Correlation of shock index and modified shock index with the outcome of adult trauma patients: a prospective study of 9860 patients

Association of Shock Indices with Peri-Intubation Hypotension and Other Outcomes: A Sub-Study of the KEEP PACE Trial

BACKGROUND

Based on current evidence, there appears to be an association between peri-intubation hypotension and patient morbidity and mortality. Studies have identified shock indices as possible pre-intubation risk factors for peri-intubation hypotension. Thus, we sought to evaluate the association between shock index (SI), modified shock index (MSI), and diastolic shock index (DSI) and peri-intubation hypotension along with other outcomes.

METHODS

The present study is a sub-study of a randomized controlled trial involving critically ill patients undergoing intubation. We defined peri-intubation hypotension as a decrease in mean arterial pressure <65 mm Hg and/or a reduction of 40% from baseline; or the initiation of, or increase in infusion dosage of, any vasopressor medication (bolus or infusion) during the 30-min period following intubation. SI, MSI, and DSI were analyzed as continuous variables and categorically using pre-established cut-offs. We also explored the effect of age on shock indices.

RESULTS

A total of 151 patients were included in the analysis. Mean pre-intubation SI was 1.0  ±  0.3, MSI 1.5  ±  0.5, and DSI 1.9  ±  0.7. Increasing SI, MSI, and DSI were significantly associated with peri-intubation hypotension (OR [95% CI] per 0.1 increase  =  1.16 [1.04, 1.30], P  =  .009 for SI; 1.14 [1.05, 1.24], P  =  .003 for MSI; and 1.11 [1.04, 1.19], P  =  .003 for DSI). The area under the ROC curves did not differ across shock indices (0.66 vs 0.67 vs 0.69 for SI, MSI, and DSI respectively; P  =  .586). Increasing SI, MSI, and DSI were significantly associated with worse sequential organ failure assessment (SOFA) score (spearman rank correlation: r  =  0.30, r  =  0.40, and r  =  0.45 for SI, MSI, and DSI, respectively, all P < .001) but not with other outcomes. There was no significant impact when incorporating age.

CONCLUSIONS

Increasing SI, MSI, and DSI were all significantly associated with peri-intubation hypotension and worse SOFA scores but not with other outcomes. Shock indices remain a useful bedside tool to assess the potential likelihood of peri-intubation hypotension.

TRIAL REGISTRATION

ClinicalTrials.gov identifier - NCT02105415.

Establishing thresholds for shock index in children to identify major trauma

BACKGROUND

An abnormal shock index (SI) is associated with greater injury severity among children with trauma. We sought to empirically-derive age-adjusted SI cutpoints associated with major trauma in children, and to compare the accuracy of these cutpoints to existing criteria for pediatric SI.

METHODS

We performed a retrospective cohort study using the 2021 National Trauma Data Bank (NTDB) Participant Use File. We included injured children (<18 years), excluding patients with traumatic arrests, mechanical ventilation upon hospital presentation, and inter-facility transfers. Our outcome was major trauma defined by the standardized triage assessment tool (STAT) criteria. Our exposure of interest was the SI. We empirically-derived upper and lower cutpoints for the SI using age-adjusted Z-scores. We compared the performance of these to the SI, pediatric-adjusted (SIPA), and the Pediatric SI (PSI). We validated the performance of the cutpoints in the 2019 NTDB.

RESULTS

We included 64,326 and 64,316 children in the derivation and validation samples, of whom 4.9 % (derivation) and 4.0 % (validation) experienced major trauma. The empirically-derived age-adjusted SI cutpoints had a sensitivity of 43.2 % and a specificity of 79.4 % for major trauma in the validation sample. The sensitivity of the PSI for major trauma was 33.9 %, with a specificity of 90.7 % among children 1-17 years of age. The sensitivity of the SIPA was 37.4 %, with a specificity of 87.8 % among children 4-16 years of age. Evaluated using logistic regression, patients with an elevated age-adjusted SI had 3.97 greater odds (95 % confidence interval [CI] 3.63-4.33) of major trauma compared to those with a normal age-adjusted SI. Patients with a depressed SI had 1.55 greater odds (95 % CI 1.36-1.78) of major trauma. The area under the receiver operator characteristic curve (AUROC) for the empirically-derived model (0.62, 95 % CI 0.61-0.63) was similar to the AUROC for PSI (0.62, 95 % CI 0.61-0.63); both of which were greater than the SIPA model (0.58, 95 % CI 0.57-0.59).

CONCLUSION

Age-adjusted SI cutpoints demonstrated a mild gain in sensitivity compared to existing measures. However, our findings suggest that the SI alone has a limited role in the identification of major trauma in children.

Tools for Screening, Predicting, and Evaluating Sepsis and Septic Shock: A Comprehensive Review

Sepsis is characterized by life-threatening organ dysfunction due to dysregulated host response to infection. It can progress to cause circulatory and cellular/metabolic abnormalities, resulting in septic shock that may significantly increase mortality. The pathophysiology of sepsis involves a complex interplay of invading pathogens and the body's immune defense, causing alteration in normal homeostasis, eventually leading to derangements in the cellular, humoral, circulatory, and metabolic functions. Several scoring systems have been developed to rapidly predict or suspect sepsis, such as Sequential Organ Failure Assessment (SOFA), modified SOFA (mSOFA), quick SOFA (qSOFA), shock index (SI), and modified SI (mSI). Each of these scores has been utilized for triaging patients with sepsis, and as per medical advancements these scoring systems have been modified to include or exclude certain criteria to improve their clinical utility. This review aims to compare the individual scores and their usage for sepsis that may be used for laying the foundation for early recognition and prediction of sepsis and for formulating more precise definitions in the future.

Use of Shock Index, Modified Shock Index, and Age-Adjusted Shock Index for Detection of Postpartum Hemorrhage

PURPOSE

The aim of this study is to evaluate the role of shock index (SI), modified shock index (MSI), and delta shock index (ΔSI) in predicting postpartum hemorrhage (PPH) and adverse maternal outcomes.

MATERIAL AND METHODS

In this cross-sectional cohort study, a study group consisting of 416 pregnant women who delivered at our hospital and had postpartum hemorrhage was compared with 467 control patients with normal follow-up. SI (pulse/systolic blood pressure), MSI (pulse/mean arterial pressure), ΔSI (input SI - 2nd- or 6th-hour SI) values were calculated.

RESULTS

A total of 883 postpartum women were included in the study. The study group had higher peripartum, 2nd-hour, and 6th-hour SI values (p=0.011, p=0.001, p<0.001, respectively). Peripartum MSI values (p=0.004), 2nd-hour MSI values (p<0.001), and 6th-hour MSI values (p<0.001) were significantly lower in the control group than in the PPH group. When the groups were evaluated, the cut-off value of the 2nd-hour SI parameter was>0.8909 (sensitivity 30%, specificity 84%), and the 6th-hour SI parameter was>0.8909 (sensitivity 40%, specificity 80%) for predicting postpartum hemorrhage requiring blood transfusion and surgical intervention. The cut-off value of the 2nd-hour MSI parameter was>1.2 (sensitivity 34%, specificity 82%), and the cut-off value of the 6th-hour MSI parameter was>1.2652 (sensitivity 32%, specificity 90%).

CONCLUSION

The 2nd- and 6th-hour SI and 2nd- and 6th-hour MSI values were significantly higher in patients with postpartum hemorrhage. Values greater than 0.89 for SI and 1.2 for MSI were considered significant for predicting postpartum hemorrhage with maternal impairment.

An Assessment of Clinical Accuracy of Vital Sign-based Triage Tools Among U.S. and Coalition Forces

INTRODUCTION

Early appropriate allocation of resources for critically injured combat casualties is essential. This is especially important when inundated with an overwhelming number of casualties where limited resources must be efficiently allocated, such as during mass casualty events. There are multiple scoring systems utilized in the prehospital combat setting, including the shock index (SI), modified shock index (MSI), simple triage and rapid treatment (START), revised trauma score (RTS), new trauma score (NTS), Glasgow Coma Scale + age + pressure (GAP), and the mechanism + GAP (MGAP) score. The optimal score for application to the combat trauma population remains unclear.

MATERIALS AND METHODS

This is a secondary analysis of a previously described dataset from the Department of Defense Trauma Registry from January 1, 2007 through March 17, 2020. We constructed univariable analyses to determine the area under the receiving operator characteristic (AUROC) for the scoring systems of interest. Our primary outcomes were early death (within 24 hours) or early massive transfusion, as defined by ≥3 units.

RESULTS

There were 12,268 casualties that met inclusion criteria. There were 168 (1%) who died within the first 24 hours and 2082 (17%) that underwent significant transfusion within the first 24 hours. When assessing the predictive capabilities for death within 24 hours, the AUROCs were 0.72 (SI), 0.69 (MSI), 0.89 (START), 0.90 (RTS), 0.83 (NTS), 0.90 (GAP), and 0.91 (MGAP). The AUROCs for massive transfusion were 0.89 (SI), 0.89 (MSI), 0.82 (START), 0.81 (RTS), 0.83 (NTS), 0.85 (MGAP), and 0.86 (GAP).

CONCLUSIONS

This study retrospectively applied seven triage tools to a database of 12,268 cases from the Department of Defense Trauma Registry to evaluate their performance in predicting early death or massive transfusion in combat. All scoring systems performed well with an AUROC >0.8 for both outcomes. Although the SI and MSI performed best for predicting massive transfusion (both had an AUROC of 0.89), they ranked last for assessment of mortality within 24 hours, with the other tools performing well. START, RTS, NTS, MGAP and GAP reliably identified early death and need for massive transfusion, with MGAP and GAP performing the best overall. These findings highlight the importance of assessing triage tools to best manage resources and ultimately preserve lives of traumatically wounded warfighters. Further studies are needed to explain the surprising performance discrepancy of the SI and MSI in predicting early death and massive transfusion.

