Initial blood pH during cardiopulmonary resuscitation in out-of-hospital cardiac arrest patients: a multicenter observational registry-based study

2024 RECOVER Guidelines: Monitoring. Evidence and knowledge gap analysis with treatment recommendations for small animal CPR

OBJECTIVE

To systematically review evidence on and devise treatment recommendations for patient monitoring before, during, and following CPR in dogs and cats, and to identify critical knowledge gaps.

DESIGN

Standardized, systematic evaluation of literature pertinent to peri-CPR monitoring following Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology. Prioritized questions were each reviewed by Evidence Evaluators, and findings were reconciled by Monitoring Domain Chairs and Reassessment Campaign on Veterinary Resuscitation (RECOVER) Co-Chairs to arrive at treatment recommendations commensurate to quality of evidence, risk:benefit relationship, and clinical feasibility. This process was implemented using an Evidence Profile Worksheet for each question that included an introduction, consensus on science, treatment recommendations, justification for these recommendations, and important knowledge gaps. A draft of these worksheets was distributed to veterinary professionals for comment for 4 weeks prior to finalization.

SETTING

Transdisciplinary, international collaboration in university, specialty, and emergency practice.

RESULTS

Thirteen questions pertaining to hemodynamic, respiratory, and metabolic monitoring practices for identification of cardiopulmonary arrest, quality of CPR, and postcardiac arrest care were examined, and 24 treatment recommendations were formulated. Of these, 5 recommendations pertained to aspects of end-tidal CO2 (ETco2) measurement. The recommendations were founded predominantly on very low quality of evidence, with some based on expert opinion.

CONCLUSIONS

The Monitoring Domain authors continue to support initiation of chest compressions without pulse palpation. We recommend multimodal monitoring of patients at risk of cardiopulmonary arrest, at risk of re-arrest, or under general anesthesia. This report highlights the utility of ETco2 monitoring to verify correct intubation, identify return of spontaneous circulation, evaluate quality of CPR, and guide basic life support measures. Treatment recommendations further suggest intra-arrest evaluation of electrolytes (ie, potassium and calcium), as these may inform outcome-relevant interventions.

Serial paired arterial and jugular venous point-of-care values in dogs undergoing manual basic life support

OBJECTIVE

To evaluate differences in point-of-care (POC) variables obtained from arterial and jugular venous blood in dogs undergoing manual basic life support (BLS) and report changes over time.

DESIGN

Experimental study.

SETTING

Small animal research facility.

ANIMALS

Twenty-four purpose-bred research dogs.

INTERVENTIONS

Dogs were anesthetized, and arterial catheters were placed before euthanasia. One minute after cardiopulmonary arrest, BLS consisting of manual chest compressions and ventilation delivered via endotracheal intubation, face mask, mouth-to-nose, or no ventilation was initiated. Paired arterial and jugular venous blood samples were obtained for POC testing before euthanasia (T0), at 3 minutes (T3), and at 6 minutes (T6) into BLS.

MEASUREMENTS AND MAIN RESULTS

The association of POC variables with arterial or venous sample type while controlling for type of ventilation and sampling timepoint was determined using a generalized linear mixed model. Variables obtained from arterial and venous blood samples were compared over time using repeated measures ANOVA or Friedman test. Pao2, anion gap, potassium, chloride, glucose concentration, and PCV were significantly higher in arterial blood samples compared with venous samples (P < 0.03). By T6, arterial glucose concentration, arterial and venous base excess, venous pH, and plasma lactate, potassium, creatinine, bicarbonate, and sodium concentrations were significantly increased, and arterial and venous Po2, ionized calcium concentration, PCV, and total plasma protein concentration were significantly decreased from T0 (P < 0.05).

CONCLUSIONS

Although statistically significant, arteriovenous differences and changes in POC blood variables during BLS were small and not clinically relevant over time. Given the challenges of arterial blood sampling, it may be reasonable to pursue venous blood sampling during CPR. Further studies in dogs undergoing BLS and advanced life support are needed to better understand the potential clinical role of POC testing during CPR.

The early change in pH values after out-of-hospital cardiac arrest is not associated with neurological outcome at hospital discharge

Background

The association between pH values and outcome for patients after out-of-hospital cardiac arrest (OHCA) was not fully elucidated; besides, the relationship of change in pH values and neurological outcome was unknown. The aim was to explore the association of pH values as well as change in pH values and neurological outcome for OHCA cardiac patients.

Methods

The adult patients with non-traumatic out-of-hospital cardiac arrest, shock-refractory ventricular fibrillation or pulseless ventricular tachycardia, and at least two arterial blood gases analysis recorded after admission were included. The change in pH values is calculated as the difference between the second and first pH value, and divided by time interval got the rate of change in pH values. The primary outcome was modified Rankin Score (mRS), dichotomized to good (mRS 0-3) and poor (mRS 4-6) outcomes at hospital discharge. The independent relationship of the first pH value, second pH value, and changes in pH values with neurological outcome was investigated with multivariable logistic regression models, respectively.

Results

A total of 1388 adult patients were included for analysis, of which 514 (37%) had good neurological outcome. The median first pH value and second pH value after admission were 7.21 (interquartile range [IQR] 7.09-7.29) and 7.28 (IQR 7.20-7.36), respectively. The median absolute, relative change, and rate of changes in pH values were 0.08 (IQR 0.01-0.16), 1.10% (IQR 0.11-2.22%), and 0.02 (IQR 0-0.06) per hour, respectively. After adjusting for confounders, the higher first pH value (odds ratio [OR] 3.81, confidence interval [CI] 1.60-9.24, P = 0.003) and higher second pH value (OR 9.54, CI 3.45-26.87, P < 0.001) after admission were associated with good neurological outcome, respectively. The absolute (OR 1.58, CI 0.58-4.30, P = 0.368) and relative (OR 1.03, CI 0.96-1.11, P = 0.399) change as well as the rate of change (OR 0.98, CI 0.33-2.71, P = 974) in pH values were not associated with neurological outcome.

Conclusions

For OHCA patients, abnormality in pH values was very common, with a more acidic pH value indicating poor neurological outcome. However, the change in pH values was not associated with outcomes.

The relationship between the initial pH and neurological outcome in patients with out-of-hospital cardiac arrest is affected by the status of recovery of spontaneous circulation on hospital arrival

The early prediction of neurological outcomes is useful for out-of-hospital cardiac arrest (OHCA). The initial pH was associated with neurological outcomes, but the values varied among the studies. Patients admitted to our division with OHCA of cardiac origin between January 2015 and December 2022 were retrospectively examined (N = 199). A good neurological outcome was defined as a Glasgow-Pittsburgh cerebral performance category (CPC) of 1-2 at discharge. Patients were divided according to the achievement of recovery of spontaneous circulation (ROSC) on hospital arrival, and the efficacy of pH in predicting good neurological outcomes was compared. In patients with ROSC on hospital arrival (N = 100), the initial pH values for good and poor neurological outcomes were 7.26 ± 0.14 and 7.09 ± 0.18, respectively (p < 0.001). In patients without ROSC on hospital arrival (N = 99), the initial pH values for good and poor neurological outcomes were 7.06 ± 0.23 and 6.92 ± 0.15, respectively (p = 0.007). The pH associated with good neurological outcome was much lower in patients without ROSC than in those with ROSC on hospital arrival (P = 0.003). A higher initial pH is associated with good neurological outcomes in patients with OHCA. However, the pH for a good or poor neurological outcome depends on the ROSC status on hospital arrival.

Prognostic value of arterial carbon dioxide tension during cardiopulmonary resuscitation in out-of-hospital cardiac arrest patients receiving extracorporeal resuscitation

BACKGROUND

Current guidelines on extracorporeal cardiopulmonary resuscitation (ECPR) recommend careful patient selection, but precise criteria are lacking. Arterial carbon dioxide tension (PaCO2) has prognostic value in out-of-hospital cardiac arrest (OHCA) patients but has been less studied in patients receiving ECPR. We studied the relationship between PaCO2 during cardiopulmonary resuscitation (CPR) and neurological outcomes of OHCA patients receiving ECPR and tested whether PaCO2 could help ECPR selection.

METHODS

This single-centre retrospective study enrolled 152 OHCA patients who received ECPR between January 2012 and December 2020. Favorable neurological outcome (FO) at discharge was the primary outcome. We used multivariable logistic regression to determine the independent variables for FO and generalised additive model (GAM) to determine the relationship between PaCO2 and FO. Subgroup analyses were performed to test discriminative ability of PaCO2 in subgroups of OHCA patients.

