Impact of Lactate Clearance on Early Outcomes in Pediatric ECMO Patients

Early outcomes of moderate-to-high-risk pediatric congenital cardiac surgery and predictors of extracorporeal circulatory life support requirement

Background

Cardiopulmonary failure refractory to medical management after moderate-to-high-risk congenital cardiac surgery may necessitate mechanical support with veno-arterial extracorporeal membrane oxygenation (ECMO). On the extreme, ECMO can also be initiated in the setting of cardiac arrest (extracorporeal cardiopulmonary resuscitation, ECPR) unresponsive to conventional resuscitative measures.

Methods

This was a single-center retrospective cohort study of patients (n = 510) aged <3 years old who underwent cardiac surgery with cardiopulmonary bypass with a RACHS-1 score ≥3 between 2011 and 2014. Perioperative factors were reviewed to identify predictors of ECMO initiation and mortality in the operating room (OR) and the intensive care unit (ICU).

Results

A total of 510 patients with a mean surgical age of 10.0 ± 13.4 months were included. Among them, 21 (4%) patients received postoperative ECMO-12 were initiated in the OR and 9 in the ICU. ECMO cannulation was associated with cardiopulmonary bypass duration, aortopulmonary shunt, residual severe mitral regurgitation, vaso-inotropic score, and postprocedural lactate (p < 0.001). Of the 32 (6%) total deaths, 7 (22%) were ECMO patients-4 were elective OR cannulations and 3 were ICU ECPR. Prematurity [hazard ratio (HR): 2.61, p < 0.01), Norwood or Damus-Kaye-Stansel procedure (HR: 4.29, p < 0.001), postoperative left ventricular dysfunction (HR: 5.10, p = 0.01), residual severe tricuspid regurgitation (HR: 6.06, p < 0.001), and postoperative ECMO (ECPR: HR: 15.42, p < 0.001 vs. elective: HR: 5.26, p = 0.01) were associated with mortality. The two patients who were electively cannulated in the ICU survived.

Discussion

Although uncommon, postoperative ECMO in children after congenital cardiac surgery is associated with high mortality, especially in cases of ECPR. Patients with long cardiopulmonary bypass time, residual cardiac lesions, or increased vaso-inotropic requirement are at higher risk of receiving ECMO. Pre-emptive or early ECMO initiation before deterioration into cardiac arrest may improve survival.

Lactate and Lactate Clearance Are Predictive Factors for Mortality in Patients with Extracorporeal Membrane Oxygenation

INTRODUCTION

Findings of inadequate tissue perfusion might be used to predict the risk of mortality. In this study, we evaluated the effects of lactate and lactate clearance on mortality of patients who had undergone extracorporeal membrane oxygenation (ECMO).

METHODS

Patients younger than 18 years old and who needed venoarterial ECMO support after surgery for congenital heart defects, from July 2010 to January 2019, were retrospectively analyzed. Patients successfully weaned from ECMO constituted Group 1, and patients who could not be weaned from ECMO were in Group 2. Postoperative clinics and follow-ups of the groups including mortality and discharge rates were evaluated.

RESULTS

There were 1,844 congenital heart surgeries during the study period, and 55 patients that required ECMO support were included in the study. There was no statistically significant difference between the groups regarding demographics and operative variables. The sixth-, 12th-, and 24th-hour lactate levels in Group 1 were statistically significantly lower than those in Group 2 (P=0.046, P=0.024, and P<0.001, respectively). There were statistically significant differences regarding lactate clearance between the groups at the 24th hour (P=0.009). The cutoff point for lactate level was found as ≥ 2.9, with 74.07% sensitivity and 78.57% specificity (P<0.001). The cutoff point for lactate clearance was determined as 69.44%, with 59.26% sensitivity and 78.57% specificity (P=0.003).

CONCLUSION

Prognostic predictive factors are important to initiate advanced treatment modalities in patients with ECMO support. In this condition, lactate and lactate clearance might be used as a predictive marker.

Association between serum lactate, lactate clearance rate, and 30-day mortality among patients undergoing mechanical ventilation: A retrospective cohort study of MIMIC-III database