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.

Shock index to predict outcomes in patients with trauma following traffic collisions: a retrospective cohort study

PURPOSE

Taiwan, which has a rate of high vehicle ownership, faces significant challenges in managing trauma caused by traffic collisions. In Taiwan, traffic collisions contribute significantly to morbidity and mortality, with a high incidence of severe bleeding trauma. The shock index (SI) and the modified shock index (MSI) have been proposed as early indicators of hemodynamic instability. In this study, we aimed to assess the efficacy of SI and MSI in predicting adverse outcomes in patients with trauma following traffic collisions.

METHODS

This retrospective cohort study was conducted at Chi Mei Hospital from January 2015 to December 2020. The comprehensive analysis included 662 patients, with data collected on vital signs and outcomes such as mortality, blood transfusion, emergent surgical intervention (ESI), transarterial embolization (TAE), and intensive care unit (ICU) admission. Optimal cutoff points for SI and MSI were identified by calculating the Youden index. Logistic regression analysis was used to assess outcomes, adjusting for demographic and injury severity variables.

RESULTS

An SI threshold of 1.11 was associated with an increased risk of mortality, while an SI of 0.84 predicted the need for blood transfusion in the context of traffic collisions. Both SI and MSI demonstrated high predictive power for mortality and blood transfusion, with acceptable accuracy for TAE, ESI, and ICU admission. Logistic regression analyses confirmed the independence of SI and MSI as risk factors for adverse outcomes, thus, providing valuable insights into their clinical utility.

CONCLUSIONS

SI and MSI are valuable tools for predicting mortality and blood transfusion needs in patients with trauma due to traffic collisions. These findings advance the quality of care for patients with trauma during their transition from the emergency room to the ICU, facilitating prompt and reliable decision-making processes and improving the care of patients with trauma.

Early Vital Sign Thresholds Associated with 24-Hour Mortality among Trauma Patients: A Trauma Quality Improvement Program (TQIP) Study

BACKGROUND

Identifying patients at imminent risk of death is critical in the management of trauma patients. This study measures the vital sign thresholds associated with death among trauma patients.

METHODS

This study included data from patients ≥15 years of age in the American College of Surgeons Trauma Quality Improvement Program (TQIP) database. Patients with vital signs of zero were excluded. Documented prehospital and emergency department (ED) vital signs included systolic pressure, heart rate, respiratory rate, and calculated shock index (SI). The area under the receiver operator curves (AUROC) was used to assess the accuracy of these variables for predicting 24-hour survival. Optimal thresholds to predict mortality were identified using Youden's Index, 90% specificity, and 90% sensitivity. Additional analyses examined patients 70+ years of age.

RESULTS

There were 1,439,221 subjects in the 2019-2020 datasets that met inclusion for this analysis with <0.1% (10,270) who died within 24 hours. The optimal threshold for prehospital systolic pressure was 110, pulse rate was 110, SI was 0.9, and respiratory rate was 15. The optimal threshold for the ED systolic was 112, pulse rate was 107, SI was 0.9, and respiratory rate was 21. Among the elderly sub-analysis, the optimal threshold for prehospital systolic was 116, pulse rate was 100, SI was 0.8, and respiratory rate was 21. The optimal threshold for ED systolic was 121, pulse rate was 95, SI was 0.8, and respiratory rate was 0.8.

CONCLUSIONS

Systolic blood pressure (SBP) and SI offered the best predictor of mortality among trauma patients. The SBP values predictive of mortality were significantly higher than the traditional 90mmHg threshold. This dataset highlights the need for better methods to guide resuscitation as initial vital signs have limited accuracy in predicting subsequent mortality.

Shock indices are associated with in-hospital mortality among patients with septic shock and normal left ventricular ejection fraction

BACKGROUND

The understanding of shock indices in patients with septic shock is limited, and their values may vary depending on cardiac function.

METHODS

This prospective cohort study was conducted across 20 university-affiliated hospitals (21 intensive care units [ICUs]). Adult patients (≥19 years) with septic shock admitted to the ICUs during a 29-month period were included. The shock index (SI), diastolic shock index (DSI), modified shock index (MSI), and age shock index (Age-SI) were calculated at sepsis recognition (time zero) and ICU admission. Left ventricular (LV) function was categorized as either normal LV ejection fraction (LVEF ≥ 50%) or decreased LVEF (<50%).

RESULTS

Among the 1,194 patients with septic shock, 392 (32.8%) who underwent echocardiography within 24 h of time zero were included in the final analysis (normal LVEF: n = 246; decreased LVEF: n = 146). In patients with normal LVEF, only survivors demonstrated significant improvement in SI, DSI, MSI, and Age-SI values from time zero to ICU admission; however, no notable improvements were found in all patients with decreased LVEF. The completion of vasopressor or fluid bundle components was significantly associated with improved indices in patients with normal LVEF, but not in those with decreased LVEF. In multivariable analysis, each of the four indices at ICU admission was significantly associated with in-hospital mortality (P < 0.05) among patients with normal LVEF; however, discrimination power was better in the indices for patients with lower lactate levels (≤ 4.0 mmol/L), compared to those with higher lactate levels.

CONCLUSIONS

The SI, DSI, MSI, and Age-SI at ICU admission were significantly associated with in-hospital mortality in patients with septic shock and normal LVEF, which was not found in those with decreased LVEF. Our study emphasizes the importance of interpreting shock indices in the context of LV function in septic shock.

Comparison of Modified Shock Index and Shock Index for Predicting Massive Transfusion in Women with Primary Postpartum Hemorrhage: A Retrospective Study

BACKGROUND The modified shock index (MSI) is calculated as the ratio of heart rate (HR) to mean arterial pressure (MAP) and has been used to predict the need for massive transfusion (MT) in trauma patients. This retrospective study from a single center aimed to compare the MSI with the traditional shock index (SI) to predict the need for MT in 612 women diagnosed with primary postpartum hemorrhage (PPH) at the Emergency Department (ED) between January 2004 and August 2023. MATERIAL AND METHODS The patients were divided into the MT group and the non-MT group. The predictive power of MSI and SI was compared using the areas under the receiver operating characteristic curve (AUC). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value were calculated. RESULTS Out of 612 patients, 105 (17.2%) required MT. The MT group had higher median values than the non-MT group for MSI (1.58 vs 1.07, P<0.001) and SI (1.22 vs 0.80, P<0.001). The AUC for MSI, with a value of 0.811 (95% confidence interval [CI], 0.778-0.841), did not demonstrate a significant difference compared to the AUC for SI, which was 0.829 (95% CI, 0.797-0.858) (P=0.066). The optimal cutoff values for MSI and SI were 1.34 and 1.07, respectively. The specificity and PPV for MT were 77.1% and 40.2% for MSI, and 83.2% and 45.9% for SI. CONCLUSIONS Both MSI and SI were effective in predicting MT in patients with primary PPH. However, MSI did not demonstrate superior performance to SI.

Shock and modified shock indices in predicting poisoning severity and outcomes in acute aluminum phosphide poisoned patients

Background

Severe refractory hypotension and cardiogenic shock are the main contributors to death in acute aluminum phosphide (ALP) poisoning. Shock index (SI) and modified shock index (MSI) are easily obtained parameters that reflect shock at an early stage.

Aim

This study aimed to evaluate the role of SI and MSI in the prediction of the severity and outcomes of acute ALP poisoned patients.

Patients and methods

This cross sectional study was conducted on patients admitted to Tanta University Poison Control Centre with acute ALP poisoning from April 2022 to March 2023. Socio-demographics and toxicological data were taken, findings of clinical examination and laboratory investigations were recoded, SI was calculated by dividing heart rate over systolic blood pressure, and MSI was obtained by dividing heart rate over mean arterial pressure. Poisoning severity was assessed using poisoning severity score (PSS). Patients were divided into groups according to intensive care unit (ICU) admission and mortality.

Results

The study enrolled 94 patients. The median values of SI and MSI were significantly higher in ICU-admitted patients and non-survivors rather than their comparable groups. Significant positive correlations were observed between each of SI and MSI and PSS. At cut-off >1.14, SI conveyed fair performance to predict ICU admission and mortality (AUC = 0.710 and 0.739, respectively). Similarly, MSI had fair performance to predict ICU admission (AUC = 0.731) and mortality (AUC = 0.744) at cut-off >1.47 and >1.5, respectively.

Conclusion

Both SI and MSI could be considered simple bedside adjuncts to predict ICU admission and mortality in acute ALP poisoning.

Is the shock index correlated with blood loss? An experimental study on a controlled hemorrhagic shock model in piglets

INTRODUCTION

The quantification of blood loss in a severe trauma patient allows prognostic quantification and the engagement of adapted therapeutic means. The Advanced Trauma Life Support classification of hemorrhagic shock, based in part on hemodynamic parameters, could be improved. The search for reproducible and non-invasive parameters closely correlated with blood depletion is a necessity. An experimental model of controlled hemorrhagic shock allowed us to obtain hemodynamic and echocardiographic measurements during controlled blood spoliation. The primary aim was to demonstrate the correlation between the Shock Index (SI) and blood depletion volume (BDV) during the hemorrhagic phase of an experimental model of controlled hemorrhagic shock in piglets. The secondary aim was to study the correlations between blood pressure (BP) values and BDV, SI and cardiac output (CO), and pulse pressure (PP) and stroke volume during the same phase.

