Friday, June 22, 2012

Bundle fumble?

This week's JAMA has an excellent review (free full text here) on the prevention of ventilator-associated pneumonia (VAP). Specifically, the authors offer a critical assessment of the widely utilized IHI VAP bundle. They offer two important conclusions:
  • "The ability of the bundle to prevent VAP has not been definitively established with high quality studies."
  • "No large randomized study has demonstrated that reducing VAP using any strategy, including the IHI bundle, is associated with improvements in clinical outcomes."
Here's another example where an intervention has been touted as gospel, pushed hard and implemented broadly without the evidence necessary for a hardline approach.

Photo: OregonLive


  1. This paper and Mike’s conclusion are important reminders of the importance of staying open but skeptical when evaluating interventions like the IHI bundle. However, I’d like to cheerfully but firmly reframe Mike’s conclusion to emphasize the need for more research – particularly, the need for studies and/or analyses that are focused on well-defined patient populations. Even with a large sample size, it is understandable that observations of clinical outcomes like ventilator days, length of hospital stay, and mortality would not be significantly different between intervention and control groups if the sample is too heterogenous. For example, the silver-coated ET tube study cited in this review (doi:10.1001/jama.300.7.805) had a sample of 2003 patients of whom 20% were intubated in the MICU, 40% in another ICU or burn unit, 30% in the OR or recovery room, and 6% in the ED or elsewhere. The VAP risk factors (COPD, trauma, etc) were similarly diverse. The age range was 18 to 102 (mean ~61, SD ~15). No post-hoc analysis was done in this study to determine if outcomes were significantly improved within intubation indication, risk factor, or intubation location strata. I wonder what would have emerged had such analysis been conducted.

    The authors of this VAP bundle review have presented us with an array of enticing ideas to test. Let’s not back down from the challenge – and let’s all think carefully about study design to maximize the specificity and utility of the conclusions that can be drawn.

    S. Timberlake, BS, BSN, RN

  2. I agree completely, and the need for well-designed studies becomes even more urgent as we get ready to roll-out a brand new definition (ventilator-associated events, or VAE) in January of 2013. Controlled trials that ignore the murky outcome measure of VAP are preferred, a good example being the Girard, et al, "wake up and breath" trial published in Lancet (reference 31 in the JAMA review). However, public reporting of an outcome measure, and/or linking it to reimbursement, changes the equation--we eventually have to demonstrate that this new measure (VAE) is preventable with specific interventions (early work has already shown it to be associated with "hard" adverse outcomes, like mortality).