RESULTS

Multivariable logistic regression showed that PaCO2 was independently associated with FO after adjusting for other favorable resuscitation characteristics (Odds ratio [OR] 0.23, 95% Confidence Interval [CI] 0.08-0.66, p-value = 0.006). GAM showed a near-linear reverse relationship between PaCO2 and FO. PaCO2 < 70 mmHg was the cutoff point for predicting FO. PaCO2 also had prognostic value in patients with less favorable characteristics, including non-shockable rhythm (OR, 3.78) or low flow time > 60 min (OR, 4.66).

CONCLUSION

PaCO2 before ECMO implementation had prognostic value for neurological outcomes in OHCA patients. Patients with PaCO2 < 70 mmHg had higher possibility of FO, even in those with non-shockable rhythm or longer low-flow duration. PaCO2 could serve as an ECPR selection criterion.

The association between blood glucose levels on arrival at the hospital and patient outcomes after out-of-hospital cardiac arrest: A multicenter cohort study

BACKGROUND

This study aimed to investigate the association between blood glucose levels on arrival at the hospital and 1-month survival and favorable neurological outcomes in patients with OHCA using a large Japanese dataset.

METHODS

This study was a secondary analysis of data from the JAAM-OHCA Registry. Adult (≥18 years) patients with witnessed OHCA transported to emergency departments and registered in the database from June 2014 to December 2019 were included in the study. The primary and secondary endpoints were 1-month survival and 1-month favorable neurological outcomes (Glasgow-Pittsburgh Cerebral Performance Category score 1 or 2), respectively. Patients were categorized into the following four groups based on blood glucose levels on arrival at the hospital: <80 mg/dL, 80-179 mg/dL, 180-299 mg/dL, and ≥300 mg/dL.

RESULTS

This study included 11,387 patients. Survival rates were 1.3%, 3.1%, 7.0%, and 5.7% in the <80 mg/dL, 80-179 mg/dL, 180-299 mg/dL, and ≥ 300 mg/dL blood glucose groups, respectively. The rates of favorable neurological outcomes in each group were 0.4%, 1.5%, 3.3%, and 2.5%, respectively. Multivariable analysis showed that 180-299 mg/dL glucose was significantly associated with 1-month survival and favorable neurological outcomes compared with 80-179 mg/dL glucose (odds ratio [OR], 1.77; 95% confidence interval [CI], 1.34-2.31; p < 0.001 and OR, 1.52; 95 % Cl, 1.02-2.25; p = 0.035, respectively). In this study, blood glucose levels with the best outcomes likely ranged from 200 to 250 mg/dL based on the cubic spline regression model.

CONCLUSIONS

Blood glucose level of 180-299 mg/dL on arrival at the hospital was significantly associated with 1-month survival and favorable neurological outcomes compared to blood glucose level of 80-179 mg/dL in patients with OHCA.

The role of point-of-care testing in cardiac arrest patients

BACKGROUND

Point-of-care testing (POCT) provides real time information to the clinical team, leading to early diagnosis and treatment. Whether POCT plays a role in improving outcomes in patients with out of hospital cardiac arrest (OHCA) remains unknown. The objective of this study was to describe use of POCT in OHCA and to explore its association with outcomes.

METHODS

We conducted a retrospective chart review on patients transferred by emergency medical services (EMS) to the ED for out-of-hospital cardiac arrest (OHCA) in 2019. Data collected from patient charts included baseline information, the Utstein criteria for cardiac arrest, whether POCT was used, whether POCT was abnormal, and what treatment was given, if any, as a result of the abnormal POCT. Outcomes included return of spontaneous circulation (ROSC) and survival to hospital discharge. Outcomes in patients with and without POCT were compared using chi-square and t-tests.

RESULTS

There were 119 study patients. Their mean (SD) age was 65 (18) years and 65% were male. Cardiac arrest was witnessed in 48% and initial rhythm was asystole in 66%. The rates of ROSC and survival were 22.7% (95%CI, 16.1-31.1) and 3.4% (95%CI, 1.3-8.3). POCT was used in 66 patients (55.4%; 95%CI, 46.5-64.1) all of whom had at least one abnormality. The results of POCT led to administration of a therapy in 60 patients (91.0%; 95%CI, 81.6-95.8). The rates of ROSC in patients with and without POCT were 22.6% vs 22.7% respectively. The rates of survival to discharge in patients with and without POCT were 0% vs 3.8% respectively.

CONCLUSIONS

POCT is commonly used in the ED for patients with OHCA and its results often lead to changes in therapies. However, use of POCT was not associated with ROSC or survival to discharge.

Ventilatory improvement with mechanical ventilator versus bag in non-traumatic out-of-hospital cardiac arrest: SYMEVECA study, phase 1

AIM

To analyze differences in ventilatory parameters and outcome with different ventilatory methods during CPR.

METHODS

Pragmatic prospective quasi-experimental study in out-of-hospital urban environment. Patients over 18 years of age in non-traumatic cardiac arrest, attended by an emergency medical service between April 2021 and September 2022, were included. Two groups were compared according to the ventilatory method: mechanical ventilator (IPPV, tidal volume 7 ml/kg, frequency 10-12 bpm) or manual resuscitator bag. The main variables of interest are those of gasometry performed 15 minutes after intubation or when spontaneous circulation is recovered and final outcome. Patients were followed up to hospital discharge.

RESULTS

Of the 359 patients attended, 150 were included (71 in IPPV and 79 with a bag). In patients with arterial blood gases, pCO2 was 67.8 ± 21.1 in the IPPV group vs 95.9 ± 39.0 mmHg in the bag group (p = 0.006) and pH was 7.00 ± 0.18 vs 6.92 ± 0.18 (p = 0.18). With a venous sample, the pCO2 was 68.1 ± 18.9 vs 89.5 ± 26.5 mmHg (p < 0.001) and the pH was 7.03 ± 0.15 vs 6.94 ± 0.17 (p = 0.005), respectively. Survival with CPC 1-2 to hospital discharge was 15.6% with IPPV and 11.3% with bag (p = 0.44).

CONCLUSION

The use of a mechanical ventilator in IPPV was associated with a better ventilatory status during CPR compared to the use of the bag, without conclusive data regarding its clinical repercussion with the sample collected.

A simple scoring rule to predict survival to discharge after out of hospital cardiac arrest at the time of ED arrival

BACKGROUND

It is important to be able to predict the chance of survival to hospital discharge upon ED arrival in order to determine whether to continue or terminate resuscitation efforts after out of hospital cardiac arrest. This study was conducted to develop and validate a simple scoring rule that could predict survival to hospital discharge at the time of ED arrival.

METHODS

This was a multicenter retrospective cohort study based on a nationwide registry (Korean Cardiac Arrest Research Consortium) of out of hospital cardiac arrest (OHCA). The study included adult OHCA patients older than 18 years old, who visited one of 33 tertiary hospitals in South Korea from September 1st, 2015 to June 30th, 2020. Among 12,321 screened, 5471 patients were deemed suitable for analysis after exclusion. Pre-hospital ROSC, pre-hospital witness, shockable rhythm, initial pH, and age were selected as the independent variables. The dependent variable was set to be the survival to hospital discharge. Multivariable logistic regression (LR) was performed, and the beta-coefficients were rounded to the nearest integer to formulate the scoring rule. Several machine learning algorithms including the random forest classifier (RF), support vector machine (SVM), and K-nearest neighbor classifier (K-NN) were also trained via 5-fold cross-validation over a pre-specified grid, and validated on the test data. The prediction performances and the calibration curves of each model were obtained. Pre-processing of the registry was done using R, model training & optimization using Python.

RESULTS

A total of 5471 patients were included in the analysis. The AUROC of the scoring rule over the test data was 0.7620 (0.7311-0.7929). The AUROCs of the machine learning classifiers (LR, SVM, k-NN, RF) were 0.8126 (0.7748-0.8505), 0.7920 (0.7512-0.8329), 0.6783 (0.6236-0.7329), and 0.7879 (0.7465-0.8294), respectively.

CONCLUSION

A simple scoring rule consisting of five, binary variables could aid in the prediction of the survival to hospital discharge at the time of ED arrival, showing comparable results to conventional machine learning classifiers.