METHODS

We analyzed data from 66 anesthetized and ventilated piglets that underwent blood spoliation at 2 mL.kg-1.min-1 until a mean arterial pressure (MAP) of 40 mmHg was achieved. During this bleeding phase, hemodynamic and echocardiographic measurements were performed regularly.

RESULTS

The correlation coefficient between the SI and BDV was 0.70 (CI 95%, [0.64; 0.75]; p < 0.01), whereas between MAP and BDV, the correlation coefficient was -0.47 (CI 95%, [-0.55; -0.38]; p < 0.01). Correlation coefficient between SI and CO and between PP and stroke volume were - 0.45 (CI 95%, [-0.53; -0.37], p < 0.01) and 0.62 (CI 95%, [0.56; 0.67]; p < 0.01), respectively.

CONCLUSIONS

In a controlled hemorrhagic shock model in piglets, the correlation between SI and BDV seemed strong.

Complementary value of the Shock Index v. the Modified Shock Index in the prediction of in-hospital intensive care unit admission and mortality: A single-centre experience

Background

Shock is a state of circulatory insufficiency that creates an imbalance between tissue oxygen supply and demand, resulting in end-organ dysfunction and hypodynamic circulatory failure. Most patients with infectious and trauma-related illnesses present to the emergency department (ED) in shock.

Objectives

To study the usefulness of the shock index (SI) and modified shock index (MSI) in identifying and triaging patients in shock presenting to the ED.

Methods

This was a year-long observational, cross-sectional study of 290 patients presenting to the ED of a tertiary hospital in compensated or overt shock. The SI and MSI were calculated at the time of first contact, and then hourly for the initial 3 hours. Relevant background investigations targeting the cause of shock and prognostic markers were done. The outcome measures of mortality and intensive care unit admission were documented for each participant.

Results

The mean age of the participants was 49 years, and 67% of them were men. In consensus with local and national data, the major medical comorbidities were hypertension (20%) and diabetes mellitus (16%). An SI ≥0.9 and an MSI ≥1.3 predicted in-hospital mortality (p<0.05) and ICU admission (p<0.05) with no significant superiority of the MSI over the SI in terms of mortality, although the MSI was a better surrogate marker for critical care admission.

Conclusion

The study showed the complementary value of the SI and MSI in triage in a busy tertiary hospital ED, surpassing their components such as blood pressure, heart rate and pulse pressure. We determined useful cut-offs for these tools for early risk assessment in the ED, and larger multicentre studies are needed to support our findings.

Study synopsis

What the study adds. The study highlights the usefulness of clinical bedside tools such as the shock index (SI) and modified shock index (MSI) in triaging patients in the emergency department, and their role in predicting morbidity and mortality.Implications of the findings. Compared with systolic blood pressure, diastolic blood pressure and mean arterial pressure, alone or in combination, the SI and MSI had higher sensitivity and specificity in terms of outcome prediction. While both an elevated SI and an elevated MSI predicted in-hospital mortality, the MSI was a better surrogate marker for ICU admission.

Prehospital shock index predicts 24-h mortality in trauma patients with a normal shock index upon emergency department arrival

BACKGROUND

The shock index (heart rate divided by systolic blood pressure) of trauma patients upon emergency department arrival predicts blood loss and death. However, some patients with normal shock indices (0.4 < shock index <0.9) upon emergency department arrival also have poor prognoses. This study aimed to determine whether abnormal prehospital shock indices in trauma patients with normal shock indices upon emergency department arrival were predictors of a high risk of mortality.

METHODS

We conducted a retrospective cohort study of emergency department-admitted trauma patients from 2004 to 2017. The study included 89,495 consecutive trauma patients aged ≥16 years, with Abbreviated Injury Scale score of ≥3, who were transported to the emergency department directly from the field and had a normal shock index upon emergency department arrival. According to the prehospital shock index scores, the patients were categorized into low shock index (≤ 0.4), normal shock index, and high shock index (≥0.9) groups. Odds ratios and 95% confidence intervals were calculated using logistic regression analysis.

RESULTS

The 89,495 patients had a median age of 64 (interquartile range: 43-79) years, and 55,484 (62.0%) of the patients were male. There were 1350 (1.5%) 24-h deaths in total; 176/4263 (4.1%), 1017/78,901 (1.3%), and 157/6331 (2.5%) patients were in the low, normal, and high prehospital shock index groups, respectively. The adjusted odds ratios for 24-h mortality compared with the normal shock index group were 1.63 (95% confidence interval: 1.34-1.99) in the low shock index group and 1.62 (95% confidence interval: 1.31-1.99) in the high shock index group.

CONCLUSION

Trauma patients with abnormal prehospital shock indices but normal shock indices upon emergency department arrival are at a higher risk of 24-h mortality. Identifying these indices could improve triage and targeted care for patients.

Discriminant ability of the shock index, modified shock index, and reverse shock index multiplied by the Glasgow coma scale on mortality in adult trauma patients: a PATOS retrospective cohort study

BACKGROUND

The shock index (SI) predicts short-term mortality in trauma patients. Other shock indices have been developed to improve discriminant accuracy. The authors examined the discriminant ability of the SI, modified SI (MSI), and reverse SI multiplied by the Glasgow Coma Scale (rSIG) on short-term mortality and functional outcomes.

METHODS

The authors evaluated a cohort of adult trauma patients transported to emergency departments. The first vital signs were used to calculate the SI, MSI, and rSIG. The areas under the receiver operating characteristic curves and test results were used to compare the discriminant performance of the indices on short-term mortality and poor functional outcomes. A subgroup analysis of geriatric patients with traumatic brain injury, penetrating injury, and nonpenetrating injury was performed.

RESULTS

A total of 105 641 patients (49±20 years, 62% male) met the inclusion criteria. The rSIG had the highest areas under the receiver operating characteristic curve for short-term mortality (0.800, CI: 0.791-0.809) and poor functional outcome (0.596, CI: 0.590-0.602). The cutoff for rSIG was 18 for short-term mortality and poor functional outcomes with sensitivities of 0.668 and 0.371 and specificities of 0.805 and 0.813, respectively. The positive predictive values were 9.57% and 22.31%, and the negative predictive values were 98.74% and 89.97%. rSIG also had better discriminant ability in geriatrics, traumatic brain injury, and nonpenetrating injury.

CONCLUSION

The rSIG with a cutoff of 18 was accurate for short-term mortality in Asian adult trauma patients. Moreover, rSIG discriminates poor functional outcomes better than the commonly used SI and MSI.

Modified Shock Index as a Predictor of Admission and In-hospital Mortality in Emergency Departments; an Analysis of a US National Database

Introduction

The modified shock index (MSI) is the ratio of heart rate to mean arterial pressure. It is used as a predictive and prognostic marker in a variety of disease states. This study aimed to derive the optimal MSI cut-off that is associated with increased likelihood (likelihood ratio, LR) of admission and in-hospital mortality in patients presenting to emergency department (ED).

Methods

We retrospectively reviewed data from the National Hospital Ambulatory Medical Care Survey between 2005 and 2010. Adults>18 years of age were included regardless of chief complaint. Basic patient demographics, initial vital signs, and outcomes were recorded for each patient. Then the optimal MSI cut-off for prediction of admission and in-hospital mortality in ED was calculated. LR ≥ 5 was considered clinically significant.

Results

567,994,402 distinct weighted adult ED patient visits were included in the analysis. 15.7% and 2.4% resulted in admissions and in-hospital mortality, respectively. MSI > 1.7 was associated with a moderate increase in the likelihood of both admission (Positive LR (+LR) = 6.29) and in-hospital mortality (+LR = 5.12). +LR for hospital admission at MSI >1.7 was higher for men (7.13; 95% CI 7.11-7.15) compared to women (5.49; 95% CI 5.47-5.50) and for non-white (7.92; 95% CI 7.88-7.95) compared to white patients (5.85; 95% CI 5.84-5.86). For MSI <0.7, the +LRs were not clinically significant for admission (+LR = 1.07) or in-hospital mortality (LR = 0.75).

Conclusion

In this largest retrospective study, to date, on MSI in the undifferentiated ED population, we demonstrated that an MSI >1.7 on presentation is predictive of admission and in-hospital mortality. The use of MSI could help guide accurate acuity designation, resource allocation, and disposition.

C-reactive Protein/Albumin Ratio as a Prognostic Indicator in Posttraumatic Shock and Outcome of Multiple Trauma Patients

OBJECTIVE

C-reactive protein (CRP)/albumin ratio (CAR) is a new inflammation-based index for predicting the prognosis of various diseases. The CAR determined on admission may help to predict the prognostic value of multiple trauma patients.

METHODS

A total of 264 adult patients with severe multiple trauma were included for the present retrospective study, together with the collection of relevant clinical and laboratory data. CAR, CRP, albumin, shock index and ISS were incorporated into the prognostic model, and the receiver operating characteristic (ROC) curve was drawn. Then, the shock index for patients with different levels of CAR was analyzed. Finally, univariate and multivariate logistic regression analyses were performed to identify the independent risk factors for the 28-day mortality of multiple trauma patients.

RESULTS

A total of 36 patients had poor survival outcomes, and the mortality rate reached 13.6%. Furthermore, after analyzing the shock index for patients with different levels of CAR, it was revealed that the shock index was significantly higher when CAR was ≥4, when compared to CAR <2 and 2≤ CAR <4, in multiple trauma patients. The multivariate logistic analysis helped to identify the independent association between the variables CAR (P=0.029) and shock index (P=0.019), and the 28-day mortality of multiple trauma patients.

