Etiology and therapeutic approach to elevated lactate levels

Adaptation of Natural Killer Cells to Hypoxia: A Review of the Transcriptional, Translational, and Metabolic Processes

As important innate immune cells, natural killer (NK) cells play an essential role in resisting pathogen invasion and eliminating transformed cells. However, the hypoxic microenvironment caused by disease conditions is an important physicochemical factor that impairs NK cell function. With the increasing prominence of NK cells in immunotherapy, there has been a surge of interest in developing biological means through which NK cells may overcome the inhibition caused by hypoxia in disease conditions. Although the effects of hypoxic conditions in shaping the functions of NK cells have been increasingly recognized and investigated, reviews have been scantly. A comprehensive understanding of how NK cells adapt to hypoxia can provide valuable insights into how the functional capacity of NK cells may be restored. This review focuses on the functional alterations of NK cells in response to hypoxia. It delineates the mechanisms by which NK cells adapt to hypoxia at the transcriptional, metabolic, translational levels. Furthermore, given the complexity of the hypoxic microenvironment, we also elucidated the effects of key hypoxic metabolites on NK cells. Finally, this review discusses the current clinical therapies derived from targeting hypoxic NK cells. The study of NK cell adaptation to hypoxia has yielded new insights into immunotherapy. These insights may lead to development of novel strategies to improve the treatment of infectious diseases and cancer.

Association between lactate-to-albumin ratio and all-cause mortality in cirrhosis patients: Analysis of the MIMIC-IV database

OBJECTIVE

This study evaluates the predictive value of the lactate/albumin ratio (LAR) for all-cause mortality in cirrhosis patients.

DESIGN

Retrospective observational study.

SETTING

Intensive care unit (ICU).

PATIENTS OR PARTICIPANTS

626 first-time ICU-admitted cirrhosis patients in the USA (MIMIC-IV v2.2).

INTERVENTIONS

None.

MAIN VARIABLES OF INTEREST

LAR index, 28-day, and 90-day all-cause mortality.

RESULTS

Of 626 patients (60.86% male), 27.80% and 39.14% died within 28 and 90 days, respectively. Multivariate Cox analysis showed a significant association between higher LAR and mortality. Adjusted for confounders, elevated LAR increased the 28-day mortality risk [HR: 1.31 (1.21-1.42), P < 0.001]. A restricted cubic spline analysis revealed non-linear relationships between LAR and mortality. For 28-day mortality, the inflection point was 1.583: below this, HR was 2.29 (95% CI: 1.61-3.27, P < 0.001); above, HR was 1.16 (95% CI: 1.02-1.31, P = 0.021; P = 0.002). For 90-day mortality, the inflection point was 1.423: below, HR was 1.60 (95% CI: 1.04-2.47, P = 0.033); above, HR was 0.94 (95% CI: 0.75-1.16, P = 0.542; P = 0.012).

CONCLUSIONS

LAR predicts 28-day and 90-day mortality with a segmented effect. An LAR ≥1.583 signals high 28-day mortality risk, necessitating intensified monitoring and potential ICU admission. For 90-day mortality, LAR near 1.423 serves as an early warning for high-risk patients and guides interventions. Continuous LAR monitoring aids management, but prospective studies are needed to confirm clinical utility.

Admission Blood Glucose Level with a Cutoff Value of 15 mmol/L Is a Reliable Predictor of Mortality in Polytraumatized Patients-a Prospective, Observational, Longitudinal Study From a North African Level One Trauma Center

Background

Abnormal admission blood glucose levels were proved to have a mortality predictive value in polytraumatized patients, as reported by studies in developed countries. Reports from developing countries are scarce.

Objective

To evaluate the reliability of on-admission blood glucose levels in predicting mortality in polytraumatized patients presented to a North African (developing country) trauma center. The secondary objectives were to investigate other possible mortality predictors and if a cutoff value for each could be obtained.

Methods

In this prospective longitudinal study, over one year, we included adult (≥18 years) patients who were polytraumatized (ISS ≥17) and presented to our trauma center within six hours of the trauma incident. Various clinical, laboratory, and trauma scores were collected. Blood glucose levels were assessed from blood samples obtained directly after admission. Patients were divided into five groups based on the admission blood glucose levels.

Results

We included 202 patients, having a mean age of 44±13.9 (20 to 70) years, and 52% were females. The mortality rate was 10.9% (including all patients presented with blood glucose levels≥15 mmol/L). The following were significant mortality predictors, admission blood glucose (OR=3.31, 95% CI=1.902-5.763, p<0.001), serum lactate levels (OR=4.017, 95% CI=1.627-9.917, p=0.003), length of hospital stay (OR=1.18, 95% CI= 1.058-1.305, p=0.003), RTS score (OR=1.43, 95% CI=1.023-2.005, p=0.037), and TRISS score (OR=1.099, 95% CI=1.052-1.148, p<0.001). Admission blood glucose levels cutoff value of 15 mmol/L can significantly differentiate between survivors and non-survivors with sensitivity, specificity, PPV, and NPV of 86.4%, 100%, 100%, and 88%, respectively.

Conclusion

Abnormal admission blood glucose with a cutoff value of 15mmol/L is a significant mortality predictor in polytraumatized patients from developing country trauma center, among other clinical, laboratory, and trauma scores parameters.