Arterial Blood Gas Analysis for Survival Prediction in Pediatric Patients with Out-of-Hospital Cardiac Arrest

Arterial blood gas analysis (ABGA) is one of the few tests performed during cardiopulmonary resuscitation (CPR). There have been some studies on the prediction of survival outcomes in adult out-of-hospital cardiac arrest (OHCA) patients during CPR using ABGA results. However, in pediatric OHCA patients, the prognosis of survival outcome based on ABGA results during CPR remains unclear. We retrospectively analyzed prospectively collected data from the Korean Cardiac Arrest Resuscitation Consortium (KoCARC) registry, a multicenter OHCA registry of Republic of Korea. We analyzed 108 pediatric (age < 19 years) OHCA patients between October 2015 and June 2022. Using multivariable logistic regression, an adjusted odds ratio (aOR) was obtained to validate the ABGA results of survival to hospital admission and survival to discharge. The variables associated with survival to hospital admission were non-comorbidities (aOR 3.03, 95% confidence interval (CI) 1.22-7.53, p = 0.017) and PaO₂ > 45.750 mmHg (aOR 2.69, 95% CI 1.13-6.42, p = 0.026). There was no variable that was statistically significant association with survival to discharge. PaO₂ > 47.750 mmHg and non-comorbidities may serve as an independent prognostic factor for survival to hospital admission in pediatric OHCA patients. However, the number of cases analyzed in our study was relatively small, and there have been few studies investigating the association between ABGA results during CPR and the survival outcome of pediatric OHCA patients. Therefore, further large-scale studies are needed.

Survival with Good Neurological Outcome despite Prolonged Cardiopulmonary Resuscitation and Extreme Acidosis after Out-of-Hospital Cardiac Arrest Due to Acute Myocardial Infarction: A Case Report and Review of the Literature

We report the case of a 49-year-old male who suffered from a myocardial infarction with subsequent cardiac arrest. The emergency medical team began cardiopulmonary resuscitation, including defibrillation of ventricular fibrillation. Although a return of spontaneous circulation was achieved after approximately 30 min of continued efforts, the patient went back into cardiac arrest on the way to the hospital and resuscitation had to be resumed. On admission, the patient was severely acidotic with a pH of 6.67, lactatemia of 19 mmol/L, and pronounced hypercapnia (pCO₂ 127 mmHg). Despite the poor prognosis, all possible efforts including coronary intervention and therapeutic hypothermia were carried out and the patient made a quick recovery with discharge from the intensive care unit on day 5. Survival of extreme acidosis, such as in this case, is rare. This is the first report of survival with good neurologic outcome in a patient with myocardial infarction, cardiac arrest, and pH of under 6.7 on admission at the clinic.

PCO2 on arrival as a predictive biomarker in patients with out-of-hospital cardiac arrest

BACKGROUND

Treating patients with out-of-hospital cardiac arrest (OHCA) requires early prediction of outcome, ideally on hospital arrival, as it can inform the clinical decisions involved. This study evaluated whether partial pressure of carbon dioxide (PCO₂) on arrival is associated with outcome at one month OHCA patients.

METHODS

This was a single-center retrospective study of adult OHCA patients treated between January 2016 and December 2020. Outcomes were defined along the Cerebral Performance Category (CPC) scale. Primary outcome was mortality (CPC 5) at one month. Secondary outcomes were death or unfavorable neurological outcome (CPC 3-5) and unfavorable neurological outcome (CPC 3-4) at one month. Multivariable analysis was adjusted for age, sex, witnessed cardiac arrest, bystander cardiopulmonary resuscitation, initial shockable rhythm, and time from call to emergency medical services to hospital arrival.

RESULTS

Out of 977 OHCA patients in the study period, 19 were excluded because they were aged under 18 years, 79 because they underwent extracorporeal cardiopulmonary resuscitation, and 101 due to lack of PCO₂ data. This study included 778 patients total; mortality (CPC 5) at one month was observed in 706 (90.7%), death or unfavorable neurological outcome (CPC 3-5) in 743 (95.5%), and unfavorable neurological outcome (CPC 3-4) in 37 (4.8%). In multivariable analysis, high PCO₂ levels showed significant association with mortality (CPC 5) at one month (odds ratio [OR] [per 5 mmHg], 1.14; 95% confidence interval [CI], 1.08-1.21), death or unfavorable neurological outcome (CPC 3-5) (OR [per 5 mmHg], 1.29; 95% CI, 1.17-1.42), and unfavorable neurological outcome (CPC 3-4) (OR [per 5 mmHg], 1.21; 95% CI, 1.04-1.41).

CONCLUSIONS

High PCO₂ on arrival was significantly associated with mortality and unfavorable neurological outcome in OHCA patients.

Termination of resuscitation in out-of-hospital cardiac arrest in women and men: An ESCAPE-NET project

AIM

Women have less favorable resuscitation characteristics than men. We investigated whether the Advanced Life Support Termination of Resuscitation rule (ALS-TOR) performs equally in women and men. Additionally, we studied whether adding or removing criteria from the ALS-TOR improved classification into survivors and non-survivors.

METHODS

We analyzed 6,931 female and 14,548 male out-of-hospital cardiac arrest (OHCA) patients from Dutch and Swedish registries, and validated in 10,772 female and 21,808 male Danish OHCA patients. Performance measures were calculated for ALS-TOR in relation to 30-day survival. Recursive partitioning analysis was performed with the ALS-TOR criteria, as well as age, comorbidities, and additional resuscitation characteristics (e.g. initial rhythm, OHCA location). Finally, we explored if we could reduce the number of ALS-TOR criteria without loss of prognostic value.

RESULTS

The ALS-TOR had a specificity and positive predictive value (PPV) of ≥99% in both women and men (e.g. PPV 99.9 in men). Classification by recursive partitioning analysis showed a high sensitivity but a PPV below 99%, thereby exceeding the acceptable miss rate of 1%. A combination of no return of spontaneous circulation (ROSC) before transport to the hospital and unwitnessed OHCA resulted in nearly equal specificity and PPV, higher sensitivity, and a lower transport rate to the hospital than the ALS-TOR.

CONCLUSION

For both women and men, the ALS-TOR has high specificity and low miss rate for predicting 30-day OHCA survival. We could not improve the classification with additional characteristics. Employing a simplified version may decrease the number of futile transports to the hospital.

Emergency Department Point-of-Care Tests during Cardiopulmonary Resuscitation to Predict Cardiac Arrest Outcomes

Introduction

This study evaluated the role of point-of-care tests (POCT) such as blood lactate, anion gap (AG), base deficit, pH, N-terminal pro B-type natriuretic peptide (NT-proBNP), and troponin as the predictors of cardiac arrest outcomes in the emergency department (ED).

Methods

We conducted a prospective, observational study in the ED of a tertiary care hospital in India. All the adult patients who received cardiopulmonary resuscitation (CPR) in the ED were included in the study. Blood samples were collected within 10 min of initiation of CPR for assay of POCTs. Outcomes assessed were the return of spontaneous circulation (ROSC), 24-h survival, survival to hospital discharge (STHD), survival at 7 days, and favorable neurological outcome (FNO) at day 7 of admission.

Results

One hundred and fifty-one patients were included in the study (median age: 50 years, 65% males). Out of 151 cases, ROSC, survival at 7 days, STHD, and FNO was observed in 86 patients, six patients, five patients, and two patients, respectively. "No-ROSC" could be significantly predicted by raised lactate (odds ratio [OR]: 1.14, 95% confidence interval: 1.07-1.22) and NT-proBNP (OR: 1.05, 1.01-1.09) values at the time of cardiac arrest. "24-h mortality" could be significantly predicted by the raised lactate (OR: 1.14, 1.01-1.28), low arterial pH (OR: 0.05, 0.01-0.52), raised AG (OR: 1.08, 1.01-1.15), and lower base deficit (<-15) (OR: 1.07, 1.01-1.14). None of the other POCTs was found to be a predictor of other cardiac arrest outcomes.

Conclusion

Among various POCTs, raised lactate assayed within 10 min of cardiac arrest can predict poor outcomes like "no-ROSC" and 24-h mortality.

TIMECARD score: An easily operated prediction model of unfavorable neurological outcomes in out-of-hospital cardiac arrest patients with targeted temperature management

BACKGROUND

Targeted temperature management (TTM) is recommended for comatose out-of-hospital cardiac arrest (OHCA) survivors. Several prediction models have been proposed; however, most of these tools require data conversion and complex calculations. Early and easy predictive model of neurological prognosis in OHCA survivors with TTM warrant investigation.

MATERIALS AND METHODS

This multicenter retrospective cohort study enrolled 408 non-traumatic adult OHCA survivors with TTM from the TaIwan network of targeted temperature ManagEment for CARDiac arrest (TIMECARD) registry during January 2014 to June 2019. The primary outcome was unfavorable neurological outcome at discharge. The clinical variables associated with unfavorable neurological outcomes were identified and a risk prediction score-TIMECARD score was developed. The model was validated with data from National Taiwan University Hospital.

