Ion shift index as a promising prognostic indicator in adult patients resuscitated from cardiac arrest

Lactate versus Phosphate as Biomarkers to Aid Mechanical Circulatory Support Decisions in Patients with Out-of-Hospital Cardiac Arrest and Return of Spontaneous Circulation

AIMS

Identifying patients who may benefit from mechanical circulatory support (MCS) after out-of-hospital cardiac arrest (OHCA) and return of spontaneous circulation (ROSC) remains challenging; thus, a search for helpful biomarkers is warranted. We aimed to evaluate phosphate and lactate levels on admission regarding their associations with survival with and without MCS.

METHODS

In 224 OHCA patients who achieved ROSC, the initial phosphate and lactate levels were investigated to discriminate in-hospital mortality by receiver operating characteristic (ROC) curves. According to the Youden Index (YI) from the respective ROC, the groups were risk stratified by both biomarkers, and 30-day mortality was analyzed in patients with and without MCS.

RESULTS

Within the entire collective, MCS was not associated with a better chance of survival. Both phosphate and lactate level elevations showed good yet comparable discriminations to predict mortality (areas under the curve: 0.80 vs. 0.79, p = 0.74). In patients with initial phosphate values > 2.2 mmol/L (>YI), 30-day mortality within the MCS cohort was lower (HR 2.3, 95% CI: 1.4-3.7; p = 0.0037). In patients with lower phosphate levels and groups stratified by lactate, 30-day mortality was similar in patients with and without MCS.

CONCLUSIONS

We found a significant association between survival and MCS therapy in patients with phosphate levels above 2.2 mmol/L (Youden Index), and a similar discrimination of patient overall survival by lactate and phosphate. Prospective studies should assess the possible independent prognostic value of phosphate and its clearance for MCS efficiency.

THE INITIAL ION SHIFT INDEX AS A PROGNOSTIC INDICATOR TO PREDICT PATIENT SURVIVAL IN TRAUMATIC DAMAGE CONTROL LAPAROTOMY PATIENTS

ABSTRACT

Objective: The ion shift index (ISI), which considers extracellular fluid ions such as phosphate, calcium, and magnesium, represents the ion shift following ischemia; concentrations of these ions are maintained within narrow normal ranges by adenosine triphosphate-dependent homeostasis. The ISI is defined as follows: {potassium (mmol/L-1) + phosphate (mmol/L-1) + Mg (mmol/L-1)}/calcium (mmol/L-1). This study investigated the possibility of predicting the 30-day survival rate of patients who underwent traumatic damage control laparotomy by comparing ISI and other laboratory findings, as well as the initial Trauma and Injury Severity Score (TRISS) and shock indices. Methods: Among the 134 patients who underwent damage control surgery between November 2012 and December 2021, 115 patients were enrolled in this study. Data regarding injury mechanism, age, sex, laboratory findings, vital signs, Glasgow Coma Scale score, Injury Severity Score, Abbreviated Injury Scale score, blood component transfusion, type of surgery, postoperative laboratory outcomes, morbidity, mortality rates, fluids administered, and volume of transfusions were collected and analyzed. Results: In univariate analysis, the odds ratio of the initial ISI was 2.875 (95% confidence interval, 1.52-5.43; P = 0.04), which showed a higher correlation with mortality compared with other indices. The receiver operating characteristic (ROC) curve and area under the ROC curve (AUC) were derived from different multivariable logistic regression models. The initial ISI had high sensitivity and specificity in predicting patient mortality (AUC, 0.7378). In addition, in the model combining the initial ISI, crystalloids, and TRISS, the AUC showed a high value (AUC, 0.8227). Conclusion: The ISI evaluated using electrolytes immediately after admission in patients undergoing traumatic damage control surgery may be a predictor of patient mortality.

The neuro-prognostic value of the ion shift index in cardiac arrest patients following extracorporeal cardiopulmonary resuscitation

BACKGROUND

The ion shift index (ISI) as a prognostic indicator that can show the severity of hypoxic-ischemic injury. We aimed to evaluate the performance of the ISI in predicting unfavorable neurological outcomes at hospital discharge in cardiac arrest (CA) patients following extracorporeal cardiopulmonary resuscitation (ECPR) and to compare its performance to other prognostic predictors.

