Frequency, Characteristics and Outcomes of Patients Returning to the PICU Within 48 Hours of Transfer

Background: Readmissions to intensive care units are associated with increased mortality in adults, less is known about the pediatric population. Furthermore, factors associated with increased risk of return to the pediatric intensive care unit (PICU) within the same hospitalization remain unclear. We sought to describe the prevalence of and identify factors associated with return to the PICU during the same hospitalization and within 48 hours of transfer.

Methods: We performed a retrospective review of clinical and resource utilization data from the Pediatric Health Information System. We included patients 0-26 years old admitted to a PICU between January 1, 2016 – December 31, 2019. Only the index PICU admission was included in the analysis. Exclusion criteria included: admission to neonatal or cardiac intensive care units or burn units, procedure code for a corrective cardiac surgery, death during index PICU admission, discharge or transfer to another hospital during index PICU admission, and history of bone marrow transplantation. Multivariable modelling was used to analyze associations between patient and clinical variables and return to PICU within the same hospitalization.

Results: In total, 389,219 encounters (median age 4 years, (IQR: 12-1), 55.2% male) were included. Of these, 2.5% were associated with a return to the PICU within 48 hours of transfer. On multivariable analysis, factors with highest odds of PICU readmission were ≥2 Complex Chronic Conditions (CCC) (aOR 3.5, 95%CI 3.3 – 3.8), parenteral nutrition (aOR 2.3, 95%CI 2.2-2.5), 1 CCC (aOR 2.0, 95%CI: 1.9-2.2), and presence of a ventriculoperitoneal shunt (aOR 1.9, 95%CI 1.7-2.2). The factors with decreased odds of PICU readmission included ECMO (aOR 0.4, 95%CI 0.3 – 0.6), cardiopulmonary resuscitation (aOR 0.8, 95%CI 0.7-0.9), and intubation (aOR 0.8, 95%CI 0.8 – 0.9), Patients requiring PICU readmission had longer overall lengths of stay (mean (SD) 28.9 (43.1) vs 10.3 (24.2) days, p<.001) and increased odds of mortality (OR 1.7, 95% CI 1.5-1.9) compared to those without a PICU readmission within 48 hours of transfer.

Conclusion: The rate of PICU readmissions during the same hospitalization and within 48 hours from transfer was 2.5%. Patients with medical complexity, including those with shunts and/or at least one complex chronic condition, were especially vulnerable. Although readmissions within 48 hours are uncommon, they are associated with worse outcomes and increased healthcare utilization. Further studies are needed to identify patients at highest risk of unplanned PICU readmission and develop interventions to mitigate modifiable risk factors.