Impact of lactate levels on admission in STEMI patients with cardiogenic shock treated with IMPELLA

The concomitant use of IMPELLA and veno-arterial extracorporeal membrane oxygenation (V-A ECMO) (ECPELLA) has been increasingly used to treat severe cardiogenic shock. However, the relationship between severity of heart failure on admission and prognosis based on differences in the mechanical circulatory support (MCS) is not fully understood. This study evaluated the association between lactate levels on admission and clinical outcomes based on differences in MCS. We identified 852 patients (median age 71 years; 78% male) with cardiogenic shock due to ST-elevation myocardial infarction (STEMI) from the Japanese Registry for Percutaneous Ventricular Assist Devices. The primary endpoint was the in-hospital mortality rate. Additionally, patients were classified into three groups based on lactate levels according to the SCAI SHOCK classification for the assessment of in-hospital mortality: group 1 (lactate level < 2 mmol/L), group 2 (lactate level 2-8 mmol/L), and group 3 (lactate level ≥ 8 mmol/L). The in-hospital mortality rate was 41.8%. The rate of V-A ECMO combined with IMPELLA use was 37.6%. The in-hospital mortality rates of the IMPELLA alone and ECPELLA group were 30.1% and 61.3%, respectively. The median lactate level was significantly higher in non-survivors than in survivors (5.7 mmol/L vs. 3.5 mmol/L, p < 0.0001). The in-hospital mortality rate with IMPELLA alone was significantly higher in group 3 compared to groups 1 and 2; however, there was no difference in in-hospital mortality with ECPELLA among the three groups. A lactate cut-off value of 6.9 mmol/L showed the best discrimination for in-hospital mortality. Patients classified as the SCAI SHOCK stage E have a higher mortality rate with IMPELLA support alone. Further research is needed to optimize management strategies for this high-risk group.

Emergency medicine updates: Management of sepsis and septic shock

INTRODUCTION

Sepsis is a common condition associated with significant morbidity and mortality. Emergency physicians play a key role in the diagnosis and management of this condition.

OBJECTIVE

This paper evaluates key evidence-based updates concerning the management of sepsis and septic shock for the emergency clinician.

DISCUSSION

Sepsis is a life-threatening syndrome, and rapid diagnosis and management are essential. Antimicrobials should be administered as soon as possible, as delays are associated with increased mortality. Resuscitation targets include mean arterial pressure ≥ 65 mmHg, mental status, capillary refill time, lactate, and urine output. Intravenous fluid resuscitation plays an integral role in those who are fluid responsive. Balanced crystalloids and normal saline are both reasonable options for resuscitation. Early vasopressors should be initiated in those who are not fluid-responsive. Norepinephrine is the recommended first-line vasopressor, and if hypotension persists, vasopressin should be considered, followed by epinephrine. Administration of vasopressors through a peripheral 20-gauge or larger intravenous line is safe and effective. Steroids such as hydrocortisone and fludrocortisone should be considered in those with refractory septic shock.

CONCLUSION

An understanding of the recent updates in the literature concerning sepsis and septic shock can assist emergency clinicians and improve the care of these patients.

Advances and Challenges in Pediatric Sepsis Diagnosis: Integrating Early Warning Scores and Biomarkers for Improved Prognosis

Identifying and managing pediatric sepsis is a major research focus, yet early detection and risk assessment remain challenging. In its early stages, sepsis symptoms often mimic those of mild infections or chronic conditions, complicating timely diagnosis. Although various early warning scores exist, their effectiveness is limited, particularly in prehospital settings where accurate, rapid assessment is crucial. This review examines the roles of clinical prediction tools and biomarkers in pediatric sepsis. Traditional biomarkers, like procalcitonin (PCT), have improved diagnostic accuracy but are insufficient alone, often resulting in overprescription of antibiotics or delayed treatment. Combining multiple biomarkers has shown promise for early screening, though this approach can be resource-intensive and less feasible outside hospitals. Predicting sepsis outcomes to tailor therapy remains underexplored. While serial measurements of traditional biomarkers offer some prognostic insight, their reliability is limited, with therapeutic decisions often relying on clinical judgment. Novel biomarkers, particularly those identifying early organ dysfunction, hold potential for improved prognostic accuracy, but significant barriers remain. Many are only available in hospitals, require further validation, or need specialized assays not commonly available, limiting broader clinical use. Further research is needed to establish reliable protocols and enhance the clinical applicability of these tools. Meanwhile, a multifaceted approach that combines clinical judgment with existing tools and biomarkers remains essential to optimize pediatric sepsis management, improving outcomes and minimizing risks.

Taurine prevents mitochondrial dysfunction and protects mitochondria from reactive oxygen species and deuterium toxicity

Taurine, although not a coding amino acid, is the most common free amino acid in the body. Taurine has multiple and complex functions in protecting mitochondria against oxidative-nitrosative stress. In this comprehensive review paper, we introduce a novel potential role for taurine in protecting from deuterium (heavy hydrogen) toxicity. This can be of crucial impact to either normal or cancer cells that have highly different mitochondrial redox status. Deuterium is an isotope of hydrogen with a neutron as well as a proton, making it about twice as heavy as hydrogen. We first explain the important role that the gut microbiome and the gut sulfomucin barrier play in deuterium management. We describe the synergistic effects of taurine in the gut to protect against the deleterious accumulation of deuterium in the mitochondria, which disrupts ATP synthesis by ATPase pumps. Moreover, taurine's derivatives, N-chlorotaurine (NCT) and N-bromotaurine (NBrT), produced through spontaneous reaction of taurine with hypochlorite and hypobromite, have fascinating regulatory roles to protect from oxidative stress and beyond. We describe how taurine could potentially alleviate deuterium stress, primarily through metabolic collaboration among various gut microflora to produce deuterium depleted nutrients and deuterium depleted water, and in this way protect against leaky gut barrier, inflammatory bowel disease, and colon cancer.

The role of neutrophilia in hyperlactatemia, blood acidosis, impaired oxygen transport, and mortality outcome in critically ill COVID-19 patients

Introduction

COVID-19 severity and high in-hospital mortality are often associated with severe hypoxemia, hyperlactatemia, and acidosis, yet the key players driving this association remain unclear. It is generally assumed that organ damage causes toxic acidosis, but since neutrophil numbers in severe COVID-19 can exceed 80% of the total circulating leukocytes, we asked if metabolic acidosis mediated by the glycolytic neutrophils is associated with lung damage and impaired oxygen delivery in critically ill patients.

