Shock index in diagnosing early acute hypovolemia

Comparison of heart rate variability, hemodynamic, metabolic and inflammatory parameters in various phases of decompansatory hemorrhagic shock of normal and vagotomized conscious male rats

BACKGROUND

Heart rate variability (HRV) analysis has shown promise as a valuable complementary tool for clinical assessment in trauma cases. This study aims to evaluate the utility of HRV in monitoring different severities of hemorrhagic shock (HS) and its correlation with traditional hemodynamic and metabolic parameters.

METHODS

Male Sprague-Dawley rats were divided into different experimental groups, including those with and without vagotomy, and were exposed to different classes of decompensatory HS. To induce varying severities of HS, volume resuscitation was delayed by gradually returning 0%, 20%, or 50% of the shed blood volume at the end of the compensation phase, referred to as 0% DFR, 20% DFR, and 50% DFR class, respectively. Hemodynamic parameters were monitored, and HRV was calculated. Levels of TNF-α and IL-10 were determined in lung tissue at the end of the experiments. Correlations between HRV, hemodynamic parameters, inflammatory gene expression and arterial blood gas variables were evaluated.

RESULTS

HRV showed increased power of the low-frequency (LF) and respiratory sinus arrhythmia (RSA) in all groups during the hypotension phase of HS (Nadir 1). Subdiaphragmatic vagotomy blunted the increase in the LF component in the Nadir 1. After volume resuscitation, systolic blood pressure (SBP), RSA and LF returned to baseline in the 0% DFR and 20% DFR classes. However, animals in 50% DFR class exhibited a reduced SBP and LF and lower pH. Notably, strong correlations were found between LF and SBP as well as tissue hypoperfusion markers. The expression of TNF-α in the lung was increased in all HS groups, while this gene expression was significantly higher in the vagotomized animals.

CONCLUSION

The alterations in HRV components were found to be significantly correlated with the hemodynamic and metabolic status of the animals, while showing no association with inflammatory responses. Additionally, the intervention of subdiaphragmatic vagotomy significantly impacted both HRV components and inflammatory responses. Collectively, these findings suggest the potential of HRV components for the assessment of the presence and severity of HS.

Association between preoperative shock index and hypotension after spinal anesthesia for non-elective cesarean section: a prospective cohort study

BACKGROUND

Shock index (SI) is calculated as heart rate divided by systolic blood pressure. In the obstetric population, SI of ≥ 0.9 is associated with maternal adverse outcomes. Our primary aim was to investigate the association between SI and post-spinal hypotension in non-elective cesarean section.

METHODS

In this prospective, observational study, term parturient of ASA physical status II, and urgency categories 2 and 3, undergoing non-elective cesarean section with spinal anesthesia were enrolled. We performed univariable and multivariable logistic regression to explore the association between baseline SI (categorized as < 0.9 and ≥ 0.9) and hypotension after spinal anesthesia. The diagnostic ability of the baseline SI to predict post-spinal hypotension was assessed using ROC (receiver operating characteristics) curves.

RESULTS

Three hundred forty-two parturient were recruited, and among them, 335 were analyzed. One hundred fifty-five (46.27%) parturients developed post-spinal hypotension, and 114 (34.03%) reported post-delivery hypotension. Preoperative SI (adjusted odds ratio [AOR], 2.77; 95% CI, 1.15-6.66; p = 0.023) and thoracic sensory block height > 4 (AOR, 2.33; 95%CI, 1.14-4.76; p = 0.020) were associated with post-spinal hypotension. Preoperative SI (AOR, 4.34; 95%CI, 1.72-10.94; p = 0.002) and anxiety (AOR,1.22; 95%CI, 1.06-1.40; p = 0.004) were associated with post-delivery hypotension. Area under the ROC curve for SI alone in predicting hypotension before and after delivery was 0.53 (95%CI 0.49-0.57) and 0.56 (95%CI 0.51-0.60) respectively. However, the model performance as reflected by ROC curve for the multivariable logistic regression analysis was 0.623 for post-spinal hypotension and 0.679 for post-delivery hypotension, respectively.

CONCLUSION

In parturients undergoing non-elective cesarean section, baseline SI ≥ 0.9 was associated with post-spinal and post-delivery hypotension. While the SI alone showed limited predictive power for post-spinal and post-delivery hypotension, integrating it with other risk factors improved the model's predictive ability.

TRIAL REGISTRATION

Registration number: NCT04692870. Date of registration: 05/01/2021. Website: https://clinicaltrials.gov .

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.

Shock index and shock index, pediatric age-adjusted as predictors of mortality in pediatric patients with trauma: A systematic review and meta-analysis

This study aimed to assess the predictive ability of the shock index (SI) and the shock index, pediatric age-adjusted (SIPA) for mortality among pediatric patients with trauma (aged ≤ 18 years). A systematic search used PubMed, Embase, and Cochrane Library databases to identify pertinent articles published from their inception to 13 February 2023. For each SI and SIPA, the pooled sensitivity, specificity, diagnostic odds ratio (DOR), and area under the summary receiver operating characteristic curve (AUC) with the corresponding 95% confidence intervals were calculated. We planned a priori meta-regression analyses to explore heterogeneity using the following covariates: country, clinical setting, type of center, data source, and cutoff value. Twelve studies were included based on the inclusion criteria. Among them, nine studies with 195,469 patients were included for the SIPA at the hospital, four studies with 4,970 patients were included for the pre-hospital SIPA, and seven studies with 606,445 patients were included to assess the ability of the SI in predicting mortality. The pooled sensitivity and specificity with 95% confidence interval for predicting mortality were as follows: 0.58 (0.44-0.70) and 0.72 (0.60-0.82), respectively, for the SIPA at the hospital; 0.61 (0.47-0.74) and 0.67 (0.61-0.73), respectively, for the pre-hospital SIPA; and 0.71 (0.59-0.81) and 0.45 (0.31-0.59), respectively for the SI. The DOR were 3.80, 3.28, and 2.06 for the SIPA at the hospital, pre-hospital SIPA, and SI, respectively. The AUC were 0.693, 0.689, and 0.618 for the SIPA at the hospital, pre-hospital SIPA, and SI, respectively. The SI and SIPA are simple predictive tools with sufficient accuracy that can be readily applied to pediatric patients with trauma, but SIPA and SI should be utilized cautiously due to their limited sensitivity and specificity, respectively.

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.

Effect of phenylephrine rescue injection on hypotension after spinal anaesthesia for caesarean delivery when guided by both heart rate and SBP during an early warning window: A randomised controlled trial

BACKGROUND

Spinal anaesthesia is now the most common technique for caesarean delivery. However, because of the intermittent nature of noninvasive blood pressure (NIBP) measurements, maternal blood pressure may become hypotensive between the measurements. There is thus an inbuilt delay before the anaesthesiologist can intervene to counteract the hypotension. Based on the principle that changes in blood pressure can induce compensatory changes in the heart rate (HR), combining the NIBP with real-time HR, we designed two warning windows to predict hypotension and hypertension.

OBJECTIVE

To evaluate whether phenylephrine administration guided by these warning windows would help maintain haemodynamic stability.

SETTING

A teaching hospital.

DESIGN

A randomised controlled trial.

PATIENTS

One hundred and ten pregnant women scheduled for elective caesarean delivery were enrolled, from which, after exclusions, 86 were eligible for the study.

INTERVENTIONS

All eligible patients received a continuous intravenous infusion of phenylephrine as soon as spinal anaesthesia was initiated. Thereafter, patients were randomly assigned to two groups. In the test group (Win-Group): rescue phenylephrine administration was triggered by an early warning window of HR above 100 beats per minute (bpm) and SBP 90 to 110 mmHg; pausing the infusion phenylephrine was triggered by a HR lower than 60 bpm and SBP greater than 90 mmHg. In the control group, phenylephrine was guided by BP only when it appeared on the monitor: SBP less than 90 mmHg was the trigger for administering rescue phenylephrine; SBP greater than 110 mmHg was the trigger for pausing the phenylephrine infusion.

MAIN OUTCOME MEASURES

The primary outcome was incidence of hypotension. Secondary outcomes were the incidence of hypertension and other adverse haemodynamic events.

RESULTS

The incidence of hypotension was significantly lower in the Win-Group than in the BP-Group (27.8 vs. 66.7%, P  = 0.001). The minimum SBP was significantly higher in Win-Group than in BP-Group (93.9 ± 9.49 vs. 86.7 ± 11.16 mmHg, P   =  0.004). There was no significant difference in the incidence of hypertension between groups.

CONCLUSION

After spinal anaesthesia for caesarean delivery, when phenylephrine infusion is guided by HR along with BP from a warning window it effectively reduces the incidence of hypotension without any significant effect on incidence of hypertension.

TRIAL REGISTRATION

Chictr.org.cn; Identifier: ChiCTR 2100041812.

Retrospective evaluation of the utility of shock index to determine the presence of congestive heart failure in dogs with myxomatous mitral valve disease (2019-2021): 98 cases

OBJECTIVES

To calculate the shock index (SI) in dogs with myxomatous mitral valve disease (MMVD) and to evaluate its use to predict the presence of congestive heart failure (CHF).