RESULTS

There were 319 (78.2%) patients presented unfavorable neurological outcomes at hospital discharge. Eight independent variables, including malignancy, no bystander cardiopulmonary resuscitation (CPR), non-shockable rhythm, call-to-start CPR duration >5 min, CPR duration >20 min, sodium bicarbonate use during resuscitation, Glasgow Coma Scale motor score of 1 at return of spontaneous circulation, and no emergent coronary angiography, revealed a significant correlation with unfavorable neurological prognosis in TTM-treated OHCA survivors. The TIMECARD score was established and demonstrated good discriminatory performance in the development cohort (area under the receiver operating characteristic curve [AUC] = 0.855) and validation cohorts (AUC = 0.918 and 0.877, respectively).

CONCLUSION

In emergency settings, the TIMECARD score is a practical and simple-to-calculate tool for predicting neurological prognosis in OHCA survivors, and may help determine whether to initiate TTM in indicated patients.

Association of point-of-care blood variables obtained from dogs and cats during cardiopulmonary resuscitation and following return of spontaneous circulation with patient outcomes

OBJECTIVE

To investigate the association of point-of-care biochemical variables obtained during CPR or within 24 hours of return of spontaneous circulation (ROSC) with patient outcomes.

DESIGN

Retrospective study.

SETTING

University teaching hospital.

ANIMALS

Ninety-four dogs and 27 cats undergoing CPR according to the Reassessment Campaign on Veterinary Resuscitation guidelines.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Blood gas, acid-base, electrolyte, glucose, and plasma lactate values obtained during CPR or within 24 hours of ROSC were retrospectively evaluated and are described. The blood sample type and collection time with respect to CPR initiation and ROSC were recorded. Measured variables, collection times, and species were included in a multivariable logistic regression model to estimate the odds ratio (OR) and 95% confidence interval of ROSC, sustained ROSC (≥20 min), and survival to hospital discharge. Significance was set at P < 0.05. Seventy-two venous blood samples obtained during CPR and 45 first venous and arterial blood samples obtained after ROSC were included in logistic regression analysis. During CPR, PvO₂ (1.09 [1.036-1.148], P = 0.001) and venous standard base excess (SBE) (1.207 [1.094-1.331], P < 0.001) were associated with ROSC. PvO₂ (1.075 [1.028-1.124], P = 0.002), SBE (1.171 [1.013-1.353], P = 0.032), and potassium concentration (0.635 [0.426-0.946], P = 0.026) were associated with sustained ROSC. Potassium concentration (0.235 [0.083-0.667], P = 0.007) was associated with survival to hospital discharge. Following ROSC, pH (69.110 [4.393-1087], P = 0.003), potassium concentration (0.222 [0.071-0.700], P = 0.010), and chloride concentration (0.805 [0.694-0.933], P = 0.004) were associated with survival to hospital discharge.

CONCLUSIONS

Biochemical variables such as PvO₂ , SBE, and potassium concentration during CPR and pH, potassium, and chloride concentration in the postarrest period may help identify dogs and cats with lower odds for ROSC or survival to hospital discharge following CPR.

The impact of on-site cardiac rhythm on mortality in patients supported with extracorporeal cardiopulmonary resuscitation: A retrospective cohort study

BACKGROUND

Extracorporeal cardiopulmonary resuscitation (ECPR) is increasingly used in patients with out-of-hospital or in-hospital cardiac arrest in whom conventional cardiopulmonary resuscitation remains unsuccessful. The aim of this study was to analyze the impact of initial cardiac rhythm-detected on-site of the cardiac arrest-on mortality.

METHODS

We performed a retrospective cohort study of patients who received ECPR in our tertiary care cardiac arrest center. Patients were divided into three groups depending on their cardiac rhythm: shockable rhythm, pulseless electrical activity, and asystole. The primary endpoint was mortality within the first 7 days after ECPR deployment. Secondary endpoints were mortality within 28 days and the impact of pre-ECPR potassium, serum lactate, pH, and pCO₂ on mortality. The association of the initial cardiac rhythm and the location of arrhythmia detection (patient monitored in hospital [category: monitored], not monitored but hospitalized [in-hospital], not monitored, not hospitalized [out-of hospital]) with the primary and secondary outcome was examined by means of univariable and multivariable logistic regression.

RESULTS

Sixty-five patients could be included in the final analysis. Thirty-two patients (49.2%, 95%CI 36.6%-61.9%) died within the first 7 days. In terms of 7-day-mortality patients differed in the initial cardiac rhythm (p = 0.040) and with respect to the location of arrhythmia detection (p = 0.002). Shockable cardiac rhythm (crude OR 0.21; 95%CI 0.03-0.98) and pulseless electrical activity (0.13; 0.02-0.61) as the initial rhythm on-site showed better odds for survival compared to asystole. However, this association did neither persist in adjusted analysis nor pairwise comparison.

DISCUSSION

The study could not demonstrate a better outcome with shockable rhythm after ECPR. More homogeneous and adequately powered cohorts are needed to better understand the impact of cardiac rhythm on patient outcomes after ECPR.

Low serum cholesterol level as a risk factor for out-of-hospital cardiac arrest: a case-control study

OBJECTIVE

We aimed to identify the association between low serum total cholesterol levels and the risk of out-of-hospital cardiac arrest (OHCA).

METHODS

This case-control study was performed using datasets from the Cardiac Arrest Pursuit Trial with Unique Registration and Epidemiologic Surveillance (CAPTURES) project and the Korea National Health and Nutrition Examination Survey (KNHANES). Cases were defined as emergency medical service-treated adult patients who experienced OHCA with a presumed cardiac etiology from the CAPTURES project dataset. Four controls from the KNHANES dataset were matched to each case based on age, sex, and county. Multivariable conditional logistic regression analysis was conducted to evaluate the effect of total cholesterol levels on OHCA.

RESULTS

A total of 607 matched case-control pairs were analyzed. We classified total cholesterol levels into six categories (<148, 148-166.9, 167-189.9, 190-215.9, 216-237.9, and ≥238 mg/dL) according to the distribution of total cholesterol levels in the KNHANES dataset. Subjects with a total cholesterol level of 167-189.9 mg/dL (25th-49th percentile of the KNHANES dataset) were used as the reference group. In both the adjusted models and sensitivity analysis, a total cholesterol level of <148 mg/dL was significantly associated with OHCA (adjusted odds ratio [95% confidence interval], 6.53 [4.47-9.56]).

CONCLUSION

We identified an association between very-low total cholesterol levels and an increased risk of OHCA in a large, community-based population. Future prospective studies are needed to better understand how a low lipid profile is associated with OHCA.

Obesity protects against sepsis-induced and norepinephrine-induced white adipose tissue browning

Sepsis is a dysregulated systemic response to infection and can lead to organ damage and death. Obesity is a significant problem worldwide and affects outcomes from sepsis. Our laboratory demonstrated that white adipose tissue (WAT) undergoes browning during sepsis, a process whereby WAT adopts a brown adipose tissue phenotype. However, this browning process was not observed in obese mice during sepsis. White adipose tissue browning is detrimental in patients with burn injury and cancer. We hypothesize that norepinephrine (NE) induces WAT browning in nonobese mice but not in obese mice similarly to sepsis-induced WAT browning. Six-week-old C57BL/6 male mice were randomized to a high-fat diet or normal diet. After 6-7 wk of feeding, polymicrobial sepsis was induced by cecal ligation and puncture (CLP). Norepinephrine was administered intraperitoneally via osmotic minipumps for 18 h or 72 h (no CLP) at which time tissue and plasma were harvested. Controls were mice that underwent CLP (no NE) with 18-h harvest. A separate group of mice underwent pretreatment with NE or vehicle infusion for 72 h, CLP was performed, and at 18 h had tissue and plasma harvested. Sepsis resulted in significant weight loss in both nonobese and obese mice. NE treatment alone caused weight loss in obese mice. Septic nonobese mice had higher uncoupling protein-1 (UCP1) expression compared with control and obese septic mice. NE treatment increased UCP1 expression in nonobese, but not obese mice. NE-treated obese septic mice had lower lung myeloperoxidase (MPO) activity, alanine aminotransferase (ALT), aspartate aminotransferase (AST), TNFα, and IL-6 levels compared with NE-treated nonobese septic mice. Obesity protects mice from septic-induced and NE-induced WAT browning.NEW & NOTEWORTHY White adipose tissue browning is detrimental in patients with burn injury and cancer. WAT browning occurs in nonobese mice and can be induced by β receptor norepinephrine infusion, but obese mice are resistant to sepsis-induced and norepinephrine-induced WAT browning. We propose that the lack of WAT browning and unchanged inflammatory cytokine response may contribute to the protection of obese mice from sepsis.