Methods

Based on prospective mortality outcome, critically ill COVID-19 patients were divided into ICU- survivors and ICU-non-survivors. Samples were analyzed to explore if correlations exist between neutrophil counts, lung damage, glycolysis, blood lactate, blood pH, hemoglobin oxygen saturation, and mortality outcome. We also interrogated isolated neutrophils, platelets, and PBMCs for glycolytic activities.

Results

Arterial blood gas analyses showed remarkable hypoxemia in non-survivors with no consistent differences in PCO2 or [HCO3 -]. The hemoglobin oxygen dissociation curve revealed a right-shift, consistent with lower blood-pH and elevated blood lactate in non-survivors. Metabolic analysis of different blood cells revealed increased glycolytic activity only when considering the total number of neutrophils.

Conclusion

This indicates the role of neutrophilia in hyperlactatemia and lung damage, subsequently contributing to mortality outcomes in severe SARS-CoV-2 infection.

Intestinal oxygen utilisation and cellular adaptation during intestinal ischaemia-reperfusion injury

The gastrointestinal tract can be deranged by ailments including sepsis, trauma and haemorrhage. Ischaemic injury provokes a common constellation of microscopic and macroscopic changes that, together with the paradoxical exacerbation of cellular dysfunction and death following restoration of blood flow, are collectively known as ischaemia-reperfusion injury (IRI). Although much of the gastrointestinal tract is normally hypoxemic, intestinal IRI results when there is inadequate oxygen availability due to poor supply (pathological hypoxia) or abnormal tissue oxygen use and metabolism (dysoxia). Intestinal oxygen uptake usually remains constant over a wide range of blood flows and pressures, with cellular function being substantively compromised when ischaemia leads to a >50% decline in intestinal oxygen consumption. Restoration of perfusion and oxygenation provokes additional injury, resulting in mucosal damage and disruption of intestinal barrier function. The primary cellular mechanism for sensing hypoxia and for activating a cascade of cellular responses to mitigate the injury is a family of heterodimer proteins called hypoxia-inducible factors (HIFs). The HIF system is connected to numerous biochemical and immunologic pathways induced by IRI and the concentration of those proteins increases during hypoxia and dysoxia. Activation of the HIF system leads to augmented transcription of specific genes in various types of affected cells, but may also augment apoptotic and inflammatory processes, thus aggravating gut injury. KEY POINTS: During intestinal ischaemia, mitochondrial oxygen uptake is reduced when cellular oxygen partial pressure decreases to below the threshold required to maintain normal oxidative metabolism. Upon reperfusion, intestinal hypoxia may persist because microcirculatory flow remains impaired and/or because available oxygen is consumed by enzymes, intestinal cells and neutrophils.

Lactate, lactate clearance, and lactate-to-albumin ratio in predicting mortality in patients with critical polytrauma: A retrospective observational study

Lactate is a product of anaerobic metabolism used to determine prognosis in critically ill trauma patients. This study investigates the mortality-predictive performance of lactate, lactate clearance, and lactate-to-albumin ratio (LAR) on admission in patients with polytrauma in a tertiary center's intensive care unit (ICU). Polytrauma patients in the ICU between June 2019 and June 2022 were evaluated. The diagnosis of polytrauma was made according to the Berlin criteria, a widely accepted and comprehensive system for classifying the severity of multiple injuries. Patients were classified into survivor and mortality groups. The predictive performance of lactate, lactate clearance (24th hour), and LAR for 28-day mortality was compared. The study included 176 patients. The median age of the entire population was 35 (24-50) years, and 78.4% (n = 138) were male. Motor vehicle accidents were the most common cause of polytrauma in patients (48.9%, n = 86). The most common head injuries were detected in the patients (59.1%, n = 104). In the mortality group, median lactate and lactate (24th hour) levels were significantly higher (P < .001). Median albumin and LAR values were significantly lower (P < .001). Although 24-hour lactate clearance was lower in the mortality group, no significant difference was detected (36.1% vs 42.3%, P = .052). In multivariate regression analysis, LAR was an independent predictor of mortality (P < .001). In receiver operating characteristics curve analysis, the cutoff value of lactate was ≥5.4, the area under the curve (AUC) was 0.75 (95% confidence interval [CI], 0.66-0.84), the cutoff value of lactate clearance was ≤39.2, AUC was 0.60, (95% CI, 0.51-0.69), and the cutoff value of LAR was value ≥1.50, AUC 0.83 (95% CI, 0.75-0.90). In critically ill polytrauma patients, LAR on ICU admission is an independent predictor of mortality and has acceptable prognostic value. LAR is superior to lactate and 24-hour lactate clearance in predicting mortality.

Lactate Is a Strong Predictor of Poor Outcomes in Patients with Severe Traumatic Brain Injury

Background: Lactate is a byproduct of glycolysis, often linked to oxygen deprivation. This study aimed to examine how lactate levels (LLs) affect clinical outcomes in patients with severe TBI, hypothesizing that higher LLs would correlate with worse outcomes. Methods: This is a level 1 single-center, retrospective study of patients with severe TBI between 1 January 2020 and 31 December 2023, inclusive. Results: Single-factor ANOVA indicated a significant decrease in LLs with increasing age. Linear regression models showed the same for hospital admission, Intensive Care Unit (ICU) admission LLs, and death LLs. Prognostic scores such as Injury Severity Scores (ISS) and Glasgow Coma Score (GCS) showed a strong correlation with both Hospital admission and ICU admission LLs. ANOVA indicated higher LLs with increasing ISS and increasing LLs with decreasing GCS. Linear regressions revealed a strong positive correlation between ISS and LLs. On linear regression, the LL measured at hospital admission and ICU admission was positively associated with the length of stay (LOS) in the hospital, LOS in the ICU, ventilator days, and mortality. Linear regression models showed that a decreased delta LL during ICU admission led to an increased LOS at the hospital and the ICU, as well as a higher number of days on a ventilator. Discussion: We discovered that high LLs were linked to higher AIS and GCS scores, longer stays in the hospital and ICU, more days requiring a ventilator, and higher mortality rates in patients with severe TBI. Conclusions: LLs can be considered a strong predictor of poor clinical outcomes in patients with severe TBI.

