Predictive value of the shock index (SI) compared to the age-adjusted pediatric shock index (SIPA) for identifying children that needed the highest-level trauma activation based on the presence of consensus criteria

Centiles for the shock index among injured children in the prehospital setting

OBJECTIVE

The shock index (SI), the ratio of heart rate to systolic blood pressure, is a clinical tool for assessing injury severity. Age-adjusted SI models may improve predictive value for injured children in the out-of-hospital setting. We sought to characterize the proportion of children in the prehospital setting with an abnormal SI using established criteria, describe the age-based distribution of SI among injured children, and determine prehospital interventions by SI.

METHODS

We performed a multi-agency retrospective cross-sectional study of children (<18 years) in the prehospital setting with a scene encounter for suspected trauma and transported to the hospital between 2018 and 2022 using the National Emergency Medical Services (EMS) Information System datasets. Our exposure of interest was the first calculated SI. We identified the proportion of children with an abnormal SI when using the SI, pediatric age-adjusted (SIPA); and the pediatric SI (PSI) criteria. We developed and internally validated an age-based distributional model for the SI using generalized additive models for location, scale, and shape to describe the age-based distribution of the SI as a centile or Z-score. We evaluated EMS interventions (basic airway interventions, advanced airway interventions, cardiac interventions, vascular access, intravenous fluids, and vasopressor use) in relation to both the SIPA, PSI, and distributional SI values.

RESULTS

We analyzed 1,007,863 pediatric EMS trauma encounters (55.0% male, median age 13 years [IQR, 8-16 years]). The most common dispatch complaint was for traffic/transport related injury (32.9%). When using the PSI and SIPA, 13.1% and 16.3% were classified as having an abnormal SI, respectively. There were broad differences in the percentage of encounters classified as having an abnormal SI across the age range, varying from 5.1 to 22.8% for SIPA and 3.7-20.1% for PSI. The SIPA values ranged from the 75th to 95th centiles, while the PSI corresponded to an SI greater than the 90th centile, except in older children. The centile distribution for SI declined during early childhood and stabilized during adolescence and demonstrated a difference of <0.1% at cutoff values. An abnormal PSI, SIPA and higher SI centiles (>90th centile and >95th centiles) were associated with interventions related to basic and advanced airway management, cardiac procedures, vascular access, and provision of intravenous fluids occurred with greater frequency at higher SI centiles. Some procedures, including airway management and vascular access, had a smaller peak at lower (<10th) centiles.

DISCUSSION

We describe the empiric distribution of the pediatric SI across the age range, which may overcome limitations of extant criteria in identifying patients with shock in the prehospital setting. Both high and low SI values were associated with important, potentially lifesaving EMS interventions. Future work may allow for more precise identification of children with significant injury using cutpoint analysis paired to outcome-based criteria. These may additionally be combined with other physiologic and mechanistic criteria to assist in triage decisions.

Admission to a Verified Pediatric Trauma Center is Associated With Improved Outcomes in Severely Injured Children

BACKGROUND

Previous studies have shown improved survival for severely injured adult patients treated at American College of Surgeons verified level I/II trauma centers compared to level III and undesignated centers. However, this relationship has not been well established in pediatric trauma centers (PTCs). We hypothesize that severely injured children will have lower mortality at verified level I/II PTCs compared to centers without PTC verification.

METHODS

All patients 1-15 years of age with ISS >15 in the 2017-2019 American College of Surgeons Trauma Quality Programs (ACS TQP) dataset were reviewed. Patients with pre-hospital cardiac arrest, burns, and those transferred out for ongoing inpatient care were excluded. Logistic regression models were used to assess the effects of pediatric trauma center verification on mortality.

RESULTS

16,301 patients were identified (64 % male, median ISS 21 [17-27]), and 60 % were admitted to verified PTCs. Overall mortality was 6.0 %. Mortality at centers with PTC verification was 5.1 % versus 7.3 % at centers without PTC verification (p < 0.001). After controlling for injury mechanism, sex, age, pediatric-adjusted shock index (SIPA), ISS, arrival via interhospital transfer, and adult trauma center verification, pediatric level I/II trauma center designation was independently associated with decreased mortality (OR 0.72, 95 % CI 0.61-0.85).

CONCLUSIONS

Treatment at ACS-verified pediatric trauma centers is associated with improved survival in critically injured children. These findings highlight the importance of PTC verification in optimizing outcomes for severely injured pediatric patients and should influence trauma center apportionment and prehospital triage.

LEVEL OF EVIDENCE

Level IV - Retrospective review of national database.

Comparison of age-adjusted shock indices as predictors of injury severity in paediatric trauma patients immediately after emergency department triage: A report from the Korean multicentre registry

INTRODUCTION

Shock index paediatric-adjusted (SIPA) was presented for early prediction of mortality and trauma team activation in paediatric trauma patients. However, the derived cut-offs of normal vital signs were based on old references. We established alternative SIPAs based on the other commonly used references and compared their predictive values.

