Lactate, lactate clearance and outcome after cardiac arrest: A post-hoc analysis of the TTM-Trial

Blood laboratory analyses preceding in-hospital cardiac arrest: A matched case-control study

BACKGROUND

Whether blood laboratory analyses differ in patients who later suffer in-hospital cardiac arrest (IHCA) compared to other hospitalised patients remains unknown. The aim of this study was to describe pre-arrest sampling frequencies, results, and trends in blood laboratory analyses in patients with IHCA compared to controls.

METHODS

This study was a matched case-control study using national registries in Denmark. Cases were defined as patients with IHCA from 2017 to 2021. Controls were defined as hospitalised patients and were matched on age, sex, and date and length of admission. Data on a total of 51 different blood laboratory analyses were obtained. The laboratory analyses of primary interest were lactate, sodium, potassium, and haemoglobin. The index time for cases was defined as the time of cardiac arrest, and a corresponding index time was defined for controls based on the time to cardiac arrest for their corresponding case. Blood sampling frequencies were reported for blood laboratory analyses obtained either within the last 24 h before the index time or between the time of hospital admission and the index time. Blood sampling results were reported for blood laboratory analyses obtained within the last 24 h before the index time.

RESULTS

A total of 9268 cases and 92,395 controls were included in this study. Cases underwent more frequent sampling of all blood laboratory analyses compared to controls. This higher sampling frequency was more pronounced for lactate compared to sodium, potassium, or haemoglobin. The last measured lactate was higher in cases (median [IQR]: 2.3 [1.3, 4.9]) compared to controls (median [IQR]: 1.3 [0.9, 2.0]). Differences in sodium, potassium, and haemoglobin were negligible. The proportion of abnormally elevated levels of lactate and potassium increased as time to cardiac arrest decreased; no such effect was seen in controls. No temporal trend was evident for sodium or haemoglobin.

CONCLUSIONS

Patients with IHCA undergo more frequent blood sampling prior to IHCA and have higher levels of lactate compared to matched controls.

Serum lactate/creatinine ratio and acute kidney injury in cardiac arrest patients

OBJECTIVES

Serum lactate and creatinine levels upon admission in cardiac arrest (CA) patients significantly correlate with acute kidney injury (AKI) post-restoration of autonomic circulation. However, the association between serum lactate/creatinine ratio (LCR) and AKI in this population remains unclear. This study aimed to explore the relationship between LCR at admission and cardiac arrest-associated acute kidney injury (CA-AKI).

DESIGN AND METHODS

We conducted a secondary analysis of previously published data on CA patient resuscitation, categorizing them into tertiles based on LCR levels. Univariate and multivariate logistic regression models and subgroup analyses were employed to investigate the association between LCR and CA-AKI. Non-linear correlations were explored using restricted cubic splines, and a two-piece wise logistic proportional hazards model for both sides of the inflection point was constructed.

RESULTS

A total of 374 patients (72.19 % male) were included, with intensive care unit mortality, in-hospital mortality, and neurologic dysfunction rates of 51.87 %, 56.95 %, and 39.57 %, respectively. The overall CA-AKI incidence was 59.09 %. Multivariate logistic proportional hazards analysis revealed a negative association between LCR and CA-AKI incidence (adjusted odds ratio [OR] 0.85, 95 % confidence intervals [CI] = 0.78-0.93, P=0.001). Triple spline restriction analysis depicted an L-shaped correlation between baseline LCR and CA-AKI incidence. Particularly, a baseline LCR<0.051 was negatively associated with CA-AKI incidence (OR 0.494, 95 % CI=0.319-0.764, P=0.002). Beyond the LCR turning point, estimated dose-response curves remained consistent with a horizontal line.

CONCLUSIONS

Baseline LCR in CA patients exhibits an L-shaped correlation with AKI incidence following restoration of autonomic circulation. The threshold for CA-AKI is 0.051. This finding suggests that LCR may aid in identifying CA patients at high risk of AKI.

Blood glucose and lactate levels as early predictive markers in patients presenting with cardiogenic shock: A retrospective cohort study

Lactate and glucose are widely used biochemical parameters in current predictive risk scores for cardiogenic shock. Data regarding the relationship between lactate and glucose levels in cardiogenic shock are limited. Thus, we aimed to analyze glucose and lactate as early markers for in-hospital mortality in cardiogenic shock. In this retrospective cohort study, 312 patients presenting with cardiogenic shock to a tertiary-care hospital between 2016 and 2018 were included. Apparent cardiogenic shock was defined as hypoperfusion with hemodynamic compromise and biochemical marker increase due to diminished tissue perfusion, corresponding to SCAI shock stages. In-hospital mortality was assessed as the primary endpoint. The median age of the study population was 71 (60-79) years and the etiology of cardiogenic shock was acute myocardial infarction in 45.8%. Overall in-hospital mortality was 67.6%. In the receiver operating curve analysis, the area under the receiver-operating curve (AUC) for prediction of in-hospital mortality was higher for lactate (AUC: 0.757) than for glucose (AUC: 0.652). Both values were significantly associated with outcome (groups created with best cutoff values obtained from the Youden index). Correlation analysis showed a significant non-linear association of both values. In a multivariable stepwise Cox regression analysis, lactate remained an independent predictor for in-hospital mortality, whilst glucose, despite being implicated in energy metabolism, was not independently predictive for mortality. Together, these data suggest that lactate at admission is superior for mortality prediction in patients with apparent cardiogenic shock. Glucose was not independently predictive for mortality.