DESIGN

Retrospective study.

SETTING

Small animal university veterinary teaching hospital.

ANIMALS

Ninety-eight dogs with MMVD and 20 healthy dogs as part of a control group.

INTERVENTIONS

Heart rate (HR) and systolic blood pressure (SBP) were recorded, and SI was calculated by dividing HR by SBP for each dog.

MEASUREMENTS AND MAIN RESULTS

The mean (SD) HR, SBP, and SI were 123/min (32.6), 147 mm Hg (21.5), and 0.86 (0.3), respectively, for dogs with MMVD and 98/min (20.9), 145 mm Hg (18.7), and 0.68 (0.13), respectively, for control dogs. Dogs with MMVD had a significantly higher HR compared with control dogs (P < 0.01), and an elevation in HR was seen as the severity of MMVD increased. Dogs in stage B2 and C/D MMVD had a significantly higher SI value compared with control dogs (P = 0.04 and P < 0.01, respectively). SI was significantly higher in dogs in stage C/D MMVD compared with dogs in stage B2 MMVD (P < 0.01). Ten of 98 (10%) dogs had an arrhythmia. HR, SBP, and SI were not significantly different between dogs with and without arrhythmias (P = 0.13, P = 0.57, and P = 0.07, respectively), but significantly more dogs with CHF had an arrhythmia (P = 0.01). SI (area under the curve [AUC]: 0.98) and HR (AUC: 0.95) were excellent indicators for the presence of CHF. An optimal SI cutoff value ≥1.1 had 92% sensitivity and 95% specificity for predicting the presence of CHF, and an optimal HR cutoff value of ≥157/min had 92% sensitivity and 93% specificity for the prediction of CHF.

CONCLUSIONS

When there are compatible clinical signs, SI values ≥1.1 may suggest the presence of CHF in dogs with MMVD.

Shock index as a predictor of postpartum haemorrhage after vaginal delivery: Secondary analysis of a multicentre randomised controlled trial

OBJECTIVE

To describe the shock index (SI) distribution during the first 2 hours after delivery and to evaluate its performance when measured 15 and 30 minutes after delivery for predicting postpartum haemorrhage (PPH) occurrence in the general population of parturients after vaginal delivery.

DESIGN

Secondary analysis of a multicentre randomised controlled trial testing prophylactic administration of tranexamic acid versus placebo in addition to prophylactic oxytocin to prevent PPH.

SETTING

15 French maternity units in 2015-2016.

SAMPLE

3891 women with a singleton live fetus ≥35 weeks, born vaginally.

METHODS

For each PPH-related predicted outcome, we calculated the area under the receiver operating characteristic curve (AUROC) values of the SI at 15 and 30 minutes after delivery and its predictive performance for SI cut-off values of 0.7, 0.9 and 1.1.

MAIN OUTCOME MEASURES

Quantitative blood loss ≥1000 ml (QBL ≥1000 ml) measured in a graduated collector bag and provider-assessed clinically significant PPH (cPPH).

RESULTS

Prevalence of QBL ≥1000 ml and cPPH was respectively 2.7% (104/3839) and 9.1% (354/3891). The distributions of the SI at 15 and 30 minutes after delivery were similar with a median value of 0.73 and 97th percentile of 1.11 for both. The AUROC values of the 15-minute SI for discriminating QBL ≥1000 ml and cPPH were respectively 0.66 (lower limit of the 95% confidence interval [LCI] 0.60) and 0.56 (LCI 0.52); and for the 30-minute SI 0.68 (LCI 0.61) and 0.49 (LCI 0.43).

CONCLUSIONS

The shock index at 15 and 30 minutes after delivery did not satisfactorily predict either QBL ≥1000 ml or clinical PPH.

Impact of Intra-Operative Shock and Resuscitation on Surgical Site Infections After Trauma Laparotomy

Background: Patients undergoing trauma laparotomy experience high rates of surgical site infection (SSI). Although intra-operative shock is a likely contributor to SSI risk, little is known about the relation between shock, intra-operative restoration of physiologic normalcy, and SSI development. Patients and Methods: A retrospective review of trauma patients who underwent emergent definitive laparotomy was performed. Using shock index and base excess at the beginning and end of laparotomy, patients were classified as normal, persistent shock, resuscitated, or new shock. Univariable and multivariable analyses were performed to identify predictors of organ/space SSI, superficial/deep SSI, and any SSI. Results: Of 1,191 included patients, 600 (50%) were categorized as no shock, 248 (21%) as resuscitated, 109 (9%) as new shock, and 236 (20%) as persistent shock, with incidence of any SSI as 51 (9%), 28 (11%), 26 (24%), and 32 (14%), respectively. These rates were similar in organ/space and superficial/deep SSIs. On multivariable analysis, resuscitated, new shock, and persistent shock were associated with increased odds of organ/space SSI (odds ratio [OR], 2.2; 95% confidence interval [CI], 1.3-3.5; p < 0.001) and any SSI (OR, 2.0; 95% CI, 1.4-3.2; p < 0.001), but no increased risk of superficial/deep SSI (OR, 1.4; 95% CI, 0.8-2.6; p = 0.331). Conclusions: Although the trajectory of physiologic status influenced SSI, the presence of shock at any time during trauma laparotomy, regardless of restoration of physiologic normalcy, was associated with increased odds of SSI. Further investigation is warranted to determine the relation between peri-operative shock and SSI in trauma patients.

Evaluation of Blood Lactate, Heart Rate, Blood Pressure, and Shock Index, and Their Association with Prognosis in Calves

Diseases in young calves received as emergencies are often associated with hypovolemic and/or septic shocks. The objectives of our study were to (1) assess the correlation between clinical hemodynamic parameters and blood L-lactates (LAC), systolic blood pressure (SBP), and the shock index (SI) recorded upon arrival; and (2) to evaluate how these parameters were related to short-term outcomes in calves under 4 months of age presented as emergencies. We conducted a single-observer prospective observational study on calves aged from 1 day to 4 months, presented to the Veterinary Clinic for Ruminants of Liège from December 2020 to May 2022. Forty-five calves were included in the study. The statistical analysis revealed a significant correlation between LAC and heart rate (r = 0.570; p < 0.05) and LAC and SI (r = 0.373; p < 0.05). A high LAC value at admission was significantly associated with a negative outcome (death) (p < 0.05). In calves suffering from obstructive digestive diseases, the SI was related to the outcome and the analysis indicated a cut-off value of 1.13 (Se = 0.77, Spe = 1). In conclusion, in our study, the initial blood L-lactate value was correlated with heart rate, the shock index, and the clinical shock score, and admission hyperlactatemia was associated with a poor prognosis in calves under 4 months of age. In this cohort, the shock index in calves suffering from digestive diseases was linked with mortality.

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.

Preoperative shock index in major abdominal emergency surgery

Introduction

Major abdominal emergency surgery (MAES) patients have a high risk of mortality and complications. The time-sensitive nature of MAES necessitates an easily calculable risk-scoring tool. Shock index (SI) is obtained by dividing heart rate (HR) by systolic blood pressure (SBP) and provides insight into a patient's haemodynamic status. We aimed to evaluate SI's usefulness in predicting postoperative mortality, acute kidney injury (AKI), requirements for intensive care unit (ICU) and high-dependency monitoring, and the ICU length of stay (LOS).

Method

We retrospectively reviewed 212,089 MAES patients from January 2013 to December 2020. The cohort was propensity matched, and 3960 patients were included. The first HR and SBP recorded in the anaesthesia chart were used to calculate SI. Regression models were used to investigate the association between SI and outcomes. The relationship between SI and survival was explored with Kaplan-Meier curves.

Results

There were significant associations between SI and mortality at 1 month (odds ratio [OR] 2.40 [1.67-3.39], P<0.001), 3 months (OR 2.13 [1.56-2.88], P<0.001), and at 2 years (OR 1.77 [1.38-2.25], P<0.001). Multivariate analysis revealed significant relationships between SI and mortality at 1 month (OR 3.51 [1.20-10.3], P=0.021) and at 3 months (OR 3.05 [1.07-8.54], P=0.034). Univariate and multivariate analysis also revealed significant relationships between SI and AKI (P<0.001), postoperative ICU admission (P<0.005) and ICU LOS (P<0.001). SI does not significantly affect 2-year mortality.

Conclusion

SI is useful in predicting postopera-tive mortality at 1 month, 3 months, AKI, postoperative ICU admission and ICU LOS.

