Neonatal-Perinatal Medicine Fellow University of Alberta Faculty of Medicine and Dentistry Edmonton, Alberta, Canada
Background: Preterm infants are at increased risk for acquired infections related to invasive devices such as endotracheal tubes (ETT). Wide heterogeneity exists in diagnostic criteria and management of ventilator-associated pneumonias (VAP), which have not been validated in the neonatal population. Objective: To determine the demographic characteristics and prevalence of VAP according to three different existing criteria used in the neonatal intensive care unit (NICU). Design/Methods: In this retrospective study, we included infants born at < 33 weeks gestational age from 3 different NICUs in Western Canada, who have been diagnosed with VAP during 2018 – 2022. Infants were diagnosed per three diagnostic criteria: (1) Diagnosed by physicians’ discretion, with ≥48 hours of mechanical ventilation and received a minimum of 4-days of antibiotics (per physician diagnoses); (2) VAP diagnostic criteria consensus adopted by some Canadian NICUs (per Canadian criteria); and (3) Criteria of a pediatric ventilator-associated condition (PVAC) with a positive respiratory diagnostic test (per PVAC criteria). [Table 1] Results: There were 185 neonates diagnosed to have VAP at physicians’ discretion during the study period, with incidences of 4.6%, 8.9%, and 5.7% in the three NICUs [Table 2]. They had a median GA of 25 weeks, a median birth weight of 748-849 grams, and a median onset of VAP ranging from 16-31 days [Table 3]. Among the VAP per physicians’ diagnoses, 18.2-55.0% of infants fulfilled the VAP criteria of Canadian consensus, and 10.9-12.5% of them fulfilled the PVAC criteria with a positive respiratory diagnostic test [Table 2]. The demographic distribution showed similar patterns across the three criteria. Staphylococcus aureus, Enterobacter cloacae complex, Klebsiella species, and oral flora were found to be the most common organisms yielded from ETT aspirate cultures.
Conclusion(s): We found that 4.6-8.9% of infants born at < 33 weeks GA had VAP diagnosed during their NICU stay. Only around one-ninth of infants fulfilled the PVAC criteria with a positive respiratory diagnostic test. Therefore, there is an urgency to develop neonatal-specific and validated diagnostic criteria for VAP.