Physiology-Guided Resuscitation: Monitoring and Augmenting Perfusion during Cardiopulmonary Arrest

Given the high morbidity and mortality associated with cardiopulmonary arrest, there have been multiple trials aimed at better monitoring and augmenting coronary, cerebral, and systemic perfusion. This article aims to elucidate these interventions, first by detailing the physiology of cardiopulmonary resuscitation and the available tools for managing cardiopulmonary arrest, followed by an in-depth examination of the newest advances in the monitoring and delivery of advanced cardiac life support.

Thiamine as a metabolic resuscitator after in-hospital cardiac arrest

INTRODUCTION

Elevated lactate is associated with mortality after cardiac arrest. Thiamine, a cofactor of pyruvate dehydrogenase, is necessary for aerobic metabolism. In a mouse model of cardiac arrest, thiamine improved pyruvate dehydrogenase activity, survival and neurologic outcome.

AIM

To determine if thiamine would decrease lactate and increase oxygen consumption after in-hospital cardiac arrest.

METHODS

Randomized, double-blind, placebo-controlled phase II trial. Adult patients with arrest within 12 hours, mechanically ventilated, with lactate ≥ 3 mmol/L were included. Randomization was stratified by lactate > 5 or ≤ 5 mmol/L. Thiamine 500 mg or placebo was administered every 12 hours for 3 days. The primary outcome of lactate was checked at baseline, 6, 12, 24, and 48 hours, and compared using a linear mixed model, accounting for repeated measures. Secondary outcomes included oxygen consumption, pyruvate dehydrogenase, and mortality.

RESULTS

Enrollments stopped after 36 patients due Data Safety and Monitoring Board concern about potential harm in an unplanned subgroup analysis. There was no overall difference in lactate (mean difference at 48 hours 1.5 mmol/L [95% CI -3.1-6.1], global p = 0.88) or any secondary outcomes. In those with randomization lactate > 5 mmol/L, mortality was 92% (11/12) with thiamine and 67% (8/12) with placebo (p = 0.32). In those with randomization lactate ≤ 5 mmol/L mortality was 17% (1/6) with thiamine and 67% (4/6) with placebo (p = 0.24). There was a significant interaction between randomization lactate and the effect of thiamine on survival (p = 0.03).

CONCLUSIONS

In this single center trial thiamine had no overall effect on lactate after in-hospital cardiac arrest.

Association between early lactate-related variables and 6-month neurological outcome in out-of-hospital cardiac arrest patients

INTRODUCTION

The role of lactate measurement in out-of-hospital cardiac arrest (OHCA) survivors remains controversial. We assessed the association between early lactate-related variables, OHCA characteristics, and long-term neurological outcome.

METHODS

In OHCA patients who received targeted temperature management, lactate levels were measured at 0, 12, and 24 h after the return of spontaneous circulation. We calculated lactate clearance and time-weighted cumulative lactate (TWCL), which represent the area under the time-lactate curve. The area under the receiver operating characteristic curve (AUC) and the adjusted odds ratios (AORs) of lactate-related variables for predicting 6-month poor outcome (Cerebral Performance Category 3-5) were evaluated. Interactions between lactate variables and characteristics of OHCA were evaluated by a multivariable logistic model with interaction terms and subgroup analysis.

RESULTS

A total of 347 OHCA patients were included. After adjustment, higher lactate levels at the three time points were associated with a poor outcome (AOR 1.10 [95% CI, 1.03-1.18], AOR 1.15 [95% CI, 1.02-1.29], and AOR 1.36 [95% CI, 1.15-1.60], respectively), while TWCL was the only lactate kinetics variable associated with a poor outcome (AOR 1.29 [95% CI, 1.12-1.49]). We identified several interactions between lactate-related variables and OHCA characteristics. In particular, the AUC of TWCL was excellent in cases of noncardiac etiology (AUC 0.92 [95% CI, 0.86-0.96] but only moderate in cardiac etiology (AUC 0.69 [95% CI, 0.62-0.75]).

CONCLUSIONS

Early lactate levels, especially at 24 h, and TWCL were independent predictors of neurologic outcome in these patients, whereas lactate clearance was not. The prognostic ability of lactate-related variables varied depending on the OHCA characteristics.

Serum lactate in refractory out-of-hospital cardiac arrest: Post-hoc analysis of the Prague OHCA study

BACKGROUND

The severity of tissue hypoxia is routinely assessed by serum lactate. We aimed to determine whether early lactate levels predict outcomes in refractory out-of-hospital cardiac arrest (OHCA) treated by conventional and extracorporeal cardiopulmonary resuscitation (ECPR).

METHODS

This study is a post-hoc analysis of a randomized Prague OHCA study (NCT01511666) assessing serum lactate levels in refractory OHCA treated by ECPR (the ECPR group) or conventional resuscitation with prehospital achieved return of spontaneous circulation (the ROSC group). Lactate concentrations measured on admission and every 4 hours (h) during the first 24 h were used to determine their relationship with the neurological outcome (the best Cerebral Performance Category score within 180 days post-cardiac arrest).

RESULTS

In the ECPR group (92 patients, median age 58.5 years, 83% male) 26% attained a favorable neurological outcome. In the ROSC group (82 patients, median age 55 years, 83% male) 59% achieved a favorable neurological outcome. In ECPR patients lactate concentrations could discriminate favorable outcome patients, but not consistently in the ROSC group. On admission, serum lactate >14.0 mmol/L for ECPR (specificity 87.5%, sensitivity 54.4%) and >10.8 mmol/L for the ROSC group (specificity 83%, sensitivity 41.2%) predicted an unfavorable outcome.

CONCLUSION

In refractory OHCA serum lactate concentrations measured anytime during the first 24 h after admission to the hospital were found to correlate with the outcome in patients treated by ECPR but not in patients with prehospital ROSC. A single lactate measurement is not enough for a reliable outcome prediction and cannot be used alone to guide treatment.