Cardiac arrest and microcirculatory dysfunction: a narrative review

PURPOSE OF REVIEW

This review provides an overview of the role of microcirculation in cardiac arrest and postcardiac arrest syndrome through handheld intravital microscopy and biomarkers. It highlights the importance of microcirculatory dysfunction in postcardiac arrest outcomes and explores potential therapeutic targets.

RECENT FINDINGS

Sublingual microcirculation is impaired in the early stage of postarrest and is potentially associated with increased mortality. Recent work suggests that the proportion of perfused small vessels is predictive of mortality. Microcirculatory impairment is consistently found to be independent of macrohemodynamic parameters. Biomarkers of endothelial cell injury and endothelial glycocalyx degradation are elevated in postarrest settings and may predict mortality and clinical outcomes, warranting further studies. Recent studies of exploratory therapies targeting microcirculation have shown some promise in animal models but still require significant research.

SUMMARY

Although research continues to suggest the important role that microcirculation may play in postcardiac arrest syndrome and cardiac arrest outcomes, the existing studies are still limited to draw any definitive conclusions. Further research is needed to better understand microcirculatory changes and their significance to improve cardiac arrest care and outcomes.

Carbohydrate metabolism in supporting and regulating neutrophil effector functions

Neutrophils, the first responders of the innate immune system, can turn on a range of effector functions upon activation. Emerging research shows activated neutrophils undergo highly dynamic metabolic rewiring. This metabolic rewiring provides energy and reducing power to fuel effector functions and modulate signaling molecules to regulate neutrophil functions. Here, we review the current understanding of the specific metabolic requirements and regulators of neutrophil migration, neutrophil extracellular traps release, and pathogen killing. Particularly, we discuss how major carbohydrate metabolic pathways, including glycolysis, glycogen cycling, pentose phosphate pathway, and TCA cycle, are rewired upon neutrophil activation to support these functions. Continued investigation into the metabolic regulators of neutrophil functions can lead to therapeutic opportunities in various diseases.

The Warburg Effect: Is it Always an Enemy?

The Warburg effect, also known as 'aerobic' glycolysis, describes the preference of cancer cells to favor glycolysis over oxidative phosphorylation for energy (adenosine triphosphate-ATP) production, despite having high amounts of oxygen and fully active mitochondria, a phenomenon first identified by Otto Warburg. This metabolic pathway is traditionally viewed as a hallmark of cancer, supporting rapid growth and proliferation by supplying energy and biosynthetic precursors. However, emerging research indicates that the Warburg effect is not just a strategy for cancer cells to proliferate at higher rates compared to normal cells; thus, it should not be considered an 'enemy' since it also plays complex roles in normal cellular functions and/or under stress conditions, prompting a reconsideration of its purely detrimental characterization. Moreover, this review highlights that distinguishing glycolysis as 'aerobic' and 'anaerobic' should not exist, as lactate is likely the final product of glycolysis, regardless of the presence of oxygen. Finally, this review explores the nuanced contributions of the Warburg effect beyond oncology, including its regulatory roles in various cellular environments and the potential effects on systemic physiological processes. By expanding our understanding of these mechanisms, we can uncover novel therapeutic strategies that target metabolic reprogramming, offering new avenues for treating cancer and other diseases characterized by metabolic dysregulation. This comprehensive reevaluation not only challenges traditional views but also enhances our understanding of cellular metabolism's adaptability and its implications in health and disease.

Lactate: a rising star in tumors and inflammation

Lactate has been traditionally regarded as a mere byproduct of glycolysis or metabolic waste. However, an increasing body of literature suggests its critical role in regulating various physiological and pathological processes. Lactate is generally associated with hypoxia, inflammation, viral infections, and tumors. It performs complex physiological roles by activating monocarboxylate transporter (MCT) or the G protein-coupled receptor GPR81 across the cell membrane. Lactate exerts immunosuppressive effects by regulating the functions of various immune cells (such as natural killer cells, T cells, dendritic cells, and monocytes) and its role in macrophage polarization and myeloid-derived suppressor cell (MDSC) differentiation in the tumor microenvironment. Lactic acid has also recently been found to increase the density of CD8+ T cells, thereby enhancing the antitumor immune response. Acute or chronic inflammatory diseases have opposite immune states in the inflammatory disease microenvironment. Factors such as cell types, transcriptional regulators, ionic mediators, and the microenvironment all contribute to the diverse functions lactate exhibits. Herein, we reviewed the pleiotropic effects of lactate on the regulation of various functions of immune cells in the tumor microenvironment and under inflammatory conditions, which may help to provide new insights and potential targets for the diagnosis and treatment of inflammatory diseases and malignancies.

Diagnostic Value of Endotoxin Activity for Acute Postoperative Complications: A Study in Major Abdominal Surgery Patients

Background/Objectives: Endotoxin, a component of lipopolysaccharide (LPS) from bacteria, disrupts the immune system, potentially leading to multiorgan failure. Unlike previous studies, we enrolled patients with mild clinical conditions after major abdominal surgery and assessed the predictive value of endotoxin activity (EA) levels for acute complications which occur within 7 days postoperatively. Also, the differential diagnostic value of EA was assessed in a subgroup of patients with abnormal liver function during the immediate postoperative period. Methods: Patients admitted to the surgical ICU of our institution following elective abdominal surgery were enrolled. Participants were classified into low/high postoperative EA groups based on EA cutoff values for predicting complications. Additionally, participants were categorized based on liver function assessed at ICU admission using total bilirubin (TB) levels. Abnormal liver function was defined as a TB level > 1.2 mg/dL. Results: 86 patients were analyzed. The EA cutoff for postoperative complications was 0.485, with 49 patients (57%) categorized in the low EA group (EA levels < 0.485) and 37 patients (43%) in the high EA group (EA levels ≥ 0.485). The high EA group experienced statistically worse outcomes, including longer ICU stays and higher mortality rates. Logistic regression analysis confirmed that EA levels and SOFA scores were significant predictors of postoperative complications. For patients with elevated TB, the EA cutoff value for postoperative complications was 0.515, which is higher than those obtained for the total patient cohort. Conclusions: EA level is a viable surveillance tool for detecting postoperative complications in the acute period among ICU patients undergoing major abdominal surgery, and must be interpreted carefully considering the patient's liver function.