METHODS

We performed a retrospective review of all paediatric trauma patients aged 1-15 years in the Emergency Department (ED)-based Injury In-depth Surveillance (EDIIS) database from January 1, 2011 to December 31, 2019. A total of 4 types of SIPA values were obtained based on the references as follows: uSIPA based on the Nelson textbook of paediatrics 21st ed., SIATLS based on the ATLS 10th guideline, SIPALS based on the PALS 2020 guideline, and SIPA. In each SIPA group, the cut-off was established by dividing the group into 4 subgroups: toddler (age 1-3), preschooler (age 4-6), schooler (age 7-12), and teenager (age 13-15). We performed an ROC analysis and calculated the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) to compare the predicted values of each SIPA in mortality, ICU admission, and emergent surgery or intervention.

RESULTS

A total of 332,271 patients were included. The proportion of patients with an elevated shock index was 14.9 % (n = 49,347) in SIPA, 22.8 % (n = 75,850) in uSIPA, 0.3 % (n = 1058) in SIATLS, and 4.3 % (n = 14,168) in SIPALS. For mortality, uSIPA achieved the highest sensitivity (57.0 %; 95 % confidence interval 56.9 %-57.2 %) compared to SIPA (49.4 %, 95 % CI 49.2 %-49.5 %), SIATLS (25.5 %, 95 % CI 25.4 %-25.7 %), and SIPALS (43.8 %, 95 % CI 43.7 %-44.0 %), but there were no significant differences in the negative predictive value (NPV) or area under the curve (AUC). The positive predictive value (PPV) was highest in SIATLS (5.7 %, 95 % CI 5.6 %-5.8 %) compared to SIPA (0.2 %, 95 % CI 0.2 %-0.3 %), uSIPA (0.2 %, 95 % CI 0.2 %-0.2 %), and SIPALS (0.7 %, 95 % CI 0.7 %-0.8 %). The same findings were presented in ICU admission and emergent operation or intervention.

CONCLUSION

The ATLS-based shock index achieved the highest PPV and specificity compared to SIPA, uSIPA, and SIPALS for adverse outcomes in paediatric trauma.

Comparison of Pediatric Trauma Scoring Tools That Incorporate Neurological Status for Trauma Team Activation

BACKGROUND

Two novel pediatric trauma scoring tools, SIPAB+ (defined as elevated SIPA with Glasgow Coma Scale ≤8) and rSIG (reverse Shock Index multiplied by Glasgow Coma Scale and defined as abnormal using cutoffs for early outcomes), which combine neurological status with Pediatric Age-Adjusted Shock Index (SIPA), have been shown to predict early trauma outcomes better than SIPA alone. We sought to determine if one more accurately identifies children in need of trauma team activation.

METHODS

Patients 1 to 18 years old from the 2014-2018 Pediatric Trauma Quality Improvement Program database were included. Sensitivity and specificity for SIPAB+ and rSIG were calculated for components of pediatric trauma team activation, based on criteria standard definitions.

RESULTS

There were 11,426 patients (1.9%) classified as SIPAB+ and 235,672 (39.0%) as having an abnormal rSIG. SIPAB+ was consistently more specific, with specificities exceeding 98%, but its sensitivity was poor (<30%) for all outcomes. In comparison, rSIG was a more sensitive tool, with sensitivities exceeding 60%, and specificity values exceeded 60% for all outcomes.

CONCLUSIONS

Trauma systems must determine their priorities to decide how best to incorporate SIPAB+ and rSIG into practice, although rSIG may be preferred as it balances both sensitivity and specificity.

LEVEL OF EVIDENCE

Level III.

Pediatric trauma smackdown: PTS vs SIPA

BACKGROUND

Different scoring tools aid prediction of pediatric trauma patients' prognosis but there's no consensus on when to apply each. Pediatric Trauma Score (PTS) was one of the first tools developed. Shock Index Pediatric Adjusted (SIPA) adapts Shock Index (SI) in predicting outcomes adjusted for age. It is unclear if either scoring tool is better at predicting outcomes.

OBJECTIVE

To compare SIPA and PTS for level I and II pediatric traumas to determine if both are equally effective in predicting outcomes for pediatric trauma patients.

DESIGN/METHODS

This is a retrospective review of patients 1-17 years with level 1 and 2 activated trauma (1/2013 - 11/2019).

OUTCOMES OF INTEREST

disposition, length of stay, ventilator use, moderate/major spleen/liver lacerations, and Index Severity Score (ISS). Patient visits were scored using both scores and placed into high/low risk category as predefined by the individual scoring tools: High risk SIPA, low risk SIPA, high risk PTS, low risk PTS.

