;
64:516-22
Have We Eliminated VAP by Calling it VAT?
• 2060 ventilated patients. Outcomes of VAT and VAP were similar:
ARE THEY REALLY THE SAME DISEASE WITH VAT
MASKING THE VAP DIAGNOSIS?
• Dallas J, et al. Chest 2011; 139:513-518
Problems with VAP Definition Are Leading to a
New Term (VAC) With No Radiograph Needed!
• CDC definition of VAP: requires a radiographic, signs and symptoms, and
laboratory assessment
• Limits of using the current definition
– Subjective interpretation of clinical signs and X-ray. Interobserver
variability. Klompas, AJIC 2010; 38: 237
– Diagnostic method: BAL vs. endotracheal aspirate
– Do antibiotics get started WITHOUT getting cultures, or for VAT?
• The concept of Ventilator Associated Complications (VAC)
– Being explored by CDC, but may not be infection-specific or preventable
– Worsening oxygenation: Measure serial PaO2/FiO2 ratio. Need at least
2 days baseline stability and FiO2 increase > 0.2 or PEEP > 3, for 2
days
– IVAC if : fever or hypothermia, leukocytosis or leukopenia, AND a new
antibiotic is started for at least 4 days
– IVAC: Is this VAP + VAT+ a lot of other things (not pneumonia)?
What Other Approaches Are Possible?
• Aim for preventability
• Our current model
– May provide little motivation to improve care
– High performers are satisfied with status quo
– Low performers discredit the adjustment model
• Link care actually received to outcomes
– How many patients with an adverse outcome had an
appropriate prevention efforts?
• Those without prevention effort are defined as avoidable
harm
• Pronovost P and Colantuoni E .JAMA 2009; 301: 1273-5
Focus on Modifiable Risk Factors: Processes of
Care that Can Be Monitored and Are Relevant
• Structure-related quality measures
– Infection surveillance system in place, feedback about surveillance data, staff eduction, nurse: patient ratio, water supply with HEP filters, alcohol-based hand rubs for hygeine, staff expertise, ventilator circuit humidification (HME), endotracheal suction devices
• Process-related quality measures
– Use of non-invasive ventilation, route of intubation (frequency of nasal vs. oral) ,reintubation rates, frequency of vent circuit changes, head of bed elevation, subglottic secretion drainage, timing of tracheostomy, transport from ICU (some may be modifiable) , mobilization of patients, compliance with hand hygeine, glycemic control, early enteral feeding, transfusion, SDD, mouth care, sedation and weaning protocols
• Outcomes other than VAP rate:
– LOS, attributable mortality, attributable costs
• Uckay I, et al. Clin Infect Dis 2008; 46: 557.
Using VAP Rates As An Indicator Of Quality Is
Dangerous
• Presumes that all VAP is preventable
– Therefore VAP is a medical error
– Assumes that hospital quality can be reflected by VAP rates
• The advent of IHI and ventilator bundles has reinforced the idea that VAP rates should be able to be reduced to ZERO in good patient care centers
– Ignores the differences in case mix between hospitals
• If VAP is considered a reflection of poor quality of care, hospitals will be tempted NOT to treat indigent, and other high risk patients with NON-MODIFIABLE risk factors
• Pressure of public reporting promotes under-reporting of VAP rates
– Hospitals with (falsely) low rates may be lulled into thinking things are fine
– Hospitals with (falsely) high rates may get penalized in “pay for performance” atmosphere, and end up with fewer resources to help patients.
– Klompas M, Platt R. Ann Intern Med 2007; 147: 803-805.
• Will eliminate research into VAP
– How and why study a disease that should not be present?