Use of serum lactate levels to predict survival for patients with out-of-hospital cardiac arrest: A cohort study

Impact of lactate/albumin ratio on prognostic outcomes in patients with concomitant heart failure and chronic kidney disease

Previous studies have linked the lactate/albumin (L/A) ratio to poor outcomes in various conditions, but its connection to mortality in patients with both heart failure (HF) and chronic kidney disease (CKD) remains unclear. Using data from 1537 patients in MIMIC-IV, this study examined the relationship between L/A ratio and in-hospital and one-year mortality, employing Cox models, Kaplan-Meier (KM) analysis, and restricted cubic splines (RCS). The non-survivor group showed higher L/A ratios than survivors (1.04 ± 0.78 vs. 0.58 ± 0.29, p < 0.001), indicating a significant link between higher L/A ratios and mortality. Cox analysis identified the L/A ratio was significantly related to all-cause mortality both in-hospital (HR 2.033; 95% CI 1.576-2.624; p < 0.001) and one-year (HR 1.723; 95% CI 1.428-2.078; p < 0.001). The association between L/A ratio and mortality was non-linear and increasing. The KM survival curves demonstrated significantly poorer survival outcomes for the high L/A group compared to the low L/A group, a difference that was statistically validated by a significant log-rank test (log-rank p < 0.001). L/A ratio has a significant association with poor prognosis in patients with HF and CKD patients in a critical condition. This finding demonstrates that L/A ratio might be useful in identifying patients with HF and CKD at high risk of all-cause death. Further large-scale prospective studies are needed to verify these results and inform clinical decisions.

Association of prehospital lactate levels with base excess in various emergencies - a retrospective study

OBJECTIVES

Blood gas analysis, including parameters like lactate and base excess (BE), is crucial in emergency medicine but less commonly utilized prehospital. This study aims to elucidate the relationship between lactate and BE in various emergencies in a prehospital setting and their prognostic implications.

METHODS

We conducted a retrospective analysis of prehospital emergency patients in Graz, Austria, from October 2015 to November 2020. Our primary aim was to assess the association between BE and lactate. This was assessed using Spearman's rank correlation and fitting a multiple linear regression model with lactate as the outcome, BE as the primary covariate of interest and age, sex, and medical emergency type as confounders.

RESULTS

In our analysis population (n=312), lactate and BE levels were inversely correlated (Spearman's ρ, -0.75; p<0.001). From the adjusted multiple linear regression model (n=302), we estimated that a 1 mEq/L increase in BE levels was associated with an average change of -0.35 (95 % CI: -0.39, -0.30; p<0.001) mmol/L in lactate levels. Lactate levels were moderately useful for predicting mortality with notable variations across different emergency types.

CONCLUSIONS

Our study highlights a significant inverse association between lactate levels and BE in the prehospital setting, underscoring their importance in early assessment and prognosis in emergency care. Additionally, the findings from our secondary aims emphasize the value of lactate in diagnosing acid-base disorders and predicting patient outcomes. Recognizing the nuances in lactate physiology is essential for effective prehospital care in various emergency scenarios.

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.

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.

DIFFERENCES IN MANAGEMENT AND PROGNOSTICATION OF CARDIOGENIC SHOCK PATIENTS IN THE PRESENCE AND ABSENCE OF OUT-OF-HOSPITAL CARDIAC ARREST

ABSTRACT

Background: The clinical spectrum of acute myocardial infarction complicated by cardiogenic shock (AMICS) varies. Out-of-hospital cardiac arrest (OHCA) can be the first sign of cardiac failure, whereas others present with various degrees of hemodynamic instability (non-OHCA). The aim of the present study was to explore differences in prehospital management and characteristics of survivors and nonsurvivors in AMICS patients with OHCA or non-OHCA. Methods: Data analysis was based on patient data from the RETROSHOCK cohort comprising consecutive AMICS patients admitted to two tertiary cardiac centers between 2010 and 2017. Results: 1,716 AMICS patients were included and 42% presented with OHCA. Mortality in OHCA patients was 47% versus 57% in the non-OHCA group. Almost all OHCA patients were intubated before admission (96%). In the non-OHCA group, prehospital intubation (25%) was associated with a better survival ( P < 0.001). Lactate level on admission demonstrated a linear relationship with mortality in OHCA patients. In non-OHCA, probability of death was higher for any given lactate level <12 mmol/L compared with OHCA. However, a lactate level >7 mmol/L in non-OHCA did not increase mortality odds any further. Conclusion: Mortality was almost doubled for any admission lactate level up to 7 mmol/L in non-OHCA patients. Above this level, mortality remained unchanged in non-OHCA patients but continued to increase in OHCA patients. Prehospital intubation was performed in almost all OHCA patients but only in one of four patients without OHCA. Early intubation in non-OHCA patients was associated with a better outcome.

