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Deriving shock index pediatric age-adjusted thresholds to predict need for emergent intervention
Zachary T Sheff1, Brett W Engbrecht2
1Eli Lilly and Company, 893 Delaware St., Indianapolis, IN 46225, USA.
Insights
The Shock Index Pediatric Age-Adjusted (SIPA) has established thresholds for identifying pediatric shock. Empirically derived SIPA cutoffs show similar accuracy to established ones, but overall predictive accuracy remains low for broad outcomes.
Area of Science:
- Pediatric Emergency Medicine
- Trauma Care
- Clinical Prediction Models
Background:
- The Shock Index (SI) is used to identify patients at risk for severe injury.
- Shock Index Pediatric Age-Adjusted (SIPA) modifies SI thresholds based on age.
- Established SIPA thresholds exist, but empirical validation is needed.
Purpose of the Study:
- To empirically derive optimal age-adjusted shock index (SIPA) cutoffs for pediatric patients.
- To compare the accuracy of empirically derived SIPA cutoffs with established SIPA thresholds.
- To evaluate the utility of SIPA in predicting the need for emergent intervention in pediatric trauma.
Main Methods:
- Analysis of a large pediatric patient dataset (n=484,586) from 2013-2020.
- Utilized the Area Under the Receiver-Operator Characteristic Curve (AUROC) to determine optimal age-specific cutoffs.
- Defined emergent intervention as specific procedures or ICU admission within 24 hours.
Main Results:
- Empirically derived SIPA cutoffs were similar to established thresholds across pediatric age groups.
- Both empirical and established cutoffs demonstrated low overall accuracy in predicting emergent intervention.
- Sensitivity and specificity showed trade-offs, with established cutoffs having higher specificity but lower sensitivity.
Conclusions:
- Empirically derived SIPA cutoffs align with established values but have limited overall accuracy for broad predictions.
- SIPA may be more effective in predicting specific outcomes, such as the need for urgent blood transfusion.
- Further research is needed to refine SIPA's utility in pediatric trauma assessment.
Background:
Shock index (SI) has been used to identify patients at risk for severe injury and predict those who require an emergent intervention. In adults, SI > 0.9 is considered elevated. Shock index pediatric age-adjusted (SIPA) modifies this threshold based on patients' age. This analysis leverages a large dataset to empirically identify threshold values of SI using a composite outcome capturing patients' need for emergent intervention.
Methods:
Pediatric patient data was abstracted from the Trauma Quality Improvement Program Participant Use Files from 2013 - 2020. 484,586 patients were included in the analysis. Area under the receiver-operator characteristic curve (AUROC) was used to empirically derive optimal cutoffs by age group. Need for emergent intervention included craniotomy, thoracotomy, laparotomy, chest tube, angioembolization, endotracheal intubation, and blood transfusion within 24 h of arrival or use of mechanical ventilation or admission to an intensive care unit.
Results:
Empirically derived SIPA-E cutoffs (1.23, 1.05, 0.95, and 0.85 for ages 1-3, 4-6, 7-12, and 13-17 years, respectively) were similar to established SIPA-L cutoffs (1.22, 1.22, 1.00, and 0.90). Overall accuracy was consistent between the two cutoffs with nearly equal trades of sensitivity for specificity but remain low overall (empirical cutoff sensitivity = 33.8 %, specificity = 79.5 %; established cutoff sensitivity = 26.5 %, specificity = 86.8 %).
Conclusions:
Empirically derived cutoffs agreed with established cutoffs for SIPA, but overall accuracy is low. Rather than predicting broad outcomes, SIPA seems better suited to narrow cases where it has shown greater accuracy, such as the need for urgent blood transfusion.
Level Of Evidence:
Prognostic/epidemiological; Level III.
