Ahmed Al Gahtani, BSRC, RRT Associate Director, Clinical EducationChairman, RTS Scheduling CommitteeDept. of Respiratory TherapyInaya Medical College Central Chapter Member, Saudi Society for Respiratory Care

VENTILATOR-ASSOCIATED EVENT (VAE)

Clear distinction between surveillance and clinical case definitions based on:

Understanding Ventilator-Associated Event (VAE) Definitions

Maryland Hospital Association

Lacked objectivity and reliability Included three components An radiographic component (required) A signs and symptoms component (required) A laboratory component (optional) Included situations where pneumonia could not be diagnosed with a

reasonable degree of certainty

NHSN Ventilator-Associated Pneumonia (VAP) surveillance definition used prior to 2013

The CDC's NHSN has been working since 2009 to develop a more objective, reliable approach to VAP surveillance, convening a VAP Surveillance Definition Working Group in collaboration with

Nationally recognized experts Several professional societies and organizations Other federal partners The CDC’s new approach centers on ventilator-associated conditions

and complications in an attempt to limit diagnostic inaccuracies. The new approach, surveillance for Ventilator-Associated Events (VAE),

was implemented for use in NHSN in January 2013.

Step ways approach (VAC, IVAC, possible or probable VAP) Simple and focuses on readily available, objective clinical data Requires a minimum period of time on the ventilator Does not include chest radiograph findings Detects ventilator-associated conditions and complications, including (but not limited to) VAP Captures important complications, most cases due to: Pneumonia Pulmonary edema ARDS (Acute Respiratory Distress Syndrome) Atelectasis Allows clinicians to identify and manage care complications that lead to VAP earlier and more

effectively than in the past

The new VAE surveillance approach

Routine bedside evaluation coupled with radiographic information provides suggestive but not definitive evidence that VAP is present or absent. Given the severity of VAP and the frequency of serious conditions that can mimic VAP, clinicians should be ready to consider additional tests that provide further evidence for VAP or that establish another diagnosis.

Klompas, et el: JAMA, April 11, 2007—Vol 297, No. 14

Objective: The objective of this study was to compare the observed rates of ventilator-associated pneumonia when using the National Healthcare Safety Network vs. the American College of Chest Physicians criteria.

Design: Prospective, observational cohort study. Setting: A 1250-bed academic tertiary care medical center. Patients: Adult medical and surgical intensive care unit patients requiring mechanical

ventilation for >48 hrs. Interventions: None.

The clinical characteristics of VAP and VAT are similar and include fever, leukocytosis, and purulent sputum. An infiltrate on chest radiograph is consistent with VAP but lacks diagnostic precision, so it is not a criterion in the proposed surveillance definition and should be interpreted cautiously by clinicians. Microbiologically, quantitative and semiquantitative endotracheal aspirate cultures may be employed to diagnose VAP and VAT. Positive bronchoalveolar lavage and protected specimen brush cultures are useful only for the diagnosis of VAP. Experts should collaborate to develop consensus definitions for VAP and VAT that can be applied in practice

Evaluated a novel surveillance paradigm for ventilator-associated complications (VAC) defined by sustained increases in patients’ ventilator settings after a period of stable or decreasing support.

Assessed 600 mechanically ventilated medical and surgical patients from three hospitals

Screening ventilator settings for VAC captures a similar set of complications to traditional VAP surveillance but is faster, more objective, and a superior predictor of outcomes.

Clinical Infectious Diseases 2011: Klompas et al

The complexity and subjectivity of ventilator-associated pneumonia (VAP) surveillance limit its value in assessing and comparing quality of care for ventilated patients. A simpler, more quantitative VAP definition may increase utility.

A streamlined version of the VAP definition was faster, more objective, and predicted patients’

outcomes almost as effectively as the conventional definition. VAP surveillance using the streamlined method may facilitate more objective and efficient quality assessment for ventilated patients.

Clinical Infectious Diseases 2012;54(3):370–7

VAEs were associated with more days to extubation (relative rate, 3.12 [95% confidence interval (CI), 2.96–3.29]), more days to hospital discharge (relative rate, 1.46 [95% CI, 1.37–1.55]), and higher hospital mortality risk (odds ratio, 1.98 [95% CI, 1.60–2.44]). Conclusions. VAEs are common and morbid. Prevention strategies targeting VAEs are needed.

Infection Control and Hospital Epidemiology, 2014

What are the big differences ?

VAP VAE

Only one outcome—either patient had VAP or didn’t

Several choices along pathway Ventilator Associated

Condition (VAC) Infection-Related

Ventilator Complication (IVAC)

Possible VAP Probable VAP

Designed for public reporting

Designed for internal

QI

VAE: Learning Your way through the new ventilator event pathway, Jo Henman

Old vs New

VAP VAE

Started with chest x-ray

Unclear definitions on when something is hospital acquired

Subjective clinical symptoms (increased sputum production)

Starts with changes in ventilator requirements

Explicit timing definitions for inclusion in surveillance

Objective clinical criteria that is clearly defined

VAE: Learning Your way through the new ventilator event pathway, Jo Henman

Criteria for surveillance Eligible patients/wards

Only for patients 18 and older Acute care, long term acute care and inpatient rehab facilities

Excluded types of ventilation High frequency ventilation (>60 breaths per minute with small tidal volumes) Extracorporeal life support NOTE: patients on airway pressure release ventilation (APRV) those in the prone

position and those receiving nitric oxide therapy should be included in surveillance

VAE: Learning Your way through the new ventilator event pathway, Jo Henman

Definitions Date of Event: FIRST day that the worsening oxygenation threshold is

met VAE Window Period: The time period when all elements of a definition

must be met. It usually includes the 2 days before and the 2 days after the date of event.

