Strain in the Pediatric Intensive Care Unit and its Association with Patient Outcomes

Abstract

Objective: To characterize measures of pediatric intensive care unit (PICU) strain and test for associations between strain and patient outcomes. We hypothesized that periods of increased strain would be associated with increased odds of experiencing a post-ICU floor escalation event. Design: Retrospective cohort study. Setting: Quaternary care children's hospital PICU. Study Population: PICU admissions (2014-2023). Interventions: None. Measurements and Main Results: We measured PICU strain metrics daily including percent occupancy, percent turnover, and acuity. Percent occupancy and turnover were higher during annual peak viral season versus non-peak season (percent occupancy: median 84.4 [interquartile range (IQR) 72.9, 91.7] versus 68.8 [IQR 56.3, 82.1], P < .001; percent turnover: median 25.0 [IQR 20.0, 31.3] versus 21.9 [IQR 15.6, 28.1], P < .001). Acuity metrics did not differ during these periods. In patients admitted for respiratory or neurologic illness, we used multivariable logistic regression to test for associations between strain metrics on the day of transfer and odds of a floor escalation event defined as an unplanned PICU readmission or rapid response or code blue activation within 48 h of transfer. Of 12 832 patient transfers, 429 (3.3%) experienced a floor escalation event. After controlling for patient and clinical characteristics, percent occupancy and turnover were independently associated with an increase in floor escalation events. This risk was not linear for occupancy: above 87.5% (95% confidence interval (CI): 80.4, 94.6%), per 5% increase in occupancy patients experienced more floor escalation events (odds ratio [OR] 1.29 [95% CI: 1.07, 1.57]). For every 5% increase in turnover, patients experienced more floor escalation events (OR 1.06 [95% CI: 1.01, 1.12]). Conclusions: Occupancy and turnover characterized recognized periods of PICU strain. High occupancy and turnover were associated with more floor escalation events. Multicenter studies are needed to evaluate the generalizability of these findings across other PICUs.