Elevated Modified Shock Index Within 24 Hours of ICU Admission Is an Early Indicator of Mortality in the Critically Ill

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

TRIAL REGISTRATION

ClinicalTrials.gov identifier - NCT02105415.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Abnormal shock index exposure and clinical outcomes among critically ill patients: A retrospective cohort analysis

PURPOSE

To assess the predictive value of a single abnormal shock index reading (SI ≥0.9; heart rate/systolic blood pressure [SBP]) for mortality, and association between cumulative abnormal SI exposure and mortality/morbidity.

MATERIALS AND METHODS

Cohort comprised of adult patients with an intensive care unit (ICU) stay ≥24-h (years 2010-2018). SI ≥0.9 exposure was evaluated via cumulative minutes or time-weighted average; SBP ≤100-mmHg was analyzed. Outcomes were in-hospital mortality, acute kidney injury (AKI), and myocardial injury.

RESULTS

18,197 patients from 82 hospitals were analyzed. Any single SI ≥0.9 within the ICU predicted mortality with 90.8% sensitivity and 36.8% specificity. Every 0.1-unit increase in maximum-SI during the first 24-h increased the odds of mortality by 4.8% [95%CI; 2.6-7.0%; p < .001]. Every 4-h exposure to SI ≥0.9 increased the odds of death by 5.8% [95%CI; 4.6-7.0%; p < .001], AKI by 4.3% [95%CI; 3.7-4.9%; p < .001] and myocardial injury by 2.1% [95%CI; 1.2-3.1%; p < .001]. ≥2-h exposure to SBP ≤100-mmHg was significantly associated with mortality.

CONCLUSIONS

A single SI reading ≥0.9 is a poor predictor of mortality; cumulative SI exposure is associated with greater risk of mortality/morbidity. The associations with in-hospital mortality were comparable for SI ≥0.9 or SBP ≤100-mmHg exposure. Dynamic interactions between hemodynamic variables need further evaluation among critically ill patients.

Hemodynamic profiles following digoxin use in patients with sepsis in the ICU

PURPOSE

To explore the impact of digoxin on hemodynamic parameters in patients with sepsis and tachycardia admitted to the intensive care unit.

MATERIALS AND METHODS

Retrospective review of adult patients admitted to the medical and mixed ICU at Mayo Clinic Rochester, Minnesota from March 2008 to February 2018, initiated on digoxin within 24 h of ICU stay. Hemodynamic parameters were reviewed before digoxin administration and at 6, 12 and 24 h after. Adverse events including new onset conduction abnormalities or arrhythmias during the first 48 h after digoxin administration were reviewed by a critical care cardiologist.

RESULTS

Study included 180 patients. We observed significant decrease in heart rate from 124 (115-138) beats/min 1 h before digoxin to 101 (87-117) 6 h after digoxin and 94 (84-112) 12 h after (p < .01). Median systolic blood pressure increased from 100 (91-112) mm Hg 1 h before to 110 (100-122) (p < .01) and 111 (103-124) at 6 and 12 h respectively after digoxin.

CONCLUSIONS

Early digoxin administration in patients with sepsis and tachycardia is uncommon but associated with improvements of hemodynamic parameters. These preliminary results will help formulate future hypotheses for focused trials on utility, efficacy and safety of digoxin in sepsis.

Shock index and modified shock index as triage screening tools for sepsis

BACKGROUND

Fever is one of the common conditions encountered in the emergency department, which related to a spectrum of diseases severity. Identifying sepsis patients from uncomplicated febrile patients is challenging in the emergency triage areas and pre-hospital settings.

OBJECTIVES

Assess the triage shock index (SI) and modified shock index (MSI) in febrile patients as predictors for sepsis and sepsis-related outcomes.

DESIGN

A retrospective cohort study.

SETTING

Patients presented to the Emergency Department of King Khalid University Hospital.

PATIENTS AND METHODS

The analysis included all febrile adult patients triaged with a temperature of 38 °C or more from January 2016 to December 2017. Based on triage vital sign we calculate the SI with cut-off levels of ≥0.7 and ≥1 and MSI with cut-off levels of ≥1 and ≥1.3. We report the Relative Risk, Sensitivity, Specificity, Positive and Negative Predictive Values of the predictors.

MAIN OUTCOME MEASURES

Sepsis and sepsis-related outcomes such as hyperlactatemia, ICU admission, and 28 days mortality.

SAMPLE SIZE

274 patients.

RESULTS

274 patients met our inclusion/exclusion criteria. Of the 274 patients, 252 patient (92%) were septic, 62 patients (22%) had hyperlactatemia, 20 patients admitted to the ICU, and 5 patient died within 28 days. An MSI of ≥1 had a sensitivity of 90% for sepsis predication, 85% for ICU admission and 100% for 28 days mortality. MSI of ≥1.3 showed a specificity (59%-100%) for all the outcomes of interest. Non-significant statistical trends of greater accuracy of MSI over SI.