Association of lactate detection with in-hospital mortality in critically ill patients with acute myocardial infarction: a retrospective cohort study

OBJECTIVES

To assess the associations of lactate level or lactate clearance at different time points with in-hospital mortality in critically ill patients with acute myocardial infarction (AMI).

DESIGN

A cohort study.

SETTING

The Medical Information Mart for Intensive Care III database.

PARTICIPANT

490 AMI patients.

INTERVENTION

None.

PRIMARY AND SECONDARY OUTCOME MEASURES

In-hospital mortality of patients.

RESULTS

In total, 120 (24.49%) patients died at the end of follow-up. After adjusting for confounders, increased risk of in-hospital mortality in patients with AMI was observed in those with high lactate level (24 hours) (HR=1.156, 95%CI: 1.002 to 1.333). Increased lactate clearance (24 hours) was correlated with a decreased risk of in-hospital mortality in patients with AMI (HR=0.995, 95% CI: 0.994 to 0.997). The area under the curves (AUCs) of lactate level (24 hours) and lactate clearance (24 hours) were 0.689 (95% CI: 0.655 to 0.723) and 0.672 (95% CI: 0.637 to 0.706), respectively. The AUC of lactate level (24 hours) and lactate clearance (24 hours) was higher than lactate level (baseline).

CONCLUSIONS

Increased lactate level (24 hours) was associated with an elevated risk of in-hospital mortality in patients with AMI and increased lactate clearance (24 hours) was correlated with a decreased risk of in-hospital mortality in patients with AMI despite the age and genders.

Neuroprognostication in the Post Cardiac Arrest Patient: A Canadian Cardiovascular Society Position Statement

Cardiac arrest (CA) is associated with a low rate of survival with favourable neurologic recovery. The most common mechanism of death after successful resuscitation from CA is withdrawal of life-sustaining measures on the basis of perceived poor neurologic prognosis due to underlying hypoxic-ischemic brain injury. Neuroprognostication is an important component of the care pathway for CA patients admitted to hospital but is complex, challenging, and often guided by limited evidence. Using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system to evaluate the evidence underlying factors or diagnostic modalities available to determine prognosis, recommendations were generated in the following domains: (1) circumstances immediately after CA; (2) focused neurologic exam; (3) myoclonus and seizures; (4) serum biomarkers; (5) neuroimaging; (6) neurophysiologic testing; and (7) multimodal neuroprognostication. This position statement aims to serve as a practical guide to enhance in-hospital care of CA patients and emphasizes the adoption of a systematic, multimodal approach to neuroprognostication. It also highlights evidence gaps.

Veno-arterial CO2 difference and lactate for prediction of early mortality after cardiac arrest

Patients admitted to intensive care after cardiac arrest are at risk of circulatory shock and early mortality due to cardiovascular failure. The aim of this study was to evaluate the ability of the veno-arterial pCO₂ difference (∆pCO₂ ; central venous CO₂ - arterial CO₂ ) and lactate to predict early mortality in postcardiac arrest patients. This was a pre-planned prospective observational sub-study of the target temperature management 2 trial. The sub-study patients were included at five Swedish sites. Repeated measurements of ∆pCO₂ and lactate were conducted at 4, 8, 12, 16, 24, 48, and 72 h after randomization. We assessed the association between each marker and 96-h mortality and their prognostic value for 96-h mortality. One hundred sixty-three patients were included in the analysis. Mortality at 96 h was 17%. During the initial 24 h, there was no difference in ∆pCO₂ levels between 96-h survivors and non-survivors. ∆pCO₂ measured at 4 h was associated with an increased risk of death within 96 h (adjusted odds ratio: 1.15; 95% confidence interval [CI]: 1.02-1.29; p = .018). Lactate levels were associated with poor outcome over multiple measurements. The area under the receiving operating curve to predict death within 96 h was 0.59 (95% CI: 0.48-0.74) and 0.82 (95% CI: 0.72-0.92) for ∆pCO₂ and lactate, respectively. Our results do not support the use of ∆pCO₂ to identify patients with early mortality in the postresuscitation phase. In contrast, non-survivors demonstrated higher lactate levels in the initial phase and lactate identified patients with early mortality with moderate accuracy.

The Association Between Induction Rate and Neurologic Outcome in Patients Undergoing Targeted Temperature Management at 33°C

To determine the association between the induction rate and 6-month neurologic outcomes in out-of-hospital cardiac arrest (OHCA) survivors who underwent targeted temperature management (TTM). This retrospective observational study analyzed data prospectively collected from adult comatose OHCA survivors treated with TTM at the Chonnam National University Hospital in Gwangju, Korea, between October 2015 and December 2020. We measured the core body temperature (BT) through an esophageal probe and recorded it every 5 minutes throughout TTM. Induction time was defined as the elapsed time between the initiation of TTM and the achievement of target BT of 33°C. We calculated the induction rate as the change of BT divided by induction time. The primary outcome was a poor 6-month neurologic outcome, defined as cerebral performance category 3-5. Of the OHCA survivors, 218 patients were included, and 137 (62.8%) patients had a poor neurologic outcome. Patients with a poor neurologic outcome had lower BT at the initiation of TTM, shorter induction time, and higher induction rate than those with good neurologic outcomes. After adjusting for confounders, induction time (odds ratio [OR] 0.995; 95% confidence interval [CI], 0.992-0.999) and induction rate (OR 2.362; 95% CI, 1.178-4.734) were independently associated with poor neurologic outcome. BT at TTM initiation was not associated with a poor neurologic outcome. Induction rate was independently associated with a poor neurologic outcome in OHCA survivors who underwent TTM at 33°C.