Efficiency of IL-6 in Early Prognosis and Follow-Up in Critically Ill Patients with Septic Shock

Background/Objectives: The aim of this study was to investigate the response of interleukin-6 (IL-6) during the first few hours of a patient's stay in the Intensive Care Unit (ICU) in a sample of critically ill patients with septic shock, compared to healthy subjects as controls. Additionally, the study examined the association of IL-6 with morbidity and mortality in these patients, as well as its relationship with biomarkers such as lactic acid, C-reactive protein (CRP) and procalcitonin (PCT). Methods: This was a prospective analytical study involving 28 critically ill patients with septic shock, monitored from ICU admission through to their first three days of stay. Demographic data, comorbidities and clinical information, including IL-6 and severity scores, were recorded. Results: IL-6 levels were significantly higher in patients with septic shock compared to healthy subjects (p < 0.001) upon admission. IL-6 levels decreased by the third day of ICU stay (p < 0.005). An association between IL-6 and mortality was observed (areas under the curve 0.826, confidence interval (CI) 95% 0.659-0.994, p < 0.008). Significant correlations between IL-6 and lactic acid (p < 0.009 and p < 0.018) and partial thromboplastin time (p < 0.004 and p < 0.007) were found on the first and third days, respectively. IL-6 was also the correlated with an anion gap at admission to the ICU (p < 0.009). Conclusions: In conclusion, this study suggests that IL-6 could be a valuable marker for early sepsis follow-up in ICU patients, particularly during the first 72 h of hospitalization, providing important prognostic information in patients with septic shock.

Survival rates with favorable neurological outcomes after in-hospital and out-of-hospital cardiac arrest: A prospective cohort study

OBJECTIVES

To evaluate the survival rates with favorable neurological outcomes among patients who experienced in-hospital cardiac arrest (IHCA) and out-of-hospital cardiac arrest (OHCA).

DESIGN

This prospective cohort study assessed 554 adult patients with IHCA or OHCA referred to Hamad General Hospital, Qatar, between February 2015 and November 2021. Neurologic outcomes were measured using the Cerebral Performance Category (CPC) score. Survival rate and neurologic status were re-evaluated at 28 days, hospital discharge, and one year after cardiac arrest (CA).

FINDINGS

For all participants, the hospital discharge and one-year survival rates with a favorable neurological outcome (CPC ≤ 2) were 18.5 % and 19.5 %, respectively. Specifically, among patients with IHCA, the rates were 20.5 % and 19 %, while in patients with OHCA, the rates were 16.4 % and 19.9 %, respectively. Multivariate regression analysis indicated that factors male sex (OR: 2.129, 95 % CI: 1.168-3.881, P = 0.014), initial shockable rhythm (OR: 1.691, 95 % CI: 1.024-2.788, P = 0.041), and the use of ECPR (OR: 1.944, 95 % CI: 1.178-3.209, P = 0.009) were associated with increased likelihood of survival with favorable neurological outcomes at 28 days. Conversely, older age, presence of comorbidities, infection, higher APACHE II score, longer hospital stays, and undergoing tracheostomy were linked to decreased chances of survival with favorable neurological outcomes at different time points.

CONCLUSION

Survival with good neurological outcomes after OHCA was 20.3 %, 16.4 %, and 19.9 % at 28 days, hospital discharge, and one year, respectively. Among patients with IHCA, survival with good neurological outcomes was 20.5 %, 20.5 %, and 19 % at 28 days, hospital discharge, and one year, respectively.

IMPLICATIONS FOR CLINICAL PRACTICE

Care of CA patients in a cardiac arrest center is associated with improved long-term survival with favorable neurological outcomes. Prioritizing early intervention for shockable rhythms and utilizing ECPR where appropriate could enhance patient prognosis.

Assessing the Role of Blood Gas Analysis in COVID-19 Patients for Early Warning and Clinical Guidance

OBJECTIVE

To assess the role of blood gas analysis as an auxiliary tool for detecting and predicting the progression of COVID-19 in patients.

RESEARCH METHODOLOGY/DESIGN

A consecutive cohort study was conducted of 106 patients diagnosed with the novel coronavirus. Patients were divided into two groups based on age and the course of the disease (mild to moderate and severe). Blood gas analysis parameters were measured for all participants and results were compared between groups.

SETTING

This study was conducted in the Department of Laboratory Medicine, The Third Affiliated Hospital, Southern Medical University, Guangzhou, China.

MAIN OUTCOME MEASURES

Arterial/alveolar oxygen partial pressure ratio, reduced hemoglobin fraction, sodium ion, lactic acid, oxygen saturation, oxygen partial pressure, and oxyhemoglobin fraction.

RESULTS

Findings indicated statistically significant differences between the two groups in the measured parameters.

CONCLUSION

Blood gas analysis has the potential to more accurately assess the progression of COVID-19 in elderly patients, specifically related to respiratory and acid-base balance issues.

IMPLICATIONS FOR CLINICAL PRACTICE

This study underscores the importance for bedside nurses to pay close attention to acid-base balance, lung ventilation/ventilation function, and hypoxia status in elderly critically ill patients with COVID-19, in order to more effectively diagnose and predict the progression of the disease.