Episode of ventilation: Days when a patient is on a vent for some portion of each consecutive day. Patient must be off ventilator for one full calendar for new episode to begin.

Definitions Location of attribution- Where patient was at date of event

Exception – If date of event occurs on the day of or day after transfer then the event is attributed to transferring location

Reporting – In 2013 MUST report all events in the VAE algorithm

VAE: Learning Your way through the new ventilator event pathway, Jo Henman

Ventilator Associated Condition (VAC)

Patient has a baseline period of stability or improvement on the ventilator, defined by ≥ 2 calendar days of stable or decreasing daily minimum FiO2 or PEEP values. The baseline period is defined as the two calendar days immediately preceding the first day of increased daily minimum PEEP or FiO2.

After a period of stability or improvement on the ventilator, the patient has at least one of the following indicators of worsening oxygenation:

1) Increase in daily minimum FiO2 of ≥ 0.20 (20 points) over the daily minimum FiO2 in the baseline period, sustained for ≥ 2 calendar days.

2) Increase in daily minimum PEEP values of ≥ 3 cmH2O over the daily minimum PEEP in the baseline period, sustained for ≥ 2 calendar days.

and

ExamplesVentilator Day FI02 PEEP

1 100% 8

2 50% 6

3 35% 5

4 35% 5

5 60% 6

6 60% 6

The next Step of the pathway…IVAC Patient meets criteria for VAC

On or after calendar day 3 of mechanical ventilation and

within 2 calendar days before or after the onset of worsening oxygenation, the patient meets both of the following criteria:

1) Temperature > 38 °C or < 36°C, OR white blood cell count ≥ 12,000 cells/mm3 or ≤ 4,000 cells/mm3

AND 2) A new antimicrobial agent(s)* is started, and is continued

for ≥ 4 calendar days.

And

What is “New Antimicrobial Start” A NEW antimicrobial that is contained in the NHSN Appendix that is

given by IV, IM, Respiratory or Digestive tract route during the VAE Window Period.

NEW means an antimicrobial that wasn’t received in the previous 2 days and continues for 4 “qualifying antimicrobial days” (QAD’s)

OK….what is a QAD? A day when the patient received a new antimicrobial agent. QAD’s must start within the VAE Window Period and continue for four

consecutive days…..KIND OF! In NHSN world if the SAME antimicrobial is given on days 1 and 3 that is

considered consecutive and would count as THREE QAD’s. There can be no more than one calendar day between doses to count as consecutive.

Another ExampleVentilator Day FI02 PEEP

1 100% 8

2 50% 6

3 40% 5

4 35% 5

5 70% 6

6 70% 6

7 40% 5

Ventilator Day 1 2 3 4 5 6VAC Criteria Stable Stable Increased vent

requirementsIncreased vent requirements

Increased vent requirements

Stable

Temp 37.5 38.9 38.0 37.5 37.0 39.0

WBC 15.0 17.5 18.5 12.0 11.5 14.0

Antimicrobial Agent

Doxy GENTAMICIN GENTAMICIN None GENTAMICIN GENTAMICIN

Another Example

Now that you’ve learned the theory behind the new VAE surveillance definitions….here is the calculator instead of pencil and paper determination

VAE Calculator

How to collect data

Manual vs. Electronic Only need to look at patients who are on the

vent for at least 4 days Probably need to partner with RT and IS Can capture from electronic charting if used Can be set up in IC software programs to run

initial algorithm if used

References

1) Behrendt CE. Acute respiratory failure in the United States: incidence and 31-day survival. Chest 2000;118:1100-5.

2) Kahn JM, Goss CH, Heagerty PJ, et al. Hospital volume and the outcomes of mechanical ventilation. N Engl J Med 2006;355:41-50.

3) Wunsch H, Linde-Zwirble WT, Angus DC, Hartman ME, Milbrandt EB, Kahn JM. The epidemiology of mechanical ventilation use in the United States. Crit Care Med 2010;38:1947-53.

4) Rubenfeld GD, Caldwell E, Peabody E, et al. Incidence and outcomes of acute lung injury. N Engl J Med 2005;353:1685-93.

5) Esteban A, Anzueto A, Frutos F, et al. Characteristics and outcomes in adult patients receiving mechanical ventilation: a 28-day international study. JAMA 2002;287:345-55.

6) Dudeck MA, Horan TC, et. al. National Healthcare Safety Network (NHSN) Report, Data Summary for 2010, Device-associated Module. Available at http://www.cdc.gov/nhsn/PDFs/dataStat/NHSNReport_DataSummaryfor2010.pdf.

7) Klompas M. Does this patient have ventilator-associated pneumonia? JAMA 2007;297:1583-93.

8) Klompas M. Interobserver variability in ventilator-associated pneumonia surveillance. Am J Infect Control 2010;38:237-9.

9) Klompas M, Kulldorff M, Platt R. Risk of misleading ventilator-associated pneumonia rates with use of standard clinical and microbiological criteria. Clin Infect Dis 2008;46:1443-6.

NHSN VAE Definition Jan 2013. http://www.cdc.gov/nhsn/PDFs/pscManual/10-VAE_FINAL.pdf .