Age-adjusted Charlson Comorbidity Index as effective predictor for in-hospital mortality of patients with cardiac arrest: a retrospective study

BACKGROUND

Cardiac arrest is currently one of the leading causes of mortality in clinical practice, and the Charlson Comorbidity Index (CCI) is widely utilized to assess the severity of comorbidities. We aimed to evaluate the relationship between the age-adjusted CCI score and in-hospital mortality in intensive care unit (ICU) patients with the diagnosis of cardiac arrest, which is important but less explored previously.

METHODS

This was a retrospective study including patients aged over 18 years from the MIMIC-IV database. We calculated the age-adjusted CCI using age information and ICD codes. The univariate analysis for varied predictors' differences between the survival and the non-survival groups was performed. In addition, a multiple factor analysis was conducted based on logistic regression analysis with the primary result set as hospitalization death. An additional multivariate regression analysis was conducted to estimate the influence of hospital and ICU stay.

RESULTS

A total of 1772 patients were included in our study, with median age of 66, among which 705 (39.8%) were female. Amongst these patients, 963 (54.3%) died during the hospitalization period. Patients with higher age-adjusted CCI scores had a higher likelihood of dying during hospitalization (P < 0.001; OR: 1.109; 95% CI: 1.068-1.151). With the age-adjusted CCI incorporated into the predictive model, the area under the receiver operating characteristic curve was 0.794 (CI: 0.773-0.814), showing that the prediction model is effective. Additionally, patients with higher age-adjusted CCI scores stayed longer in the hospital (P = 0.026, 95% CI: 0.056-0.896), but there was no significant difference between patients with varied age-adjusted CCI scores on the days of ICU stay.

CONCLUSION

The age-adjusted CCI is a valid indicator to predict death in ICU patients with cardiac arrest, which can offer enlightenment for both theory literatures and clinical practice.

Lactate metabolism in human health and disease

The current understanding of lactate extends from its origins as a byproduct of glycolysis to its role in tumor metabolism, as identified by studies on the Warburg effect. The lactate shuttle hypothesis suggests that lactate plays an important role as a bridging signaling molecule that coordinates signaling among different cells, organs and tissues. Lactylation is a posttranslational modification initially reported by Professor Yingming Zhao’s research group in 2019. Subsequent studies confirmed that lactylation is a vital component of lactate function and is involved in tumor proliferation, neural excitation, inflammation and other biological processes. An indispensable substance for various physiological cellular functions, lactate plays a regulatory role in different aspects of energy metabolism and signal transduction. Therefore, a comprehensive review and summary of lactate is presented to clarify the role of lactate in disease and to provide a reference and direction for future research. This review offers a systematic overview of lactate homeostasis and its roles in physiological and pathological processes, as well as a comprehensive overview of the effects of lactylation in various diseases, particularly inflammation and cancer.

Myocardial dysfunction after cardiac arrest: tips and pitfalls

Postcardiac arrest shock (PCAS) is defined by hemodynamic instability occurring in the first hours after cardiac arrest (CA) and is a major cause of mortality among patients hospitalized after CA. It includes vasoplegia and myocardial dysfunction. This postcardiac arrest myocardial dysfunction is supposed to recover within the 3 days. However, there are many unknowns regarding its definition, its prognosis value and its management. In this review dedicated to emergency physicians, we choose to address tips and pitfalls they should know regarding this prevalent syndrome.

Differential Effectiveness of Hypothermic Targeted Temperature Management According to the Severity of Post-Cardiac Arrest Syndrome

International guidelines recommend targeted temperature management (TTM) to improve the neurological outcomes in adult patients with post-cardiac arrest syndrome (PCAS). However, it still remains unclear if the lower temperature setting (hypothermic TTM) or higher temperature setting (normothermic TTM) is superior for TTM. According to the most recent large randomized controlled trial (RCT), hypothermic TTM was not found to be associated with superior neurological outcomes than normothermic TTM in PCAS patients. Even though this represents high-quality evidence obtained from a well-designed large RCT, we believe that we still need to continue investigating the potential benefits of hypothermic TTM. In fact, several studies have indicated that the beneficial effect of hypothermic TTM differs according to the severity of PCAS, suggesting that there may be a subgroup of PCAS patients that is especially likely to benefit from hypothermic TTM. Herein, we summarize the results of major RCTs conducted to evaluate the beneficial effects of hypothermic TTM, review the recent literature suggesting the possibility that the therapeutic effect of hypothermic TTM differs according to the severity of PCAS, and discuss the potential of individualized TTM.

Effect of Shenfu Injection () on Lactate and Lactate Clearance in Patients with Post-cardiac Arrest Syndrome: A Post Hoc Analysis of a Multicenter Randomized Controlled Trial

OBJECTIVE

To assess the effects of Shenfu Injection (, SFI) on blood lactate, and secondarily its effect on the lactate clearance (LC) in patients with post cardiac arrest syndrome (PCAS).

METHODS

The present study is a post hoc study of a randomized, assessor-blinded, controlled trial. Patients experienced in-hospital cardiac arrest between 2012 and 2015 were included in the predefined post hoc analyses. Of 1,022 patients enrolled, a total of 978 patients were allocated to the control group (486 cases) and SFI (492 cases) group, receiving standardized post-resuscitation care bundle (PRCB) treatment or PRCB combined with SFI (100 mL/d), respectively. Patients' serum lactate was measured simultaneously with artery blood gas, lactate clearance (LC) was calculated on days 1, 3, and 7 after admission and compared between groups. Lactate and LC were also compared between the survivors and non-survivors according to the 28-d mortality, as well as the survivors and non-survivors subgroups both in the SFI and control groups.

