593 - Incidence and Outcomes of Late-Onset Neonatal Septic Shock: A Nationwide Population-Based Observational Study

Publication Number: 593.5405

Ashraf Kharrat, Mount Sinai Hospital, Toronto, ON, Canada; Marc Beltempo, McGill University Faculty of Medicine and Health Sciences, Monreal, PQ, Canada; Joseph Ting, University of Alberta, Edmonton, AB, Canada; Thuy Mai Luu, Centre Hospitalier Universitaire Sainte-Justine, Montreal, PQ, Canada; Kamini Raghuram, Mount Sinai Hospital, Toronto, ON, Canada; Amber E. Reichert, University of Alberta, Edmonton, AB, Canada; Kristine Russell, Sepsis Canada/McMaster University, Medicine Hat, AB, Canada; Eugene W. Yoon, Mount Sinai Hospital, Toronto, ON, Canada; Prakesh S. Shah, Mount Sinai Hospital, Toronto, ON, Canada

Background: Septic shock is a major complication among preterm infants. Despite its frequency in the neonatal intensive care unit (NICU), there are little data available on the incidence and associated health and developmental outcomes among preterm infants with septic shock.

Objective: To describe the short-term and long-term outcomes of preterm infants with septic shock occurring due to culture-positive late-onset sepsis (LOS-shock).

Design/Methods: We conducted a national, multicentre, retrospective cohort study of infants born from January 2011 to December 2020 and admitted to 32 tertiary NICUs across Canada. Infants born < 29 weeks gestational age (GA) with their LOS episode occurring > 3 days of age were eligible. Infants with LOS-shock, defined as the receipt of vasopressors, inotropes or corticosteroids within the first 3 days of LOS diagnosis, were included. Details of infants’ NICU course were obtained from the Canadian Neonatal Network database, and linked 18-24 month neurodevelopmental (ND) outcome data were obtained from the Canadian Neonatal Follow-Up Network database. Significant NDI (sNDI) was defined as any of: Bayley-III cognitive, language or motor score < 70; cerebral palsy with Gross Motor Function Classification System III-V; hearing aid or cochlear implant; or bilateral visual impairment.

Results: Overall, 3810 patients with LOS were identified, of whom 840 (22%) developed LOS-shock, with a mortality rate of 49% (n=410). Among infants with LOS-shock, non-survivors were more frequently born by vaginal delivery, be invasively ventilated prior to LOS, had lower age at illness, and had a higher incidence of gram-negative organism (p < 0.01 for all). Among survivors, adverse ND outcome rates were higher in those infants with LOS-shock versus those without shock across all domains, with significant delays noted in language development (p < 0.01 for all). Multivariable regression analysis showed that the need for invasive ventilation prior to LOS (1.76 [1.20, 2.56]), exposure to corticosteroids prior to LOS (1.40 [1.01, 1.92]), and presence of gram-negative organism (1.74 [1.28, 2.37]) were associated with mortality. Presence of a central line at infection (2.73 [1.05, 7.07]) and gram-negative organism (2.09 [1.19, 3.68]) were associated with sNDI. The incidence of LOS-shock and associated mortality remained stable over the 10-year study period.

Conclusion(s): Septic shock is a common complication among preterm neonates and is associated with a high risk of mortality and developmental impairment among survivors. Future work is needed to investigate the impact of management strategies on improving outcomes.

Table 1. Demographic, baseline and illness seveirty variables among survivors and non-survivors of late-onset septic shock, and among those with septic shock who did and did not develop significant neurodevelopmental impairment.
Data are presented as mean (standard deviation) or median (interquartile range) as appropriate.
sNDI: significant neurodevelopmental impairment, defined as any one of: Bayley-III cognitive, language or motor score < 70; cerebral palsy with Gross Motor Function Classification System III-V; hearing aid or cochlear implant; or bilateral visual impairment.
*Site incidence rates were divided as low (lowest third, 11 sites), middle (middle third, 10 sites) and high (highest third, 10 sites).



Table 2. Neurodevelopmental outcomes of survivors with and without late-onset septic shock.
Data are presented as n (%) or median (interquartile range) as appropriate.
In-person neurodevelopmental assessment conducted at 18-24 months were done using the Bayley Scales of Infant and Toddler Development-3rd Edition (BSID-III).

Table 3. Risk factors for mortality and, among survivors, for significant neurodevelopmental impairment among infants with late-onset septic shock.
Significant neurodevelopmental impairment was defined as any one of: Bayley-III cognitive, language or motor score < 70; cerebral palsy with Gross Motor Function Classification System III-V; hearing aid or cochlear implant; or bilateral visual impairment.

*Site incidence rates were divided as low (lowest third, 11 sites), middle (middle third, 10 sites) and high (highest third, 10 sites). Each variable was adjusted for all other variables in the model.