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 between lactate/albumin ratio and all-cause mortality in critical patients with acute myocardial infarction

It has been demonstrated that lactate/albumin (L/A) ratio is substantially relevant to the prognosis of sepsis, septic shock, and heart failure. However, there is still debate regarding the connection between the L/A ratio and severe acute myocardial infarction (AMI). The aim of this study is to determine the prognostic role of L/A ratio in patients with severe AMI. Our retrospective study extracted data from the Medical Information Mart for Intensive Care III (MIMIC-III) database, included 1,134 patients diagnosed with AMI. Based on the tertiles of L/A ratio, the patients were divided into three groups: Tertile1 (T1) group (L/A ratio<0.4063, n=379), Tertile2 (T2) group (0.4063≤L/A ratio≤0.6667, n =379), and Tertile3 (T3) group (L/A ratio>0.6667, n =376). Uni- and multivariate COX regression model were used to analyze the relationship between L/A ratio and 14-day, 28-day and 90-day all-cause mortality. Meanwhile, the restricted cubic spline (RCS) model was used to evaluate the effect of L/A ratio as a continuous variable. Higher mortality was observed in AMI patients with higher L/A ratio. Multivariate Cox proportional risk model validated the independent association of L/A ratio with 14-day all-cause mortality [hazard ratio (HR) 1.813, 95% confidence interval (CI) 1.041-3.156 (T3 vs T1 group)], 28-day all-cause mortality [HR 1.725, 95% CI 1.035-2.874 (T2 vs T1 group), HR 1.991, 95% CI 1.214-3.266 (T3 vs T1 group)], as well as 90-day all-cause mortality [HR 1.934, 95% CI 1.176-3.183 (T2 vs T1 group), HR 2.307, 95% CI 1.426-3.733 (T3 vs T1 group)]. There was a consistent trend in subgroup analysis. The Kaplan-Meier (K-M) survival curves indicated that patients with L/A ratio>0.6667 had the highest mortality. Even after adjusting the confounding factors, RCS curves revealed a nearly linearity between L/A ratio and 14-day, 28-day and 90-day all-cause mortality. Meanwhile, the areas under the receiver operating characteristic (ROC) curve (AUC) of 14-day, 28-day and 90-day all-cause mortality were 0.730, 0.725 and 0.730, respectively. L/A ratio was significantly associated with 14-day, 28-day and 90-day all-cause mortality in critical patients with AMI. Higher L/A ratio will be considered an independent risk factor for higher mortality in AMI patients.

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.

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.

Associations between red cell distribution width and outcomes of adults with in-hospital cardiac arrest: A retrospective study

Previous studies found that high red cell distribution width (RDW) value is associated with poor outcomes among out-of-hospital cardiac arrest survivors. The aim of this study was to investigate whether post-ROSC RDW value was associated with survival and neurological outcomes of in-hospital cardiac arrest (IHCA) patients achieving return of spontaneous circulation (ROSC) but remaining critically ill.This retrospective single-center observational study included IHCA adults with sustained ROSC between January 1, 2017 and January 1, 2021 at an academic medical center in China. PostROSC RDW values were measured within 1 hour after sustained ROSC. The primary outcome was survival to hospital discharge and the secondary outcome was favorable neurological outcome at hospital discharge. The associations between postROSC RDW value and outcomes among IHCA patients with ROSC were evaluated by using multivariate logistic regression.A total of 730 patients with sustained ROSC following IHCA were ultimately included in this study. Of whom 194 (26.6%) survived to hospital discharge and 116 (15.9%) had a favorable neurological outcome at hospital discharge. In multivariable logistic regression analysis, lower postROSC RDW value was independently associated with survival to hospital discharge (odds ratio 0.19, 95% confidence interval 0.15-0.63, P = .017, cut-off value: 15.5%) and favorable neurological outcome at hospital discharge (odds ratio 0.23, 95% confidence interval 0.07-0.87, P < .001, cut-off value: 14.6%). Other independent factors including younger age, initial shockable rhythm, shorter total cardiopulmonary resuscitation duration and post-ROSC percutaneous coronary intervention were also associated with survival to hospital discharge. Regarding favorable neurological outcome at hospital discharge, significant variables other than the aforementioned factors included postROSC targeted temperature management and absence of pre-existing neurological insufficiency.Low postROSC RDW value was associated with survival to hospital discharge and favorable neurological outcome at hospital discharge.

The role of the lactate/albumin ratio in predicting survival outcomes in patients resuscitated after out-of-hospital cardiac arrest: A preliminary report

OBJECTIVE

To investigate the effect of lactate/albumin (L/A) ratio on survival to discharge in patients who have had out-of-hospital cardiac arrest (OHCA).

METHODS

We analyzed adult patients (aged ≥18 years) who were admitted to our hospital's emergency department (ED) due to OHCA between January 2018 and June 2020 and who achieved return of spontaneous circulation after successful resuscitation. Blood lactate and albumin concentrations were obtained within the first 10 min after admission to the ED. Patients were grouped according to clinical outcomes. The primary outcome was survival until hospital discharge. The groups were then statistically compared.

RESULTS

In this study, 235 OHCA patients were analyzed, 42 (17.9%) of whom had survived until discharge. The L/A ratio was higher in the non-survivor group than in the survivor group (2.0 (interquartile range: 1.4-2.8) vs 1.4 (0.9-1.9); P < 0.001). A low L/A ratio was significantly associated with survival at discharge (odds ratio: 2.55; 95% confidence interval (CI): 3.24-11.08; P < 0.001). In the prediction of survival to discharge, the area under the curve (AUC) for the L/A ratio (AUC: 0.823) was higher than that for lactate (AUC: 0.762) or albumin (AUC: 0.722) alone. Moreover, the predictive value of L/A ratio for survival to discharge might significantly improve when the cutoff value is higher than 1.62.