Challenges of implementing the hour-1 sepsis bundle: a qualitative study from a secondary hospital in Indonesia

BACKGROUND

Good sepsis management is key to successful sepsis therapy and optimal patient outcomes. Objectives: This study aimed to determine obstacles among nurses and doctors to implementing the hour-1 sepsis bundle in a secondary hospital in Indonesia.

METHODS

This was a qualitative study with a phenomenological approach. Data were obtained from one-on-one in-depth interviews with 13 doctors and nurses in the intensive care unit and emergency department who were purposively sampled. Data were analyzed using content analysis.

RESULTS

Five main themes were revealed in the analysis: incomplete implementation of the hour-1 sepsis bundle, lack of knowledge about the hour-1 sepsis bundle, cost issues, lack of supporting facilities, and lack of coordination among health workers.

CONCLUSIONS

Optimizing regional health laboratories, optimizing the use of quick Sequential Organ Failure Assessment (qSOFA) and SOFA, and creating a series of sepsis protocols within the hospital are some solutions that secondary hospitals can implement to ensure appropriate management of sepsis cases. Involvement of health policyholders and hospital management is needed to address these challenges.

Molecular biomarkers of blunt cardiac injury: recent advances and future perspectives

INTRODUCTION

Blunt cardiac injury (BCI), associated with high morbidity and mortality, involves multiple injuries. With no widely accepted gold standard diagnostic test and molecular biomarkers still in debate and far from application in clinical practice, exploring specific molecular biomarkers of BCI is of great significance. The clarification of molecular biomarkers can improve the diagnosis of BCI, leading to more precise care for victims in various situations.

AREAS COVERED

Using the search term 'Biomarker AND Blunt cardiac injury,' we carefully reviewed related papers from June 2004 to June 2024 in PubMed and CNKI. After reviewing, we included 20 papers, summarizing the biomarkers reported in previous studies, and then reviewed molecular biomarkers such as troponins, Nterminal proBtype natriuretic peptide (NT proBNP), hearttype fatty acid binding protein (hFABP), and lactate for BCI diagnosis. Finally, valuable views on future research directions for diagnostic biomarkers of BCI were presented.

EXPERT OPINION

Several advanced technologies have been introduced into clinical medicine, which have ultimately changed the research on cardiac diseases in recent years. Some biomarkers have been identified and utilized for BCI diagnosis. Herein, we summarize the latest relevant information as a reference for clinical practice and future studies.

Lactate Contributes to Remote Ischemic Preconditioning-Mediated Protection Against Myocardial Ischemia Reperfusion Injury by Facilitating Autophagy via the AMP-Activated Protein Kinase-Mammalian Target of Rapamycin-Transcription Factor EB-Connexin 43 Axis

Remote ischemic preconditioning (RIPC) exerts a protective role on myocardial ischemia/reperfusion (I/R) injury by the release of various humoral factors. Lactate is a common metabolite in ischemic tissues. Nevertheless, little is known about the role lactate plays in myocardial I/R injury and its underlying mechanism. This investigation revealed that RIPC elevated the level of lactate in blood and myocardium. Furthermore, AZD3965, a selective monocarboxylate transporter 1 inhibitor, and 2-deoxy-d-glucose, a glycolysis inhibitor, mitigated the effects of RIPC-induced elevated lactate in the myocardium and prevented RIPC against myocardial I/R injury. In an in vitro hypoxia/reoxygenation model, lactate markedly mitigated hypoxia/reoxygenation-induced cell damage in H9c2 cells. Further studies suggested that lactate contributed to RIPC, rescuing I/R-induced autophagy deficiency by promoting transcription factor EB (TFEB) translocation to the nucleus through activating the AMP-activated protein kinase (AMPK)-mammalian target of rapamycin (mTOR) pathway without influencing the phosphatidylinositol 3-kinase-Akt pathway, thus reducing cardiomyocyte damage. Interestingly, lactate up-regulated the mRNA and protein expression of connexin 43 (CX43) by facilitating the binding of TFEB to CX43 promoter in the myocardium. Functionally, silencing of TFEB attenuated the protective effect of lactate on cell damage, which was reversed by overexpression of CX43. Further mechanistic studies suggested that lactate facilitated CX43-regulated autophagy via the AMPK-mTOR-TFEB signaling pathway. Collectively, this research demonstrates that RIPC protects against myocardial I/R injury through lactate-mediated myocardial autophagy via the AMPK-mTOR-TFEB-CX43 axis.

Acute Alcohol Intoxication-Related Metabolic and Biochemical Disturbances in Adolescents: A Matched Case-Control Study

We aimed to investigate clinical and laboratory characteristics of acute alcohol intoxication (AAI) in adolescents who presented to the pediatric emergency department (ED) at a tertiary referral center from 2006 to 2019. All consecutive adolescents with AAI (n = 335) and their sex- and age-matched control subjects (n = 335) with undetectable ethanol levels were included in this case-matched study. Mean serum ethanol level was 156.4 ± 58.4 (range: 50.8-341.2) mg/dL in the acute alcohol intoxication (AAI) group. Glasgow coma scores were lower in AAI group (14 [14-15] vs 15 [15-15], P < .001). Acidosis (16.3%), hyperlactatemia (60.9%), hypoglycemia (1.7%), hypernatremia (2.2%), hypokalemia (12.3%), hyperchloremia (20.4%), hypocalcemia (13.9%), hypermagnesemia (9.7%), and hyperalbuminemia (10.4%) were significantly more common in the AAI group than the control group. Blood pH, lactate, Na+, K+, Ca++, Mg++, albumin, blood urea nitrogen (BUN), and uric acid levels were correlated with serum ethanol levels. This study shows that AAI frequently leads to mild to moderate metabolic/biochemical derangements in adolescents.

