Current Pneumonia Surveillance Methodology: Similar Underestimation in Trauma and Surgical Patients in the Intensive Care Unit.

BACKGROUND: In 2013, the Centers for Disease Control and Prevention (CDC) developed new surveillance definitions for ventilator-associated events (VAE), leading to concerns that hospitals may be underreporting the true incidence of ventilator-associated pneumonias (VAPs). We sought to compare rates of clinically diagnosed VAP with CDC defined possible VAPs (PVAPs) in patients with a VAE in the surgical/trauma intensive care unit (STICU).

HYPOTHESIS: Significant difference exists between rates of clinical VAP and PVAP in patients with at least one VAE.

PATIENTS AND METHODS: All STICU patients with ≥1 VAE, between 1/1/2013 and 10/31/2015 were identified. Age, length of stay (LOS), ICU and ventilator days were collected.

RESULTS: There were 134 patients who had ≥1 VAE. Mean age was 54.3 (±17.1) years. Mean LOS, median ICU, and median ventilator days were 26.3 (±14.1), 21.0 (17.0-33.0), and 17.0 (12.8-24.0) days, respectively. There were 68 cases of clinically diagnosed VAP, but only 37% met PVAP criteria. We compared 43 cases of clinical VAP, not meeting PVAP criteria, with the 25 PVAPs. Both groups had similar outcomes. The PVAPs were more likely to have an abnormal temperature (48.0% vs. 14.0%, p = 0.004), abnormal white blood cell count (84.0% vs. 18.6%, p < 0.001), or new antibiotic agent initiated (100% vs. 18.6%, p < 0.001) as VAE triggers. Comparison of the 93 trauma and 41 surgical patients demonstrated trauma patients were younger (51.2 vs. 61.5 y, p = 0.001), but had similar outcomes and rates of clinical VAP (48.4% and 43.9%, p = NS). Only 20.4% of trauma and 14.6% of surgical patients, however, had a PVAP reported. For patients with at least one VAE, the sensitivity and specificity for PVAP detecting VAP was 36.8% and 96.0%, respectively.

CONCLUSION: The new CDC definition for PVAP grossly underestimates the clinical diagnosis of VAP and reports less than a third of the patients treated for VAP. Reporting differences were similar for trauma and surgical patients.