CONCLUSION

The L/A ratio is more valuable than the lactate or albumin levels alone in predicting survival to discharge. Our findings indicate that a combination of these parameters might increase the predictability of survival to discharge in OHCA patients.

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.

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.

Admission C-reactive protein concentrations are associated with unfavourable neurological outcome after out-of-hospital cardiac arrest

Whether admission C-reactive protein (aCRP) concentrations are associated with neurological outcome after out-of-hospital cardiac arrest (OHCA) is controversial. Based on established kinetics of CRP, we hypothesized that aCRP may reflect the pre-arrest state of health and investigated associations with neurological outcome. Prospectively collected data from the Vienna Clinical Cardiac Arrest Registry of the Department of Emergency Medicine were analysed. Adults (≥ 18 years) who suffered a non-traumatic OHCA between January 2013 and December 2018 with return of spontaneous circulation, but without extracorporeal cardiopulmonary resuscitation therapy were eligible. The primary endpoint was a composite of unfavourable neurologic function or death (defined as Cerebral Performance Category 3–5) at 30 days. Associations of CRP levels drawn within 30 min of hospital admission were assessed using binary logistic regression. ACRP concentrations were overall low in our population (n = 832), but higher in the unfavourable outcome group [median: 0.44 (quartiles 0.15–1.44) mg/dL vs. 0.26 (0.11–0.62) mg/dL, p < 0.001]. The crude odds ratio for higher aCRP concentrations was 1.19 (95% CI 1.10–1.28, p < 0.001, per mg/dL) to have unfavourable neurological outcome. After multivariate adjustment for traditional prognostication markers the odds ratio of higher aCRP concentrations was 1.13 (95% CI 1.04–1.22, p = 0.002). Sensitivity of aCRP was low, but specificity for unfavourable neurological outcome was 90% for the cut-off at 1.5 mg/dL and 97.5% for 5 mg/dL CRP. In conclusion, high aCRP levels are associated with unfavourable neurological outcome at day 30 after OHCA.

The prognostic value of early lactate clearance for survival after out-of-hospital cardiac arrest

BACKGROUND

Prognostication of survival after out-of-hospital cardiac arrest (OHCA) remains challenging with current guidelines recommending the prognostication no earlier than 72 h after return of spontaneous circulation (ROSC). Prognostic factors that could be used earlier after ROSC, like lactate clearance, are still being studied.

OBJECTIVES

This paper aims to investigate the prognostic strength of early lactate clearance for survival after OHCA.

METHODS

This retrospective observational single-center study focuses on patients for whom ROSC was achieved after OHCA. Patients ≥18 years admitted between September 2012 and January 2019, for which arterial serum lactate measurements were available immediately at and 3 h after hospital admission (T0 and T3), were included.

RESULTS

192 patients were included. Lactate clearance at T3 (p < 0.001) was identified as an independent predictor for 24 h, 48 h and 72 h survival. Witnessed arrest, bystander CPR and initial shockable rhythm were independent significant predictors for long term survival after ROSC (1 month, 3 months and 1 year; p < 0.05), but not for 24 h survival. Age (above or below 65 years) was not significant for predicting survival. Upon combination of witnessed arrest, bystander CPR and initial shockable rhythm in a multivariate logistic regression model for long term survival, the initial rhythm was the dominant factor in the combined model, making witnessed arrest and bystander CPR redundant.

CONCLUSION

Lactate clearance at T3 after ROSC is associated with 24 h, 48 h and 72 h survival. Further research is needed to determine how to incorporate lactate clearance as part of a clinically useful tool to predict long term survival.

The Prognostic Value of Prehospital Blood Lactate Levels to Predict Early Mortality in Acute Cardiovascular Disease

INTRODUCTION

The knowledge of the prognostic value of prehospital lactate (PLA) is limited. Our objective was to evaluate the predictive capacity of PLA to predict early mortality (within 48 h) from the index event in acute cardiovascular disease (ACVD).

METHODS

Prospective, longitudinal, multicenter, observational study in patients, attended by advanced life support units, transferred to the emergency department of their reference hospital and diagnosed with ACVD. We collected demographic, physiological, clinical, analytical variables, main cardiological diagnosis, and data on hospital admission and early mortality. The main outcome variable was mortality from any cause within 2 days.

RESULTS

Between March 1, 2018 and January 31, 2019, a total of 492 patients were included in our study. Early mortality after the index event within the first 48 h affected 27 patients (5.5%). The most frequent cause of care demand was chest pain with 223 cases (45.3%). The predictive power of PLA to discriminate mortality at 2 days obtained an area under the curve of 0.911 (95% confidence interval [CI]: 0.83-0.98, P < 0.001). A value equal or superior to 4.3 mmol/L globally attained a sensitivity of 92.6% (95% CI, 76.6-97.9) with a specificity of 82.8% (95% CI, 79.1-86.0), with a positive predictive value of 23.8 (16.7-32.8) and a negative predictive value of 99.5 (98.1-99.9).

CONCLUSION

PLA represents a prognostic biomarker with excellent predictive capacity for ACVD. Prehospital Emergency Services (PhEMS) should incorporate this test routinely in their usual procedures.