CONCLUSION

CAR is higher in patients with severe multiple trauma. Furthermore, CAR serves as a risk factor for independently predicting the 28-day mortality of multiple trauma patients. The shock index was significantly higher when CAR was ≥4 in multiple trauma patients.

A Comparative Study on Predictive Validity of Modified Shock Index, Shock Index, and Age Shock Index in Predicting the Need for Mechanical Ventilation among Sepsis Patients in a Tertiary Care Hospital

Introduction

The shock index (SI), modified shock index (MSI), and age multiplied by SI (ASI) are used to assess the severity of shock. They are also used to predict the mortality of trauma patients, but their validity for sepsis patients is controversial. The aim of this study is to assess the predictive value of the SI, MSI, and ASI in predicting the need for mechanical ventilation after 24 h of admission among sepsis patients.

Methods

A prospective observational study was conducted in a tertiary care teaching hospital. Patients with sepsis (235) diagnosed based on systemic inflammatory response syndrome criteria and quick sequential organ failure assessment were included in the study. The need for mechanical ventilation after 24 h is the outcome variables MSI, SI, and ASI were considered as predictor variables. The utility of MSI, SI, and ASI in predicting mechanical ventilation was assessed by receiver operative curve analysis. Data were analyzed using coGuide.

Results

Among the study population, the mean age was 56.12 ± 17.28 years. MSI value at the time of disposition from the emergency room had good predictive validity in predicting mechanical ventilation after 24 h, as indicated by the area under the curve (AUC) of 0.81 (P < 0.001), SI and ASI had fair predictive validity for mechanical ventilation as indicated by AUC (0.78, P < 0.001) and (0.802, P < 0.001), respectively.

Conclusion

SI had better sensitivity (78.57%) and specificity (77.07%) compared to ASI and MSI in predicting the need for mechanical ventilation after 24 h in sepsis patients admitted to intensive care units.

Shock index and modified shock index are predictors of long-term mortality not only in STEMI but also in NSTEMI patients

BACKGROUND

Shock index (SI) and modified shock index (mSI) are useful instruments for early risk stratification in acute myocardial infarction (AMI) patients. They are strong predictors for short-term mortality. Nevertheless, the association between SI or mSI and long-term mortality in AMI patients has not yet been sufficiently examined.

MATERIAL AND METHODS

For this study, a total of 10,174 patients with AMI was included. All cases were prospectively recorded by the population-based Augsburg Myocardial Infarction Registry from 2000 until 2017. Endpoint was all-cause mortality with a median observational time of 6.5 years [IQR: 3.5-7.4]. Using ROC analysis and calculating Youden-Index, the sample was dichotomized into a low and a high SI and mSI group, respectively. Moreover, multivariable adjusted COX regression models were calculated. All analyses were performed for the total sample as well as for STEMI and NSTEMI cases separately.

RESULTS

Optimal cut-off values were 0.580 for SI and 0.852 for mSI (total sample). AUC values were 0.6382 (95% CI: 0.6223-0.6549) for SI and 0.6552 (95% CI: 0.6397-0.6713) for mSI. Fully adjusted COX regression models revealed significantly higher long-term mortality for patients with high SI and high mSI compared to patients with low indices (high SI HR: 1.42 [1.32-1.52], high mSI HR: 1.46 [1.36-1.57]). Furthermore, the predictive ability was slightly better for mSI compared to SI and more reliable in NSTEMI cases compared to STEMI cases (for SI and mSI).

CONCLUSION

High SI and mSI are useful tools for early risk stratification including long-term outcome especially in NSTEMI cases, which can help physicians to make decision on therapy. NSTEMI patients with high SI and mSI might especially benefit from immediate invasive therapy.Key messagesShock index and modified shock index are predictors of long-term mortality after acute myocardial infarction.Both indices predict long-term mortality not only for STEMI cases, but even more so for NSTEMI cases.

Multifactorial Shock: A Neglected Situation in Polytrauma Patients

Background: Shock after traumatic injury is likely to be hypovolemic, but different types of shock (distributive shock, obstructive shock, or cardiogenic shock) can occur in combination, known as multifactorial shock. Multifactorial shock is a neglected area of study, and is only reported sporadically. Little is known about the incidence, characteristics, and outcomes of multifactorial shock after polytrauma. Methods: A retrospective, observational, multicenter study was conducted in four Level I trauma centers involving 1051 polytrauma patients from June 2020 to April 2022. Results: The mean Injury Severity Score (ISS) was 31.1, indicating a severely injured population. The most common type of shock in the early phase after polytrauma (≤48 h) is hypovolemic shock (83.2%), followed by distributive shock (14.4%), obstructive shock (8.7%), and cardiogenic shock (3.8%). In the middle phase after polytrauma (>48 h or ≤14 days), the most common type of shock is distributive shock (70.7%), followed by hypovolemic shock (27.2%), obstructive shock (9.9%), and cardiogenic shock (7.2%). Multifactorial shock accounted for 9.7% of the entire shock population in the early phase and 15.2% in the middle phase. In total, seven combinations of multifactorial shock were described. Patients with multifactorial shock have a significantly higher complication rate and mortality than those with single-factor shock. Conclusions: This study characterizes the incidence of various types of shock in different phases after polytrauma and emphasizes that different types of shock can occur simultaneously or sequentially in polytrauma patients. Multifactorial shock has a relatively high incidence and mortality in polytrauma patients, and trauma specialists should be alert to the possibility of their occurrence.

Evaluation of SI, MSI and DSI for very early (3-day) mortality in patients with septic shock

BACKGROUND

Septic shock is associated with increased mortality. Predicting mortality, including early prediction for septic shock patients in intensive care units (ICUs), remains an important challenge.

METHOD

We searched the Medical Information Mart for Intensive Care IV database. Odds ratios (ORs) with 95% confidence intervals (CIs) of the relationships between shock index (SI), modified SI (MSI), and diastolic SI (DSI) of patients with septic shock requiring vasopressors and 3-day/in-hospital mortality were calculated using logistic regression models. The time-course changes of these parameters were compared between survivors and non-survivors. The performance of the different parameters was described by the area under the receiver operating characteristic (ROC) curve (AUC) and compared with DeLong analysis.

RESULTS

A total of 1266 patients with septic shock requiring vasopressors were identified. The 3-day mortality rate and in-hospital mortality rate were 8.7% and 23.5%, respectively. Multivariable logistic regression analysis showed significant associations between pre-vasopressor SI/MSI/DSI and 3-day mortality in patients with septic shock requiring vasopressors in fully adjusted models (Ps for trend < 0.01). The AUCs of pre-vasopressor SI, MSI, and DSI were 0.746, 0.710, and 0.732 for 3-day mortality, respectively. There were significant differences in the time-course of SI, MSI, and DSI between survivors and non-survivors at 3-day/in-hospital mortality among patients with septic shock requiring vasopressors (repeated-measures ANOVA, inter-subjects difference P < 0.001).

CONCLUSION

Pre-vasopressor SI, MSI, and DSI values identified patients with septic shock requiring vasopressors who are at increased risk of early death. Of these easy-to-acquire values, SI and MSI show a comparatively better performance.

Heart rate and diastolic arterial pressure in cardiac arrest patients: A nationwide, multicenter prospective registry

Background

Guidelines have recommended monitoring mean arterial pressure (MAP) and systolic arterial pressure (SAP) in cardiac arrest patients, but there has been relatively little regard for diastolic arterial pressure (DAP) and heart rate (HR). We aimed to determine the prognostic significance of hemodynamic parameters at all time points during targeted temperature management (TTM).

Methods

We reviewed the SAP, DAP, MAP, and HR data in out-of-hospital cardiac arrest (OHCA) survivors from the prospective multicenter registry of 22 teaching hospitals. This study included 1371 patients who underwent TTM among 10,258 cardiac arrest patients. The hemodynamic parameters were recorded every 6 hours from the return of spontaneous circulation (ROSC) to 4 days. The risks of those according to time points during TTM were compared.

Results

Of the included patients, 943 (68.8%) had poor neurological outcomes. The predictive ability of DAP surpassed that of SAP and MAP at all time points, and among the hemodynamic variables HR/DAP was the best predictor of the poor outcome. The risks in patients with DAP < 55 to 70 mmHg and HR > 70 to 100 beats/min were steeply increased for 2 days after ROSC and correlated with the poor outcome at all time points. Bradycardia showed lower risks only at 6 hours to 24 hours after ROSC.

Conclusion

Hemodynamic parameters should be intensively monitored especially for 2 days after ROSC because cardiac arrest patients may be vulnerable to hemodynamic instability during TTM. Monitoring HR/DAP can help access the risks in cardiac arrest patients.

The relationship between age shock index, and severity of stroke and in-hospital mortality in patients with acute ischemic stroke

BACKGROUND

Shock index (SI) has been reported to help us predict adverse prognosis in patients with acute ischemic stroke (AIS). However, the prognostic value of age SI and age modified shock index (MSI) in acute ischemic stroke is unknown. In our study, we aimed to examine the association between the severity of the stroke and in-hospital mortality, age SI and age MSI in patients with AIS.