Comparison of National Early Warning Score with shock index in patients with necrotizing fasciitis

Shock index (SI) and national early warning score (NEWS) are more frequently used as assessment tools in acute illnesses, patient disposition and early identification of critical condition. Both they are consisted of common vital signs and parameters including heart rate, systolic blood pressure, respiratory rate, oxygen saturation and level of conscious, which made it easy to evaluate in medical facilities. Its ability to predict mortality in patients with necrotizing fasciitis (NF) in the emergency department remains unclear. This study was conducted to compare the predictive capability of the risk scores among NF patients. A retrospective cohort study of hospitalized patients with NF was conducted in 2 tertiary teaching hospitals in Taiwan between January 2013 and March 2015. We investigated the association of NEWS and SI with mortality in NF patients. Of the 395 NF patients, 32 (8.1%) died in the hospital. For mortality, the area under the receiver curve value of NEWS (0.81, 95% confidence interval 0.76-0.86) was significantly higher than SI (0.76, 95% confidence interval 0.73-0.79, P = .016). The sensitivities of NEWS of 3, 4, and 5 for mortality were 98.1%, 95.6%, and 92.3%. On the contrast, the sensitivities of SI of 0.5, 0.6, and 0.7 for mortality were 87.8%, 84.7%, and 81.5%. NEWS had advantage in better discriminative performance of mortality in NF patients. The NEWS may be used to identify relative low risk patients among NF patients.

Biomarker-Based Assessment Model for Detecting Sepsis: A Retrospective Cohort Study

The concept of the quick sequential organ failure assessment (qSOFA) simplifies sepsis detection, and the next SOFA should be analyzed subsequently to diagnose sepsis. However, it does not include the concept of suspected infection. Thus, we simply developed a biomarker-based assessment model for detecting sepsis (BADS). We retrospectively reviewed the electronic health records of patients admitted to the intensive care unit (ICU) of a 2000-bed university tertiary referral hospital in South Korea. A total of 989 patients were enrolled, with 77.4% (n = 765) of them having sepsis. The patients were divided into a ratio of 8:2 and assigned to a training and a validation set. We used logistic regression analysis and the Hosmer-Lemeshow test to derive the BADS and assess the model. BADS was developed by analyzing the variables and then assigning weights to the selected variables: mean arterial pressure, shock index, lactate, and procalcitonin. The area under the curve was 0.754, 0.615, 0.763, and 0.668 for BADS, qSOFA, SOFA, and acute physiology and chronic health evaluation (APACHE) II, respectively, showing that BADS is not inferior in sepsis prediction compared with SOFA. BADS could be a simple scoring method to detect sepsis in critically ill patients quickly at the bedside.

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.

[Correlation between the shock index and the anaerobic index]

Background

Shock is defined as an acute circulatory insufficiency that causes cellular dysfunction. The shock index (SI) and the anaerobic index or the relationship between the veno-arterial gradient of carbon dioxide and the difference between the arterial and venous content of O₂ [∆P(v-a)CO2/ΔC(a-v)O2] are markers of systemic hypoperfusion.

Objective

To determine if there is a correlation between the SI and the anaerobic index in patients with circulatory shock.

Material and methods

Observational and prospective study in patients with circulatory shock. The SI and the anaerobic index were calculated at admission to the intensive care unit (ICU) and during their stay. Pearson's correlation coefficient was calculated and the association of SI with mortality was explored with bivariate logistic regression.

Results

59 patients aged 55.5 (± 16.5) years, 54.3% men, were analyzed. The most frequent type of shock was hypovolemic (40.7%). They had SOFA score: 8.4 (± 3.2) and APACHE II: 18.5 (± 6). The SI was: 0.93 (± 0.32) and the anaerobic index: 2.3 (± 1.3). Global correlation was r = 0.15; at admission r = 0.29; after 6 hours: r = 0.19; after 24 hours: r = 0.18; after 48 hours: r = 0.44, and after 72 hours: r = 0.66. The SI > 1 at ICU admission had an OR 3.8 (95% CI: 1.31-11.02), p = 0.01.

Conclusions

The SI and the anaerobic index have a weak positive correlation during the first 48 hours of circulatory shock. The SI > 1 is a possible risk factor for death in patients with circulatory shock.

Shock index as predictor of massive transfusion and mortality in patients with trauma: a systematic review and meta-analysis

BACKGROUND

Management of bleeding trauma patients is still a difficult challenge. Massive transfusion (MT) requires resources to ensure the safety and timely delivery of blood products. Early prediction of MT need may be useful to shorten the time process of blood product preparation. The primary aim of this study was to assess the accuracy of shock index to predict the need for MT in adult patients with trauma. For the same population, we also assessed the accuracy of SI to predict mortality.

METHODS

This systematic review and meta-analysis was performed in accordance with the PRISMA guidelines. We performed a systematic search on MEDLINE, Scopus, and Web of Science from inception to March 2022. Studies were included if they reported MT or mortality with SI recorded at arrival in the field or the emergency department. The risk of bias was assessed using the QUADAS-2.

RESULTS

Thirty-five studies were included in the systematic review and meta-analysis, for a total of 670,728 patients. For MT the overall sensibility was 0.68 [0.57; 0.76], the overall specificity was 0.84 [0.79; 0.88] and the AUC was 0.85 [0.81; 0.88]. Positive and Negative Likelihood Ratio (LR+; LR-) were 4.24 [3.18-5.65] and 0.39 [0.29-0.52], respectively. For mortality the overall sensibility was 0.358 [0.238; 0.498] the overall specificity 0.742 [0.656; 0.813] and the AUC 0.553 (confidence region for sensitivity given specificity: [0.4014; 0.6759]; confidence region for specificity given sensitivity: [0.4799; 0.6332]). LR+ and LR- were 1.39 [1.36-1.42] and 0.87 [0.85-0.89], respectively.

CONCLUSIONS

Our study demonstrated that SI may have a limited role as the sole tool to predict the need for MT in adult trauma patients. SI is not accurate to predict mortality but may have a role to identify patients with a low risk of mortality.

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.

Clinical factors predicting return emergency department visits in chemotherapy-induced febrile neutropenia patients

BACKGROUND

Although chemotherapy-induced febrile neutropenia (FN) is the most common and life-threatening oncologic emergency, the characteristics and outcomes associated with return visits to the emergency department (ED) in these patients are uncertain. Hence, we aimed to investigate the predictive factors and clinical outcomes of chemotherapy-induced FN patients returning to the ED.

METHOD

This single-center, retrospective observational study spanning 14 years included chemotherapy-induced FN patients who visited the ED and were discharged. The primary outcome was a return visit to the ED within five days. We conducted logistic regression analyses to evaluate the factors influencing ED return visit.

RESULTS

This study included 1318 FN patients, 154 (12.1%) of whom revisited the ED within five days. Patients (53.3%) revisited the ED owing to persistent fever (56.5%), with no intensive care unit admission and only one mortality case who was discharged hopelessly. Multivariable analysis revealed that shock index >0.9 (odds ratio [OR]: 1.45, 95% confidence interval [CI], 1.01-2.10), thrombocytopenia (<100 × 10³/uL) (OR: 1.64, 95% CI, 1.11-2.42), and lactic acid level > 2 mmol/L (OR: 1.51, 95% CI, 0.99-2.25) were associated with an increased risk of a return visit to the ED, whereas being transferred into the ED from other hospitals (OR: 0.08; 95% CI, 0.005-0.38) was associated with a decreased risk of a return visit to the ED.

CONCLUSION

High shock index, lactic acid, thrombocytopenia, and ED arrival type can predict return visits to the ED in chemotherapy-induced FN patients.

Development and Validation of a Prediction Model for Need for Massive Transfusion During Surgery Using Intraoperative Hemodynamic Monitoring Data

Importance

Massive transfusion is essential to prevent complications during uncontrolled intraoperative hemorrhage. As massive transfusion requires time for blood product preparation and additional medical personnel for a team-based approach, early prediction of massive transfusion is crucial for appropriate management.

Objective

To evaluate a real-time prediction model for massive transfusion during surgery based on the incorporation of preoperative data and intraoperative hemodynamic monitoring data.

Design, Setting, and Participants

This prognostic study used data sets from patients who underwent surgery with invasive blood pressure monitoring at Seoul National University Hospital (SNUH) from 2016 to 2019 and Boramae Medical Center (BMC) from 2020 to 2021. SNUH represented the development and internal validation data sets (n = 17 986 patients), and BMC represented the external validation data sets (n = 494 patients). Data were analyzed from November 2020 to December 2021.

Exposures

A deep learning-based real-time prediction model for massive transfusion.

Main Outcomes and Measures

Massive transfusion was defined as a transfusion of 3 or more units of red blood cells over an hour. A preoperative prediction model for massive transfusion was developed using preoperative variables. Subsequently, a real-time prediction model using preoperative and intraoperative parameters was constructed to predict massive transfusion 10 minutes in advance. A prediction model, the massive transfusion index, calculated the risk of massive transfusion in real time.

Results

Among 17 986 patients at SNUH (mean [SD] age, 58.65 [14.81] years; 9036 [50.2%] female), 416 patients (2.3%) underwent massive transfusion during the operation (mean [SD] duration of operation, 170.99 [105.03] minutes). The real-time prediction model constructed with the use of preoperative and intraoperative parameters significantly outperformed the preoperative prediction model (area under the receiver characteristic curve [AUROC], 0.972; 95% CI, 0.968-0.976 vs AUROC, 0.824; 95% CI, 0.813-0.834 in the SNUH internal validation data set; P < .001). Patients with the highest massive transfusion index (ie, >90th percentile) had a 47.5-fold increased risk for a massive transfusion compared with those with a lower massive transfusion index (ie, <80th percentile). The real-time prediction model also showed excellent performance in the external validation data set (AUROC of 0.943 [95% CI, 0.919-0.961] in BMC).