Does cerebral near-infrared spectroscopy (NIRS) help to predict futile cannulation in extracorporeal cardiopulmonary resuscitation (ECPR)?

AIM OF THE STUDY

Extracorporeal cardiopulmonary resuscitation (ECPR) is an evolving technique to improve cardiopulmonary resuscitation (CPR) outcomes. Identifying a readily available tool helpful for predicting patient's outcome is warranted. The aim of the study was to evaluate the capability of cranial near-infrared spectroscopy (cNIRS) to identify non-survivors or patients with unfavorable neurologic outcome prior to cannulation for ECPR to avoid futile cannulations.

METHODS

Retrospective analysis (2015-2021) of 97 patients requiring ECPR due to cardiac arrest with prior cNIRS measurement, which was performed immediately after ECPR team arrived on scene. Lowest possible regional cerebral oxygen saturation (rSO₂) is 15%.

RESULTS

Mortality was 72.1% (70/97). Survivors showed in 88.9% (24/27) good neurological outcome (Cerebral Performance Category (CPC) 1 + 2). rSO2 = 15% (11/97) prior to cannulation was only found in non-survivors. Among survivors, initial rSO₂ was not associated with neurological outcome. Non-shockable initial rhythm was associated with higher mortality (44/50). In survivors, time to ECPR was shorter (p = 0.006), and initial lactate was significantly lower, whereas initial pH and hemoglobin levels were higher (p = 0.001). Survivors and those with favorable neurological outcome showed lower maximal NSE levels in the first 72 hours (p < 0.001; p = 0.041).

CONCLUSION

In our patient cohort, rSO₂ = 15% immediately prior to cannulation for ECPR did not result in any survivors, thus might be a marker for futile cannulation in ECPR. Higher rSO₂ values were not associated with favorable neurologic outcome. Lower initial lactate and lower maximal NSE within the first 72 h after arrest were associated with favorable outcome.

A retrospective study on the therapeutic effects of sodium bicarbonate for adult in-hospital cardiac arrest

To investigate whether the effects of sodium bicarbonate (SB) during cardiopulmonary resuscitation (CPR) would be influenced by blood pH and administration timing. Adult patients experiencing in-hospital cardiac arrest (IHCA) from 2006 to 2015 were retrospectively screened. Early intra-arrest blood gas data were obtained within 10 min of CPR. Multivariable logistic regression analysis and generalised additive models were used for effect estimation and data exploration, respectively. A total of 1060 patients were included. Only 59 patients demonstrated favourable neurological status at hospital discharge. Blood pH ≤ 7.18 was inversely associated with favourable neurological outcome (odds ratio [OR], 0.24; 95% confidence interval [CI], 0.11-0.52; p value < 0.001) while SB use was not. In the interaction analysis for favourable neurological outcome, significant interactions were noted between SB use and time to SB (SB use × time to SB ≥ 20 min; OR 6.16; 95% CI 1.42-26.75; p value = 0.02). In the interaction analysis for survival to hospital discharge, significant interactions were noted between SB use and blood pH (Non-SB use × blood pH > 7.18; OR 1.56; 95% CI 1.01-2.41; p value = 0.05). SB should not be empirically administered for patients with IHCA since its effects may be influenced by blood pH and administration timing.

Change of Hemoglobin Levels in the Early Post-cardiac Arrest Phase Is Associated With Outcome

Background: The post-cardiac arrest (CA) phase is characterized by high fluid requirements, endothelial activation and increased vascular permeability. Erythrocytes are large cells and may not leave circulation despite massive capillary leak. We hypothesized that dynamic changes in hemoglobin concentrations may reflect the degree of vascular permeability and may be associated with neurologic function after CA.

Methods: We included patients ≥18 years, who suffered a non-traumatic CA between 2013 and 2018 from the prospective Vienna Clinical Cardiac Arrest Registry. Patients without return of spontaneous circulation (ROSC), with extracorporeal life support, with any form of bleeding, undergoing surgery, receiving transfusions, without targeted temperature management or with incomplete datasets for multivariable analysis were excluded. The primary outcome was neurologic function at day 30 assessed by the Cerebral Performance Category scale. Differences of hemoglobin concentrations at admission and 12 h after ROSC were calculated and associations with neurologic function were investigated by uni- and multivariable logistic regression.

Results: Two hundred and seventy-five patients were eligible for analysis of which 143 (52%) had poor neurologic function. For every g/dl increase in hemoglobin from admission to 12 h the odds of poor neurologic function increased by 26% (crude OR 1.26, 1.07–1.49, p = 0.006). The effect remained unchanged after adjustment for fluid balance and traditional prognostication markers (adjusted OR 1.27, 1.05–1.54, p = 0.014).

Conclusion: Increasing hemoglobin levels in spite of a positive fluid balance may serve as a surrogate parameter of vascular permeability and are associated with poor neurologic function in the early post-cardiac arrest period.

Blood gas phenotyping and tracheal intubation timing in adult in-hospital cardiac arrest: a retrospective cohort study

To investigate whether the optimal time to tracheal intubation (TTI) during cardiopulmonary resuscitation would differ by different blood gas phenotypes. Adult patients experiencing in-hospital cardiac arrest (IHCA) from 2006 to 2015 were retrospectively screened. Early intra-arrest blood gas analysis, performed within 10 min of resuscitation, was used to define different phenotypes. In total, 567 patients were included. Non-severe acidosis (pH≧7.15) was associated with favourable neurological outcome (odds ratio [OR]: 4.60, 95% confidence interval [CI] 1.63–12.95; p value = 0.004) and survival (OR: 3.25, 95% CI 1.72–6.15; p value < 0.001) in the multivariable logistic regression analyses. In the interaction analysis, normal blood gas phenotype (pH: 7.35–7.45, PCO₂: 35–45 mm Hg, HCO₃⁻ level: 22–26 mmol/L) × TTI ≦ 6.3 min (OR: 20.40, 95% CI 2.53–164.75; p value = 0.005) and non-severe acidosis × TTI ≦ 6.3 min (OR: 3.35, 95% CI 1.00–11.23; p value = 0.05) were associated with neurological recovery while metabolic acidosis × TTI ≦ 5.7 min (OR: 3.63, 95% CI 1.36–9.67; p value = 0.01) and hypercapnic acidosis × TTI ≦ 10.4 min (OR: 2.27, 95% CI 1.20–4.28; p value = 0.01) were associated with survival. Intra-arrest blood gas analysis may help guide TTI during for patients with IHCA.

Early blood pH as an independent predictor of neurological outcome in patients with out-of-hospital cardiac arrest: A retrospective observational study

ABSTRACT

Metabolic acidosis is observed in 98% of patients with out-of-hospital cardiac arrest (OHCA). The longer the no-flow or low-flow duration, the more severe is the acidosis in these patients. This study explored whether blood pH in early stages of advanced life support (ALS) was an independent predictor of neurological prognosis in patients with OHCA.We retrospectively enrolled patients with OHCA from January 2012 to June 2018 in a single-medical tertiary hospital in Taiwan. Patients with OHCA whose blood gas analyses within 5 minutes after receiving ALS at the emergency department (ED) were enrolled. Patients younger than 20 years old, with cardiac arrest resulting from traumatic or circumstantial causes, with return of spontaneous circulation (ROSC) before ED arrival, lacking record of initial blood gas analysis, and with do-not-resuscitate orders were excluded. The primary outcome of this study was neurological status at hospital discharge.In total, 2034 patients with OHCA were enrolled. The majority were male (61.89%), and the average age was 67.8 ± 17.0 years. Witnessed OHCA was noted in 571 cases, cardiopulmonary resuscitation was performed before paramedic arrival in 512 (25.2%) cases, and a shockable rhythm was observed in 269 (13.2%). Blood pH from initial blood gas analysis remained an independent predictor of neurological outcome after multivariate regression.Blood pH at early stages of ALS was an independent prognostic factor of post-OHCA neurological outcome. Blood gas analysis on arrival at the ED may provide additional information about the prognosis of patients with OHCA.