RESULTS

In both groups, compared with pre-treatment levels, mean arterial pressure (MAP) and PaO₂ were significantly improved on 1, 3, 7 d after treatment (P<0.05), while heart rate (HR) and blood glucose levels were significantly decreased on 1, 3 and 7 d after treatment (P<0.05). compared with control group, SFI treatment improved the values of MAP and PaO₂ (P<0.05), and significantly decreased the levels of HR and the blood glucose level on 3 and 7 d after treatment (P<0.05). Compared with the control group, lactate levels decreased faster in the SFI group versus the control group on 3 and 7 d (P<0.05). From initiation of treatment and the following 3 and 7 d, SFI treatment greatly increased the LC compared with that in the control group (P<0.05). Compared with survivors, non-survivors had higher admission lactate levels (7.3 ±1.1 mmol/L vs. 5.5 ±2.3 mmol/L; P<0.01), higher lactate levels on days 1, 3 and 7 (P<0.05), and LC were decreased significantly on 3 and 7 d after treatment (P<0.05). Similar results were also found both in the SFI and control groups between survivors and non-survivors subgroups.

CONCLUSION

SFI in combination with PRCB treatment is effective at lowering lactate level and resulted in increasing LC in a targeted population of PCAS patients.

Initial Blood pH, Lactate and Base Deficit Add No Value to Peri-Arrest Factors in Prognostication of Neurological Outcome After Out-of-Hospital Cardiac Arrest

Background: In cardiac arrest survivors, metabolic parameters [pH value, lactate concentration, and base deficit (BD)] are routinely added to peri-arrest factors (including age, sex, bystander cardiopulmonary resuscitation, shockable first rhythm, resuscitation duration, adrenaline dose) to enhance early outcome prediction. However, the additional value of this strategy remains unclear.

Methods: We used our resuscitation database to screen all patients ≥18 years who had suffered in- or out-of-hospital cardiac arrest (IHCA, OHCA) between January 1st, 2005 and May 1st, 2019. Patients with incomplete data, without return of spontaneous circulation or treatment with sodium bicarbonate were excluded. To analyse the added value of metabolic parameters to prognosticate neurological function, we built three models using logistic regression. These models included: (1) Peri-arrest factors only, (2) peri-arrest factors plus metabolic parameters and (3) metabolic parameters only. Receiver operating characteristics curves regarding 30-day good neurological function (Cerebral Performance Category 1-2) were analysed.

Results: A total of 2,317 patients (OHCA: n = 1842) were included. In patients with OHCA, model 1 and 2 had comparable predictive value. Model 3 was inferior compared to model 1. In IHCA patients, model 2 performed best, whereas both metabolic (model 3) and peri-arrest factors (model 1) demonstrated similar power. PH, lactate and BD had interchangeable areas under the curve in both IHCA and OHCA.

Conclusion: Although metabolic parameters may play a role in IHCA, no additional value in the prediction of good neurological outcome could be found in patients with OHCA. This highlights the importance of accurate anamnesis especially in patients with OHCA.

The Prognostic Usefulness of the Lactate/Albumin Ratio for Predicting Clinical Outcomes in Out-of-Hospital Cardiac Arrest: a Prospective, Multicenter Observational Study (koCARC) Study

BACKGROUND AND PURPOSE

We aimed to evaluate the lactate/albumin ratio (LAR) to identify its significance as a prognostic marker for favorable neurologic outcome and survival in patients with return of spontaneous circulation after out-of-hospital cardiac arrest (OHCA). Based on the LAR and multiple parameters, we developed new nomograms and externally validated the tools.

METHODS

We conducted an observational study using a prospective, multicenter registry of out-of-cardiac arrest resuscitation provided by the Korean Cardiac Arrest Research Consortium registry from October 2015 to June 2017.

RESULTS

A total of 524 patients were included in this study. An increased LAR was significantly associated with decreased favorable neurologic outcomes (odds ratio [OR] 0.787; 95% confidence interval [CI], 0.630-0.983; P = 0.035) and survival at discharge (OR 0.744; 95% CI, 0.638-0.867; P < 0.001). The areas under the curve (AUCs) for predicting neurologic outcome and survival to discharge using the LAR were 0.824 (P < 0.001) and 0.781 (P < 0.001), respectively. An LAR value of more than the optimal cutoff values of 2.82 and 3.62 could significantly improve prediction of decreased favorable neurologic outcome and survival to discharge, respectively. We constructed nomograms based on the multivariate logistic model. The model for predicting favorable neurologic outcomes and survival discharge had AUCs of 0.927 (P < 0.001) and 0.872 (P < 0.001), respectively.

CONCLUSION

The prognostic performance of the LAR was superior to a single measurement of lactate for predicting favorable neurologic outcomes and survival to discharge after OHCA. The newly developed nomograms can provide rapid prediction of probability of clinical outcomes.

Plasma proenkephalin A 119-159 and dipeptidyl peptidase 3 on admission after cardiac arrest help predict long-term neurological outcome

BACKGROUND

A large proportion of adult survivors of cardiac arrest have a poor neurological outcome. Guidelines recommend multimodal neuro-prognostication no earlier than 72-96 h after cardiac arrest. There is great interest in earlier prognostic markers, including very early markers at admission. The novel blood biomarkers proenkephalin A 119-159 (penKid), bioactive adrenomedullin (bio-ADM) and circulating dipeptidyl peptidase 3 (cDPP3) have not been previously investigated for the early prognosis of cardiac arrest survivors.