Conclusions and Relevance

The findings of this prognostic study suggest that the real-time prediction model for massive transfusion showed high accuracy of prediction performance, enabling early intervention for high-risk patients. It suggests strong confidence in artificial intelligence-assisted clinical decision support systems in the operating field.

Evaluation of Intravascular Volume Using the Internal Jugular Vein Cardiac Collapse Index in the Emergency Department: A Preliminary Prospective Observational Study

A non-invasive method for assessment of intravascular volume for optimal fluid administration is needed. We here conducted a preliminary study to confirm whether cardiac variation in the internal jugular vein (IJV), evaluated by ultrasound, predicts fluid responsiveness in patients in the emergency department. Patients who presented to the emergency department between August 2019 and March 2020 and required infusions were enrolled. We recorded a short-axis video of the IJV, respiratory variability in the inferior vena cava and stroke volume variations using the ClearSight System (Edwards Lifesciences, Irvine, CA, USA) before infusion of 500 mL of crystalloid fluid. Cardiac variations in the cross-sectional area of the IJV were measured by speckle tracking. Among the 148 patients enrolled, 105 were included in the final analysis. Fluid responsiveness did not correlate with the cardiac collapse index (13.6% vs. 16.8%, p = 0.24), but correlated with stroke volume variations (12.5% vs. 15.6%, p = 0.026). Although it is a simple correction, the cardiac collapse index correlated with stroke volume corrected by age (r = 0.25, p = 0.01), body surface area (r = 0.33, p = 0.002) and both (r = 0.35, p = 0.001). Cardiac variations in the IJV did not predict fluid responsiveness in the emergency department, but may reflect stroke volume.

Derivation and Validation of an Improved Pediatric Shock Index for Predicting Need for Early Intervention and Outcomes in Pediatric Trauma

BACKGROUND

Shock index, pediatric adjusted (SIPA) has been widely applied in pediatric trauma but has limited precision due to the reference ranges used in its derivation. We hypothesized that a Pediatric Shock Index (PSI) equation based on age-based vital signs would outperform SIPA.MethodsRetrospective cohort of trauma patients age 1 to 18 years from Trauma Quality Programs - Participant Use File (TQP-PUF) 2010-2018. A random 70% training subset was used to derive Youden index-optimizing SI cutoffs by age for blood transfusion within 4 hours. We used linear regression to derive equations representing the PSI cutoff for children <=12 years and ≥ 13 years old. For children ≥13 years old, the well-established shock index of 0.9 remained optimal, consistent with SIPA and other indices. For children <=12 years in the 30% validation subset, we compared our age-based PSI to SIPA as predictors of early transfusion, mortality, PICU admission, and injury severity score ≥ 25. For bedside use, a simplified "rapid PSI" (rPSI) equation was also derived and compared to SIPA.

RESULTS

439,699 patients aged 1 through 12 years met inclusion criteria with 2,718 (1.3% of those with available outcome data) requiring transfusion within 4 hours of presentation. In the validation set, positive predictive values (PPV) for early transfusion were higher for PSI (8.3%, 95%CI: 7.5 - 9.1%) and rPSI (6.3%, 95%CI: 5.7 - 6.9%) than SIPA (4.3%, 95%CI: 3.9 - 4.7%). For early transfusion, negative predictive values (NPV) for both PSI (99.3%, 95%CI: 99.2 - 99.3%) and rPSI (99.3%, 95%CI: 99.2 - 99.4%) were similar to SIPA (99.4%, 95%CI: 99.3 - 99.4%).ConclusionsWe derived the PSI and rPSI for use in pediatric trauma using empiric, age-based shock index cutoffs. The PSI and rPSI achieved higher PPVs and similar NPVs to SIPA in predicting the need for early blood transfusion and mortality.

LEVEL OF EVIDENCE

Prognostic study, Level III.

Detection of Hemodynamic Status Using an Analytic Based on an Electrocardiogram Lead Waveform

OBJECTIVES

Delayed identification of hemodynamic deterioration remains a persistent issue for in-hospital patient care. Clinicians continue to rely on vital signs associated with tachycardia and hypotension to identify hemodynamically unstable patients. A novel, noninvasive technology, the Analytic for Hemodynamic Instability (AHI), uses only the continuous electrocardiogram (ECG) signal from a typical hospital multiparameter telemetry monitor to monitor hemodynamics. The intent of this study was to determine if AHI is able to predict hemodynamic instability without the need for continuous direct measurement of blood pressure.

DESIGN

Retrospective cohort study.

SETTING

Single quaternary care academic health system in Michigan.

PATIENTS

Hospitalized adult patients between November 2019 and February 2020 undergoing continuous ECG and intra-arterial blood pressure monitoring in an intensive care setting.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

One million two hundred fifty-two thousand seven hundred forty-two 5-minute windows of the analytic output were analyzed from 597 consecutive adult patients. AHI outputs were compared with vital sign indications of hemodynamic instability (heart rate > 100 beats/min, systolic blood pressure < 90 mm Hg, and shock index of > 1) in the same window. The observed sensitivity and specificity of AHI were 96.9% and 79.0%, respectively, with an area under the curve (AUC) of 0.90 for heart rate and systolic blood pressure. For the shock index analysis, AHI's sensitivity was 72.0% and specificity was 80.3% with an AUC of 0.81.

CONCLUSIONS

The AHI-derived hemodynamic status appropriately detected the various gold standard indications of hemodynamic instability (hypotension, tachycardia and hypotension, and shock index > 1). AHI may provide continuous dynamic hemodynamic monitoring capabilities in patients who traditionally have intermittent static vital sign measurements.

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.

Contact-Free Monitoring of Pulse Rate For Triage of Patients Presenting to the Emergency Department

BACKGROUND

The evaluation of a patient's pulse rate (PR) plays a key role in emergency triage and is commonly measured in a contact-dependent way.

OBJECTIVE

Our aims were to evaluate a camera-based prototype application (CBPA) measuring PR in an emergency department (ED) as an alternative to the current contact-dependent method of pulse oximetry and to determine the correlation between CBPA and pulse oximetry in measuring PR.

METHODS

We simultaneously measured PR with CBPA and pulse oximetry as a reference method on a large group of ED walk-in patients. We then estimated correlation and agreement between the two methods, as well as the corresponding 95% confidence intervals.

RESULTS

In a convenience sample of 446 patients, the correlation between CBPA and pulse oximetry in measuring PR was 0.939 (95% confidence interval [CI] 0.927-0.949) and the intraclass correlation was 0.939 (95% CI 0.927-0.949).

CONCLUSIONS

Our study found that CBPA seems to be a viable alternative to the current method of measuring PR at triage. ClinicalTrials.gov identifier: NCT03393585.

Factors for unsuccessful endoscopic hemostasis in patients with severe peptic ulcer bleeding

OBJECTIVES

Although the first approach for peptic ulcer bleeding is endoscopic hemostasis, quick determination of a hemostatic strategy is important in patients with vitals indicating shock. However, the unsuccessful factors for endoscopic treatment have yet to be sufficiently examined. We aimed to investigate the factors for unsuccessful endoscopic hemostasis in severe peptic ulcer bleeding.

MATERIALS AND METHODS

Unsuccessful factors were retrospectively investigated in 150 eligible patients who underwent endoscopic hemostasis for shock-presenting peptic ulcer bleeding at our critical care center between April 2007 and March 2021.

RESULTS

There were 123 and 27 cases of successful and unsuccessful endoscopic hemostasis, respectively. Causative diseases included gastric ulcer bleeding in 124 patients (82.7%) and duodenal ulcer bleeding in 26 patients (17.3%). Shock index (SI) (1.46 vs. 1.60) (p = .013), exposed blood vessel diameter (1.4 mm vs. 3.1 mm) (p < .001) identified on contrast-enhanced computed tomography (CE-CT), duodenal ulcer bleeding (p = .012), and Forrest classification Ia (p = .004) were extracted as independent factors for unsuccessful endoscopic hemostasis. In receiving operating curve analysis, when the cut-off value for the SI was set at 1.53, the sensitivity and specificity were 70.4% and 63.4%, respectively. When the cut-off value for the exposed blood vessel diameter was set at 1.9 mm, these were 88.9% and 83.7%, respectively.

CONCLUSIONS

When these factors (SI ≥ 1.53, exposed blood vessel diameter ≥1.9 mm identified on CE-CT, duodenal ulcer bleeding, and Forrest Ia) are present in patients with severe peptic ulcer bleeding, non-endoscopic hemostasis, such as interventional radiology (IVR) and surgery, should be considered.

Shock index predicts up to 90-day mortality risk after intracerebral haemorrhage

BACKGROUND

Shock index (SI - heart rate/systolic blood pressure) has been studied as a measure of haemodynamic status. We aimed to determine whether SI measures within 72 h of admission were associated with adverse outcomes in intracerebral haemorrhage (ICH).