The Prognostic Role of Lactate Concentrations after Aneurysmal Subarachnoid Hemorrhage

Blood lactate concentrations are often used to assess global tissue perfusion in critically ill patients; however, there are scarce data on lactate concentrations after subarachnoid hemorrhage (SAH). We aimed to assess the prognostic role of serial blood lactate measurements on hospital mortality and neurological outcomes at 3 months after SAH. We reviewed all SAH patients admitted to the intensive care unit from 2007 to 2019 and recorded the highest daily arterial lactate concentration for the first 6 days. Patients with no lactate concentration were excluded. Hyperlactatemia was defined as a blood lactate concentration >2.0 mmol/L. A total of 456 patients were included: 158 (35%) patients died in hospital and 209 (46%) had an unfavorable outcome (UO) at 3 months. The median highest lactate concentration was 2.7 (1.8–3.9) mmol/L. Non-survivors and patients with UO had significantly higher lactate concentrations compared to other patients. Hyperlactatemia increased the chance of dying (OR 4.19 (95% CI 2.38–7.39)) and of having UO in 3 months (OR 4.16 (95% CI 2.52–6.88)) after adjusting for confounding factors. Therefore, initial blood lactate concentrations have prognostic implications in patients with SAH; their role in conjunction with other prognostic indicators should be evaluated in prospective studies.

Accuracy of prehospital point-of-care lactate in early in-hospital mortality

BACKGROUND

Emergency medical services (EMS) routinely face complex scenarios where decisions should be taken with limited clinical information. The development of fast, reliable and easy to perform warning biomarkers could help in such decision-making processes. The present study aims at characterizing the validity of point-of-care lactate (pLA) during prehospital tasks for predicting in-hospital mortality within two days after the EMS assistance.

MATERIALS AND METHODS

Prospective, multicentric, ambulance-based and controlled observational study without intervention, including six advanced life support and five hospitals. The pLA levels were recorded during EMS assistance of adult patients. The validity of pLA to determine the in-hospital mortality was assessed by the area under the curve (AUC) of the receiver operating curve (ROC).

RESULTS

A total of 2997 patients were considered in the study, with a median of 69 years (IQR 54-81) and 41.4% of women. The median pLA value was 2.7 mmol/L (1.9-3.8) in survivors and 5.7 mmol/L (4.4-7.6) in nonsurvivors. The global discrimination level of pLA reached an AUC of 0.867, being 1.9 mmol/L and 4 mmol/L the cut-off point for low and high mortality. The discrimination value of pLA was not affected by sex, age or pathology.

CONCLUSIONS

Our results highlight the clinical importance of prehospital pLA to determine the in-hospital risk of mortality. The incorporation of pLA into the EMS protocols could improve the early identification of risky patients, leading to a better care of such patients.

Prolonged Activated Partial Thromboplastin Time after Successful Resuscitation from Cardiac Arrest is Associated with Unfavorable Neurologic Outcome

Coagulation abnormalities after successful resuscitation from cardiac arrest may be associated with unfavorable neurologic outcome. We investigated a potential association of activated partial thromboplastin time (aPTT) with neurologic outcome in adult cardiac arrest survivors. Therefore, we included all adults ≥18 years of age who suffered a nontraumatic cardiac arrest and had achieved return of spontaneous circulation between January 2013 and December 2018. Patients receiving anticoagulants or thrombolytic therapy and those subjected to extracorporeal membrane oxygenation support were excluded. Routine blood sampling was performed on admission as soon as a vascular access was available. The primary outcome was 30-day neurologic function, assessed by the Cerebral Performance Category scale (3-5 = unfavorable neurologic function). Multivariable regression was used to assess associations between normal (≤41 seconds) and prolonged (>41 seconds) aPTT on admission (exposure) and the primary outcome. Results are given as odds ratio (OR) with 95% confidence intervals (95% CIs). Out of 1,591 cardiac arrest patients treated between 2013 and 2018, 360 patients (32% female; median age: 60 years [interquartile range: 48-70]) were eligible for analysis. A total of 263 patients (73%) had unfavorable neurologic function at day 30. aPTT prolongation >41 seconds was associated with a 190% increase in crude OR of unfavorable neurologic function (crude OR: 2.89; 95% CI: 1.78-4.68, p < 0.001) and with more than double the odds after adjustment for traditional risk factors (adjusted OR: 2.01; 95% CI: 1.13-3.60, p = 0.018). In conclusion, aPTT prolongation on admission is associated with unfavorable neurologic outcome after successful resuscitation from cardiac arrest.

Lactate and hypotension as predictors of mortality after in-hospital cardiac arrest

AIM

Guidance on post-cardiac arrest prognostication is largely based on data from out-of-hospital cardiac arrest (OHCA), despite clear differences between the OHCA and in-hospital cardiac arrest (IHCA) populations. Early prediction of mortality after IHCA would be useful to help make decisions about post-arrest care. We evaluated the ability of lactate and need for vasopressors after IHCA to predict hospital mortality.

METHODS

Single center retrospective observational study of adult IHCA patients who achieved sustained return of spontaneous circulation (ROSC), required mechanical ventilation peri-arrest and had a lactate checked within 2 h after ROSC. We evaluated the association of post-ROSC lactate and need for vasopressors with mortality using multivariate logistic regression.