Pulseless Electrical Activity: Detection of Underlying Causes in a Prehospital Setting

The proportion of out-of-hospital cardiac arrests (OHCAs) with pulseless electrical activity (PEA) as initial rhythm is increasing. PEA should be managed by identifying the underlying cause of the arrest and treating it accordingly. This often poses a challenge in the chaotic prehospital environment with only limited resources available. The aim of this study was to review the diagnostic tools available in a prehospital setting, and their interpretation during cardiac arrest (CA) with PEA as initial rhythm. A systematic literature search of the PubMed database was performed. Articles were assessed for eligibility by title, abstract, and full text. Ultrasonography has become a great asset in detecting underlying causes, and a variety of protocols have been proposed. There are currently no studies comparing these protocols regarding their feasibility and their effect on patient survival. Further research concerning the relationship between electrocardiogram characteristics and underlying causes is required. Limited evidence suggests a role for point-of-care testing in detecting hyperkalemia and a role for capnography in the diagnosis of asphyxia CA. Multiple studies describe a prognostic potential. Although evidence about the prognostic potential of cerebral oximetry in OHCA is accumulating, its diagnostic potential is still unknown. In the management of OHCA, anamnestic and clinical information remains the initial source of information in search for an underlying cause. Ultrasonographic evaluation should be performed subsequently, both for detecting an underlying cause and discriminating between true PEA and pseudo PEA. Comparative studies are required to identify the best ultrasonographic protocol, which can be included in resuscitation guidelines.

The association of pH values during the first 24 h with neurological status at hospital discharge and futility among patients with out-of-hospital cardiac arrest

STUDY OBJECTIVE

Post-resuscitation prognostic biomarkers for out-of-hospital cardiac arrest (OHCA) outcomes have not been fully elucidated. We examined the association of acid-base blood values (pH) with patient outcomes and calculated the pH test performance to predict prognosis.

METHODS

This was a post-hoc analysis of data from the continuous chest compression trial, which enrolled non-traumatic adult emergency medical system-treated OHCA in Canada and the United States. We examined cases who survived a minimum of 24 h post hospital arrival. The independent variables of interest were initial pH, final pH, and the change in pH (δpH). The primary outcome was neurological status at hospital discharge, with favorable status defined as modified Rankin Scale (mRS) ≤ 3. We reported adjusted odds ratios for favorable neurological outcome using multivariable logistic regression models. We calculated the test performance of increasing pH thresholds in 0.1 increments to predict unfavorable neurological status (defined as mRS >3) at hospital discharge.

RESULTS

We included 4189 patients. 32% survived to hospital discharge with favorable neurological status. In the adjusted analysis, higher initial pH (OR 6.82; 95% CI 3.71-12.52) and higher final pH (OR 7.99; 95% CI 3.26-19.62) were associated with higher odds of favorable neurological status. pH thresholds with highest positive predictive values were initial pH < 6.8 (92.5%; 95% CI 86.2 %-98.8%) and final pH < 7.0 (100%; 95% CI 95.2 %-100%).

CONCLUSION

In patients with OHCA, pH values were associated with patients' subsequent neurological status at hospital discharge. Final pH may be clinically useful to predict unfavorable neurological status at hospital discharge.

A walk through the progression of resuscitation medicine

Cardiac arrest (CA) is a sudden and devastating disease process resulting in more deaths in the United States than many cancers, metabolic diseases, and even car accidents. Despite such a heavy mortality burden, effective treatments have remained elusive. The past century has been productive in establishing the guidelines for resuscitation, known as cardiopulmonary resuscitation (CPR), as well as developing a scientific field whose aim is to elucidate the underlying mechanisms of CA and develop therapies to save lives. CPR has been successful in reinitiating the heart after arrest, enabling a survival rate of approximately 10% in out-of-hospital CA. Although current advanced resuscitation methods, including hypothermia and extracorporeal membrane oxygenation, have improved survival in some patients, they are unlikely to significantly improve the national survival rate any further without a paradigm shift. Such a change is possible with sustained efforts in the basic and clinical sciences of resuscitation and their implementation. This review seeks to discuss the current landscape in resuscitation medicine-how we got here and where we are going.

QTc interval in survivors of out of hospital cardiac arrest

BACKGROUND

QTc interval (QTc) prolongation is seen on the post-arrest electrocardiogram (ECG) of many out of hospital cardiac arrest (OHCA) survivors. It remains unclear whether this is a transient phenomenon or a manifestation of an underlying arrhythmic substrate. This observational study assessed the trend of QTc in an unselected group of patients presenting with OHCA. We sought to identify any relationship between QTc, gender and aetiology of arrest. We observed whether targeted temperature management (TTM) is associated with malignant arrhythmia.

METHOD

We analysed 60 patients presenting with OHCA to the Bristol Heart Institute during a 20-month period. We measured QTc on admission and assessed for persistence, development and resolution of prolongation at up to 5 time points post-OHCA. Aetiology of arrest was divided into coronary, non-coronary or primary arrhythmic to investigate for patterns in QTc behaviour.

RESULTS

81.7% (49/60) of arrests were attributed to an acute coronary event. 55% (33/60) had QTc prolongation on admission, of which 79% resolved. There were no significant differences in QTc behaviour by aetiology. One patient presenting with a normal QTc, developed prolongation during admission and received a genetic diagnosis of Long QT Syndrome. TTM was employed in 57/60, with no increased incidence of malignant arrhythmia.

CONCLUSIONS

Prolonged QTc on admission does not imply a primary arrhythmic aetiology and resolves in the majority pre-discharge. However, an initial normal QTc post-OHCA does not preclude a diagnosis of Long QT syndrome, highlighting the importance of thorough investigations in these patients. TTM appears safe from a cardiac perspective.

Acidemia Detected on Venous Blood Gas After Out-of-Hospital Cardiac Arrest Predicts Likelihood to Survive to Hospital Discharge

BACKGROUND

Sudden cardiac arrest is the most common cause of death worldwide, and prognostication after survival remains challenging. Decisions regarding prognosis can be fraught with error in the immediate postarrest period, with guidelines recommending the use of various tests, including blood gas pH, to determine which interventions to perform. Despite these recommendations, the prognostic utility of blood gas pH remains unclear.

OBJECTIVES

In this retrospective cohort study, we aimed to demonstrate the prognostic utility of emergency department blood gas pH after return of spontaneous circulation (ROSC) in out-of-hospital cardiac arrest.

METHODS

A retrospective cohort study was performed, including all adult survivors of out-of-hospital cardiac arrest (n = 79). Primary disease-oriented outcome was venous blood pH after ROSC and survival to hospital discharge.

RESULTS

In patients with out-of-hospital cardiac arrest, pH < 7.2 was associated with decreased likelihood of survival to hospital discharge (odds ratio 0.06), with every 0.1-unit increase in pH being associated with an increased likelihood of survival (1.98). Based on the area under the receiver curve, the pH that optimizes sensitivity and specificity for predicting survival was 7.04.

CONCLUSION

Both presence and degree of acidemia on initial blood gas after ROSC was associated with a decreased likelihood of survival to hospital discharge. The optimal cutoff for prediction in this cohort of patients was 7.04. Using a higher pH cutoff would result in fewer patients receiving intervention that would otherwise have survived.

Association between low pH and unfavorable neurological outcome among out-of-hospital cardiac arrest patients treated by extracorporeal CPR: a prospective observational cohort study in Japan

Background

We aimed to identify the association of pH value in blood gas assessment with neurological outcome among out-of-hospital cardiac arrest (OHCA) patients treated by extracorporeal cardiopulmonary resuscitation (ECPR).

Methods

We retrospectively analyzed the database of a multicenter prospective observational study on OHCA patients in Osaka prefecture, Japan (CRITICAL study), from July 1, 2012 to December 31, 2016. We included adult OHCA patients treated by ECPR. Patients with OHCA from external causes such as trauma were excluded. We conducted logistic regression analysis to identify the odds ratio (OR) and 95% confidence interval (CI) of the pH value for 1 month favorable neurological outcome adjusted for potential confounders including sex, age, witnessed by bystander, CPR by bystander, pre-hospital initial cardiac rhythm, and cardiac rhythm on hospital arrival.

Results

Among the 9822 patients in the database, 260 patients were finally included in the analysis. The three groups were Tertile 1: pH ≥ 7.030, Tertile 2: pH 6.875–7.029, and Tertile 3: pH < 6.875. The adjusted OR of Tertiles 2 and 3 compared with Tertile 1 for 1 month favorable neurological outcome were 0.26 (95% CI 0.10–0.63) and 0.24 (95% CI 0.09–0.61), respectively.