METHODS

Patients were drawn from the Virtual International Stroke Trials Archive-Intracerebral Haemorrhage (VISTA-ICH). Multivariable Cox regressions modelled the relationship between SI (on admission, 24, 48, 72 h) and mortality (at 3-, 7-, and 90-days), 90-day incident pneumonia and cardiovascular events (MACE). Ordinal logistic regressions modelled the relationship between SI and 90-day modified Rankin Scale (mRS).

RESULTS

979 patients were included. Baseline SI was not associated with mortality. 24 h SI > 0.7 was associated with 7-day mortality (hazard ratio (95% confidence interval) = 3.14 (1.37-7.19)). 48 h and 72 h SI > 0.7 were associated with 7-day (4.23 (2.07-8.66) and 3.24 (1.41-7.42) respectively) and 90-day mortality (2.97 (1.82-4.85) and 2.05 (1.26-3.61) respectively). SI < 0.5 at baseline, 48 h and 72 h was associated with decreased pneumonia risk. 24 h and 48 h SI > 0.7was associated with increased MACE risk. 48 h and 72 h SI > 0.7 was associated with increased odds of higher 90-day mRS.

CONCLUSION

Higher-than-normal SI subsequent to initial encounter was associated with higher post-ICH mortality at 3, 7, and 90 days. Lower-than-normal SI was associated with a decreased risk of incident pneumonia.

Machine Learning for Military Trauma: Novel Massive Transfusion Predictive Models in Combat Zones

BACKGROUND

Damage control resuscitation has become the standard of care in military and civilian trauma. Early identification of blood product requirements may aid in optimizing the clinical decision-making process while improving trauma related outcomes. This study aimed to assess and compare multiple machine learning models for predicting patients at highest risk for massive transfusion on the battlefield.

METHODS

Supervised machine learning approaches using logistic regression, support vector machine, neural network, and random forest techniques were used to create predictive models for massive transfusion using standard prehospital and arrival data points from the Department of Defense Trauma Registry, 2008-2016. Seventy percent of the population was used for model development and performance was validated using the remaining 30%. Models were tested for accuracy and compared by standard performance statistics.

RESULTS

A total of 22,158 patients (97% male, 58% penetrating injury, median age 25-29 y/o, average Injury Severity Score 9, with an overall mortality of 3%) were included in the analysis. Massive transfusion was required by 7.4% of patients. Overall accuracy was found to be above 90% in all models tested. Following cross validation and model training, the random forest model outperformed the alternatively tested models for precision, recall, and area under the curve.

CONCLUSION

Machine learning techniques may allow for more optimal and rapid identification of combat trauma patients at highest risk for massive transfusion. These powerful approaches may uncover novel correlations and help improve triage, activation of massive transfusion resources, and trauma-related outcomes. Further research seeking to optimize and apply these algorithms to trauma-centered research should be pursued.

Prognostic value of shock index in patients admitted with non-ST-segment elevation myocardial infarction: the ARIC study community surveillance

AIMS

Shock index (SI), defined as the ratio of heart rate (HR) to systolic blood pressure (SBP), is easily obtained and predictive of mortality in patients with ST-segment elevation myocardial infarction. However, large-scale evaluations of SI in patients with non-ST-segment elevation myocardial infarction (NSTEMI) are lacking.

METHODS AND RESULTS

Hospitalizations for acute myocardial infarction were sampled from four US areas by the Atherosclerosis Risk in Communities (ARIC) study and classified by physician review. Shock index was derived from the HR and SBP at first presentation and considered high when ≥0.7. From 2000 to 2014, 18 301 weighted hospitalizations for NSTEMI were sampled and had vitals successfully obtained. Of these, 5753 (31%) had high SI (≥0.7). Patients with high SI were more often female (46% vs. 39%) and had more prevalent chronic kidney disease (40% vs. 32%). TIMI (Thrombolysis in Myocardial Infarction) risk scores were similar between the groups (4.3 vs. 4.2), but GRACE (Global Registry of Acute Coronary Syndrome) score was higher with high SI (140 vs. 118). Angiography, revascularization, and guideline-directed medications were less often administered to patients with high SI, and the 28-day mortality was higher (13% vs. 5%). Prediction of 28-day mortality by SI as a continuous measurement [area under the curve (AUC): 0.68] was intermediate to that of the GRACE score (AUC: 0.87) and the TIMI score (AUC: 0.54). After adjustments, patients with high SI had twice the odds of 28-day mortality (odds ratio = 2.02; 95% confidence interval: 1.46-2.80).

CONCLUSION

The SI is easily obtainable, performs moderately well as a predictor of short-term mortality in patients hospitalized with NSTEMI, and may be useful for risk stratification in emergency settings.

Shock Index as a Predictor for Angiographic Hemostasis in Life-Threatening Traumatic Oronasal Bleeding

The objective of this retrospective study was to identify predictors of angiographic hemostasis among patients with life-threatening traumatic oronasal bleeding (ONB) and determine the threshold for timely referral or intervention. The diagnosis of traumatic, life-threatening ONB was made if the patient suffered from craniofacial trauma presenting at triage with unstable hemodynamics or required a definitive airway due to ONB, without other major bleeding identified. There were 4404 craniofacial trauma patients between January 2015 and December 2019, of which 72 (1.6%) fulfilled the diagnosis of traumatic life-threatening ONB. Of these patients, 39 (54.2%) received trans-arterial embolization (TAE), 11 (15.3%) were treated with other methods, and 22 (30.5%) were excluded. Motor vehicle accidents were the most common cause of life-threatening ONB (52%), and the internal maxillary artery was the most commonly identified hemorrhaging artery requiring embolization (84%). Shock index (SI) was significantly higher in the angiographic hemostasis group (p < 0.001). The AUC-ROC was 0.87 (95% CI, 0.88-1.00) for SI to predict angiographic hemostasis. Early recognition and timely intervention are crucial in post-traumatic, life-threatening ONB management. Patients initially presenting with SI > 0.95 were more likely to receive TAE, with the TAE group having statistically higher SI than the non-TAE group whilst receiving significantly more packed red blood cells. Hence, for patients presenting with life-threatening traumatic ONB and a SI > 0.95, TAE should be considered if preliminary attempts at hemostasis have failed.

Analysis of Clinical Outcome and Predictors of Mortality in Pediatric Trauma Population: Evidence from a 10 Year Analysis in a Single Center

The shock index (SI) is a useful tool for predicting the injury severity and mortality in patients with trauma. However, pediatric physiology differs from that of adults. In the pediatric trauma population, the shock status may be obscured within the normal range of vital signs. Pediatric age-adjusted SI (SIPA) is reported more accurately compared to SI. In our study, we conducted a 10 year retrospective cohort study of pediatric trauma population to evaluate the SI and SIPA in predicting mortality, intensive care unit (ICU) admission, and the need for surgery. This retrospective cohort study included 1265 pediatric trauma patients from January 2009 to June 2019 at the Taipei Tzu Chi Hospital, who had a history of hospitalization. The primary outcome of this investigation was in-hospital mortality, and the secondary outcomes were the length of hospital and ICU stay, operation times, and ICU admission times. The SIPA group can detect changes in vital signs early to reflect shock progression. In the elevated SIPA group, more severe traumatic injuries were identified, including high injury severity score (ISS), revised trauma score (RTS), and new injury severity score (NISS) scores than SI > 0.9. The odds ratio of elevated SIPA and SI (>0.9) to predict ISS ≥ 16 was 3.593 (95% Confidence interval [CI]: 2.175–5.935, p < 0.001) and 2.329 (95% CI: 1.454–3.730, p < 0.001). SI and SIPA are useful for identifying the compensatory phase of shock in prehospital and hospital settings, especially in corresponding normal to low-normal blood pressure. SIPA is effective in predicting the mortality and severity of traumatic injuries in the pediatric population. However, SI and SIPA were not significant predictors of ICU admission and the need for surgery analysis.

Early packed red blood cell transfusion in major trauma patients: Evaluation and comparison of different prediction scores for massive transfusion

BACKGROUND AND OBJECTIVES

Our study sought to evaluate and compare different prediction scores for massive transfusion in-hospital packed red blood cell (PRBC) transfusions.

MATERIALS AND METHODS

Between January 2013 and December 2018, 1843 trauma patients were enrolled in the registry of a level-1 trauma centre. All prehospital and in-hospital variables needed to calculate the Shock Index and RED FLAG, Assessment of Blood Consumption (ABC) and Trauma Associated Severe Hemorrhage (TASH) scores were prospectively collected in the registry. The primary endpoint was the initiation of transfusion within the first hour of the patient's arrival at the hospital.

RESULTS

A total of 1767 patients were included for analysis with a mean age of 43 years (±19) and a mean Injury Severity Score of 15 (±14). The in-hospital TASH score had the highest predictive performance overall (area under the curve [AUC] = 0.925, 95% confidence interval [CI] [0.904-0.946]), while the RED FLAG score (AUC = 0.881, 95% CI [0.854-0.908]) had the greatest prehospital predictive performance compared to the ABC score (AUC = 0.798, 95% CI [0.759-0.837]) and Shock Index (AUC = 0.795, 95% CI [0.752-0.837]). Using their standard thresholds, the RED FLAG score was the most efficient in predicting early transfusion (sensitivity: 87%, specificity: 76%, positive predictive value: 25%, negative predictive value: 99%, Youden index: 0.63).