RESULTS

A total of 364 patients were included. Patients who received vasopressors within 3 h after ROSC had significantly higher mortality compared to patients who did not receive vasopressors (58% vs. 43%, p = 0.03). Elevated lactate level was associated with mortality (44% if lactate <5 mmol/L, 58% if lactate 5-10 mmol/L, and 73% if lactate >10 mmol/L, p < 0.01). A multivariable model with lactate group and post-ROSC vasopressor use as predictors demonstrated moderate discrimination (AUC 0.64 [95%CI:0.59-0.70]). Including other variables, the most parsimonious model included lactate, age, body mass index, race, and history of arrhythmia, cancer and/or liver disease (AUC 0.70 [95% CI: 0.64-0.75]).

CONCLUSION

Post-ROSC lactate and need for vasopressors may be helpful in stratifying mortality risk in patients requiring mechanical ventilation after IHCA.

Trimethylamine-N-oxide (TMAO) predicts short- and long-term mortality and poor neurological outcome in out-of-hospital cardiac arrest patients

Objectives

Prior research found the gut microbiota-dependent and pro-atherogenic molecule trimethylamine-N-oxide (TMAO) to be associated with cardiovascular events as well as all-cause mortality in different patient populations with cardiovascular disease. Our aim was to investigate the prognostic value of TMAO regarding clinical outcomes in patients after out-of-hospital cardiac arrest (OHCA).

Methods

We included consecutive OHCA patients upon intensive care unit admission into this prospective observational study between October 2012 and May 2016. We studied associations of admission serum TMAO with in-hospital mortality (primary endpoint), 90-day mortality and neurological outcome defined by the Cerebral Performance Category (CPC) scale.

Results

We included 258 OHCA patients of which 44.6% died during hospitalization. Hospital non-survivors showed significantly higher admission TMAO levels (μmol L-1) compared to hospital survivors (median interquartile range (IQR) 13.2 (6.6-34.9) vs. 6.4 (2.9-15.9), p<0.001). After multivariate adjustment for other prognostic factors, TMAO levels were significantly associated with in-hospital mortality (adjusted odds ratios (OR) 2.1, 95%CI 1.1-4.2, p=0.026). Results for secondary outcomes were similar with significant associations with 90-day mortality and neurological outcome in univariate analyses.

Conclusions

In patients after OHCA, TMAO levels were independently associated with in-hospital mortality and other adverse clinical outcomes and may help to improve prognostication for these patients in the future. Whether TMAO levels can be influenced by nutritional interventions should be addressed in future studies.

A spatially explicit, empirical estimate of tree-based biological nitrogen fixation in forests of the United States

Quantifying human impacts on the N cycle and investigating natural ecosystem N cycling depend on the magnitude of inputs from natural biological nitrogen fixation (BNF). Here, we present two bottom-up approaches to quantify tree-based symbiotic BNF based on forest inventory data across the coterminous US plus SE Alaska. For all major N-fixing tree genera, we quantify BNF inputs using (1) ecosystem N accretion rates (kg N ha-1 yr-1) scaled with spatial data on tree abundance and (2) percent of N derived from fixation (%Ndfa) scaled with tree N demand (from tree growth rates and stoichiometry). We estimate that trees fix 0.30-0.88 Tg N yr-1 across the study area (1.4-3.4 kg N ha-1 yr-1). Tree-based N fixation displays distinct spatial variation that is dominated by two genera, Robinia (64% of tree-associated BNF) and Alnus (24%). The third most important genus, Prosopis, accounted for 5%. Compared to published estimates of other N fluxes, tree-associated BNF accounted for 0.59 Tg N yr-1, similar to asymbiotic (0.37 Tg N yr-1) and understory symbiotic BNF (0.48 Tg N yr-1), while N deposition contributed 1.68 Tg N yr-1 and rock weathering 0.37 Tg N yr-1. Overall, our results reveal previously uncharacterized spatial patterns in tree BNF that can inform large-scale N assessments and serve as a model for improving tree-based BNF estimates worldwide. This updated, lower BNF estimate indicates a greater ratio of anthropogenic to natural N inputs, suggesting an even greater human impact on the N cycle.

The Glucagon-Like Peptide-1 Analog Exenatide Increases Blood Glucose Clearance, Lactate Clearance, and Heart Rate in Comatose Patients After Out-of-Hospital Cardiac Arrest

OBJECTIVES

To investigate the effects of the glucagon-like peptide-1 analog exenatide on blood glucose, lactate clearance, and hemodynamic variables in comatose, resuscitated out-of-hospital cardiac arrest patients.

DESIGN

Predefined post hoc analyzes from a double-blind, randomized clinical trial.

SETTING

The ICU of a tertiary heart center.

PATIENTS

Consecutive sample of adult, comatose patients undergoing targeted temperature management after out-of-hospital cardiac arrest from a presumed cardiac cause, irrespective of the initial cardiac rhythm.

INTERVENTIONS

Patients were randomized 1:1 to receive 6 hours and 15 minutes of infusion of either 17.4 μg of the glucagon-like peptide-1 analog exenatide (Byetta; Lilly) or placebo within 4 hours from sustained return of spontaneous circulation. The effects of exenatide were examined on the following prespecified covariates within the first 6 hours from study drug initiation: lactate level, blood glucose level, heart rate, mean arterial pressure, and combined dosage of norepinephrine and dopamine.

