Is a ventilator-associated pneumonia rate of zero really possible?

Abstract

The increasing number of hospitals reporting ventilator-associated pneumonia (VAP) rates at or close to zero begs the question of whether zero should become the national benchmark for VAP. This article explores the significance of very low VAP rates, reviews differences in surveillance and clinical rates, proposes reasons for their discrepancies, and suggests possible objective alternatives for surveillance. Surveillance rates of VAP are decreasing, whereas clinical diagnoses and antibiotic prescribing remain prevalent. This growing discrepancy reflects the lack of objective and definitive signs to diagnose VAP. External reporting pressures may be encouraging stricter interpretation of subjective signs and other surveillance initiatives that can artifactually lower rates. It is impossible to disentangle the relative contribution of care improvements versus surveillance effects to currently observed low VAP rates. The increasing mismatch between surveillance rates and clinical diagnoses limits the utility of official VAP rates to estimate disease burden and guide quality improvement. Advocates are advised to consider objective alternatives such as average duration of mechanical ventilation, length of stay, mortality, and antibiotic prescribing. Emerging surveillance definitions that use more objective criteria may better reflect and inform future clinical practice.