CONCLUSION

The RED FLAG score appears to outperform both the ABC score and the Shock Index in predicting early in-hospital transfusion in trauma patients managed by pre-hospital teams. If adopted, this score could be used to give advance warning to trauma centres or even to initiate early transfusion during pre-hospital care.

Evaluation of the ability of haemodynamic variables obtained with minimally invasive techniques to assess fluid responsiveness in endotoxaemic Beagles

OBJECTIVE

To examine the ability of different haemodynamic variables recorded by minimally invasive monitoring techniques to assess fluid responsiveness (FR) in endotoxaemic Beagles.

STUDY DESIGN

Prospective terminal experimental study.

ANIMALS

A group of six healthy, purpose-bred Beagle dogs (three intact females and males), age 5-9.8 years (range) and weighing 11.4-17.9 kg.

METHODS

Endotoxaemic shock was induced by injecting 1 mg kg^-1Escherichia coli lipopolysaccharide (LPS) intravenously in six sevoflurane-anaesthetized mechanically ventilated Beagles for another project. After 10 minutes, three Ringer's acetate boluses (10 mL kg^-1) were administered each over 10 minutes with collection of haemodynamic data immediately before and after each bolus. Thereafter, arterial hypotension was treated with noradrenaline ± dexmedetomidine until arterial pressures increased to a target value. After a wash-out period of 20 minutes another three boluses of fluid were administered and measurements were repeated equally. For each fluid bolus, FR was considered positive when change (Δ) in stroke volume measured by pulmonary artery thermodilution was ≥15%. To test predictive accuracy for FR, we recorded heart rate, invasive arterial, right atrial and pulmonary capillary wedge pressures, pulse wave transit time with haemodynamic monitors, calculated pulse pressure, shock index and rate over pressure evaluation (ROPE) and measured stroke distance and corrected flow time (FTc) with oesophageal Doppler monitoring.

RESULTS

A total of 35 measurements (19 positive and 16 negative responses) were evaluated. A FTc < 330 ms, Δ pulse pressure ≥20%, Δ shock index ≤-14% and ΔROPE ≤-17% were the most significant indicators of positive FR with an area under the receiver operating characteristics curve between 0.72 and 0.74.

CONCLUSIONS AND CLINICAL RELEVANCE

In endotoxaemic Beagles, none of the assessed haemodynamic variables could predict FR with high sensitivity and specificity.

A Multicentric, Randomized, Controlled Phase III Study of Centhaquine (Lyfaquin®) as a Resuscitative Agent in Hypovolemic Shock Patients

Introduction

Centhaquine (Lyfaquin^®) showed significant safety and efficacy in preclinical and clinical phase I and II studies.

Methods

A prospective, multicentric, randomized phase III study was conducted in patients with hypovolemic shock, systolic blood pressure (SBP) ≤ 90 mmHg, and blood lactate levels ≥ 2 mmol/L. Patients were randomized in a 2:1 ratio to the centhaquine group (n = 71) or the control (saline) group (n = 34). Every patient received standard of care (SOC) and was followed for 28 days. The study drug (normal saline or centhaquine 0.01 mg/kg) was administered in 100 mL of normal saline infusion over 1 h. The primary objectives were to determine changes (mean through 48 h) in SBP, diastolic blood pressure (DBP), blood lactate levels, and base deficit. The secondary objectives included the amount of fluids, blood products, and vasopressors administered in the first 48 h, duration of hospital stay, time in intensive care units, time on ventilator support, change in acute respiratory distress syndrome (ARDS), multiple organ dysfunction syndrome (MODS), and the proportion of patients with 28-day all-cause mortality.

Results

The demographics of patients and baseline vitals in both groups were comparable. The cause of hypovolemic shock was trauma in 29.4 and 47.1% of control group and centhaquine group patients, respectively, and gastroenteritis in 44.1 and 29.4%, respectively. Shock index (SI) and quick sequential organ failure assessment at baseline were similar in the two groups. An equal amount of fluids and blood products were administered in both groups during the first 48 h of resuscitation. A lesser amount of vasopressors was needed in the first 48 h of resuscitation in the centhaquine group. An increase in SBP from baseline was consistently higher up to 48 h (12.9% increase in area under the curve from 0 to 48 h [AUC_0–48]) in the centhaquine group than in the control group. A significant increase in pulse pressure (48.1% increase in AUC_0–48) in the centhaquine group compared with the control group suggests improved stroke volume due to centhaquine. The SI was significantly lower in the centhaquine group from 1 h (p = 0.032) to 4 h (p = 0.049) of resuscitation. Resuscitation with centhaquine resulted in a significantly greater number of patients with improved blood lactate (control 46.9%; centhaquine 69.3%; p = 0.03) and the base deficit (control 43.7%; centhaquine 69.8%; p = 0.01) than in the control group. ARDS and MODS improved with centhaquine, and an 8.8% absolute reduction in 28-day all-cause mortality was observed in the centhaquine group.

Conclusion

Centhaquine is an efficacious resuscitative agent for treating hypovolemic shock. The efficacy of centhaquine in distributive shock is being explored.

Trial Registration

Clinical Trials Registry, India; ctri.icmr.org.in, CTRI/2019/01/017196; clinicaltrials.gov, NCT04045327.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40265-021-01547-5.

A multicentric, randomized, controlled phase III study of centhaquine (Lyfaquin ® ) as a resuscitative agent in hypovolemic shock patients

INTRODUCTION

Centhaquine (Lyfaquin ^® ) showed significant safety and efficacy in preclinical and clinical phase I and II studies.

METHODS

A prospective, multicentric, randomized phase III study was conducted in patients with hypovolemic shock having systolic blood pressure (SBP) of ≤90 mm Hg and blood lactate levels of ≥2 mmol/L. Patients were randomized in a 2:1 ratio, 71 patients to the centhaquine group and 34 patients to the control (saline) group. Every patient received standard of care (SOC) and was followed for 28 days. The study drug (normal saline or centhaquine (0.01 mg/kg)) was administered in 100 mL of normal saline infusion over 1 hour. The primary objectives were to determine changes (mean through 48 hours) in SBP, diastolic blood pressure (DBP), blood lactate levels, and base deficit. The secondary objectives included the amount of fluids, blood products, vasopressors administered in the first 48 hours, duration of hospital stay, time in ICU, time on the ventilator support, change in patient's Acute Respiratory Distress Syndrome (ARDS), Multiple Organ Dysfunction Syndrome (MODS) scores, and the proportion of patients with 28-day all-cause mortality.

RESULTS

The demographics of patients and baseline vitals in both groups were comparable. Trauma was the cause of hypovolemic shock in 29.41% of control and 47.06% of centhaquine, gastroenteritis in 44.12% of control, and 29.41% of centhaquine patients. An equal amount of fluids and blood products were administered in both groups during the first 48 hours of resuscitation. A lesser amount of vasopressors was needed in the first 48 hours of resuscitation in the centhaquine group. An increase in SBP from the baseline was consistently higher in the centhaquine group than in the control. A significant increase in pulse pressure in the centhaquine group than the control group suggests improved stroke volume due to centhaquine. The shock index was significantly lower in the centhaquine group than control from 1 hour (p=0.0320) till 4 hours (p=0.0494) of resuscitation. Resuscitation with centhaquine had a significantly greater number of patients with improved blood lactate and the base deficit than the control group. ARDS and MODS improved with centhaquine, and an 8.8% absolute reduction in 28-day all-cause mortality was observed in the centhaquine group.

CONCLUSION

Centhaquine is a highly efficacious resuscitative agent for treating hypovolemic shock. The efficacy of centhaquine in distributive shock due to sepsis and COVID-19 is being explored.

TRIAL REGISTRATION

Clinical Trials Registry, India; ctri.icmr.org.in, CTRI/2019/01/017196; clinicaltrials.gov, NCT04045327 .

KEY SUMMARY POINTS

A multicentric, randomized, controlled trial was conducted to evaluate the efficacy of centhaquine in hypovolemic shock patients.One hundred and five patients were randomized 2:1 to receive centhaquine or saline. Centhaquine was administered at a dose of 0.01 mg/kg in 100 mL saline and infused over 1 hour. The control group received 100 mL of saline over a 1-hour infusion.Centhaquine improved blood pressure, shock index, reduced blood lactate levels, and improved base deficit. Acute Respiratory Distress Syndrome (ARDS) and Multiple Organ Dysfunction Syndrome (MODS) score improved with centhaquine.An 8.8% absolute reduction in 28-day all-cause mortality was observed in the centhaquine group. There were no drug-related adverse events in the study.