Conclusions

This multi-institutional observational study showed that low pH value (< 7.03) before the implementation of ECPR was associated with 1 month unfavorable neurological outcome among OHCA patients treated with ECPR. It may be helpful to consider the candidate for ECPR.

Prognostic value of the delta neutrophil index in pediatric cardiac arrest

The delta neutrophil index (DNI), which reflects the ratio of circulating immature neutrophils, has been reported to be highly predictive of mortality in systemic inflammation. We investigated the prognostic significance of DNI value for early mortality and neurologic outcomes after pediatric cardiac arrest (CA). We retrospectively analyzed the data of eligible patients (<19 years in age). Among 85 patients, 55 subjects (64.7%) survived and 36 (42.4%) showed good outcomes at 30 days after CA. Cox regression analysis revealed that the DNI values immediately after the return of spontaneous circulation, at 24 hours and 48 hours after CA, were related to an increased risk for death within 30 days after CA (P < 0.001). A DNI value of higher than 3.3% at 24 hours could significantly predict both 30-day mortality (hazard ratio: 11.8; P < 0.001) and neurologic outcomes (odds ratio: 8.04; P = 0.003). The C statistic for multivariable prediction models for 30-day mortality (incorporating DNI at 24 hours, compression time, and serum sodium level) was 0.799, and the area under the receiver operating characteristic curve of DNI at 24 hours for poor neurologic outcome was 0.871. Higher DNI was independently associated with 30-day mortality and poor neurologic outcomes after pediatric CA.

Prognostic value of venous blood analysis at the start of CPR in non-traumatic out-of-hospital cardiac arrest: association with ROSC and the neurological outcome

BACKGROUND

The knowledge of new prognostic factors in out-of-hospital cardiac arrest (OHCA) that can be evaluated since the beginning of cardiopulmonary resuscitation (CPR) manoeuvres could be helpful in the decision-making process of prehospital care. We aim to identify metabolic variables at the start of advanced CPR at the scene that may be associated with two main outcomes of CPR (recovery of spontaneous circulation (ROSC) and neurological outcome).

METHODS

Prospective observational study of all non-traumatic OHCA in patients older than 17 years assisted by emergency medical services (EMS), with doctor and nurse on board, between January 2012 and December 2017. Venous blood gases were sampled upon initially obtaining venous access to determine the initial values of pH, pCO₂, HCO₃^-, base excess (BE), Na⁺, K⁺, Ca²⁺ and lactate. ROSC upon arrival at the hospital and neurological status 30 days later (Cerebral Performance Categories (CPC) scale) were recorded.

RESULTS

We included 1552 patients with OHCA with blood test data in a 6-year period. ROSC was achieved in 906 cases (58.4%), and good neurological recovery at 30 days (CPC I-II) occurred in 383 cases (24.68%). In multivariate analysis, we found a significant relationship between non-recovery of spontaneous circulation (no-ROSC) and low pH levels (adjusted odds ratio (OR) 0.03 (0.002-0.59), p = 0.020), high pCO₂ levels (adjusted OR 1.03 [1.01-1.05], p = 0.008) and high potassium levels (adjusted OR 2.28 [1.43-3.61], p = 0.008). Poor neurological outcomes were associated with low pH levels (adjusted OR 0.06 [0.02-0.18], p < 0.001), high pCO₂ (adjusted OR 1.05 [1.03-1.08], p < 0.001), low HCO₃^- (adjusted OR 0.97 [0.94-0.999], p = 0.044), low BE (adjusted OR 0.96 [0.93-0.98], p < 0.001) and high potassium levels (adjusted OR 1.37 [1.16-1.60], p < 0.001).

CONCLUSION

There is a significant relationship between severe alterations of venous blood-gas variables and potassium at the start of CPR of non-traumatic OHCA and low-ROSC rate and neurological prognosis.

[Recommendations for extracorporeal cardiopulmonary resuscitation (eCPR) : Consensus statement of DGIIN, DGK, DGTHG, DGfK, DGNI, DGAI, DIVI and GRC]

Extracorporeal cardiopulmonary resuscitation (eCPR) may be considered as a rescue attempt for highly selected patients with refractory cardiac arrest and potentially reversible etiology. Currently there are no randomized, controlled studies on eCPR, and valid predictors of benefit and outcome which might guide the indication for eCPR are lacking. Currently selection criteria and procedures differ across hospitals and standardized algorithms are lacking. Based on expert opinion, the present consensus statement provides a proposal for a standardized treatment algorithm for eCPR.

Diagnostic et Prise en Charge de l’Acidose Métabolique Recommandations formalisées d’experts communes Société de réanimation de langue française (SRLF) – Société française de médecine d’urgence (SFMU)

L’acidose métabolique est un trouble fréquemment rencontré en médecine d’urgence et en médecine intensive réanimation. La littérature s’étant enrichie de nouvelles données concernant la prise en charge de l’acidose métabolique, la Société de Réanimation de Langue Française (SRLF) et la Société Française de Médecine d’Urgence (SFMU) ont élaboré des recommandations formalisées d’experts selon la méthodologie GRADE. Les champs de la stratégie diagnostique, de l’orientation et de la prise en charge thérapeutique ont été traités et vingt-neuf recommandations ont été formulées : quatre recommandations fortes (Grade 1), dix recommandations faibles (Grade 2) et quinze avis d’experts. Toutes ont obtenu un accord fort. L’application des méthodes d’Henderson-Hasselbalch et de Stewart pour le diagnostic du mécanisme de l’acidose métabolique est discutée et un algorithme diagnostique est proposé. L’utilisation de la cétonémie et des lactatémies veineuse et capillaire est également traitée. L’intérêt du pH, de la lactatémie et de sa cinétique pour l’orientation des patients en pré-hospitalier et aux urgences est envisagé. Enfin, les modalités de l’insulinothérapie au cours de l’acidocétose diabétique, les indications de la perfusion de bicarbonate de sodium et de l’épuration extra-rénale ainsi que les modalités de la ventilation mécanique au cours des acidoses métaboliques sévères sont traitées dans la prise en charge thérapeutique.

Recovery from profound acidosis (pH 6.685) in multi-organ dysfunction syndrome

Acidosis is a common feature of patients referred to critical care from the emergency department. We present the case of a 49-year-old female with multi-organ dysfunction syndrome (MODS) and an arterial pH of 6.685 on arrival to the emergency department. This case is unique as the patient was in circulatory shock with MODS from rhabdomyolysis on arrival and had not suffered a cardiac arrest. We believe this to be the first reported case of full recovery from such an extreme metabolic disturbance in this context, and discuss the relevance of profound acidosis to early clinical decision-making.

Diagnosis and management of metabolic acidosis: guidelines from a French expert panel

Metabolic acidosis is a disorder frequently encountered in emergency medicine and intensive care medicine. As literature has been enriched with new data concerning the management of metabolic acidosis, the French Intensive Care Society (Société de Réanimation de Langue Française [SRLF]) and the French Emergency Medicine Society (Société Française de Médecine d’Urgence [SFMU]) have developed formalized recommendations from experts using the GRADE methodology. The fields of diagnostic strategy, patient assessment, and referral and therapeutic management were addressed and 29 recommendations were made: 4 recommendations were strong (Grade 1), 10 were weak (Grade 2), and 15 were experts’ opinions. A strong agreement from voting participants was obtained for all recommendations. The application of Henderson–Hasselbalch and Stewart methods for the diagnosis of the metabolic acidosis mechanism is discussed and a diagnostic algorithm is proposed. The use of ketosis and venous and capillary lactatemia is also treated. The value of pH, lactatemia, and its kinetics for the referral of patients in pre-hospital and emergency departments is considered. Finally, the modalities of insulin therapy during diabetic ketoacidosis, the indications for sodium bicarbonate infusion and extra-renal purification as well as the modalities of mechanical ventilation during severe metabolic acidosis are addressed in therapeutic management.

Effect of estimated glomerular filtration rate (eGFR) on incidence of out-of-hospital cardiac arrests: A case-control study

OBJECTIVES

Serum creatinine levels in the post-resuscitative state have been associated with poor prognosis for out-of-hospital cardiac arrest (OHCA). Several studies have focused on kidney dysfunction in the general population, and the results suggested that serum creatinine level elevation or reduction of the estimated glomerular filtration rate (eGFR) are associated with increased risk of death and cardiovascular events. However, it is uncertain whether the serum creatinine levels or eGFR of OHCA patients are related to the incidence of OHCA. The aim of this study was to determine the association between eGFR and the incidence of OHCA.