METHODS

This multicentre observational study included adult survivors of cardiac arrest admitted to intensive care at four Swedish intensive care units (ICUs) during 2016. Blood samples were collected at ICU admission and batch analysed. The association between admission plasma penKid, bio-ADM and cDPP3 and poor long-term neurological outcome, according to the Cerebral Performance Category (CPC) scale, was assessed by binary logistic regression. Their prognostic performance was assessed using the area under the receiver operating characteristic curve (AUC).

RESULTS

A total of 190 patients were included, of which 136 patients had suffered out-of-hospital and 54 patients in-hospital cardiac arrest. Poor long-term neurological outcome was associated with elevated admission plasma concentrations of penKid and cDPP3, but not with bio-ADM. The association for penKid, but not for cDPP3, remained after adjusting for clinical cardiac arrest variables with prognostic value (time to return of spontaneous circulation (ROSC), initial rhythm, admission Glasgow coma scale (GCS) motor score and absence of pupillary reflexes). The prognostic performance of above mentioned clinical cardiac arrest variables alone was very good with an AUC of 0.90 (95% confidence interval, CI, 0.86-0.95), but improved further with the addition of penKid resulting in an AUC of 0.93 (95% CI 0.89-0.97, p < 0.026). Plasma penKid and cDPP3 alone provided moderate long-term prognostic information with AUCs of 0.70 and 0.71, respectively.

CONCLUSION

After cardiac arrest, admission plasma levels of penKid and cDPP3, but not bio-ADM, predicted long-term neurological outcome. When added to clinical cardiac arrest variables, penKid further improved prognostic performance.

Association between serum lactate level during cardiopulmonary resuscitation and survival in adult out-of-hospital cardiac arrest: a multicenter cohort study

We aimed to investigate the association between serum lactate levels during cardiopulmonary resuscitation (CPR) and survival in patients with out-of-hospital cardiac arrest (OHCA). From the database of a multicenter registry on OHCA patients, we included adult nontraumatic OHCA patients transported to the hospital with ongoing CPR. Based on the serum lactate levels during CPR, the patients were divided into four quartiles: Q1 (≤ 10.6 mEq/L), Q2 (10.6-14.1 mEq/L), Q3 (14.1-18.0 mEq/L), and Q4 (> 18.0 mEq/L). The primary outcome was 1-month survival. Among 5226 eligible patients, the Q1 group had the highest 1-month survival (5.6% [74/1311]), followed by Q2 (3.6% [47/1316]), Q3 (1.7% [22/1292]), and Q4 (1.0% [13/1307]) groups. In the multivariable logistic regression analysis, the adjusted odds ratio of Q4 compared with Q1 for 1-month survival was 0.24 (95% CI 0.13-0.46). 1-month survival decreased in a stepwise manner as the quartiles increased (p for trend < 0.001). In subgroup analysis, there was an interaction between initial rhythm and survival (p for interaction < 0.001); 1-month survival of patients with a non-shockable rhythm decreased when the lactate levels increased (p for trend < 0.001), but not in patients with a shockable rhythm (p for trend = 0.72). In conclusion, high serum lactate level during CPR was associated with poor 1-month survival in OHCA patients, especially in patients with non-shockable rhythm.

Cerebrospinal Fluid Lactate Levels, Brain Lactate Metabolism and Neurologic Outcome in Patients with Out-of-Hospital Cardiac Arrest

BACKGROUND/OBJECTIVE

Cerebrospinal fluid (CSF) and serum lactate levels were assessed to predict poor neurologic outcome 3 months after return of spontaneous circulation (ROSC). We compared arterio-CSF differences in the lactate (ACDL) levels between two neurologic outcome groups.

METHODS

This retrospective observational study involved out-of-hospital cardiac arrest (OHCA) survivors who had undergone target temperature management. CSF and serum samples were obtained immediately (lactate₀), and at 24 (lactate₂₄), 48 (lactate₄₈), and 72 (lactate₇₂) h after ROSC, and ACDL was calculated at each time point. The primary outcome was poor 3-month neurologic outcome (cerebral performance categories 3-5).

RESULTS

Of 45 patients, 27 (60.0%) showed poor neurologic outcome. At each time point, CSF lactate levels were significantly higher in the poor neurologic outcome group than in the good neurologic outcome group (6.97 vs. 3.37, 4.20 vs. 2.10, 3.50 vs. 2.00, and 2.79 vs. 2.06, respectively; all P < 0.05). CSF lactate's prognostic performance was higher than serum lactate at each time point, and lactate₂₄ showed the highest AUC values (0.89, 95% confidence interval, 0.75-0.97). Over time, ACDL decreased from - 1.30 (- 2.70-0.77) to - 1.70 (- 3.2 to - 0.57) in the poor neurologic outcome group and increased from - 1.22 (- 2.42-0.32) to - 0.64 (- 2.31-0.15) in the good neurologic outcome group.

CONCLUSIONS

At each time point, CSF lactate showed better prognostic performance than serum lactate. CSF lactate₂₄ showed the highest prognostic performance for 3-month poor neurologic outcome. Over time, ACDL decreased in the poor neurologic outcome group and increased in the good neurologic outcome group.

Veno-arterial CO2 difference and respiratory quotient after cardiac arrest: An observational cohort study

PURPOSE

To characterize venous-arterial CO₂ difference (ΔpCO₂) and the respiratory quotient (RQ) in post cardiac arrest patients and evaluate the association between these parameters and patient outcome.

MATERIALS AND METHODS

Data were obtained retrospectively from post cardiac arrest patients admitted between 2007 and 2016 to a medical intensive care unit. Comatose, adult patients in whom arterial and venous blood gas analyses were concomitantly performed in the first 24 h were included. Patients were grouped according to the time-point of sampling; 0-6, 6-12 and 12-24 h after admission.