Elderly patients (≥ 80 years) with acute calculous cholangitis have similar outcomes as non-elderly patients (< 80 years): Propensity score-matched analysis

BACKGROUND

Acute cholangitis (AC) is a disease spectrum with varying extent of severity. Age ≥ 75 years forms part of the criteria for moderate (Grade II) severity in both the Tokyo Guidelines (TG13 and TG18). Aging is associated with reduced physiological reserves, frailty, and sarcopenia. However, there is evidence that age itself is not the determinant of inferior outcomes in elective and emergency biliary diseases. There is a paucity of reports comparing clinical outcomes amongst elderly patients vs non-elderly patients with AC.

AIM

To investigate the effect of age (≥ 80 years) on AC's morbidity and mortality using propensity score matching (PSM).

METHODS

This is a single-center retrospective cohort study of all patients diagnosed with calculous AC (January 2016 to December 2016) and ≥ 80 years old (January 2012 to December 2016) at a tertiary university-affiliated teaching hospital. Inclusion criteria were patients who were treated for suspected or confirmed AC secondary to biliary stones. Patients with AC on a background of hepatobiliary malignancy, indwelling permanent metallic biliary stents, or concomitant pancreatitis were excluded. Elderly patients were defined as ≥ 80 years old in our study. A 1:1 PSM analysis was performed to reduce selection bias and address confounding factors. Study variables include comorbidities, vital parameters, laboratory and radiological investigations, and type of biliary decompression, including the time for endoscopic retrograde cholangiopancreatography (ERCP). Primary outcomes include in-hospital mortality, 30-d and 90-d mortality. Length of hospital stay (LOS) was the secondary outcome.

RESULTS

Four hundred fifty-seven patients with AC were included in this study (318 elderly, 139 non-elderly). PSM analysis resulted in a total of 224 patients (112 elderly, 112 non-elderly). The adoption of ERCP between elderly and non-elderly was similar in both the unmatched (elderly 64.8%, non-elderly 61.9%, P = 0.551) and matched cohorts (elderly 68.8% and non-elderly 58%, P = 0.096). The overall in-hospital mortality, 30-d mortality and 90-d mortality was 4.6%, 7.4% and 8.5% respectively, with no statistically significant differences between the elderly and non-elderly in both the unmatched and matched cohorts. LOS was longer in the unmatched cohort [elderly 8 d, interquartile range (IQR) 6-13, vs non-elderly 8 d, IQR 5-11, P = 0.040], but was comparable in the matched cohort (elderly 7.5 d, IQR 5-11, vs non-elderly 8 d, IQR 5-11, P = 0.982). Subgroup analysis of patients who underwent ERCP demonstrated the majority of the patients (n = 159/292, 54.5%) had delayed ERCP (> 72 h from presentation). There was no significant difference in LOS, 30-d mortality, 90-d mortality, and in-hospital mortality in patients who had delayed ERCP in both the unmatched and matched cohort (matched cohort: in-hospital mortality [n = 1/42 (2.4%) vs 1/26 (3.8%), P = 0.728], 30-d mortality [n = 2/42 (4.8%) vs 2/26 (7.7%), P = 0.618], 90-d mortality [n = 2/42 (4.8%) vs 2/26 (7.7%), P = 0.618], and LOS (median 8.5 d, IQR 6-11.3, vs 8.5 d, IQR 6-15.3, P = 0.929).

CONCLUSION

Mortality is indifferent in the elderly (≥ 80 years old) and non-elderly patients (< 80 years old) with AC.

Validation of shock index for predicting mortality in older patients with dengue fever

BACKGROUND

Older adults have a higher mortality for dengue fever (DF). However, the best method for predicting mortality is still unclear.

AIMS

We conducted this study to evaluate the shock index (SI) for this issue.

METHODS

A retrospective case-control study was conducted by recruiting older patients (≥ 65 years old) with DF who visited the study hospital in southern Taiwan during the 2015 DF outbreak. Demographic data, vital signs, past histories, decision groups, complications, and mortality were included in the analyses. We evaluated the accuracy of SI ≥ 1 for predicting 30-day mortality in this population.

RESULTS

A total of 626 patients with a mean age of 74.1 years and nearly equal sex distribution were recruited. The mean of SI (± standard deviation [SD]) was 0.6 (± 0.2) and patients with a SI ≥ 1 accounted for 3.5% of the total patients. Logistic regression showed that patients with SI ≥ 1 had a higher mortality than those with SI < 1 (odds ratio: 8.49; 95% confidence interval: 1.76-17.92). The area under the receiver-operating characteristic was 0.76, and the Hosmer-Lemeshow goodness of fit test was 0.48. The SI ≥ 1 had a sensitivity, specificity, positive predictive value, and negative predictive value of 14.8%, 97.0%, 18.2%, and 96.2% for predicting mortality.

CONCLUSIONS

The SI ≥ 1 is an easy tool that can be potentially used to predict 30-day mortality in older DF patients, especially in DF outbreak. It has a high specificity and negative predictive value for excluding patients with high-risk mortality.

Utility of triage shock index in predicting patient outcome in calcium channel blocker poisoning

Introduction:

Shock index is defined as heart rate divided by systolic blood pressure. It is reported as a predictor of morbidity and mortality in trauma and acute myocardial infarction in previous studies. It may be valuable in evaluation of calcium channel blocker poisoning. The objective of this study is to examine the probability of serious outcome based on first measured shock index in patients who presented to emergency department with calcium channel blocker poisoning.

Methods:

A retrospective chart review was conducted on calcium channel blocker poisoning cases in Hong Kong Poison Information Centre from 1 July 2008 to 30 June 2017. Shock index was calculated with blood pressure and pulse measurement at emergency department triage. Odds ratios of various variables for major outcome, mortality, intensive care unit admission, length of stay in acute hospital were calculated by multivariate analysis or negative binomial regression where appropriate. The performance of shock index in predicting major outcome was evaluated with receiver operating characteristic curve.

Results:

A total of 390 cases were identified, of whom 25.1% developed major outcome and 5.6% died. Shock index showed significant association with major outcome (odds ratio: 17.017, 95% confidence interval: 5.521–52.455). The area under the receiver operating characteristic curve for shock index in predicting major outcome was 0.7008 (95% confidence interval: 0.64–0.76).

Conclusion:

Higher shock index is associated with worse patient outcome in calcium channel blocker poisoning. However, shock index alone is not reliable in predicting patient outcome. Further research is needed before shock index can be incorporated for use in patient management in poisoning with calcium channel blocker or other anti-hypertensives.

Perfusion indices can predict early volume depletion in a blood donor model

INTRODUCTION

Blood donation from healthy donors is used experimental model that surrogates for class 1 hemorrhage in humans. We examined changes in the perfusion index (PI) and plethysmographic variability index (PVI) in healthy blood donors after donating a unit of blood, and we evaluated the usability of these indices in detecting blood loss volumes of less than 750 mL (class 1 hemorrhagic shock trauma patients).

MATERIALS AND METHODS

This study is a prospective, cross-sectional study. 180 healthy volunteers aged 18 and over, who donated blood at the local blood bank, were included in the study consecutively. The age, gender, and body mass index of the volunteers were recorded and, before and after the blood donation, the vital signs and perfusion indices were measured.

RESULTS

Of the donors, 61.7% were men (n = 111), and the median age of all donors was 32 (IQR: 21-39). A statistically significant difference was found between the hemodynamic parameters and PIs before and after the blood donation (p < 0.01 for all parameters; median difference of PI [- 1.45, 95% CI: (- 0.9)-( - 2)], median difference of PVI [6, 95% CI: 7.77-4.23].

CONCLUSION

We evaluated the perfusion indices in the early diagnosis of blood volume loss in patients admitted to the emergency department due to trauma. After the participants donated one unit of blood, we found that their PI decreased and PVI increased compared to the measurements before the blood donation. Considering that major bleeding starts in the very early stage as minor bleeding, it is essential for emergency physicians to recognize class 1 hemorrhagic shock patients. Further, non-invasive and straightforward procedures, such as measuring PI and PVI, can be particularly useful in identifying blood loss volumes of less than 750 mL.

A Noninvasive Stroke Volume Monitoring for Early Detection of Minimal Blood Loss: A Pilot Study

INTRODUCTION

Alternation in traditional vital signs can only be observed during advanced stages of hypovolemia and shortly before the hemodynamic collapse. However, even minimal blood loss induces a decrease in the cardiac preload which translates to a decrease in stroke volume, but these indices are not readily monitored. We aimed to determine whether minor hemodynamic alternations induced by controlled and standardized hypovolemia can be detected by a whole-body bio-impedance technology.

METHODS

This was a non-randomized controlled trial that enrolled healthy blood donors. Vital signs, as well as shock index and stroke volume (SV), were recorded using noninvasive cardiac system, a noninvasive whole-body impedance-based hemodynamic analysis system, during phlebotomy.

RESULTS

Sixty subjects were included in the study group and 20 in the control group. Blood loss of 450 mL resulted in a significant decrease in systolic blood pressure (5 mm Hg; 95% CI 3, 6) and SV (5.07 mL; 95% CI 3.21, 6.92), and increase in shock index (0.03 bpm/mm Hg; 95% CI 0.01, 0.05). Clinically detectable changes (≥10%) in blood pressure and shock index were detectable in 15% and 5%, respectively. SV decreased by more than 10% in 40% of blood donors. No significant changes occurred in the control group.