Intraoperative haemodynamic monitoring and management of adults having non-cardiac surgery: Guidelines of the German Society of Anaesthesiology and Intensive Care Medicine in collaboration with the German Association of the Scientific Medical Societies

Haemodynamic monitoring and management are cornerstones of perioperative care. The goal of haemodynamic management is to maintain organ function by ensuring adequate perfusion pressure, blood flow, and oxygen delivery. We here present guidelines on "Intraoperative haemodynamic monitoring and management of adults having non-cardiac surgery" that were prepared by 18 experts on behalf of the German Society of Anaesthesiology and Intensive Care Medicine (Deutsche Gesellschaft für Anästhesiologie und lntensivmedizin; DGAI).

Discovery of Hypoxanthine and Inosine as Robust Biomarkers for Predicting the Preanalytical Quality of Human Plasma and Serum for Metabolomics

In cold human blood, the anomalous dynamics of adenosine triphosphate (ATP) result in the progressive accumulation of adenosine diphosphate (ADP), adenosine monophosphate (AMP), inosine monophosphate (IMP), inosine, and hypoxanthine. While the ATP, ADP, AMP, and IMP are confined to red blood cells (RBCs), inosine and hypoxanthine are excreted into plasma/serum. The plasma/serum levels of inosine and hypoxanthine depend on the temperature of blood and the plasma/serum contact time with the RBCs, and hence they represent robust biomarkers for evaluating the preanalytical quality of plasma/serum. These biomarkers are highly specific since they are generally absent or at very low levels in fresh plasma/serum and are highly sensitive since they are derived from ATP, one of the most abundant metabolites in blood. Further, whether blood was kept at room temperature or on ice could be predicted based on inosine levels. An analysis of >2000 plasma/serum samples processed for metabolomics-centric analyses showed alarmingly high levels of inosine and hypoxanthine. The results highlight the gravity of sample quality challenges with high risk of grossly inaccurate measurements and incorrect study outcomes. The discovery of these robust biomarkers provides new ways to address the longstanding and underappreciated preanalytical sample quality challenges in the blood metabolomics field.

Lactate/Pyruvate Ratio as an Early Predictor of Mortality in Patients with Sepsis: A Cohort Study

Background: The lactate/pyruvate (LP) ratio has been studied as an alternative to serum lactate to determine clinical prognosis. Despite its clinical utility, there is a paucity of evidence evaluating the role of the L/P ratio in patients with sepsis. Methods: We assessed the clinical utility of the L/P ratio in patients with sepsis. The L/P ratio was measured at baseline, 4 and 8 h after admission. Our primary outcome was to determine the prognostic utility of the L/P ratio on the 15-day mortality risk. Our secondary outcomes were to compare the L/P ratio across time and its prognostic utility against standard risk calculators such as APACHE-II and SOFA scores. Results: We had a total of 80 patients, with 18 (22.5%) survivors and 62 (77.5%) non-survivors. While we found that patients having higher L/P ratios at 8 h had an increased 30-mortality risk (OR 1.08, 95% CI 1.02-1.18), the model's performance showed no difference when compared to other measurements of the L/P ratio that showed no association with mortality (p-value: 0.45). For our secondary outcome, we found that the APACHE-II and SOFA scores have better performance and predictability than the L/P ratio (AUC 0.83 and AUC 0.80, respectively), but showed no association with mortality (OR 1.07, 95% CI 1.01-1.17 and OR 1.08, 95% CI 1.02-1.18). Conclusions: Based on our findings, the L/P ratio appears to function more effectively as an early predictor of mortality when used as an adjuvant biomarker with other clinical parameters.

Lactate's impact on immune cells in sepsis: unraveling the complex interplay

Lactate significantly impacts immune cell function in sepsis and septic shock, transcending its traditional view as just a metabolic byproduct. This review summarizes the role of lactate as a biomarker and its influence on immune cell dynamics, emphasizing its critical role in modulating immune responses during sepsis. Mechanistically, key lactate transporters like MCT1, MCT4, and the receptor GPR81 are crucial in mediating these effects. HIF-1α also plays a significant role in lactate-driven immune modulation. Additionally, lactate affects immune cell function through post-translational modifications such as lactylation, acetylation, and phosphorylation, which alter enzyme activities and protein functions. These interactions between lactate and immune cells are central to understanding sepsis-associated immune dysregulation, offering insights that can guide future research and improve therapeutic strategies to enhance patient outcomes.

Sulfated Bile Acids in Serum as Potential Biomarkers of Disease Severity and Mortality in COVID-19

The fight against coronavirus disease 2019 (COVID-19) continues. Since the pandemic's onset, several biomarkers have been proposed to assess the diagnosis and prognosis of this disease. This research aimed to identify potential disease severity biomarkers in serum samples of patients with COVID-19 during the disease course. Data were collected using untargeted and targeted mass spectrometry methods. The results were interpreted by performing univariate and multivariate analyses. Important metabolite classes were identified by qualitative untargeted metabolomics in 15 serum samples from survivors of COVID-19. Quantitative targeted metabolomics on a larger patient cohort including 15 non-survivors confirmed serum 3-sulfate bile acids (i.e. GLCA-3S) were significantly increased in non-survivors compared to survivors during the early disease stage (p-value < 0.0001). Notably, it was associated with a higher risk of mortality (odds ratio of 26). A principal component analysis showed the ability to discriminate between survivors and non-survivors using the BA concentrations. Furthermore, increased BA-S is highly correlated with known parameters altered in severe clinical conditions.

Relationship between lactate and thiamine-responsive disorders in hospitalised infants and children in Lao PDR: secondary analysis of a prospective cohort study

BACKGROUND

Lactate is a by-product of thiamine-deficient cellular metabolism, and hyperlactataemia can indicate severe illness. However, little is known about the clinical significance of hyperlactataemia in thiamine deficiency disorders.

AIM

To describe the relationship between whole-blood lactate level and thiamine-responsive disorders (TRDs) in children with signs/symptoms of thiamine deficiency in a high-risk region.