METHODS

This was a retrospective observational study including adult CA patients treated with ECPR between January 2018 and December 2022 in a tertiary hospital. Data regarding clinical characteristics and laboratory parameters were collected from medical records. The ISI was determined based on the first available serum electrolyte levels after ECPR. The primary outcome was unfavorable neurological status at hospital discharge, defined as Cerebral Performance Categories 3-5. Comparisons of the characteristics between the two groups were made using the χ2 test for categorical variables and the t-test or non-parametric Mann-Whitney U-test for continuous variables, as appropriate. Correlation analysis was performed using Spearman's rank correlation coefficient. A two-tailed P-value <0.05 was considered statistically significant.

RESULTS

Among the 122 patients involved, 46 (37.7%) had out-of-hospital CA, and 88 had unfavorable neurological outcomes. The ISI was significantly higher in the unfavorable outcome group than in the favorable outcome group (3.74 [3.15-4.57] vs. 2.69 [2.51-3.07], P<0.001). A higher ISI level was independently related to unfavorable outcome (odds ratio=6.529, 95% confidence interval 2.239-19.044, P=0.001). An ISI level >3.12 predicted unfavorable outcomes with a sensitivity and specificity of 74.6% and 85.2%, respectively (P<0.001). The prognostic performance of ISI (area under the curve [AUC]=0.887) was similar to that of other predictors, such as gray-to-white matter ratio (AUC=0.850, P=0.433) and neuron-specific enolase (AUC=0.925, P=0.394).

CONCLUSION

ISI may be used as a prognostic biomarker to predict neurological outcomes in CA patients following ECPR.

Predicting neurological outcome in adult patients with cardiac arrest: systematic review and meta-analysis of prediction model performance

This work aims to assess the performance of two post-arrest (out-of-hospital cardiac arrest, OHCA, and cardiac arrest hospital prognosis, CAHP) and one pre-arrest (good outcome following attempted resuscitation, GO-FAR) prediction model for the prognostication of neurological outcome after cardiac arrest in a systematic review and meta-analysis. A systematic search was conducted in Embase, Medline, and Web of Science Core Collection from November 2006 to December 2021, and by forward citation tracking of key score publications. The search identified 1'021 records, of which 25 studies with a total of 124'168 patients were included in the review. A random-effects meta-analysis of C-statistics and overall calibration (total observed vs. expected [O:E] ratio) was conducted. Discriminatory performance was good for the OHCA (summary C-statistic: 0.83 [95% CI 0.81-0.85], 16 cohorts) and CAHP score (summary C-statistic: 0.84 [95% CI 0.82-0.87], 14 cohorts) and acceptable for the GO-FAR score (summary C-statistic: 0.78 [95% CI 0.72-0.84], five cohorts). Overall calibration was good for the OHCA (total O:E ratio: 0.78 [95% CI 0.67-0.92], nine cohorts) and the CAHP score (total O:E ratio: 0.78 [95% CI 0.72-0.84], nine cohorts) with an overestimation of poor outcome. Overall calibration of the GO-FAR score was poor with an underestimation of good outcome (total O:E ratio: 1.62 [95% CI 1.28-2.04], five cohorts). Two post-arrest scores showed good prognostic accuracy for predicting neurological outcome after cardiac arrest and may support early discussions about goals-of-care and therapeutic planning on the intensive care unit. A pre-arrest score showed acceptable prognostic accuracy and may support code status discussions.

Ion Shift Index at the Immediate Post-Cardiac Arrest Period as an Early Prognostic Marker in Out-of-Hospital Cardiac Arrest Survivors

