Shock index is better than conventional vital signs for assessing higher level of care and mortality in severe sepsis or shock

Association between the shock index on admission and in-hospital mortality in the cardiac intensive care unit

BACKGROUND

An elevated shock index (SI) predicts worse outcomes in multiple clinical arenas. We aimed to determine whether the SI can aid in mortality risk stratification in unselected cardiac intensive care unit patients.

METHODS

We included admissions to the Mayo Clinic from 2007 to 2015 and stratified them based on admission SI. The primary outcome was in-hospital mortality, and predictors of in-hospital mortality were analyzed using multivariable logistic regression.

RESULTS

We included 9,939 unique cardiac intensive care unit patients with available data for SI. Patients were grouped by SI as follows: < 0.6, 3,973 (40%); 0.6-0.99, 4,810 (48%); and ≥ 1.0, 1,156 (12%). After multivariable adjustment, both heart rate (adjusted OR 1.06 per 10 beats per minute higher; CI 1.02-1.10; p-value 0.005) and systolic blood pressure (adjusted OR 0.94 per 10 mmHg higher; CI 0.90-0.97; p-value < 0.001) remained associated with higher in-hospital mortality. As SI increased there was an incremental increase in in-hospital mortality (adjusted OR 1.07 per 0.1 beats per minute/mmHg higher, CI 1.04-1.10, p-Value < 0.001). A higher SI was associated with increased mortality across all examined admission diagnoses.

CONCLUSION

The SI is a simple and universally available bedside marker that can be used at the time of admission to predict in-hospital mortality in cardiac intensive care unit patients.

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.

A Temperature- and Age-Adjusted Shock Index for Emergency Department Identification of Pediatric Sepsis

OBJECTIVE

To empirically derive a novel temperature- and age-adjusted mean shock index (TAMSI) for early identification of sepsis and septic shock in children with suspected infection.

METHODS

We performed a retrospective cohort study of children aged 1 month to <18 years presenting to a single emergency department with suspected infection over a 10-year period. TAMSI was defined as (pulse rate - 10 × [temperature - 37])/(mean arterial pressure). The primary outcome was sepsis, and the secondary outcome was septic shock. In the two-thirds training set, we determined TAMSI cutoffs for each age group using a minimum sensitivity of 85% and Youden Index. In the one-third validation data set, we calculated test characteristics for the TAMSI cutoffs and compared them with those for the Pediatric Advanced Life Support (PALS) tachycardia or systolic hypotension cutoffs.

RESULTS

In the sepsis validation data set, the sensitivity-targeting TAMSI cutoff yielded a sensitivity of 83.5% (95% confidence interval [CI] 81.7% to 85.4%) and specificity of 42.8% (95% CI 42.4% to 43.3%) versus a sensitivity of 77.7% (95% CI 75.7% to 79.8%) and specificity of 60.0% (95% CI 59.5% to 60.4%) for PALS. For septic shock, the sensitivity-targeting TAMSI cutoff achieved a sensitivity of 81.3% (95% CI 75.2% to 87.4%) and a specificity of 83.5% (95% CI 83.2% to 83.8%) versus a sensitivity of 91.0% (95% CI 86.5% to 95.5%) and a specificity of 58.8% (95% CI 58.4% to 59.3%) for PALS. TAMSI yielded an increased positive likelihood ratio and similar negative likelihood ratio versus PALS.

CONCLUSIONS

TAMSI achieved a similar negative likelihood ratio and improved positive likelihood ratio compared with PALS vital sign cutoffs for the prediction of septic shock, but it did not improve on PALS for sepsis prediction, among children with suspected infection.

Shock Index for the Prediction of Interventions and Mortality in Patients With Blunt Thoracic Trauma

INTRODUCTION

Shock index (SI) is a bedside simple scoring tool; however, it has not yet been tested in blunt thorax trauma (BTT). We sought to evaluate the prognostic value of SI for chest interventions (thoracostomy tube or thoracotomy), blood transfusion, and mortality in patients with BTT. We hypothesized that high SI is associated with worse outcomes in patients with BTT.

METHODS

We conducted a retrospective analysis of all BTT patients (chest Abbreviated Injury Score [AIS] > 1) hospitalized in a level 1 trauma center between 2011 and 2020. Patients with AIS >1 for head or abdominal injuries and patients undergoing open reduction and internal fixation surgery or penetrating injuries were excluded. Patients were categorized into two groups (low SI <0.80 versus high SI ≥0.80) based on the receiver operating characteristic curve analysis. Multivariable regression analysis was performed to identify the predictors of mortality.

RESULTS

A total of 1645 patients were admitted with BTT; of them, 24.5% had high SI. The mean age was 39.2 ± 15.2 y, and most were males (91%). Patients with high SI were younger, had sustained severer injuries, and required more chest interventions (P = 0.001), blood transfusion (P = 0.001), and massive transfusion protocol activation (P = 0.001) compared with low SI group. The overall in-hospital mortality rate was 2.6%, which was more in the high SI group (8.2% versus 0.8%; P = 0.001). SI significantly correlated with age (r = -0.281), injury severity score (r = 0.418), Glasgow Come Score on arrival (r = -0.377), Trauma and Injury Severity Score (r = -0.144), Revised Trauma Score (r = -0.219), serum lactate (r = 0.434), blood transfusion units (r = 0.418), and chest AIS (r = 0.066). SI was an independent predictor of mortality (odds ratio 3.506; 95% confidence interval 1.389-8.848; P = 0.008), and this effect persisted after adjustment for chest intervention (odds ratio 2.923; 95% confidence interval 1.146-7.455; P = 0.02).

CONCLUSIONS

The present study highlights the prognostic value of SI as a rapid bedside tool to predict the use of interventions and the risk of mortality in patients with BTT. The study findings help the emergency physicians for early and appropriate risk stratification and triaging of patients with BTT.