METHODS

A total of 256 patients were enrolled in this study. The National Institutes of Health Stroke Scale (NIHSS) was used to determine the severity of stroke. Patients were divided into two groups according to the NIHSS score calculated during hospitalization (NIHSS>14: severe disability group, NIHSS<15: moderate and mild disability group). Shock indexes were calculated using the blood pressure and heart rate values measured as a result of the cardiovascular examinations of the patients. We looked for correlations between increased NIHSS and in-hospital mortality with age shock index and age modified shock index.

RESULTS

Age SI and age MSI values were higher in the severe disability group than those without severe disability, and the results were statistically significant (p<0.001, p<0.001, respectively). Also, a positive correlation was determined between the height of NIHSS and the age SI and the age MSI (p=0.002, r=0.197, p=0.001, r=0.215, respectively). Thirty-two (12.5%) of 256 patients included in the study died during hospitalization. Patients who died were older (77.1±11.0 vs. 67.5±13.5, respectively; p<0.001). According to Point-Biserial correlation analysis, there was a positive correlation between mortality and age SI, and age MSI (p<0.001, r=0.258 ve p<0.001, r=0.274, respectively).

CONCLUSIONS

As a result of our study, the relationship between stroke severity and increasing age SI and age MSI was significant and there was a positive correlation. In addition, there was a significant and positive relationship between in-hospital mortality and age SI and age MSI.

Modified Shock Index as Simple Clinical Independent Predictor of In-Hospital Mortality in Acute Coronary Syndrome Patients: A Retrospective Cohort Study

Introduction

Despite being the current most accurate risk scoring system for predicting in-hospital mortality for patients with acute coronary syndrome (ACS), the Global Registry of Acute Coronary Events (GRACE) risk score is time consuming due to the requirement for electrocardiography and laboratory examinations. This study is aimed to evaluate the association between modified shock index (MSI), as a simple and convenient index, with in-hospital mortality and revascularization in hospitalized patients with ACS.

Methods

A single-centered, retrospective cohort study, involving 1,393 patients with ACS aged ≥ 18 years old, was conducted between January 2018 and January 2022. Study subjects were allocated into two cohorts: high MSI ≥ 1 (n = 423) and low MSI < 1 group (n = 970). The outcome was in-hospital mortality and revascularization. The association between MSI score and interest outcomes was evaluated using binary logistic regression analysis. The area under the curve (AUC) between MSI and GRACE score was compared using De Long’s method.

Results

Modified shock index ≥ 1 had 61.1% sensitivity and 73.7% specificity. A high MSI score was significantly and independently associated with in-hospital mortality in patients with ACS [odds ratio (OR) = 2.72(1.6–4.58), p < 0.001]. However, ST-segment elevation myocardial infarction (STEMI) and non-STEMI (NSTEMI) patients with high MSI did not significantly increase the probability of revascularization procedures. Receiver operating characteristic (ROC) analysis demonstrated that although MSI and GRACE scores were both good predictors of in-hospital mortality with the AUC values of 0.715 (0.666–0.764) and 0.815 (0.775–0.855), respectively, MSI was still inferior as compared to GRACE scores in predicting mortality risk in patients with ACS (p < 0.001).

Conclusion

Modified shock index, particularly with a score ≥ 1, was a useful and simple parameter for predicting in-hospital mortality in patients presenting with ACS.

Prognostic Performance of Shock Index, Diastolic Shock Index, Age Shock Index, and Modified Shock Index in COVID-19 Pneumonia

OBJECTIVE

We aimed to compare the prognostic accuracy of shock indexes in terms of mortality in patients hospitalized with coronavirus disease 2019 (COVID-19) pneumonia.

METHODS

Hospitalized patients whose COVID-19 reverse transcriptase-polymerase chain reaction (RT-PCR) test results were positive, had thoracic computed tomography (CT) scan performed, and had typical thoracic CT findings for COVID-19 were included in the study.

RESULTS

Eight hundred one patients were included in the study. Chronic obstructive pulmonary disease, congestive heart failure, chronic neurological diseases, chronic renal failure, and a history of malignancy were found to be chronic diseases that were significantly associated with mortality in patients with COVID-19 pneumonia. White blood cell, neutrophil, lymphocyte, C reactive protein, creatinine, sodium, aspartate aminotransferase, alanine aminotransferase, total bilirubin, high sensitive troponin, d-dimer, hemoglobin, and platelet had a statistically significant relationship with in-hospital mortality in patients with COVID-19 pneumonia. The area under the curve (AUC) values of shock index (SI), age shock index (aSI), diastolic shock index (dSI), and modified shock index (mSI) calculated to predict mortality were 0.772, 0.745, 0.737, 0.755, and Youden Index J (YJI) values were 0.523, 0.396, 0.436, 0.452, respectively.

CONCLUSIONS

The results of this study show that SI, dSI, mSI, and aSI are effective in predicting in-hospital mortality.

Modified Shock Index as a Predictor for Mortality and Hospitalization Among Patients With Dementia

BACKGROUND

One in four older adults in the Emergency Department (ED) suffers from severe cognitive impairment, creating great difficulty for the emergency physicians who determine the urgency of their patients' condition, which informs decisions regarding discharge or hospitalization.

OBJECTIVE

Our objective was to determine whether modified shock index (MSI) can be a clinical mortality and hospitalization predictor when applied to older patients with dementia in the ED.

METHODS

Included in the research were all patients with dementia, > 65 years old, who arrived at the Soroka University Medical Center ED during 2014-2017. The population was divided into three groups according to their MSI score, calculated as heart rate/mean arterial pressure: MSI < 0.7; 0.7 > MSI < 1.3; and MSI > 1.3. We performed multivariable logistic regression as a predictor of death within 30 days, Cox analysis for number of days to death, and a negative binominal regression for predicting the number of admission days.

RESULTS

Included were 1437 patients diagnosed with dementia. Patients with an MSI > 1.3 vs. those with MSI < 0.7 had an odds ratio of 8.23 (95% confidence interval [CI] 4.64-4.54) for mortality within 30 days, increased mortality risk within 180 days (hazard ratio 4.42; 95% CI 2.64-7.41), and longer hospitalization duration (incidence rate ratio 1.8; 95% CI 1.32-2.45).

CONCLUSIONS

High MSI scores were associated with high mortality rates and longer hospitalization duration for patients diagnosed with dementia who were > 65 years old. We suggest performing prospective studies utilizing the MSI score as an indicator in ED triage settings to classify patients with dementia by their severity of risk, to determine if this benefits health, minimizes expenses, and prevents unnecessary hospitalizations.

Predicting morbidity and mortality in Australian paediatric trauma with the Paediatric Age-Adjusted Shock Index and Glasgow Coma Scale

BACKGROUND

Paediatric age-adjusted shock index (SIPA) has emerged as a predictor of morbidity and mortality in trauma. Poor sensitivity and low generalisability demonstrated in previous studies have limited its use. We evaluate the use of SIPA in the general Australian paediatric trauma population and the combination of SIPA with GCS.

METHODS

All patients from January 2015 to August 2020 at a major Australian paediatric trauma centre were reviewed. Pre-arrival SIPA (pSIPA) and arrival SIPA (aSIPA) were calculated. If SIPA was elevated or the Glasgow Coma Scale ≤ 13, SIPA with mental state (SIPAms) was marked positive for pre-arrival (pSIPAms) and arrival (aSIPAms) respectively.

RESULTS/DISCUSSION

Data from 480 patients were analysed. pSIPA and aSIPA poorly predicted outcomes of morbidity. Only aSIPA predicted mortality. However, both pre-arrival and arrival SIPAms variables predict mortality, major trauma (ISS≥12), hospital LOS, need for ICU admission, and major surgery. Furthermore, median ISS and lactate were significantly higher in positive pSIPA, aSIPA, pSIPAms, and aSIPAms groups than negative. aSIPAms has a sensitivity of 76% and specificity of 70% for major trauma.

CONCLUSION

Broad inclusion criteria reduce SIPA's ability to predict morbidity. Combining it with GCS improves this and is most valuable when calculated at arrival. In addition, the score is more reliable for major trauma (ISS≥12). Future studies should evaluate the use of SIPAms in activation criteria.

Shock index as a predictor for mortality in trauma patients: a systematic review and meta-analysis

PURPOSE

The primary aim was to determine whether a shock index (SI) ≥ 1 in adult trauma patients was associated with increased in-hospital mortality compared to an SI < 1.

METHODS

This systematic review including a meta-analysis was performed in accordance with the PRISMA guidelines. EMBASE, MEDLINE, and Cochrane Library were searched, and two authors independently screened articles, performed the data extraction, and assessed risk of bias. Studies were included if they reported in-hospital, 30-day, or 48-h mortality, length of stay, massive blood transfusion or ICU admission in trauma patients with SI recorded at arrival in the emergency department or trauma center. Risk of bias was assessed using the Newcastle-Ottawa Scale, and the strength and quality of the body of evidence according to GRADE. Data were pooled using a random effects model. Inter-rater reliability was assessed with Cohen's kappa.

RESULTS

We screened 1350 citations with an inter-rater reliability of 0.90. Thirty-eight cohort studies were included of which 14 reported the primary outcome. All studies reported a significant higher in-hospital mortality in adult trauma patients with an SI ≥ 1 compared to those having an SI < 1. Twelve studies involving a total of 348,687 participants were included in the meta-analysis. The pooled risk ratio (RR) of in-hospital mortality was 4.15 (95% CI 2.96-5.83). The overall quality of evidence was low.

CONCLUSIONS

This systematic review found a fourfold increased risk of in-hospital mortality in adult trauma patients with an initial SI ≥ 1 in the emergency department or trauma center.