Serum lactate has been used as a prognostic indicator in intensive care unit patients, and however, the single lactate value may not be enough to reflect changes during illness conditions. Herein, this study aims to explore the association between serum lactate and lactate clearance rate and 30-day mortality in patients undergoing mechanical ventilation (MV). Demographic and clinical data of 2628 adults were extracted from the medical information mart for intensive care-III clinical database in this retrospective cohort study. The lactate clearance rate was calculated using the serum lactate at the beginning of MV (T0), and serum lactate at the12 hours after MV beginning (T1). Univariate and multivariate Cox regression analyses were used to screen covariates, and explore the association between serum lactate and lactate clearance rate and 30-day mortality. We also explored these associations in different T0 serum lactate level subgroups. The evaluation indexes were hazard ratios (HRs) and 95% CIs. In addition, receiver operator characteristic (ROC) curve with area under the curve (AUC) was used to reflect the predictive performance of serum lactate and lactate clearance rate on 30-day mortality. A total of 827 (31.47%) mechanically ventilated patients died within 30 days. After adjusting for covariates, elevated T0 (HR = 1.04, 95%CI: [1.02-1.07]) and T1 (HR = 1.07, 95%CI: [1.04-1.10]) serum lactate was both associated with an increased risk of 30-day mortality, while higher lactate clearance rate was negatively associated with the risk of 30-day mortality (HR = 0.64, 95%CI: [0.50-0.81]). Among patients with T0 lactate ≥2 mmol/L, T1 serum lactate ≥4 mmol/L was associated with an increased risk of 30-day mortality, while lactate clearance rate ≥50 was associated with a decreased risk (all P < .05). Moreover, T1 serum lactate had a potential predictive value on 30-day mortality with an AUC of 0.605. Serum lactate and lactate clearance rate were both associated with 30-day mortality in patients undergoing MV. Our results may provide some references for further studies to explore the roles of serum lactate and lactate clearance rate in prognoses of critical patients.

Positive association between arterial blood lactate level before extra-corporeal membrane oxygenation and 30-day mortality in pediatric patients with severe cardiopulmonary failure

INTRODUCTION

This study aimed to investigate the relationship between blood lactate level and mortality in pediatric patients receiving extracorporeal membrane oxygenation (ECMO) for severe cardiopulmonary failure.

METHODS

A retrospective observational study was conducted on pediatric patients who received ECMO from January 2013 to December 2021 at the Seventh Medical Center of PLA General Hospital. Patient demographic characteristics, arterial blood lactate level prior to ECMO (pre-ECMO), ECMO settings, ECMO duration, and 30-days mortality were retrieved from patients' medical records. The relationships between pre-ECMO blood lactate level and mortality were interpreted using the logistic regression analysis and Kaplan-Meier survival analysis.

RESULTS

A total of 160 pediatric patients who had either refractory respiratory failure (n = 89) or circulatory failure (n = 71) and received ECMO were included in this study. In both the respiratory failure and circulatory failure groups, the non-survivors showed a higher mean pre-ECMO arterial blood lactate level than the survivors. In the respiratory failure group, a pre-ECMO lactate concentration at ≥11.6 mmol/L had a sensitivity of 51% and a specificity of 82% for predicting mortality. In the circulatory failure group, a pre-ECMO lactate concentration at ≥7.2 mmol/L had a sensitivity of 90% and a specificity of 57% for predicting mortality. The Kaplan-Meier survival curves showed that respiratory failure patients with a pre-ECMO lactate level over 11.6 mmol/L or circulatory failure patients with a pre-ECMO lactate level over 7.2 mmol/L had a higher 30-days mortality rate than those with a lower lactate level.

CONCLUSIONS

High pre-ECMO arterial blood lactate level serves as an independent risk factor for mortality in pediatric patients who receive ECMO for severe cardiopulmonary failure.

Evaluation of plasma lactate parameters for predicting mortality of septic patients

Objective

To compare the accuracy of serum lactate parameters, including lactate peak concentration (LACpeak), lactate time area (LACarea), and lactate clearance (LC) for predicting mortality of the septic patients, and to compare with the predictive accuracy of National Early Warning Score (NEWS) and Sequential Organ Failure Assessment (SOFA) scores.

Methods

This study retrospectively screened the septic patients admitted to the ICU in the Medical Information Mart for Intensive Care IV (MIMIC-IV) from 2008 to 2019. The baseline data and outcomes of patients were gathered. The subjects were divided into the non-survival group and the survival group. SOFA, NEWS, LACpeak, and LACarea were recorded. The LC was calculated 6 h after LACpeak. The above parameters were compared by the T-test and Mann-Whitney U test, and odds ratios were calculated adjusting for age and sex. The receiver operating characteristic curves (ROCs) of subjects were plotted according to SOFA, NEWS, LACpeak, and LACarea within 24h, and LC at 6h of ICU admission. The Areas under the ROC curve (AUCs), sensitivity, and specificity were compared with R version 4.1.1.

