135 - Shock Index as a Predictive Metric for In-Hospital Outcomes in the Pediatric Population

Publication Number: 135.6634

Rohan Bhargava, Northwestern University The Feinberg School of Medicine, Chicago, IL, United States; Jillian Gorski, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States; Remle P.. Crowe, ESO, Austin, TX, United States; Christian Martin-Gill, UPMC, Pittsburgh, PA, United States; Sriram Ramgopal, Ann & Robert H. Lurie Children's Hospital of Chicago, Oak Park, IL, United States

Background: Trauma is the leading cause of mortality among children in the United States. Existing pediatric trauma activation criteria highlight the need for more accurate triage approaches. Various criteria have suggested a role for the Shock Index (SI), defined as the heart rate divided by the systolic blood pressure, in improving the triage of injured children.

Objective: To evaluate the association between differing criteria of the prehospital SI and in-hospital outcomes in injured children.

Design/Methods: We conducted a retrospective cross-sectional analysis of injured children ( < 18 years) from a multi-agency prehospital electronic record system between 2018 and 2022. We evaluated three criteria for the SI: Shock Index Pediatric Age-Adjusted (SIPA), Pediatric Shock Index (PSI), and criteria derived from Z-scored cutpoints (Table 1). We analyzed the association of the first-measured prehospital SI with in-hospital outcomes of mortality, admission, and elevated Injury Severity Score (ISS >15) using measures of diagnostic accuracy and univariable logistic regression.

Results: We identified 49,079 injured children with in-hospital data (median age 13 years [IQR 8-16]). Most encounters were from urban areas (93.6%, Table 2). Overall, 24.1%, 14.4%, and 20.2% of encounters were classified as abnormal when using the SIPA, PSI, and z-score derived cutpoints, respectively. An abnormal SI according to both SIPA and PSI was associated with increased mortality (OR 2.50 [95% CI 1.65-3.75] and 3.88 [95% CI 2.63-5.69], respectively). The z-score criteria was associated with higher odds of mortality for both elevated (OR 4.57 [95% CI 3.02-6.86]) and depressed (OR 5.03 [95% CI 2.66-8.16], Table 3). An abnormal SI using any criteria was associated with admission (SIPA: 1.38 [95% CI 1.28-1.49], PSI: 1.75 [1.62-1.88], elevated z-score: 1.76 [95% CI 1.62-1.90], depressed z-score: 1.41 [95% CI 1.26-1.57]). Only a depressed z-score-based SI (OR 1.40 [95% CI 1.26-1.57]) was associated with elevated ISS. For all in-hospital outcomes, all SI criteria demonstrated poor sensitivity (39.4-54.3% for mortality, 21.6-29.6% for admission, 14.5-24.4% for elevated ISS).

Conclusion(s): The prehospital SI is associated with in-hospital mortality and admission. However, all criteria demonstrated limited diagnostic accuracy for in-hospital outcomes. Additional research is needed to identify indicators to improve the triage of injured children.

Table 1.
Shock Index Criteria.

Table 2.
Demographic Characteristics of the Study Sample.

Table 3.
Statistical and diagnostic analyses of each SI criterion in relation to each outcome. Numbers in parenthesis represent 95% confidence intervals.