RESULTS

308 patients were included; 174 (56%) died before ICU discharge and 212 (69%) had an unfavorable neurologic outcome. RQ was associated with ICU mortality (OR:1.09 (95%CI: 1.04-1.14; p < 0.01)), although not with neurological outcome. ΔpCO₂ was negatively associated with both ICU mortality (OR: 0.92 (95%CI: 0.86-0.99; p = 0.02)) and poor neurologic outcome (adjusted OR: 0.93 (95%CI: 0.87-0.99; p = 0.02)). ΔpCO₂ predicted an elevated RQ; a ΔpCO₂ above 8.5 mmHg identified a high RQ with reasonable sensitivity and specificity.

CONCLUSIONS

RQ was associated with ICU mortality and ΔpCO₂ identified elevated RQ in the early phase after cardiac arrest. However, ΔpCO₂ were negatively associated with both ICU mortality and neurologic outcome.

Clinical significance of the level of fibrin degradation products in drowning patients without cardiac arrest

Objective: This study aimed to retrospectively investigate the clinical significance of the level of fibrin degradation products in drowning patients without cardiac arrest.

Patients and Methods: All drowning patients who were transported to our department from January 2011 to December 2019 were retrospectively investigated through a medical chart review and included as subjects in the present study. The exclusion criteria were the occurrence of cardiac arrest before patient arrival to our department and lack of measurement of the fibrin degradation product level on arrival. The subjects were divided into two groups: early discharge group, which included patients who were discharged within 3 days, and late discharge group, which included patients who were discharged after 3 days.

Results: The early discharge group included 10 subjects and the late discharge group included 39 subjects. No significant differences were observed in age, sex, proportion of freshwater drowning cases, proportion of alcohol drinkers, vital signs, blood gas analysis findings, proportion of lung lesions, or survival rate between the two groups. The levels of glucose and fibrin degradation products on arrival were significantly greater in the early discharge group than in the late discharge group. A multivariate analysis showed that the only significant predictor of early discharge was the fibrin degradation product level among variables identified in a univariate analysis.

Conclusion: This is the first study to show that the level of fibrin degradation products on arrival can predict early or late discharge in drowning patients without cardiac arrest before arriving to the hospital.

Shock Severity and Hospital Mortality In Out of Hospital Cardiac Arrest Patients Treated With Targeted Temperature Management

BACKGROUND

Shock in patients resuscitated after out of hospital cardiac arrest (OHCA) is associated with an increased risk of mortality. We sought to determine the associations between lactate level, mean arterial pressure (MAP), and vasopressor/inotrope doses with mortality.

METHODS

Retrospective cohort study of adult patients with OHCA of presumed cardiac etiology treated with targeted temperature management (TTM) between December 2005 and September 2016. Multivariable logistic regression was performed to determine predictors of hospital death.

RESULTS

Among 268 included patients, the median age was 64 (55, 71.8) years, including 27% females. OHCA was witnessed in 89%, OHCA rhythm was shockable in 87%, and bystander CPR was provided in 64%. Vasopressors were required during the first 24 h in 60%. Hospital mortality occurred in 104 (38.8%) patients. Higher initial lactate, peak Vasoactive-Inotropic Score (VIS), and lower mean 24-h MAP were associated with higher hospital mortality (all P < 0.001). After multivariable regression, both higher initial lactate (adjusted OR 1.15 per 1 mmol/L higher, 95% CI 1.00-1.31, P = 0.03) and higher peak VIS (adjusted OR 1.20 per 10 units higher, 95% CI 1.10-1.54, P = 0.003) were associated with higher hospital mortality, but mMAP was not (P = 0.92). However, patients with a mMAP < 70 mm Hg remained at higher risk of hospital mortality after multivariable adjustment (adjusted OR 9.30, 95% CI 1.39-62.02, P = 0.02).

CONCLUSIONS

In patients treated with TTM after OHCA, greater shock severity, as reflected by higher lactate levels, mMAP < 70 mmHg, and higher vasopressor requirements during the first 24 h was associated with an increased rate of hospital mortality.

Outcomes in 886 Critically Ill Patients After Near-Hanging Injury

BACKGROUND

Near-hanging experiences are life-threatening events about which few data are available.

RESEARCH QUESTION

What are the outcomes and early predictors of hospital mortality in critically ill patients who have undergone a near-hanging experience?

STUDY DESIGN AND METHODS

Adult patients who were resuscitated successfully after suicidal near-hanging injury admitted to 31 university or university-affiliated ICUs in France and Belgium between 1992 and 2014 were studied retrospectively. Patients were identified by searching the hospital databases for International Statistical Classification of Diseases and Related Health Problems, 9th and 10th revisions, codes and hospital charts for hanging. Logistic multivariate regression was performed to identify factors associated vital and functional outcomes at hospital discharge as the primary end points. Secondary outcomes were evaluation of temporal trends and identification of predictors of hospital mortality.

RESULTS

Of the 886 patients (181 women and 705 men; median age, 43 years; interquartile range, 34-52 years), 266 (30.0%) had attempted suicide previously, 600 (67.7%) had a diagnosed mental illness, and 55 (6.2%) attempted hanging while hospitalized. Median time from hanging awareness to unhanging was 0 min (interquartile range [IQR], 0-0; range, 0-82 min). Median Glasgow Coma Scale score was 3 (IQR, 3-5) at ICU admission. Hanging induced cardiac arrest in 450 of 886 patients (50.8%). Overall, 497 of 886 patients (56.1%) were alive at hospital discharge, including 479 of 497 patients (96.4%) with a favorable neurocognitive outcome (defined as a Glasgow Outcome Scale score of 4 or 5). By multivariate analysis, factors associated with hospital mortality were hanging-induced cardiac arrest (OR, 19.50; 95% CI, 7.21-60.90; P < .00001) and findings at ICU admission of glycemia level > 1.4 g/L (OR, 4.34; 95% CI, 1.82-10.81; P = .0007) and of lactate level > 3.5 mmol/L (OR, 9.98; 95% CI, 4.17-25.36; P < .00001).

