The incidence and characteristics of ventilator-associated pneumonia in a regional nontertiary Australian intensive care unit: A retrospective clinical audit study

Background: Ventilator-associated pneumonia (VAP) is a common complication of mechanical ventilation in the intensive care unit. The incidence, patient characteristics, and outcomes have not been described in a regional Australian setting. Objectives: Τhe primary objective was to establish the incidence of VAP in a regional intensive care unit using predetermined diagnostic criteria. The secondary objective was to compare the agreement between criteria-based and physician-based diagnostic processes. The tertiary objectives were to compare patient characteristics and clinical outcomes of cases with and without VAP. Methods: A retrospective clinical audit was performed of adult patients admitted to Rockhampton Intensive Care Unit, Australia, between 2013 and 2016. We included all patients ventilated for ≥72 h and not diagnosed with a pneumonia before or during the first 72 h of ventilation. Results: A total of 170 cases met the inclusion criteria. The incidence of VAP as per the criteria-based diagnosis was 27.3 cases per 1000 ventilator days (95% confidence interval [CI]: 18.4–36.2) and as per the physician-based diagnosis was 25.8 cases per 1000 ventilator days (95% CI: 17.1–34.4). There was a moderate chance-corrected agreement between the criteria- and physician-based diagnosis. Very obese cases (body mass index [BMI] ≥40) were nearly four times more likely to develop VAP than cases with normal BMI (BMI <30) (odds ratio: 3.664; 95% CI: 1.394–9.634; p = 0.008). After controlling for sex, BMI category, comorbidities, and Acute Physiology and Chronic Health Evaluation II scores, there was a trend (p = 0.283) for higher adjusted mortality rate for cases with VAP (10.1%, 95% CI: 4.8–21.5) than for those without VAP (6.1%, 95% CI: 3.0–12.4). Cases with VAP had a higher total hospital cost ($123,223 AUD vs $66,425 AUD, p < 0.001), than cases without VAP. Conclusions: This is the first study reporting incidence of VAP in an Australian regional intensive care unit setting. An increased length of stay and significantly higher hospital costs warrant research investigating reliable and valid clinical prediction rules to forecast those at risk of VAP.