Dr Kwan Ming Chit; Supervisor: Dr Yan Wing Wa; Pamela Youde Nethersole Eastern Hospital
Abstract: Background: Various clinical diagnostic criteria for ventilator associated pneumonia (VAP) had been evolved but data on comparing the diagnostic accuracy amongst various criteria is scarce. Furthermore, despite there was a scoring system developed to assess the severity and to stratify the mortality risk of VAP, there is no published data to validate such scoring system.
Objective: To identify and compare the incidence of VAP with adoption of various clinical diagnostic criteria and to validate the VAP-PIRO (Predisposition, Insult, Response, Organ Dysfunction) score in a local Chinese cohort.
Design: A prospective, observational, cohort study performed in a general medical-surgical adult Intensive Care Unit (ICU) in a local tertiary care centre.
Intervention: None
Methods: A prospective, observational cohort study was performed including 269 patients admitted to ICU who had been intubated and mechanically ventilated for more than 24 hours. VAP was diagnosed by utilizing various clinical criteria including National Healthcare Safety Network NHSN-PNU1, Clinical Pulmonary Infection Score (CPIS) and Johanson criteria. Clinical characteristics and the time when VAP was diagnosed were compared. Moreover, the VAP-PIRO score of each VAP case was calculated. The medical resource use and mortality in each PIRO risk group was compared. The data was finally compared to the original VAP-PIRO cohort.
Results: Of 269 patients admitted to ICU during a 8-month period there were in total 59 VAP cases by using NHSN-PNU1 criteria. The VAP incidence was 47.81 per 1,000 ventilator days. By using CPIS and Johanson criteria, only 47 and 42 VAP cases were diagnosed respectively (Incidence: 38.08 per 1,000 ventilator days and 34.04 per 1,000 ventilator days). The mean duration when VAP was diagnosed was 5.30 days and there was no significant difference in time amongst the three diagnostic criteria used. VAP-PIRO score was unable to stratify medical resource use and mortality in our cohort of patient.
Conclusion: A higher incidence VAP was observed as compared to CPIS and Johanson criteria when NHSN-PNU1 criteria was adopted in the diagnosis of VAP. No significant delay in the diagnosis of VAP was envisaged amongst the three diagnostic criteria used. Although there was a trend towards higher mortality in patients with higher VAP-PIRO score, it cannot significantly differentiate mortality and usage of medical resources in our cohort.
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