MEASUREMENTS AND MAIN RESULTS

The population consisted of 106 patients receiving either exenatide or placebo. During the first 6 hours from study drug initiation, the levels of blood glucose and lactate decreased 17% (95% CI, 8.9-25%; p = 0.0004) and 21% (95% CI, 6.0-33%; p = 0.02) faster in patients receiving exenatide versus placebo, respectively. Exenatide increased heart rate by approximately 10 beats per minute compared to placebo (p < 0.0001). There was no effect of exenatide on other hemodynamic variables.

CONCLUSIONS

In comatose out-of-hospital cardiac arrest patients, infusion with exenatide lowered blood glucose and resulted in increased clearance of lactate as well as increased heart rate. The clinical importance of these physiologic effects remains to be investigated.

Is prehospital lactate testing useful in improving clinical assessment?

Introduction:

Lactate devices offer the potential for paramedics to improve patient triage and escalation of care for specific presentations. There is also scope to improve existing prehospital tools by including lactate measurement.

Method:

A literature search was conducted using the Medline, CINAHL, Academic Search Premier, Sciencedirect and Scopus databases.

Findings:

Acquiring prehospital lactate measurement in trauma settings improved triage and recognition of the need for critical care. Within a medical setting, studies offered mixed results in relating prehospital lactate measurement to diagnosis, escalating treatments and mortality. The accuracy of prehospital lactate measurements acquired varies, which could impact decision making.

Conclusion:

Prehospital lactate thresholds could aid decision making, although the literature is limited and evidence varies. Lactate values of ≥4 mmol/litre in medical and ≥2.5 mmol/litre in trauma patients could signify that care should be escalated to an appropriate facility, and that resuscitative measures should be initiated, particularly with sepsis, as reflected by standardised lactate values that guide treatment in hospitals. Similarly, a lactate value of <2 mmol/litre could mean de-escalating care into the community, although further research is warranted on this.

Early Lactate Dynamics in Critically Ill Non-Traumatic Patients in a Resuscitation Room of a German Emergency Department (OBSERvE-Lactate-Study)

BACKGROUND

Management of critically ill non-trauma patients in the resuscitation room of an emergency department (ED) is very challenging, and it is difficult to identify patients with a higher risk of death. Previous studies have shown that lactate indices can predict survival for selected diseases and syndromes.

OBJECTIVE

As reported for other patient populations, we set out to determine whether admission lactate or lactate dynamics (LD) within 24 h can predict 30-day mortality in unselected critically ill non-traumatic patients.

METHODS

In this retrospective study over a 1-year period, admission lactate, time weighted average lactate (Lac_TW) and LD of all critically ill adult patients admitted from ED to intensive care unit were analyzed. A linear regression model was implemented to estimate lactate data 1 h after admission.

RESULTS

The admission lactate, Lac_TW, and LD within 24 h were analyzed from 392 critically ill patients. The overall 30-day mortality rate was around 29%. Admission lactate (4.1 ± 4.0 mmol/L vs. 6.6 ± 6.1 mmol/L; p < 0.01) and Lac_TW (1.8 ± 1.7 mmol/L vs. 4.1 ± 4.8 mmol/L; p < 0.01) were different between survivors and non-survivors. LD between survivors and non-survivors did not differ at 1 h, 6 h, 12 h, or 24 h. After excluding patients with out-of-hospital or in-hospital cardiac arrest during resuscitation room management, admission lactate and LD between survivors and non-survivors did not differ at 1 h, 12 h, and 24 h. LD at 6 h (44% ± 42% vs. 33% ± 58%; p = 0.042) and Lac_TW (1.7 ± 1.6 mmol/L vs. 2.6 ± 3.0 mmol/L; p < 0.01) did differ.

CONCLUSIONS

In critically ill ED patients initially requiring treatment in a resuscitation room setting, LD at 6 h and Lac_TW may predict their survival beyond 30 days. These findings need to be confirmed in a prospective study design.

Prognostic value of lactate in prehospital care as a predictor of early mortality

BACKGROUND

Prehospital Emergency Medical Services must attend to patients with complex physiopathological situations with little data and in the shortest possible time. The objective of this work was to study lactic acid values and their usefulness in the prehospital setting to help in clinical decision-making.

STUDY DESIGN

We conducted a longitudinal prospective, observational study on patients over 18 years of age who, after being evaluated by the Advanced Life Support Unit, were taken to the hospital between April and June 2018. We analyzed demographic variables, prehospital lactic acid values and early mortality (<30 days). The area under the curve of the receiver operating characteristic was calculated for the prehospital value of lactic acid.

RESULTS

A total of 279 patients were included in our study. The median age was 68 years (interquartile range: 54-80 years). Overall 30-day mortality was 9% (25 patients). The area under the curve for lactic acid to predict overall mortality at 30 days of care was 0.82 (95% CI: 0.76-0.89). The lactate value with the best sensitivity and specificity overall was 4.25 mmol/L with a sensitivity of 84% (95% CI: 65.3-93.6) and specificity of 70% (95% CI: 65.0-76.1).

CONCLUSIONS

The level of lactic acid can be a complementary tool in the field of prehospital emergencies that will guide us early in the detection of critical patients.

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

BACKGROUND

Admission lactate and lactate clearance are implemented for risk stratification in sepsis and trauma. In out-of-hospital cardiac arrest, results regarding outcome and lactate are conflicting.