The ion shift index (ISI) is a suggested marker to reflect the magnitude of ischemic damage. This study aimed to investigate the prognostic value of the ISI for predicting poor neurological outcomes at 6 months in comatose out-of-hospital cardiac arrest (OHCA) survivors by comparing it with the OHCA and Cardiac Arrest Hospital Prognosis (CAHP) scores. This observational registry-based cohort study included adult comatose OHCA survivors admitted to a tertiary care hospital in Korea between 2015 and 2021. The ISI was calculated using the serum electrolyte levels obtained within one hour of resuscitation. The primary outcome was poor neurological function (Cerebral Performance Category score of 3−5) at 6 months. Of the 250 OHCA survivors, 164 (65.6%) had poor neurological outcomes. These patients had a higher median ISI than those with good neurological outcomes (4.95 vs. 3.26, p < 0.001). ISI (adjusted odds ratio, 2.107; 95% confidence interval, 1.350−3.288, p = 0.001) was associated with poor neurological outcomes. The prognostic performance of ISI (area under the curve [AUC], 0.859) was similar to that of the OHCA score (AUC, 0.858; p = 0.968) and the CAHP score (AUC, 0.894; p = 0.183). ISI would be a prognostic biomarker for comatose OHCA survivors that is available during the immediate post-cardiac arrest period.

Association between ion shift index and prognosis in severe trauma patients without isolated head injury

INTRODUCTION

This study aimed to investigate the ion shift index (ISI) as a prognostic factor of severe trauma. We hypothesized that the initial ISI measured in the emergency department (ED) is associated with discharge survival in severe non-isolated head injury (IHI) patients.

MATERIALS AND METHODS

This retrospective observational study included severe trauma patients with available medical records from January 2017 to December 2018 but excluded those with IHI. Logistic regression analysis was conducted to identify the risk factors for mortality in non-IHI patients, and adjustments were performed for relevant covariates. An area under the receiver operating characteristics curve (AUROC) analysis was performed to examine the primary outcome of our study, which was mortality at hospital discharge in severe non-IHI trauma patients.

RESULTS

Of the 483 severe non-IHI trauma patients included in the study, 86 patients (17.8 %) died. The multiple logistic regression analysis demonstrated ISI (odds ratio [OR], 2.300; 95% CI, 1.183-4.470) was significantly associated with mortality in the non-IHI group. Additionally, trauma and injury severity score (TRISS; OR, 0.538; 95% CI, 0.447-0.649), lactate (OR, 1.410; 95% CI, 1.252-1.588), creatinine (OR, 1.554; 95% CI, 1.221-1.979), and activated partial thromboplastin time (aPTT; OR, 1.050; 95% CI, 1.021-1.080) were independently associated with mortality at hospital discharge. The AUROC values for TRISS, lactate, aPTT, creatinine, and ISI were as follows: 0.892 (95% CI, 0.861-0.918), 0.838 (95% CI, 0.803-0.870), 0.754 (95% CI, 0.712-0.792), 0.650 (95% CI, 0.606-0.693), and 0.848 (95% CI, 0.813-0.879), respectively. The AUROC for the multiple logistic regression model with ISI was 0.942 (95% CI, 0.917-0.962). In a model in which TRISS was omitted, the addition of ISI to other predictors significantly improved the AUROC to 0.900 (95% CI, 0.869-0.925) (p=0.039).

CONCLUSION

The initial ISI in the ED after trauma was associated with mortality in severe non-IHI trauma patients. In conjunction with other prognostic indicators, it could be used as an early prognostic marker, particularly if TRISS is unavailable.

PROLOGUE (PROgnostication using LOGistic regression model for Unselected adult cardiac arrest patients in the Early stages): Development and validation of a scoring system for early prognostication in unselected adult cardiac arrest patients

BACKGROUND

Early prognostication after cardiac arrest would be useful. We aimed to develop a scoring model for early prognostication in unselected adult cardiac arrest patients.

METHODS

We retrospectively analysed data of adult non-traumatic cardiac arrest patients treated at a tertiary hospital between 2014 and 2018. The primary outcome was poor outcome at hospital discharge (cerebral performance category, 3-5). Using multivariable logistic regression analysis, independent predictors were identified among known outcome predictors, that were available at intensive care unit admission, in patients admitted in the first 3 years (derivation set, N = 671), and a scoring system was developed with the variables that were retained in the final model. The scoring model was validated in patients admitted in the last 2 years (validation set, N = 311).