Results

1,169 septic patients were involved, and 366 (31.3%) patients died within 28 days. Compared to the survival group, the LACpeak of the non-survival group was higher [4.85 (3.2, 7.9) vs. 3.4 (2.6, 5.25) mmol/L, adjusted odds ratio 1.18, P < 0.001], and the LACarea of the non-survivals was higher than the survivals too [18.44 (10.36, 27.63) vs. 13.65 (9.01, 21.73), adjusted odds ratio 1.03, P < 0.001)]. The LC of the survivals at 6 h after LACpeak was significantly higher than that of the non-survivals [0.26 (0.14.0.42) vs. 0.19 (0.10, 0.33), adjusted odds ratio 0.06, P < 0.01]. Within 24h of ICU admission, the AUCs of mortality prediction in descending order were NEWS [0.73 (0.70, 0.76)], SOFA [0.69 (0.66, 0.73)], LACpeak [0.64 (0.61, 0.68)], and LACarea [0.60 (0.56, 0.63)]. There were 204 patients with 6-hour LC after LACpeak the AUCs of LACarea, LACpeak and LC were 0.73(0.65, 0.80), 0.71(0.62,0.78) and 0.65 (0.56, 0.73), respectively.

Conclusions

The predictive accuracy of LC was not superior to LACpeak and LACarea for the mortality of the septic patients and the predictive value of all the above lactate parameters for mortality maybe not better than SOFA and NEWS.

Could lactate clearance be a marker of mortality in pediatric intensive care unit?

BACKGROUND

Hyperlactatemia is a common finding in critically ill patients and has significant prognostic implications. However, a single lactate measurement has not been correlated to mortality consistently. In this study, we aimed to correlate the clinical efficacy of lactate clearance for the prediction of mortality in pediatric intensive care unit patients.

METHODS

This retrospective observational study was performed in the pediatric intensive care unit in patients with lactate level >3 mmol/lt. Initial, 6th h, and 24th h lactate levels were recorded and lactate clearance was calculated using these values (lactate level at admission - level 6 h later × 100/lactate level at admission).

RESULTS

A total of 172 patients were included in the study. Forty-four out of 172 patients died. Median (IQR) lactate (mmol/L) at admission was low in those who survived in comparison to nonsurvivors 4.4 (3.1) vs. 5.75 (7.7) (p = 0.002). Clearance at 6th h was significantly lower in those who died (11.7%) than those who survived (36.7) (p = 0.001). 6th h lactate clearance level <20.7% predicted mortality with a sensitivity of 63.6% and specificity of 69.5% along with a positive predictive value of 41.8 and a negative predictive value of 84.8 (p = 0.004). Both lactate levels and lactate clearance values were significantly predictive factors for mortality (p < 0.05). Only a positive moderate correlation was found between the percentage of PRISM-IV % and 6th h lactate level.

DISCUSSION

The present study revealed that lactate clearance is a simple and rapid risk-stratification tool holding to be a potential biomarker of managing the treatment efficacy of children in the pediatric intensive care unit.

Mortality prediction in pediatric postcardiotomy veno-arterial extracorporeal membrane oxygenation: A comparison of scoring systems

Background

Pediatric postcardiotomy veno-arterial extracorporeal membrane oxygenation (VA-ECMO) patients have high mortality and morbidity. There are currently three scoring systems available to predict mortality: the Pediatric Extracorporeal Membrane Oxygenation Prediction (PEP) model, Precannulation Pediatric Survival After VA-ECMO (Pedi-SAVE) score, and Postcannulation Pedi-SAVE score. These methods provide risk stratification scores for pediatric patients requiring ECMO for cardiac support. However, comparative validation of these scoring systems remains scarce. We aim to assess the ability of these models to predict outcomes in a cohort of pediatric patients undergoing VA-ECMO after cardiac surgery, and identify predictors of in-hospital mortality.

Methods

A retrospective analysis of 101 children admitted to Fuwai Hospital who received VA-ECMO from January 1, 2010 to December 31, 2020 was performed. Patients were divided into two groups, survivors (n = 49) and non-survivors (n = 52) according to in-hospital mortality. PEP model and Pedi-SAVE scores were calculated. The primary outcomes were the risk factors of in-hospital mortality, and the ability of the PEP model, Precannulation Pedi-SAVE and Postcannulation Pedi-SAVE scores to predict in-hospital mortality.

Results

Postcannulation Pedi-SAVE score accessing the entire ECMO process had the greatest area under receiver operator curve (AUROC), 0.816 [95% confidence interval (CI): 0.733–0.899]. Pre-ECMO PEP model could predict in-hospital mortality [AUROC = 0.691 (95% CI: 0.565–0.817)], and Precannulation Pedi-SAVE score had the poorest prediction [AUROC = 0.582(95% CI: 0.471–0.694)]. Lactate value at ECMO implantation [OR = 1.199 (1.064–1.351), P = 0.003] and infectious complications [OR = 5.169 (1.652–16.172), P = 0.005] were independent risk factors for in-hospital mortality.

Conclusion

Pediatric cardiac ECMO scoring systems, including multiple risk factors before and during ECMO, were found to be useful in this cohort. Both the pre-ECMO PEP model and the Postcannulation Pedi-SAVE score were found to have high predictive value for in-hospital mortality in pediatric postcardiotomy VA-ECMO.