RESULTS

There were 750 patients who met inclusion criteria, 35 visits scored high with both tools and 543 visits scored low. The odds ratio (OR) for each tool showed high risk scores were more likely to be associated with increased likelihood of outcomes. When both high-risk groups were compared, PTS had an increased OR for most outcomes. SIPA had an increased OR for receiving fluid bolus.

CONCLUSION

This study externally validates both scoring tools for the same cohort. Both tools were reliable predictors, but PTS identifies more "high risk" visits. PTS requires more variables to calculate than SIPA. SIPA may be an effective way to triage when resources are scarce. However, there's still a need for a pediatric trauma triage score that can encompass the accuracy of PTS and the convenience of SIPA.

Adding age-adjusted shock index to the American College of Surgeons' trauma team activation criteria to predict severe injury in children

BACKGROUND

The American College of Surgeons (ACS) requires trauma centers to use six minimum criteria (ACS-6) for full trauma team activation. Our goal was to evaluate the effect of adding age-adjusted shock index (SI) to the ACS-6 for the prediction of severe injury among pediatric trauma patients with the hypothesis that SI would significantly improve sensitivity with an acceptable decrease in specificity.

METHODS

We performed a secondary analysis of prospectively collected EMS and trauma registry data from two urban pediatric trauma centers. Age-adjusted SI thresholds were calculated as heart rate divided by systolic blood pressure using 2020 Pediatric Advanced Life Support SI vital sign ranges and previously published Shock Index, Pediatric Adjusted (SIPA) thresholds. The primary outcome was a composite of emergency operative (within 1 hour of arrival) or emergency procedural intervention (EOPI) or Injury Severity Score (ISS) greater than 15. Sensitivities, specificities, and 95% CIs were calculated for the ACS-6 alone and in combination with age-adjusted SI.

RESULTS

There were 8,078 patients included; 20% had an elevated age-adjusted SI and 17% met at least one ACS minimum criterion; 1% underwent EOPI; and 17% had ISS >15. Sensitivity and specificity of the ACS-6 for EOPI or ISS > 5 were 45% (95% confidence interval [CI], 41-50%) and 89% (95% CI, 81-96%). Inclusion of Pediatric Advanced Life Support-SI and SIPA resulted in sensitivities of 51% (95% CI, 47-56%) and 69% (95% CI, 65-72%), and specificities of 80% (95% CI, 71-89%) and 60% (95% CI, 53-68%), respectively. Similar trends were seen for each secondary outcome.

CONCLUSION

In this cohort of pediatric trauma registry patients, the addition of SIPA to the ACS-6 for trauma team activation resulted in significantly increased sensitivity for EOPI or ISS greater than 15 but poor specificity. Future investigation should explore using age-adjusted shock index in a two-tiered trauma activation system, or in combination with novel triage criteria, in a population-based cohort.

LEVEL OF EVIDENCE

Diagnostic Tests or Criteria; Level II.

Pediatric age-adjusted shock index as a tool for predicting outcomes in children with or without traumatic brain injury

BACKGROUND

The pediatric age-adjusted shock index (SIPA) accurately identifies severely injured children following trauma without accounting for neurological status. Understanding how the presence of traumatic brain injury (TBI) affects the generalizability of SIPA as a bedside triage tool is important given high rates of TBI in the pediatric trauma population. We hypothesized that SIPA combined with TBI (SIPAB+) would more accurately identify severely injured children.

METHODS

Patients (1-18 years old) in the American College of Surgeons Pediatric Trauma Quality Improvement Program database (2014-2017) with an elevated SIPA upon arrival to a pediatric trauma center were included. Pediatric age-adjusted shock index combined with TBI was defined as elevated SIPA with Glasgow Coma Scale score of ≤8. Pediatric age-adjusted shock index without TBI (SIPAB-) was defined as elevated SIPA with Glasgow Coma Scale score of >9. Patients were stratified into SIPAB+ and SIPAB-. A subanalysis of patients with isolated brain injury and those with brain injury and multisystem injuries was also performed. Data were compared through univariate models and three separate logistic regression models.

RESULTS

Overall, 25,068 had an elevated SIPA, with 12.3% classified as SIPAB+ and the remainder SIPAB-. Patients classified as SIPAB+ received more blood transfusions within 4 hours of injury and had higher mortality rates. On logistic regression, SIPAB+ patients had significantly higher odds of early blood transfusion and a combination of both. Mortality and early blood transfusion were also higher in SIPAB+ patients on subanalysis for patients with isolated TBI and those with multisystem injuries.

CONCLUSION

The use of SIPAB+ as a bedside triage tool accurately identifies traumatically injured children at high risk for early blood transfusion and/or death while incorporating the presence of neurological injury. This is true for patients with isolated TBI and those with multisystem injury, indicating its utility in predicting outcomes for TBI patients with elevated SIPA regardless of presence of concomitant injuries. Incorporation of this as a triage tool should be considered to better predict resources in this population.

LEVEL OF EVIDENCE

Prognostic, level III.