METHODS

This is a post-hoc analysis of the Target Temperature Management trial in which 950 unconscious patents after out-of-hospital cardiac arrest were randomized to a temperature intervention of 33°C or 36°C. Serial lactate samples during the first 36 hours were collected. Admission lactate, 12-hour lactate, and the clearance of lactate within 12 hours after admission were analyzed and the association with 30-day mortality assessed.

RESULTS

Samples from 877 patients were analyzed. In univariate logistic regression analysis, the odds ratio for death by day 30 for each mmol/L was 1.12 (1.08-1.16) for admission lactate, P < .01, 1.21 (1.12-1.31) for 12-hour lactate, P < .01, and 1.003 (1.00-1.01) for each percentage point increase in 12-hour lactate clearance, P = .03. Only admission lactate and 12-hour lactate levels remained significant after adjusting for known predictors of outcome. The area under the receiver operating characteristic curve was 0.65 (0.61-0.69), P < .001, 0.61 (0.57-0.65), P < .001, and 0.53 (0.49-0.57), P = .15 for admission lactate, 12-hour lactate, and 12-hour lactate clearance, respectively.

CONCLUSIONS

Admission lactate and 12-hour lactate values were independently associated with 30-day mortality after out-of-hospital cardiac arrest while 12-hour lactate clearance was not. The clinical value of lactate as the sole predictor of outcome after out-of-hospital cardiac arrest is, however, limited.

Routine blood markers from different biological pathways improve early risk stratification in cardiac arrest patients: Results from the prospective, observational COMMUNICATE study

INTRODUCTION

Prognostication of cardiac arrest patients admitted to the intensive care unit (ICU) may influence treatment decision, but remains challenging. We evaluated the incremental usefulness of routine blood markers from different biological pathways for predicting fatal outcome and neurological deficits in cardiac arrest patients.

METHODS

We prospectively included consecutive, adult cardiac arrest patients upon ICU admission. We recorded initial clinical parameters and measured blood markers of cardiac injury/stress (troponin, BNP, CK), inflammation/infection (WBC, CRP, procalcitonin) and shock (lactate, creatinine, urea). The primary and secondary endpoints were all-cause in-hospital mortality and bad neurological outcome defined by the Cerebral Performance Category (CPC) score.

RESULTS

Mortality in the 321 included patients was 49% (n = 156). Procalcitonin (adjusted odds ratio 1.84, 95%CI 1.34 to 2.53, p < 0.001; AUC 0.73) and lactate (adjusted odds ratio 7.29, 95%CI 3.05 to 17.42, p < 0.001; AUC 0.70) were identified as independent prognostic factors for mortality and significantly improved discrimination of a parsimonious clinical model including resuscitation measures (no-flow time, shockable rhythm) and initial vital signs (Glasgow coma scale, respiratory rate) from an AUC of 0.79 to 0.84 (p < 0.001). Cardiac markers did not further improve the model. Results for neurological outcome were similar with model improvements by procalcitonin and lactate from AUC 0.83 to 0.87 (p = 0.004).

CONCLUSION

Assessment of routine markers of inflammation/infection and shock provide significant improvements for prognostication of cardiac arrest patients, while cardiac markers did not further improve statistical models. Combination of blood markers and clinical parameters may help to improve initial management decisions in this vulnerable patient population.

A 12-Month Clinical Audit Comparing Point-of-Care Lactate Measurements Tested by Paramedics with In-Hospital Serum Lactate Measurements

Objective

Prehospital point-of-care lactate (pLA) measurement may be a useful tool to assist paramedics with diagnosing a range of conditions, but only if it can be shown to be a reliable surrogate for serum lactate (sLA) measurement. The aim of this study was to determine whether pLA is a reliable predictor of sLA.

Methods

This was a retrospective study of adult patients over a 12-month period who had pLA measured by paramedics in an urban Australian setting and were transported by ambulance to a tertiary hospital where sLA was measured. Patients were excluded if they suffered a cardiopulmonary arrest at any time, had missing data, or if sLA was not measured within 24 hours of arrival. Levels of agreement were determined using methods proposed by Bland and Altman.

Results

A total of 290 patients were transported with a pLA recorded. After exclusions, there were 155 patients (55.0% male; age 71 [SD=18] years) remaining who had sLA recorded within 24 hours. Elevated pLA (>2.0mMol/L) was associated with sLA measurement (76.1% vs 23.9%; OR 3.18; 95% CI, 1.88-5.37; P<.0001). Median time between measurements was 89 minutes (IQR=75). Overall, median pLA was higher than sLA (3.0 [IQR=2.0] mMol/L vs 1.7 [IQR=1.3]; P<.001). Bland-Altman analysis on all participants showed a mean difference of 1.48 mMol/L (95% CI, -3.34 to 6.31). Normal pLA was found to be a true negative in 82.9% of cases, and elevated pLA was a true positive in 48.3% of cases. When the time between measurements was less than 60 minutes (n=25), normal pLA predicted normal sLA with 100% accuracy, with a false-positive rate of 18.2%. As time between measurements increased, accuracy diminished and the false-positive rate increased.

Conclusions

Overall, the level of agreement between pLA and sLA was poor. Accuracy of pLA diminished markedly as the time between the two measurements increased. It may be possible to use pLA as a screening tool; when considered this way, pLA performed much better, though larger prospective trials would be needed to confirm this.