RESULTS

The poor outcome rates at hospital discharge were similar between the derivation (66.0%) and validation sets (64.3%). Age <59 years, witnessed collapse, shockable rhythm, adrenaline dose <2 mg, low-flow duration <18 min, reactive pupillary light reflex, Glasgow Coma Scale motor score ≥2, and levels of creatinine <1.21 mg dl^-1, potassium <4.4 mEq l^-1, phosphate <5.8 mg dl^-1, haemoglobin ≥13.2 g dl^-1, and lactate <8 mmol l^-1 were retained in the final multivariable model and used to develop the scoring system. Our model demonstrated excellent discrimination in the validation set (area under the curve of 0.942, 95% confidence interval 0.917-0.968).

CONCLUSIONS

We developed a scoring model for early prognostication in unselected adult cardiac arrest patients. Further validations in various cohorts are needed.

Clinical Predictive Models of Sudden Cardiac Arrest: A Survey of the Current Science and Analysis of Model Performances

Background

More than 500 000 sudden cardiac arrests (SCAs) occur annually in the United States. Clinical predictive models (CPMs) may be helpful tools to differentiate between patients who are likely to survive or have good neurologic recovery and those who are not. However, which CPMs are most reliable for discriminating between outcomes in SCA is not known.

Methods and Results

We performed a systematic review of the literature using the Tufts PACE (Predictive Analytics and Comparative Effectiveness) CPM Registry through February 1, 2020, and identified 81 unique CPMs of SCA and 62 subsequent external validation studies. Initial cardiac rhythm, age, and duration of cardiopulmonary resuscitation were the 3 most commonly used predictive variables. Only 33 of the 81 novel SCA CPMs (41%) were validated at least once. Of 81 novel SCA CPMs, 56 (69%) and 61 of 62 validation studies (98%) reported discrimination, with median c‐statistics of 0.84 and 0.81, respectively. Calibration was reported in only 29 of 62 validation studies (41.9%). For those novel models that both reported discrimination and were validated (26 models), the median percentage change in discrimination was −1.6%. We identified 3 CPMs that had undergone at least 3 external validation studies: the out‐of‐hospital cardiac arrest score (9 validations; median c‐statistic, 0.79), the cardiac arrest hospital prognosis score (6 validations; median c‐statistic, 0.83), and the good outcome following attempted resuscitation score (6 validations; median c‐statistic, 0.76).

Conclusions

Although only a small number of SCA CPMs have been rigorously validated, the ones that have been demonstrate good discrimination.

Turn-to-Shockable Rhythm Has Comparable Neurologic Outcomes to Initial Shockable Rhythm in Out-of-Hospital Cardiac Arrest Patients Who Underwent Targeted Temperature Management

Shockable rhythm in out-of-hospital cardiac arrest (OHCA) implies better outcome and underlying coronary stenosis. We investigated the neurologic outcome and coronary lesions between initial shockable rhythm and turn-to-shockable rhythm. This multicenter, retrospective observational study included adult nontraumatic OHCA survivors with any shockable rhythm during cardiopulmonary resuscitation (CPR) who underwent targeted temperature management between January 2010 and December 2016. Patients were divided into two groups according to the first monitored rhythm: initial shockable rhythm or turn-to-shockable rhythm. The primary outcome was good neurologic outcome at discharge based on cerebral performance categories, and the secondary outcomes were survival discharge, recurrent arrest, and coronary lesions. The two groups were matched in a 1:1 ratio using propensity score (PS). Of 426 patients, 137 and 289 patients were divided into the turn-to-shockable and initial shockable rhythm groups, respectively. Overall, 224 (52.6%) patients had good neurologic outcomes. The turn-to-shockable rhythm group had less patients with good neurologic outcome (57/137 vs. 167/289; p = 0.002) and less culprit lesions in the left anterior descending and left circumflex arteries. However, survival discharge and recurrent arrest were not different between the two groups, and the turn-to-shockable rhythm had no independent association with neurologic outcome (odds ratio, 1.874; 95% confidence interval, 0.909-3.863). In the PS-matched cohort, the turn-to-shockable rhythm group had similar good neurologic outcome (47/100 vs. 35/100, p = 0.083). Survival discharge, recurrent arrest, and coronary culprit lesions were not different between the two groups. In this PS-matched study, OHCA with any shockable rhythm during CPR had similar neurologic outcome and coronary culprit lesions, irrespective of the first monitored rhythm.