CONCLUSION

MSI and SI were found to be promising predictors in triaging febrile patients. However no single cut-off values of MSI or SI were found to have an optimal accuracy for prediction of sepsis and sepsis-related outcomes. Further studies are required to assess the incorporation of MSI in a multi-item scaling system for the prediction of sepsis and its related outcomes.

LIMITATIONS

Small single center study and the results may not be generalizable.

A clinical prediction model to identify patients at high risk of hemodynamic instability in the pediatric intensive care unit

Background

Early recognition and timely intervention are critical steps for the successful management of shock. The objective of this study was to develop a model to predict requirement for hemodynamic intervention in the pediatric intensive care unit (PICU); thus, clinicians can direct their care to patients likely to benefit from interventions to prevent further deterioration.

Methods

The model proposed in this study was trained on a retrospective cohort of all patients admitted to a tertiary PICU at a single center in the United States, and validated on another retrospective cohort of all patients admitted to the PICU at a single center in the United Kingdom. The PICU clinical information system database (Intellivue Clinical Information Portfolio, Philips, UK) was interrogated to collect physiological and laboratory data. The model was trained using a variant of AdaBoost, which learned a set of low-dimensional classifiers, each of which was age adjusted.

Results

A total of 7052 patients admitted to the US PICU was used for training the model, and a total of 970 patients admitted to the UK PICU was used for validation. On the training/validation datasets, the model showed better prediction of hemodynamic intervention (area under the receiver operating characteristic (AUROC) = 0.81/0.81) than systolic blood pressure-based (AUCROC = 0.58/0.67) or shock index-based (AUCROC = 0.63/0.65) models. Both of these models were age adjusted using the same classifier.

Conclusions

The proposed model reliably predicted the need for hemodynamic intervention in PICU patients and provides better classification performance when compared to systolic blood pressure-based or shock index-based models alone. This model could readily be built into a clinical information system to identify patients at risk of hemodynamic instability.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-017-1874-z) contains supplementary material, which is available to authorized users.

Predictors of hemodynamic derangement during intubation in the critically ill: A nested case-control study of hemodynamic management-Part II

PURPOSE

Our primary aim was to identify predictors of immediate hemodynamic decompensation during the peri-intubation period.

METHODS

We conducted a nested case-control study of a previously identified cohort of adult patients needing intubation admitted to a medical-surgical ICU during 2013-2014. Hemodynamic derangement was defined as cardiac arrest and/or the development of systolic blood pressure <90mmHg and/or mean arterial pressure <65mmHg 30min following intubation. Data during the peri-intubation period was analyzed.

RESULTS

The final cohort included 420 patients. Immediate hemodynamic derangement occurred in 170 (40%) patients. On multivariate modeling, age/10year increase (OR 1.20, 95% CI 1.03-1.39, p=0.02), pre-intubation non-invasive ventilation (OR 1.71, 95% CI 1.04-2.80, p=0.03), pre-intubation shock index/1 unit (OR 5.37 95% CI 2.31-12.46, p≤0.01), and pre-intubation modified shock index/1 unit (OR 2.73 95% CI 1.48-5.06, p≤0.01) were significantly associated with hemodynamic derangement. Those experiencing hemodynamic derangement had higher ICU [47 (28%) vs. 33 (13%); p≤0.001] and hospital [69 (41%) vs. 51 (20%); p≤0.001] mortality.

CONCLUSIONS

Hemodynamic derangement occurred at a rate of 40% and was associated with increased mortality. Increasing age, use of non-invasive ventilation before intubation, and increased pre-intubation shock and modified shock index values were significantly associated with hemodynamic derangement post-intubation.

Elevated modified shock index in early sepsis is associated with myocardial dysfunction and mortality

PURPOSE

The aim of this study was to explore the association of an elevated modified shock index (MSI) in sepsis and myocardial dysfunction.

METHODS

This single center exploratory retrospective cohort study was conducted at Mayo Clinic from 2011 to 2014. It includes adults admitted to the medical intensive care unit with severe sepsis or septic shock. The time MSI>1.3, area under the curve, in the first 6h was assessed using logistic regression for primary outcomes of myocardial dysfunction and depression and secondary outcomes including mortality and SOFA score.

RESULTS

Overall 578 individuals met inclusion criteria, 169 (29%) developed myocardial dysfunction and 23 (4%) myocardial depression. Adjusted for age, gender, Charlson score, and baseline APACHE 3 score, area MSI>1.3 was associated with increased odds of myocardial dysfunction (OR 1.10, 95% CI 1.00-1.21; p=0.058) and depression (OR 1.28, 95% CI 1.07-1.53; p=0.007). Associations were also seen with ICU mortality (OR 1.17, 95% CI 1.04-1.32; p=0.011), hospital mortality (OR 1.13, 95% CI 1.02-1.25; p=0.025) and SOFA score.

CONCLUSION

Elevated modified shock index during early sepsis is associated with the development of myocardial dysfunction and depression, SOFA score and mortality.