Shock Index in COVID Era

The health care burden and risks to health care workers imposed by novel coronavirus disease 2019 (COVID-19) mandated the need for a simple, noninvasive, objective, and parsimonious risk stratification system predicting the level of care, need for definitive airway, and titration of the ongoing patient care. Shock index (SI = heart rate/systolic blood pressure) has been evaluated in emergency triage, sepsis, and trauma settings including different age group of patients. The ever accumulating girth of evidences demonstrated a superior predictive value of SI over other hemodynamic parameters. Inclusion of respiratory and/or neurological parameters and adjustment of the cutoffs appropriate to patient age increase the predictability in the trauma and sepsis scenario. Being reproducible, dynamic, and simple, SI can be a valuable patient risk stratification tool in this ongoing era of COVID-19 pandemic.

Prognostic utility of shock index and modified shock index on long-term mortality in acute decompensated heart failure; Persian Registry of cardioVascular diseasE/Heart Failure (PROVE/HF) study

BACKGROUND

Shock index (SI) and modified SI (MSI) are used for prognosis in patients with cardiovascular diseases (CVDs), especially myocardial infarction. However, the utility of these indices in heart failure(HF) is less frequently investigated. We aimed to evaluate the long-term prognostic capability of SI and MSI among Iranian HF patients.

METHODS

This retrospective cohort study was implemented in the context of the Persian Registry Of cardioVascular diseasE/HF (PROVE/HF). A total of 3896 acute decompensated HF (ADHF) patients were enrolled from March 2016 to March 2020. SI and MSI were assessed at admission. Receiver operating characteristic (ROC) and Kaplan-Meier curves were used to define optimum SI and MSI cut-off points and depict mortality during follow-up, respectively. The association of CVD death according to different SI and MSI cut-off points and quartiles was assessed through univariate and multivariate regression hazard models.

RESULTS

Mean age of participants was 70.22 ± 12.65 years (males: 62.1%). We found 0.66 (sensitivity:62%, specificity: 51%) and 0.87 (sensitivity: 61%, specificity: 51%) as optimised cut-off points for SI and MSI, respectively. Mean follow-up was 10.26 ± 7.5 months and 1110 (28.5%) deaths occurred during this time. Multivariate adjusted models revealed patients had SI ≥ 0.66 or within the third and fourth quartiles had higher likelihood of mortality compared to reference group (hazard ratio(HR): 1.58, 95%CI: 1.39-1.80, p < 0.001, HR: 1.38,95%CI:1.14-1.66, p = 0.001 and HR:2.00,95%CI:1.68-2.38, p < 0.001, respectively). MSI outcomes were similar (MSI ≥ 0.87: HR: 1.52,95%CI: 1.34-1.72, p < 0.001, third quartile (0.89 ≤ MSI < 1.00):HR:1.23,95%CI:1.009-1.50, p = 0.041, fourth quartile (MSI ≥ 1.00): HR: 1.80,95%CI: 1.53-2.13, p < 0.001). Kaplan-Meier curves showed patients with higher SI and MSI cut-off values and quartiles had lower survival rates.

CONCLUSION

Higher SI and MSI values were associated with increased mortality risk, and these two bedside indices could be appropriately considered for long-term prognosis in ADHF patients.

Modified Shock Index as an Indicator for Prognosis Among Sepsis Patients With and Without Comorbidities Presenting to the Emergency Department

OBJECTIVES

Modified shock index (MSI) is a simple bedside tool used in the emergency department. There are a few studies suggesting MSI as a good prognostic indicator than shock index in sepsis patients. However, there is not enough research emphasizing the role of MSI in patients with comorbidities. Hence, this study aims to assess the predictive validity of MSI in predicting the prognosis of sepsis patients with and without co-morbidities.

METHODS

From January to December 2020, a prospective observational study was conducted in a tertiary care teaching hospital. Patients with sepsis diagnosed based on systemic inflammatory response syndrome criteria and quick sequential organ failure assessment (qSOFA) were included. The need for mechanical ventilation and step down from the intensive care unit were outcome variables, MSI was considered as a predictor variable, and co-morbidities as an explanatory variable.

RESULTS

Among people with co-morbidities, the MSI value on arrival to the emergency department had fair predictive validity in predicting the need for mechanical ventilation after 24 hours, as indicated by the area under the curve of 0.749 (95% CI: 0.600-0.897; p-value = 0.002) and a sensitivity of 68.75% in predicting mechanical ventilation after 24 hours (MSI ≥ 1.59). Among people without co-morbidities, the MSI value on arrival to the emergency department had fair predictive validity in predicting the need for mechanical ventilation after 24 hours, as indicated by the area under the curve of 0.879 (95% CI: 0.770-0.988; p-value <0.001) and a sensitivity of 83.33% in predicting the need for mechanical ventilation after 24 hours (MSI ≥ 1.67).

CONCLUSION

MSI can be used as an indicator in predicting the prognosis of sepsis patients in the emergency department. A simple bedside calculation of the MSI can indicate the need for mechanical ventilation and step down from the intensive care unit after 24 hours in patients with co-morbidities and without co-morbidities.

Early Maladaptive Cardiovascular Responses are Associated with Mortality in a Porcine Model of Hemorrhagic Shock

BACKGROUND

Hemorrhage is a leading cause of death on the battlefield. Current methods for predicting hemodynamic deterioration during hemorrhage are of limited accuracy and practicality. During a study of the effects of remote ischemic preconditioning in pigs that underwent hemorrhage, we noticed arrhythmias among all pigs that died before the end of the experiment but not among surviving pigs. The present study was designed to identify and characterize the early maladaptive hemodynamic responses (tachycardia in the presence of hypotension without a corresponding increase in cardiac index or mean arterial blood pressure) and their predictive power for early mortality in this experimental model.

METHODS

Controlled hemorrhagic shock was induced in 16 pigs. Hemodynamic parameters were monitored continuously for 7 h following bleeding. Changes in cardiovascular and laboratory parameters were analyzed and compared between those that had arrhythmia and those that did not.

RESULTS

All animals had similar changes in parameters until the end of the bleeding phase. Six animals developed arrhythmias and died early, while 10 had no arrhythmias and survived longer than 6 h or until euthanasia. Unlike survivors, those that died did not compensate for cardiac output (CO), diastolic blood pressure (DBP), and stroke volume (SV). Oxygen delivery (DO2) and mixed venous saturation (SvO2) remained low in animals that had arrhythmia, while achieving certain measures of recuperation in animals that did not. Serum lactate increased earlier and continued to rise in all animals that developed arrhythmias. No significant differences in hemoglobin concentrations were observed between groups.

CONCLUSIONS

Despite similar initial changes in variables, we found that low CO, DBP, SV, DO2, SvO2, and high lactate are predictive of death in this animal model. The results of this experimental study suggest that maladaptive responses across a range of cardiovascular parameters that begin early after hemorrhage may be predictive of impending death, particularly in situations where early resuscitative treatment may be delayed.

Comparison of shock index-based risk indices for predicting in-hospital outcomes in patients with ST-segment elevation myocardial infarction undergoing percutaneous coronary intervention

Objective

We aimed to determine whether the prognostic value of the shock index (SI) and its derivatives is better than that of the Thrombolysis In Myocardial Infarction risk index (TRI) for predicting adverse outcomes in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI).

Methods

A total of 257 patients with STEMI undergoing primary PCI from January 2018 to June 2019 were analyzed in a retrospective cohort study. The SI, modified shock index (MSI), age SI (age × the SI), age MSI (age × the MSI), and TRI at admission were calculated. Clinical endpoints were in-hospital complications, including all-cause mortality, acute heart failure, cardiac shock, mechanical complications, re-infarction, and life-threatening arrhythmia.

Results

Multivariate analyses showed that a high SI, MSI, age SI, age MSI, and TRI at admission were associated with a significantly higher rate of in-hospital complications. The predictive value of the age SI and age MSI was comparable with that of the TRI (area under the receiver operating characteristic curve: z = 1.313 and z = 0.882, respectively) for predicting in-hospital complications.

Conclusions

The age SI and age MSI appear to be similar to the TRI for predicting in-hospital complications in patients with STEMI undergoing primary PCI.

Use of age shock index in determining severity of illness in patients presenting to the emergency department with gastrointestinal bleeding

OBJECTIVES

This study aimed to make a comparison between classical shock index (SI), modified shock index (MSI), and age shock index (age SI) for predicting critical patients presenting to the emergency department (ED) with gastrointestinal bleeding (GIS).

METHODS

The study, which was planned retrospectively, consisted of patients diagnosed with GIS bleeding at the ED admission. Triage time vital signs were used to calculate SI, MSI, and age SI. These results were compared with intensive care admission, endoscopic/colonoscopic (E/C) intervention, blood transfusion, and mortality criteria, which we define as adverse outcomes.

RESULTS

The study included 151 patients. Seventy-nine (52.32%) of the patients had at least one adverse outcome. Of the 151 patients, 19 (12.58%) had ICU admission, 27 (17.88%) underwent endoscopic/colonoscopic (E/C) intervention, 68 (45.03%) received a blood transfusion, and 6 (3.97%) died. There was a significant difference between patients who had no adverse outcome and those who had at least one adverse outcome in terms of SI, age SI, and MSI. We performed ROC curve analyses to evaluate the diagnostic performances of all indices for predicting adverse outcomes. AUC (area under the curve) values for age SI was the highest (age SI AUC = 0.711, p < 0.001; SI AUC = 0.616; MSI AUC = 0.617). The performance of the age SI was significantly higher than the SI (p = 0.013) and the MSI (p = 0.024) for predicting adverse outcomes. The cut-off value for the age shock index was 45.12.