SwanKL, KeeneT, AvardBJ. A 12-month clinical audit comparing point-of-care lactate measurements tested by paramedics with in-hospital serum lactate measurements. Prehosp Disaster Med. 2018;33(1):36–42.

Effect of initial lactate level on short-term survival in patients with out-of-hospital cardiac arrest

Purpose

This study evaluated whether serum lactate levels (SLL) at admission in patients with cardiac arrest (CA) can predict successful return of spontaneous circulation (ROSC) or short-term survival, especially within the first 24 h.

Materials and methods

This prospective, observational study was conducted in the emergency department (ED) of a training and research hospital from April 2015 through February 2016. It included all patients older than 18 years who presented to the ED during the study period with non-traumatic out-of-hospital cardiac arrest (OHCA). The study measured two outcomes: whether ROSC was achieved and whether short-term survival was achieved. ROSC was defined as the presence of spontaneous circulation for the first hour after cardiopulmonary resuscitation (CPR). Survival was defined as having survived for a minimum of 24 h after ROSC.

Results

The study included 140 patients who were admitted to the ED with OHCA. ROSC was achieved in 55 patients (39.3%), and survival for 24 h following CA was achieved in 42 patients (30%). The mean SLL in the ROSC (+) and ROSC (-) groups were 9.1 ± 3.2 mmol/L and 9.8 ± 2.9 mmol/L, respectively. The mean SLL in the survivor and non-survivor groups were 8.6 ± 2.9 mmol/L and 10 ± 3.1 mmol/L, respectively. These differences were not statistically significant (p = 0.1). A multivariate regression model assessing the factors that predicted both ROSC and 24-h survival showed the odds ratio (OR) of initial SLL was 1.3 (95% CI: 1.05–1.6) and 1.1 (95% CI: 0.9–1.3), respectively.

Conclusions

This study showed that in OHCA patients, SLL on admission was not associated with increased ROSC achievement or 24-h survival.

Association between lactate clearance during post-resuscitation care and neurologic outcome in cardiac arrest survivors treated with targeted temperature management

Objective

We investigated the association between lactate clearance or serum lactate levels and neurologic outcomes or in-hospital mortality in cardiac arrest survivors who were treated with targeted temperature management (TTM).

Methods

A retrospective analysis of data from cardiac arrest survivors treated with TTM between 2012 and 2015 was conducted. Serum lactate levels were measured on admission and at 12, 24, and 48 hours following admission. Lactate clearance at 12, 24, and 48 hours was also calculated. The primary outcome was neurologic outcome at discharge. The secondary outcome was in-hospital mortality.

Results

The study included 282 patients; 184 (65.2%) were discharged with a poor neurologic outcome, and 62 (22.0%) died. Higher serum lactate levels at 12 hours (odds ratio [OR], 1.157; 95% confidence interval [CI], 1.006 to 1.331), 24 hours (OR, 1.320; 95% CI, 1.084 to 1.607), and 48 hours (OR, 2.474; 95% CI, 1.459 to 4.195) after admission were associated with a poor neurologic outcome. Furthermore, a higher serum lactate level at 48 hours (OR, 1.459; 95% CI, 1.181 to 1.803) following admission was associated with in-hospital mortality. Lactate clearance was not associated with neurologic outcome or in-hospital mortality at any time point after adjusting for confounders.

Conclusion

Increased serum lactate levels after admission are associated with a poor neurologic outcome at discharge and in-hospital mortality in cardiac arrest survivors treated with TTM. Conversely, lactate clearance is not a robust surrogate marker of neurologic outcome or in-hospital mortality.

The value of blood lactate kinetics in critically ill patients: a systematic review

BACKGROUND

The time course of blood lactate levels could be helpful to assess a patient's response to therapy. Although the focus of published studies has been largely on septic patients, many other studies have reported serial blood lactate levels in different groups of acutely ill patients.

METHODS

We performed a systematic search of PubMed, Science Direct, and Embase until the end of February 2016 plus reference lists of relevant publications. We selected all observational and interventional studies that evaluated the capacity of serial blood lactate concentrations to predict outcome. There was no restriction based on language. We excluded studies in pediatric populations, experimental studies, and studies that did not report changes in lactate values or all-cause mortality rates. We separated studies according to the type of patients included. We collected data on the number of patients, timing of lactate measurements, minimum lactate level needed for inclusion if present, and suggested time interval for predictive use.

RESULTS

A total of 96 studies met our criteria: 14 in general ICU populations, five in general surgical ICU populations, five in patients post cardiac surgery, 14 in trauma patients, 39 in patients with sepsis, four in patients with cardiogenic shock, eight in patients after cardiac arrest, three in patients with respiratory failure, and four in other conditions. A decrease in lactate levels over time was consistently associated with lower mortality rates in all subgroups of patients. Most studies reported changes over 6, 12 or 24 hrs, fewer used shorter time intervals. Lactate kinetics did not appear very different in patients with sepsis and other types of patients. A few studies suggested that therapy could be guided by these measurements.

CONCLUSIONS

The observation of a better outcome associated with decreasing blood lactate concentrations was consistent throughout the clinical studies, and was not limited to septic patients. In all groups, the changes are relatively slow, so that lactate measurements every 1-2 hrs are probably sufficient in most acute conditions. The value of lactate kinetics appears to be valid regardless of the initial value.