549 - Vital Sign Trajectories of Emergency Transfers from the Acute Care Unit to the Pediatric ICU

Publication Number: 549.7050

Olivia Post, Cincinnati Children's Hospital Medical Center, Loveland, OH, United States; Yin Zhang, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States; Bin Huang, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States; Patrick W. Brady, Cincinnati Children's Hospital, Cincinnati, OH, United States; Laura Brower, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, United States

Background: Pediatric patients who require emergency transfer (ET) to a critical care unit have worse outcomes, longer length of stay (LOS) post-transfer, and higher in-hospital mortality than matched controls. An ET is a floor to ICU transfer in which one of the following interventions occurs within one hour of transfer: intubation, receipt of inotropes, or at least 60 mL/kg of fluid resuscitation (including blood products). Implementation of processes that identify and address risk factors for clinical deterioration have successfully decreased the rate of safety events.

Objective: To understand the vital sign patterns of clinical deterioration in the 16 hours preceding transfer to the ICU.

Design/Methods: We conducted a case-cohort study of patients admitted to the acute care units at a quaternary pediatric care facility over 3 years who required emergent or non-emergent transfer to the ICU. Exposure variables included vital signs (heart and respiratory rate normalized by use of age-adjusted z-scores) at time of transfer as well as at 4-,8-, 12-, and 16-hours before transfer. The mean arterial pressure (MAP) was used for blood pressure comparison. ANCOVA modeling was used to compare the longitudinal trajectories of vital signs in both groups with adjustments for patient’s sex, age, primary service, and unit.

Results: Patients who required emergency transfer to the ICU had higher heart rates at time of transfer in comparison to those who transferred non-emergently (p=0.03) (Figure 1A). MAP was consistently lower in patients requiring ET starting at 12 hours prior to transfer and persisting up to time of transfer (p < 0.05). Additionally, MAP gradually decreased in the ET group compared to the non-emergent transfer group where it was highest at transfer (Figure 1B). There was no statistically significant difference in respiratory rate between groups at any of the time points.

Conclusion(s): Patients requiring an ET to the ICU had lower blood pressures for up to 12 hours prior to transfer despite only having a significantly higher heart rate at time of transfer. This suggests that some patients may not become tachycardic even with worsening hypotension, potentially increasing the risk of unrecognized deterioration. Prospective multi-center studies should build upon these findings.

Figure 1.
ANCOVA modeling of longitudinal trajectory of (A) heart rate z-score and (B) mean arterial pressure (MAP) in 16 hours preceding transfer in patients requiring emergency transfer versus non-emergent transfer. The presence of a star indicates a significant difference.