CONCLUSIONS

In patients with GIS bleeding, age SI, which can be easily calculated in triage, is more significant than SI and MSI for predicting the critical patient.

Prehospital shock index outperforms hypotension alone in predicting significant injury in trauma patients

BACKGROUND

The American College of Surgeons Resources for Optimal Care of the Injured Patient recommends using hypotension, defined as systolic blood pressure ≤90 mm Hg, as an indicator of a full team trauma activation. We hypothesized that an elevated shock index (SI) predicts significant traumatic injuries better than hypotension alone.

METHODS

This is a retrospective cohort study analyzing full team trauma activations between February 2018 and January 2020, excluding transfers and those who had missing values for prehospital blood pressure or heart rate. We reviewed patients' demographics, prehospital and emergency department vitals, injury pattern, need for operation, and clinical outcomes. The primary outcome was rate of significant injury defined as identified injured liver, spleen, or kidney, pelvis fracture, long bone fracture, significant extremity soft tissue damage, hemothorax, or pneumothorax.

RESULTS

Among 544 patients, 82 (15.1%) had prehospital hypotension and 492 had normal blood pressure. Of the patients with prehospital hypotension, 34 (41.5%) had a significant injury. There was no difference in age, gender, medical history, or injury pattern between the two groups. There was no difference between the two groups in rate of serious injury (41.5% vs. 46.1%, NS), need for emergent operation (31.7% vs. 28.1%, NS) or death (20.7% vs. 18.8%, NS). On the other hand, SI ≥1 was associated with increased rate of serious injury (54.6% vs. 43.4%, p=0.04). On a logistic regression analysis, prehospital hypotension was not associated with significant injury or need for emergent operation (OR 0.83, 95% CI 0.51 to 1.33 and OR 1.32, 95% CI 0.79 to 2.25, respectively). SI ≥1 was associated with both increased odds of significant injury and need for emergent operation (OR 1.57, 95% CI 1.01 to 2.44 and OR 1.64, 95% CI 1.01 to 2.66).

DISCUSSION

SI was a better indicator and could replace hypotension to better categorize and triage patients in need of higher level of care.

LEVEL OF EVIDENCE

Prognostic and epidemiologic, level III.

Developing a Low-resource Approach to Trauma Patient Care - Findings from a Nigerian Trauma Registry

Background:

Trauma is a worldwide problem that results in significant morbidity and mortality in developing countries.

Objective:

This study looks at the demography of trauma from data abstracted from a Nigerian trauma registry and considers the peculiarities of a low-resource setting from this perspective.

Methods:

Trauma registry data from January 2013 to June 2014 were analyzed.

Results:

A total of 542 patients were included in the study. The mean age of the patients was 33.43 ± 12.79 years; the median time from injury to arrival at the hospital was 3 h (interquartile range IQR 1 – 5.1 h); three-quarters of the patients sustained their injuries on the road-tricycles were rarely involved in road traffic injuries (RTIs) (6.9% of RTIs) but were used in transporting a third of the patients whose data on means of transportation were captured. There were 15 (2.7%) deaths in the first 24 h period postinjury covered by the study – 13 (86.7%) of these patients had head-and-neck injury. About half of the assault injury (50.5%) was from persons known to the victim. The shock indices suggested that a majority of the patients were not at a high risk of mortality.

Conclusion:

Most of the trauma patients at our hospital were in low- to middle-income categories. The median time to arrival of injured patients was 3 h (IQR 1 – 6 h). Most injuries occurred on the road because of RTIs. The involvement of tricycles in accidents was uncommon, but they were used fairly commonly by lay responders in transporting the injured victim to hospital. A high proportion of assailants were known to the victim. The use of trauma registries provides essential data for prioritizing limited resources and can guide a contextualized approach to reducing trauma and improving trauma patient care.

A Simple Cardiovascular Model for the Study of Hemorrhagic Shock

Hemorrhagic shock is the number one cause of death on the battlefield and in civilian trauma as well. Mathematical modeling has been applied in this context for decades; however, the formulation of a satisfactory model that is both practical and effective has yet to be achieved. This paper introduces an upgraded version of the 2007 Zenker model for hemorrhagic shock termed the ZenCur model that allows for a better description of the time course of relevant observations. Our study provides a simple but realistic mathematical description of cardiovascular dynamics that may be useful in the assessment and prognosis of hemorrhagic shock. This model is capable of replicating the changes in mean arterial pressure, heart rate, and cardiac output after the onset of bleeding (as observed in four experimental laboratory animals) and achieves a reasonable compromise between an overly detailed depiction of relevant mechanisms, on the one hand, and model simplicity, on the other. The former would require considerable simulations and entail burdensome interpretations. From a clinical standpoint, the goals of the new model are to predict survival and optimize the timing of therapy, in both civilian and military scenarios.

Predicting the need for massive transfusion in the prehospital setting

INTRODUCTION

Massive transfusion (MT) prediction scores allowed for the early identification of patients with massive hemorrhage likely to require large volumes of blood products. Despite their utility, very few MT scoring systems have shown promise in the pre-hospital setting due to their complexity and resource limitations.

AREAS COVERED

Pub med database was utilized to identify supporting literature for this review which discusses the importance of blood-based resuscitation and highlights the utility of scoring systems to predict the need of massive transfusion. MTP scoring systems effective in the prehospital setting are specifically discussed.

EXPERT OPINION

Massive transfusions scores are useful in alerting hospitals to the severity of trauma patients and organizing resources necessary for appropriate patient care but should not completely replace clinical . The opportunity exists to extend their use to the pre-hospital setting to allow for even earlier notification and to triage patients to trauma centers best able to treat severely injured.

A Proxy for Detecting IUGR Based on Gestational Age Estimation in a Guatemalan Rural Population

In-utero progress of fetal development is normally assessed through manual measurements taken from ultrasound images, requiring relatively expensive equipment and well-trained personnel. Such monitoring is therefore unavailable in low- and middle-income countries (LMICs), where most of the perinatal mortality and morbidity exists. The work presented here attempts to identify a proxy for IUGR, which is a significant contributor to perinatal death in LMICs, by determining gestational age (GA) from data derived from simple-to-use, low-cost one-dimensional Doppler ultrasound (1D-DUS) and blood pressure devices. A total of 114 paired 1D-DUS recordings and maternal blood pressure recordings were selected, based on previously described signal quality measures. The average length of 1D-DUS recording was 10.43 ± 1.41 min. The min/median/max systolic and diastolic maternal blood pressures were 79/102/121 and 50.5/63.5/78.5 mmHg, respectively. GA was estimated using features derived from the 1D-DUS and maternal blood pressure using a support vector regression (SVR) approach and GA based on the last menstrual period as a reference target. A total of 50 trials of 5-fold cross-validation were performed for feature selection. The final SVR model was retrained on the training data and then tested on a held-out set comprising 28 normal weight and 25 low birth weight (LBW) newborns. The mean absolute GA error with respect to the last menstrual period was found to be 0.72 and 1.01 months for the normal and LBW newborns, respectively. The mean error in the GA estimate was shown to be negatively correlated with the birth weight. Thus, if the estimated GA is lower than the (remembered) GA calculated from last menstruation, then this could be interpreted as a potential sign of IUGR associated with LBW, and referral and intervention may be necessary. The assessment system may, therefore, have an immediate impact if coupled with suitable intervention, such as nutritional supplementation. However, a prospective clinical trial is required to show the efficacy of such a metric in the detection of IUGR and the impact of the intervention.

The ratio of shock index to pulse oxygen saturation predicting mortality of emergency trauma patients

OBJECTIVE

To test the following hypothesis: the ratio of shock index to pulse oxygen saturation can better predict the mortality of emergency trauma patients than shock index.

METHODS

1723 Patients of trauma admitted to the Emergency Department of the First Affiliated Hospital of Soochow University from 1 November 2016 to 30 November 2019 were retrospectively evaluated. We defined SS as the ratio of SI to SPO2, and the mortality of trauma patients in the emergency department as end-point of outcome. We calculated the crude HR of SS and adjusted HR with the adjustment for risk factors including sex, age, revised trauma score (RTS) by Cox regression model. ROC curve analyses were performed to compare the area under the curve (AUC) of SS and SI.

RESULTS

The crude HR of SS was: 4.31, 95%CI (2.89-6.42) and adjusted HR: 3.01, 95%CI(1.86-4.88); ROC curve analyses showed that AUC of SS was higher than that of shock index (SI), and the difference was statistically significant: 0.69, 95%CI(0.55-0.83) vs 0.65, 95%CI (0.51-0.79), P = 0.001.

CONCLUSION

The ratio of shock index to pulse oxygen saturation is good predictor for emergency trauma patients, which has a better prognostic value than shock index.

Factors Associated with Survival After Emergency Department Thoracotomy for Adult Trauma Patients in the United States

BACKGROUND

Emergency department thoracotomy (EDT) is done to control life threatening hemorrhage and injuries. Literature examining this topic is limited to relatively small studies from single trauma centers.

OBJECTIVE

This study identifies factors associated with survival to hospital discharge of patients undergoing EDT using the largest U.S. national trauma database.

METHODS

This retrospective cohort study used the U.S. National Trauma Data Bank 2015. We conducted univariate and bivariate analyses followed by a multivariate analysis that adjusted for confounders to identify factors associated with survival.