CONCLUSION

Continuous noninvasive monitoring of SV may be superior to conventional indices (e.g., heart rate, blood pressure, or shock index) for early identification of acute blood loss. As an operator-independent and point-of-care technology, the SV whole body bio-impedance measurement may assist in accurate monitoring of potentially bleeding patients and early identification of hemorrhage.

Optimal Prospective Predictors of Mortality in Austere Environments

BACKGROUND

Prospective predictors of trauma-related outcomes have been validated to guide management in low-resource settings. The primary objective of this study was to determine the optimal prospective prediction method for mortality within combat and humanitarian trauma.

MATERIALS AND METHODS

Retrospective review of the Department of Defense Trauma Registry from 2008 to 2016 was performed for adult patients. Areas under receiver operating characteristic curves (AUROCs) were calculated to assess the predictability of shock index (SI), reverse SI × Glasgow Coma Scale (rSIG), SI × Glasgow Coma Scale (SIG), Revised Trauma Score, and Trauma and Injury Severity Score (TRISS) on mortality at point of injury, arrival in emergency department (ED), and the difference in vital signs between those time points.

RESULTS

A total of 22,218 patients were included. Overall, 97.1% were male, median age range 25-29 y, Injury Severity Score 9.4 ± 0.07, with predominantly penetrating injuries (58.1%), and mortality of 3.4%. ED vitals yielded higher predictability of mortality for all tests based on higher AUROCs. TRISS and rSIG demonstrated the highest AUROCs (0.955 and 0.923, respectively). The optimal cutoff value for rSIG was 14.1 (sensitivity 89% and specificity 87%). rSIG values <14.1 were significantly associated with mortality (P < 0.01; odds ratio = 5.901).

CONCLUSIONS

Initial ED vital signs represented a better predictor of early mortality compared with point of injury vital signs for all predictive tools assessed. TRISS and rSIG proved to be most predictive of mortality. However, of the prospective tools assessed, rSIG may be optimal scoring tool because of its ease of calculation and its increased ability to predict mortality.

Blood Loss Estimation in Small Animals and Assessment of a Pictorial Tool to Improve Accuracy in a Global Population of Veterinary Anesthesia Staff

Visual estimation of blood loss is the most common form of evaluating intraoperative hemorrhage, and is also the most inaccurate. This study investigated the visual estimation accuracy of a global population of anesthesia staff and students as an initial estimation and also with the assistance of a pictorial guide. A voluntary, two-part, online, anonymous survey was distributed to members of two email databases with an interest in anesthesia, including students, nurses, interns, residents, general practitioners, and specialists. The survey consisted of visual and brief descriptive depictions of blood loss scenarios involving small animals, principally including images of common surgical items and receptacles containing a blood-like substance. Each participant estimated the blood volume (in mL) for each scenario twice, initially (Pre-Guide [PGD]) and then with the aid of a pictorial guide (With-Guide [WGD]). The pictorial guide used similar images labeled with corresponding volumes. Data was analyzed for normality with the Shapiro-Wilks test, corrected to absolute error and compared for statistical significance using the Wilcoxon signed-ranks test or the Kruskal-Wallis test as appropriate. The overall raw PGD phase median estimation error was−27 mL (range −99 to 248 mL). The PGD raw median error increased with scenario complexity. There were no differences between role, gender, experience, or country of origin. The overall median raw estimation error for the WGD phase was 13 mL (range −80 ml to 143 mL) (p = 0.0128). Visual blood loss estimation is inaccurate amongst veterinary anesthetists and associated staff, showing decreasing accuracy with increasing complexity. A pictorial guide improves the accuracy generally, and specifically for more complex scenarios which are likely to reflect the clinical situation.

Artificial Intelligence and Machine Learning in Anesthesiology

Commercial applications of artificial intelligence and machine learning have made remarkable progress recently, particularly in areas such as image recognition, natural speech processing, language translation, textual analysis, and self-learning. Progress had historically languished in these areas, such that these skills had come to seem ineffably bound to intelligence. However, these commercial advances have performed best at single-task applications in which imperfect outputs and occasional frank errors can be tolerated.The practice of anesthesiology is different. It embodies a requirement for high reliability, and a pressured cycle of interpretation, physical action, and response rather than any single cognitive act. This review covers the basics of what is meant by artificial intelligence and machine learning for the practicing anesthesiologist, describing how decision-making behaviors can emerge from simple equations. Relevant clinical questions are introduced to illustrate how machine learning might help solve them-perhaps bringing anesthesiology into an era of machine-assisted discovery.

Ability of an Arterial Waveform Analysis-Derived Hypotension Prediction Index to Predict Future Hypotensive Events in Surgical Patients

BACKGROUND

Intraoperative hypotension is associated with worse perioperative outcomes for patients undergoing major noncardiac surgery. The Hypotension Prediction Index is a unitless number that is derived from an arterial pressure waveform trace, and as the number increases, the risk of hypotension occurring in the near future increases. We investigated the diagnostic ability of the Hypotension Prediction Index in predicting impending intraoperative hypotension in comparison to other commonly collected perioperative hemodynamic variables.

METHODS

This is a 2-center retrospective analysis of patients undergoing major surgery. Data were downloaded and analyzed from the Edwards Lifesciences EV1000 platform. Receiver operating characteristic curves were constructed for the Hypotension Prediction Index and other hemodynamic variables as well as event rates and time to event.

RESULTS

Two hundred fifty-five patients undergoing major surgery were included in the analysis yielding 292,025 data points. The Hypotension Prediction Index predicted hypotension with a sensitivity and specificity of 85.8% (95% CI, 85.8%-85.9%) and 85.8% (95% CI, 85.8%-85.9%) 5 minutes before a hypotensive event (area under the curve, 0.926 [95% CI, 0.925-0.926]); 81.7% (95% CI, 81.6%-81.8%) and 81.7% (95% CI, 81.6%-81.8%) 10 minutes before a hypotensive event (area under the curve, 0.895 [95% CI, 0.894-0.895]); and 80.6% (95% CI, 80.5%-80.7%) and 80.6% (95% CI, 80.5%-80.7%) 15 minutes before a hypotensive event (area under the curve, 0.879 [95% CI, 0.879-0.880]). The Hypotension Prediction Index performed superior to all other measured hemodynamic variables including mean arterial pressure and change in mean arterial pressure over a 3-minute window.

CONCLUSIONS

The Hypotension Prediction Index provides an accurate real time and continuous prediction of impending intraoperative hypotension before its occurrence and has superior predictive ability than the commonly measured perioperative hemodynamic variables.

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.

Shock index in patients with traumatic solid organ injury as a predictor of massive blood transfusion protocol activation

Purpose

We aimed to assess the utility of shock index (SI) to predict the need for massive transfusion protocol (MTP) in patients with solid organ injury (SOI) in a Level 1 Trauma center.

Methods

We conducted a retrospective analysis for patients with SOI between 2011 and 2014. Patients were categorized according to on-admission SI into low (< 0.8) and high SI (≥0.8) group.

Results

A total of 4500 patients were admitted with trauma, of them 572 sustained SOIs (289 patients had SI ≥0.8). In comparison to low SI, patients with high SI were younger, had higher injury severity scores (ISS) and lower Trauma and Injury Severity Score (TRISS); (p < 0.001). The proportion of exploratory laparotomy (EXLap), blood transfusion (BT), MTP activation, sepsis and hospital mortality were significantly higher in patients with high SI. Serum lactate (r = 0.34), hematocrit (r = − 0.34), ABC score (r = 0.62), ISS (r = 0.35), and amount of transfused blood (r = 0.22) were significantly correlated with SI. On multivariable regression analysis using 9 relevant variables (age, sex, ISS, ED GCS, serum lactate, hematocrit, Abdomen AIS and Focused assessment with sonography in trauma (FAST) and SI), SI ≥ 0.8 was an independent predictor of BT (OR 2.80; 95%CI 1.56–4.95) and MTP (OR 2.81;95% CI 1.09–7.21) .

Conclusions

In patients with SOI, SI is a simple bedside predictor for BT and MTP activation. Further prospective studies are needed to support our findings.

Shock index in the emergency department: utility and limitations

Shock index (SI) is defined as the heart rate (HR) divided by systolic blood pressure (SBP). It has been studied in patients either at risk of or experiencing shock from a variety of causes: trauma, hemorrhage, myocardial infarction, pulmonary embolism, sepsis, and ruptured ectopic pregnancy. While HR and SBP have traditionally been used to characterize shock in these patients, they often appear normal in the compensatory phase of shock and can be confounded by factors such as medications (eg, antihypertensives, beta-agonists). SI >1.0 has been widely found to predict increased risk of mortality and other markers of morbidity, such as need for massive transfusion protocol activation and admission to intensive care units. Recent research has aimed to study the use of SI in patients immediately on arrival to the emergency department (ED). In this review, we summarize the literature pertaining to use of SI across a variety of settings in the management of ED patients, in order to provide context for use of this measure in the triage and management of critically ill patients.