METHODS

This study was a case-control study performed using the Cardiac Arrest Pursuit Trial with Unique Registration and Epidemiologic Surveillance (CAPTURES) project dataset and the Korea National Health and Nutrition Examination Survey (KNHANES) dataset. Cases were defined as emergency medical service-treated adult OHCA patients with presumed cardiac etiology collected from the CAPTURES dataset. Four controls from the KNHANES dataset were matched to one case based on age, gender, and county. Multivariable conditional logistic regression analysis was conducted to evaluate the effect of eGFR on the incidence of OHCA.

RESULTS

A total of 1211 matched case-control pairs were included in the study analysis. We classified eGFR into 6 categories (≥90, 60-89, 45-59, 30-44, 15-29, and <15 mL/min/1.73 m²) according to the chronic kidney disease stage. Subjects with an eGFR ≥90 mL/min/1.73 m² were used as the reference group. In both the unadjusted and adjusted models, lower eGFR was significantly associated with OHCA incidence. The odds ratio (OR) for OHCA incidence increased sharply as the eGFR declined; the adjusted OR (95% CI) for OHCA incidence was 4.09 (2.81-5.95) with an eGFR of 60-89 mL/min/1.73 m², 36.59 (22.24-60.21) with an eGFR of 45-59 mL/min/1.73 m², 55.26(29.66-102.94) with an eGFR of 30-44 mL/min/1.73 m², 89.65 (37.25-215.79) with an eGFR of 15-29 mL/min/1.73 m², and 241.87 (73.49-796.01) with an eGFR of less than 15 mL/min/1.73 m².

CONCLUSION

In this study, we observed an association between reduced eGFR and the risk of OHCA incidence in a large, community-based population. Future prospective studies are needed to better understand how reduced renal function is associated with OHCA occurrence as well as the impact of intensive risk management and intervention of renal function on OHCA incidence.

Serum potassium level on hospital arrival and survival after out-of-hospital cardiac arrest: The CRITICAL study in Osaka, Japan

BACKGROUND

Little is known about the association between serum potassium level on hospital arrival and neurological outcome after out-of-hospital cardiac arrest (OHCA). We investigated whether the serum potassium level on hospital arrival had prognostic indications for patients with OHCA.

METHODS

This prospective, multicenter observational study conducted in Osaka, Japan (CRITICAL study) enrolled consecutive patients with OHCA transported to 14 participating institutions from 2012 to 2016. We included adult patients aged ⩾18 years with OHCA of cardiac origin who achieved return of spontaneous circulation and whose serum potassium level on hospital arrival was available. Based on the serum potassium level, patients were divided into four quartiles: Q1 (K ⩽3.8 mEq/L), Q2 (3.8< K⩽4.5 mEq/L), Q3 (4.5< K⩽5.6 mEq/L) and Q4 (K >5.6 mEq/L). The primary outcome was one-month survival with favorable neurological outcome, defined as cerebral performance category scale 1 or 2.

RESULTS

A total of 9822 patients were registered, and 1516 of these were eligible for analyses. The highest proportion of favorable neurological outcome was 44.8% (189/422) in Q1 group, followed by 30.3% (103/340), 11.7% (44/375) and 4.5% (17/379) in the Q2, Q3 and Q4 groups, respectively (p<0.001). In the multivariable analysis, the proportion of favorable neurological outcome decreased as the serum potassium level increased (p<0.001).

CONCLUSIONS

High serum potassium level was significantly and dose-dependently associated with poor neurological outcome. Serum potassium on hospital arrival would be one of the effective prognostic indications for OHCA achieving return of spontaneous circulation.

Initial arterial pH as a predictor of neurologic outcome after out-of-hospital cardiac arrest: A propensity-adjusted analysis

BACKGROUND

Lower pH after out-of-hospital cardiac arrest (OHCA) has been associated with worsening neurologic outcome, with <7.2 identified as an "unfavorable resuscitation feature" in consensus treatment algorithms despite conflicting data. This study aimed to describe the relationship between decremental post-resuscitation pH and neurologic outcomes after OHCA.

METHODS

Consecutive OHCA patients treated with targeted temperature management (TTM) at multiple US centers from 2008 to 2017 were evaluated. Poor neurologic outcome at hospital discharge was defined as cerebral performance category ≥3. The exposure was initial arterial pH after return of spontaneous circulation (ROSC) analyzed in decremental 0.05 thresholds. Potential confounders (demographics, history, resuscitation characteristics, initial studies) were defined a priori and controlled for via ATT-weighting on the inverse propensity score plus direct adjustment for the linear propensity score.

RESULTS

Of 723 patients, 589 (80%) experienced poor neurologic outcome at hospital discharge. After propensity-adjustment with excellent covariate balance, the adjusted odds ratios for poor neurologic outcome by pH threshold were: ≤7.3: 2.0 (1.0-4.0); ≤7.25: 1.9 (1.2-3.1); ≤7.2: 2.1 (1.3-3.3); ≤7.15: 1.9 (1.2-3.1); ≤7.1: 2.4 (1.4-4.1); ≤7.05: 3.1 (1.5-6.3); ≤7.0: 4.5 (1.8-12).

CONCLUSIONS

No increased hazard of progressively poor neurologic outcomes was observed in resuscitated OHCA patients treated with TTM until the initial post-ROSC arterial pH was at least ≤7.1. This threshold is more acidic than in current guidelines, suggesting the possibility that post-arrest pH may be utilized presently as an inappropriately-pessimistic prognosticator.

Multimodal assessment using early brain CT and blood pH improve prediction of neurologic outcomes after pediatric cardiac arrest

BACKGROUND

Early prediction of neurologic prognosis in children resuscitated from cardiac arrest is a major challenge. This study aimed to investigate the usefulness of a combined model based on brain computed tomography (CT) and initial blood gas analysis to predict neurologic prognoses in pediatric patients after cardiac arrest.

METHODS

We retrospectively analyzed the medical records of patients resuscitated after cardiac arrest from 2000 to 2018. Patients aged one month to 18 years were included. Gray to white matter ratio (GWR), ambient cistern effacement (ACE), and blood gas analysis were studied. The primary outcome was neurological prognosis, which was evaluated using the Pediatric Cerebral Performance Category (PCPC) scale at discharge.

RESULTS

Of 97 resuscitated patients, 64 brain CT images were available. Fourteen patients had a good neurologic outcome (PCPC 1-3) and 50 patients a poor neurologic outcome (PCPC 4-6). The multimodal model (AUC 0.897) containing GWR of basal ganglia (BG), ACE, and blood pH was found to be superior for predicting poor neurologic prognosis than single variable models (AUC of GWR-BG: 0.744, ACE: 0.804, pH: 0.747). Interestingly, we found the GWR-BG cutoff value for specificity 100% differed significantly between patients <4 years (cutoff value: 1.08, p = 0.04) and ≥4 years (cutoff value: 1.18, p = 0.004).

CONCLUSIONS

The combination of GWR-BG, ambient cistern effacement, and blood pH was found to usefully predict neurological outcome in children resuscitated from cardiac arrest. In addition, the cutoff value of GWR-BG for the prediction of neurologic outcome was found to increase with age.

[Which patients benefit from transport with ongoing cardiopulmonary resuscitation? : Retrospective analysis of 70 patients with refractory preclinical cardiac arrest]

BACKGROUND

Mortality in patients with out-of-hospital cardiac arrest (OHCA) remains very high despite advances in resuscitation algorithms. Most of these patients die at the scene and do not reach hospital. It is currently the subject of discussion whether transport to hospital with ongoing cardiopulmonary resuscitation (CPR) improves survival and neurological outcome in patients with OHCA.

OBJECTIVE

The aim of this study was to identify predictors of survival and good neurological outcome in patients after OHCA who were transported to hospital with ongoing CPR.

PATIENTS AND METHODS

A total of 70 consecutive patients with refractory OHCA (mean age 54.7 ± 15 years) transported to hospital with ongoing CPR were retrospectively analyzed. Neurological outcome was assessed after 30 days based on the Glasgow-Pittsburgh cerebral performance category (CPC).

RESULTS

After 30 days 82.9% of the patients enrolled in the trial died (CPC score of 5), 8 patients (11.4%) showed a good neurological recovery with CPC scores of 1-2 and 4 patients (5.7%) had a poor neurological outcome with CPC scores of 3-4. Predictors of good neurological outcome were witnessed arrest, initial defibrillatable rhythm and serum lactate levels on admission. In all patients with good outcome, the index event for OHCA was from cardiac causes.

CONCLUSION

Selected patient collectives can benefit from transport to hospital with ongoing cardiopulmonary resuscitation (CPR).