RESULTS

Two thousand four hundred eighty-six patients who underwent EDT were included. Most patients were 16 to 64 years of age (92.3%) with a male predominance (84.9%) and without any previous comorbidities (62.8%). Penetrating injury was most common (60.2%), mainly as a result of assault (51.0%) by firearm (45.1%). Overall survival to hospital discharge was 38.2%. After adjusting for confounders, factors associated with increased survival were cut/piece injuries, presenting with signs of life, Glasgow Coma Scale score ≥8, systolic blood pressure >90 mm Hg, and transportation to the ED through helicopter/fixed-wing ambulance or public/private vehicle (reference, ground ambulance).

CONCLUSIONS

Factors associated with survival in patients undergoing EDT were identified. The clinical indication of presence of appropriate resources to continue and repair EDT was validated, along with the contraindications of lack of signs of life and presence of major nonsurvivable injuries. Future studies should focus on validation of all criteria of EDT, namely hemodynamic instability despite appropriate fluid resuscitation, duration of time of cardiopulmonary resuscitation and pulselessness, cardiac rhythm on arrival, and the presence of pericardial tamponade.

The use of the shock index to predict hemodynamic collapse in hypotensive sepsis patients: A cross-sectional analysis

Objectives:

Septic shock, defined as sepsis with hypotension not responding to fluid resuscitation or requiring vasopressor support, results in the worst outcomes in sepsis patients. This subtype of the patient is often difficult to detect. The shock index (SI) has demonstrated the potential for predicting hemodynamic compromise and collapse and predicting patient outcomes in multiple medical and surgical settings. In our study, we assessed the utility of the SI as a hemodynamic screening tool to identify patients likely to fail to respond to fluids and ultimately to be diagnosed with septic shock.

Methodology:

A single-center cross-sectional analysis of patients presenting with hypotension and septicemia over 1 year. The study was conducted using the electronic medical records of the emergency department patients presenting to King Saud University Medical City. The charts were reviewed from 2 May 2015 to 24 April 2016 using the local medical registry. The study was approved by the hospital institutional review board (IRB). Data extraction was performed using a standardized form.

Results:

The area under the curve was 0.77 (P < 0.001) for the prediction of hemodynamic collapse. An initial SI ≥0.875 had a sensitivity of 81% and a specificity of 72% for the identification of patients in whom fluid resuscitation would fail.

Conclusions:

Based on our findings, we found that the SI was a reliable screening tool for the identification of hypotensive patients with sepsis who would ultimately be diagnosed with septic shock.

Pre-hospital modified shock index for prediction of massive transfusion and mortality in trauma patients

BACKGROUND

Modified shock index (MSI) is a useful predictor in trauma patients. However, the value of prehospital MSI (preMSI) in trauma patients is unknown. The aim of this study was to investigate the accuracy of preMSI in predicting massive transfusion (MT) and hospital mortality among trauma patients.

METHODS

This was a retrospective, observational, single-center study. Patients presenting consecutively to the trauma center between January 2016 and December 2017, were included. The predictive ability of both prehospital shock index (preSI) and preMSI for MT and hospital mortality was assessed by calculating the areas under the receiver operating characteristic curves (AUROCs).

RESULTS

A total of 1007 patients were included. Seventy-eight (7.7%) patients received MT, and 30 (3.0%) patients died within 24 h of admission to the trauma center. The AUROCs for predicting MT with preSI and preMSI were 0.773 (95% confidence interval [CI], 0.746-0.798) and 0.765 (95% CI, 0.738-0.791), respectively. The AUROCs for predicting 24-hour mortality with preSI and preMSI were 0.584 (95% CI, 0.553-0.615) and 0.581 (95% CI, 0.550-0.612), respectively.

CONCLUSIONS

PreSI and preMSI showed moderate accuracy in predicting MT. PreMSI did not have higher predictive power than preSI. Additionally, in predicting hospital mortality, preMSI was not superior to preSI.

Potential predictors of hospital length of stay and hospital charges among patients with all-terrain vehicle injuries in rural Northeast Texas

Background:

All-Terrain Vehicles (ATVs) have become popular for recreation use in recent years. Texas has had more ATV related fatalities than any other state in the nation, with rural Northeast Texas having even higher rates of injuries. There is limited data examining the relationship between ATV injuries and the length of hospital stay, as well as hospital costs. This paper examines both issues in children as well as adults.

Methods:

The regional trauma registry was analyzed for all ATV related injuries between January 2011- October 2016. Injury Severity Score, Glasgow Coma Scale and if they are seen at a Level I Trauma center are predictive for both hospital length of stay and charges.

Results:

Length of Stay was predicted positively by Injury Severity Score, Emergency Department Respi-ration Rate and facility at which patients were treated and negatively by Glasgow Coma Scale. Hospital charges were predicted positively by age, Injury Severity Score, facility of treatment, means of transportation, and Emergency Department pulse and negatively by Glasgow Coma Scale.

Conclusions:

The study found that vital signs can be useful in predicting length of stay and hospital charges. This study not only confirms the findings of other studies regarding what predictors can be used, but expands the research into rural traumatic injuries. It is hoped that this data can help contribute to the development of algorithms to predict which patients will be most likely to require resource intensive treatment.

Optimal Hemodynamic Parameter to Predict the Neurological Outcome in Out-of-Hospital Cardiac Arrest Survivors Treated with Target Temperature Management

Current guidelines suggest the maintenance of systolic blood pressure (SBP) at >90 mmHg and mean arterial pressure (MAP) at >65 mmHg in postcardiac arrest patients. There remains a lack of clarity regarding optimal values and timing of blood pressure parameters associated with the improvement of neurologic outcome. We investigated the association of time-weighted average (TWA) blood pressure parameters with favorable neurological outcome (FO) in postcardiac arrest patients. This was a registry-based observational study with consecutive adult out-of-hospital cardiac arrest (OHCA) survivors who were treated using targeted temperature management (TTM). During 72 hours of TTM period, we abstracted hemodynamic parameters such as SBP, diastolic blood pressure, pulse rate (PR), and MAP. Shock index (SI; PR/SBP) and modified shock index (MSI; PR/MAP) were calculated from each measured hemodynamics. Logistic regression was performed to assess the associations between TWA blood pressure parameters and FO, defined as cerebral performance category 1 or 2 at hospital discharge. Among the 173 patients (median age: 58 years; 64% male), 51 (29.3%) had FO in this study. MAP, SI, and MSI at 6 hours after return of spontaneous circulation (ROSC) showed considerable differences in patients with FO (MAP: 89.1 ± 14.7 vs. 83.6 ± 15.8 mmHg, p = 0.033, SI: 0.7 ± 0.2 vs. 0.9 ± 0.9, p = 0.002, MSI: 1.0 ± 0.3 vs. 1.2 ± 0.3, p ≤ 0.001). Among them, MSI, especially at 6 hours, had the highest area under the curve for prediction of FO (0.685; 95% confidence interval: 0.597-0.772, p < 0.001). Also, MSI <1.0 had a sensitivity of 64.7%, a specificity of 64.2% to predict FO. In comatose survivors of OHCA with TTM, MSI at 6 hours after ROSC had the highest prognostic value for neurologic outcome among blood pressure parameters.

Age shock index and age-modified shock index are strong predictors of outcomes in ST-segment elevation myocardial infarction patients undergoing emergency percutaneous coronary intervention

BACKGROUND

Early identification of high-risk patients provides clinicians with greater decision-making time and better informs strategies to cope with disease. The predictive values of age shock index (age SI) and age-modified shock index (age MSI) in ST-segment elevation myocardial infarction (STEMI) patients undergoing emergency percutaneous coronary intervention (PCI) have rarely been reported, especially compared with those for SI, MSI, and the Global Registry of Acute Coronary Events (GRACE) risk score.

PATIENTS AND METHODS

Nine hundred and eighty-three STEMI patients undergoing emergency PCI between January 2014 and September 2017 were analyzed in a retrospective cohort study. The primary outcomes were rates of in-hospital cardiovascular events, and 6-month and long-term all-cause mortality.

RESULTS

In multivariate analyses, the predictive values of age SI and age MSI were comparable to that of the GRACE score, but superior to those of SI and MSI for in-hospital cardiac mortality [age SI: odds ratio (OR) = 1.05, P < 0.001, area under the receiver operating characteristic (ROC-AUC) = 0.805, P < 0.001; age MSI: OR = 1.04, P < 0.001, ROC-AUC = 0.813, P < 0.001; GRACE score: OR = 1.03, P < 0.001, ROC-AUC = 0.827, P < 0.001], 6-month all-cause mortality (age SI: OR = 1.04, P < 0.001, ROC-AUC = 0.791, P < 0.001; age MSI: OR = 1.03, P < 0.001, ROC-AUC = 0.801, P < 0.001; GRACE score: ROC-AUC = 0.828, P < 0.001), long-term all-cause mortality [age SI: hazard ratio (HR) = 1.06, P < 0.001, ROC-AUC = 0.798, P < 0.001; age MSI: HR = 1.04, P < 0.001, ROC-AUC = 0.84, P < 0.001; GRACE score: ROC-AUC = 0.822, P < 0.001] and post-discharge all-cause mortality (age SI: HR = 1.05, P < 0.001, ROC-AUC = 0.78, P = 0.001; age MSI: HR = 1.05, P < 0.001, ROC-AUC = 0.789, P < 0.001; GRACE score: ROC-AUC = 0.812, P < 0.001).

CONCLUSION

Age SI and age MSI are stronger predictors than SI and MSI for in-hospital cardiovascular events, and 6-month and long-term all-cause mortality in STEMI patients undergoing emergency PCI. Age SI and age MSI appear to be convenient and simpler indicators than the GRACE score.