INTERPRETATION

The findings from this large multicenter retrospective cohort emphasize the very high mortality after hanging injury chiefly because of hanging-induced cardiac arrest. However, patients who survive near-hanging experiences achieve excellent neurocognitive recovery. Studies of early neuroprotective strategies for patients who have undergone near-hanging experiences are warranted.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT04096976; URL: www.clinicaltrials.gov.

Slow Heart Rate Within 72 Hours After Cardiac Arrest Is Associated with Good Neurologic Outcome in Out-of-Hospital Cardiac Arrest Survivors Who Undergo Targeted Temperature Management with 33°C

We aimed to verify whether slow heart rate (HR) is associated with neurologic outcome and the factors that can contribute to the development of bradycardia in out-of-hospital cardiac arrest (OHCA) survivors who underwent targeted temperature management (TTM). We extracted the data of comatose adult OHCA survivors who underwent TTM between October 2015 and December 2018 from the prospective multicenter registry. Data on HR recorded every 6 hours within 72 hours after return of spontaneous circulation and calculated minimal, mean, and maximal HR and time to the lowest HR were obtained. HR <50 bpm was defined as bradycardia. The primary outcome was a 6-month neurologic outcome based on Pittsburgh-Glasgow Cerebral Performance Category Scale. Of the 814 included patients, 508 (62.4%) had poor neurologic outcome and 197 (24.2%) had bradycardia. Bradycardia (odds ratio [OR], 0.574; 95% confidence interval [CI], 0.362-0.192), minimal HR (OR, 1.023; 95% CI, 1.008-1.037), and mean HR (OR, 1.016; 95% CI, 1.002-1.030) were independently associated with poor neurologic outcome, but not maximal HR and time to the lowest HR. Preexisting arrhythmia (OR, 2.067; 95% CI, 1.037-4.118), renal disease (OR, 2.028; 95% CI, 1.153-3.567), cardiac etiology (OR, 1.526; 95% CI, 1.045-2.228), downtime (OR, 0.985; 95% CI, 0.974-0.996), and serum lactate levels (OR, 0.936; 95% CI, 0.900-0.974) were independently associated with bradycardia. Bradycardia and decreased mean and minimal HR were independently associated with good neurologic outcomes. Bradycardia was associated with preexisting arrhythmia, renal disease, cardiac etiology, shorter downtime, and lower serum lactate level.

Efficacy of Thiamine in the Treatment of Postcardiac Arrest Patients: A Randomized Controlled Study

Background

Thiamine administration has been shown to improve survival in a postcardiac arrest animal study. We aimed to evaluate the efficacy of thiamine in comatose out-of-hospital cardiac arrest (OHCA) patients following return of spontaneous circulation.

Methods

A randomized, double-blinded, placebo-controlled study was conducted. Thirty-seven OHCA patients were randomly assigned to receive either thiamine 100 mg every 8 hours or a placebo. The primary outcome was 28-day all-cause mortality.

Results

Over the course of 2 years, 37 patients were randomized to either receive thiamine (n = 20) or a placebo (n = 17). The primary outcome was not different between the groups: 10/20 (50%) in the thiamine group vs. 8/17 (47.1%) in the placebo group (P=0.93 by the log-rank test). There were no significant differences in secondary outcomes between the groups (good neurological outcome, lactate level, and S100B level).

Conclusions

In this study, there were no significant differences in survival outcome. Further studies with a larger population are necessary to confirm these results.

The effect of blood lactate and NT-proBNP predict the survival in patients with invasive mechanical ventilation

Background

Respiratory failure is one of the most common critical diseases. It has already been reported that invasive mechanical ventilation (IMV) should be used to treat respiratory failure. The present study aims to evaluate the prognostic value of blood lactate and NT-proBNP in patients with IMV.

Methods

We retrospectively included 353 patients who were hospitalized in the emergency department of Shanghai Sixth People’s Hospital from 2016 to 2019. All patients had IMV. R&D Human Premixed Multi-Analyte Kit detected the expression of various inflammatory factors in serum. Receiver operating characteristic (ROC) curve analysis, survival analysis, and multivariate cox proportional hazards analysis were implemented as statistical analysis methods.

Results

The mean duration of hospitalization was 25.5±20.6 days. Twenty-four men and 41 women died. Compared with the survivors, the nonsurvivors were older, had different types of diagnosis, longer ventilation time, and shorter survival time (P<0.05). Also, the expression levels of PCT, NT-proBNP, lactate in 12 h and lactate in 24 h in the nonsurvivors were significantly higher than those in the survivor group (P<0.05). There was a significant correlation between these parameters and ventilation times (P<0.001). The results showed that age, NT-proBNP, and lactate were independent predictors of survival rate. ROC analysis showed that the cut-off values of age, NT-proBNP and lactate were 61.5 years, 230.5 pg/mL and 3.7 mmol/L, respectively. Patients aged ≥61.5 years or NT-proBNP ≥230.5 pg/mL or lactate ≥3.7 mmol/L had a worse prognosis. Therefore, patients with three parameters higher than cut-off value had the lowest survival rate, while patients with three parameters lower than cut-off value had the best survival rate.

Conclusions

Blood lactate and NT-proBNP may be used as biomarkers to predict the prognosis of patients undergoing IMV.