Evaluation of characteristics, clinical relevance and outcome of ventilator associated pneumonia and ventilator associated events algorithm

Background: Surveillance for ventilator-associated pneumonia (VAP) has long been a challenge because of the lack of objective, reliable definitions. Hence, National Healthcare Safety Network (NHSN) has introduced ventilator-associated events (VAEs) as a surveillance definition. While VAE identifies all the possible complications in a mechanically ventilated patient, VAP recognises only the infective complications. There are several retrospective studies reporting no concordance between the occurrence of VAE and VAP. A prospective, observational study in medical intensive care unit (ICU) was conducted over 1 year with the objective of comparing all three tiers of VAE, which are ventilator-associated condition (VAC), infection-related ventilator-associated complication (iVAC) and possible VAP (PVAP), along with VAP in terms of predictive value, characteristics and clinical relevance. Materials and Methods: A prospective cohort study was conducted from July 2018 to June 2019 at PGIMER, Chandigarh, in a 12-bedded medical ICU. All patients with more than 48 h of mechanical ventilation (MV) were included. The demographic data, Acute Physiology and Chronic Health Evaluation-II at 24 h of admission, days of MV, length of ICU stay and outcome of patients were recorded. The patients were screened for both VAP and VAE. Results: Out of a total of 405 patients, 274 patients were included with 3945 patient days and 3330 MV days. The incidence of VAP, VAC, iVAC and PVAP was 6.91, 8.41, 5.41 and 1.50/1000 ventilator days, respectively. Kendall's W-test showed that there was no concordance between VAP and VAE. Conclusion: The study concluded no concordance between cases identified as VAE and VAP.