Can a Multicenter Pneumonia Zero Bundle Reduce Ventilator-Associated Pneumonias?*
In this issue of Critical Care Medicine, Alvarez-Lerma et al (1) present the results of the Zero VAP project, the largest prospective, interventional, multicenter study across 181 Spanish ICUs. The VAP prevention bundle included seven basic mandatory measures (e.g., hand hygiene with alcohol solutions, oral hygiene with chlorhexidine, semirecumbent positioning) and three highly recommended measures (e.g., continuous aspiration of subglottic secretions). The adjusted VAP frequency deceased from 9.83 per 1,000 ventilator days to 4.34 per 1,000 ventilator days in a 21-month period. With compliance being measured by internal audits and surveys, the use of the bundle was associated with a decreased adjusted VAP incidence from 9.83 per 1,000 ventilator days to 4.34 per 1,000 ventilator days in a 21-month period. The Zero VAP bundle allowed for a 2.4–1.2% (50%) reduction in VAP rates and 10.9–7.7% reduction in VAP recurrence.
The strength of evidence marshaled in support of the various VAP bundle components is uneven. Although components like sedation breaks and daily ventilator liberation assessments have consistently been linked to better outcomes, other elements, including elevation of head-of-bed and stress ulcer prophylaxis, have had mixed results (2, 3). Therefore, a robust evaluation of the bundle efficacy must be done prior to global application of a QI bundle. Interestingly, the VAP bundle in the Zero VAP QI program did not include stress ulcer or deep venous thrombosis prophylaxis, daily sedation assessments, or spontaneous breathing trials. Although included in the Institute for Healthcare Improvement 100,000 Lives Campaign, these bundle components are less clearly related to the prevention of VAP (4). Perhaps the implementation of bundle components only with proven efficacy in VAP prevention allowed for the VAP reduction. Furthermore, bundles are more than the sum of their components; institutions should not expect, nor will they achieve, optimal results with partial compliance (4).
Adoption of a QI bundle commonly requires a multifaceted approach. They must be widely effective and carry minimal risk of harm. Success of a VAP QI initiative has at least three dependencies: First, every healthcare provider must know the components. The Zero VAP program, for example, trained 18,000 (83%) of their multidisciplinary ICU healthcare workers through training modules. This project addressed several broad categories of potential barriers to evidence-based practice, including provider knowledge, attitudes, and behaviors described by Cabana et al (5). Second, component compliance must be monitored by a bundle conformity leader. The VAP Zero project may have been successful from the high-level monitoring of bundle compliance. Third, feedback and continuing education aimed at increasing proper use of each component are vital. Knowledge, compliance, and feedback can be enhanced through a pyramidal (hierarchical) administration with required reporting. The pyramidal organization at a national, regional, and hospital level may have contributed to the successful implementation of this initiative.
In a time when increasing VAP studies are criticized as failing to demonstrate clinical and cost effectiveness, this national QI project supports the use of VAP bundle compliance to cut VAP and mechanical ventilation days by nearly half (6). The definition of VAP remains in flux. Attempts to simplify, streamline, objectify, and automate assessments for VAP are ongoing. Whether the bundle is effective in reducing the newer and more broadly conceived “ventilator-associated events” cannot be assumed; rather, it is a hypothesis requiring evaluation.
Prevention may be our best hope for reducing VAP- associated morbidity and mortality.