METHODS

This is a secondary analysis of data from the Lao Thiamine study, a prospective cohort study which enrolled hospitalised infants and children (aged 21 days to <18 months) who had at least one sign or symptom suggestive of thiamine deficiency in Lao PDR. Therapeutic thiamine was administered, and clinical evaluations were completed at several time-points over the next 72 h. Three paediatricians reviewed individual case reports to evaluate clinical response to thiamine and assigned TRD status. Data from 402 children were analysed by logistic regression and predictive modelling to examine the relationship between hyperlactataemia and TRDs.

RESULTS

Baseline hyperlactataemia (lactate >4.0 mmol/L) was associated with an increased odds of clinical improvement after thiamine administration [OR (95% CI) 2.32 (1.28-4.45), p = 0.007]. Baseline hyperlactataemia was a significant predictor of thiamine deficiency (thiamine diphosphate <40 nmol/L) [area under the receiver operating curve (95% CI) 0.76 (0.67-0.84), p < 0.001], and increased odds of mortality [OR (95% CI) 3.51 (1.38-8.94), p = 0.009].

CONCLUSIONS

In children with signs/symptoms of thiamine deficiency, hyperlactataemia is associated with a favourable clinical response to thiamine, biochemical thiamine deficiency, and increased odds of mortality. Lactate may be useful in identifying children who might benefit from therapeutic thiamine.

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.

Mitochondrial Biomarkers and Metabolic Syndrome in Bipolar Disorder

The object of this study is test whether mitochondrial blood-based biomarkers are associated with markers of metabolic syndrome in bipolar disorder, hypothesizing higher lactate but unchanged cell-free circulating mitochondrial DNA levels in bipolar disorder patients with metabolic syndrome. In a cohort study, primary testing from the FondaMental Advanced Centers of Expertise for bipolar disorder (FACE-BD) was conducted, including 837 stable bipolar disorder patients. The I-GIVE validation cohort consists of 237 participants: stable and acute bipolar patients, non-psychiatric controls, and acute schizophrenia patients. Multivariable regression analyses show significant lactate association with triglycerides, fasting glucose and systolic and diastolic blood pressure. Significantly higher levels of lactate were associated with presence of metabolic syndrome after adjusting for potential confounding factors. Mitochondrial-targeted metabolomics identified distinct metabolite profiles in patients with lactate presence and metabolic syndrome, differing from those without lactate changes but with metabolic syndrome. Circulating cell-free mitochondrial DNA was not associated with metabolic syndrome. This thorough analysis mitochondrial biomarkers indicate the associations with lactate and metabolic syndrome, while showing the mitochondrial metabolites can further stratify metabolic profiles in patients with BD. This study is relevant to improve the identification and stratification of bipolar patients with metabolic syndrome and provide potential personalized-therapeutic opportunities.

Lactate Monitoring in Intensive Care: A Comprehensive Review of Its Utility and Interpretation

Lactate monitoring is critical in managing critically ill patients in intensive care settings. Elevated lactate levels often signify underlying metabolic disturbances such as tissue hypoxia, anaerobic metabolism, or impaired lactate clearance, which are prevalent in conditions like sepsis, shock, and trauma. Understanding the physiological basis of lactate production and its significance in clinical practice is essential for interpreting its diagnostic and prognostic value. This comprehensive review aims to explore the utility of lactate monitoring across various critical care scenarios. It provides an overview of lactate's metabolic pathways, methods of measurement, and the clinical implications of interpreting lactate levels in different contexts. Additionally, the review discusses current evidence on lactate-guided therapeutic interventions and highlights challenges and limitations to their application. By synthesizing the existing literature and clinical insights, this review aims to enhance the understanding of the role of lactate monitoring in assessing disease severity, guiding treatment strategies, and predicting outcomes in critically ill patients. Ultimately, this review underscores the importance of integrating lactate monitoring into routine clinical practice to optimize patient care and improve clinical outcomes in intensive care settings.

Lactate to albumin ratio as a prognosis predictor in gastrointestinal bleeding in the emergency department

Gastrointestinal bleeding (GIB) is a common cause of emergency department (ED) visits, and has various prognoses. This study aimed to verify the prognostic ability of the lactate/albumin (L/A) ratio in patients with GIB compared with the AIMS65 score and blood urea nitrogen/albumin (B/A) ratio. This retrospective study included patients with GIB symptoms who visited the ED in 2019. Baseline characteristics and laboratory data were obtained to calculate the L/A and B/A ratios and AIMS65 score. Each score was evaluated as a predictor of intensive care unit (ICU) admission and in-hospital mortality by using the area under the receiver operating characteristic (AUROC) curve. The multivariate logistic regression analysis revealed that the L/A ratio significantly predicted ICU admission and in-hospital mortality. The AUROC curve for predicting ICU admission were 0.788, 0.695, and 0.586 for the L/A, B/A, and AIMS65 scores, respectively, while the AUROC curve for predicting in-hospital mortality were 0.807, 0.799, and 0.683 for the L/A, B/A, and AIMS65 scores, respectively. The L/A ratio, which consists of the serum lactate and albumin levels, showed superior performance relative to the B/A ratio and AIMS65 score in predicting the prognosis of patients with GIB.

Clinical characteristics of extracorporeal cardiopulmonary resuscitation in China: a multicenter retrospective study

PURPOSE

Extracorporeal cardiopulmonary resuscitation (ECPR) might markedly increase the survival of selected patients with refractory cardiac arrest. But the application situation and indications remained unclear.

MATERIALS AND METHODS

We respectively reviwed all adult patients who underwent ECPR from January 2017 to March 2021. Patient characteristics, initiation and management of ECMO, complications, and outcomes were collected and compared between the survivors and nonsurvivors. LASSO regression was used to screen risk factors. Multivariate logistic regression was performed with several parameters screened by LASSO regression.

RESULTS

Data were reported from 42 ECMO centers covering 19 provinces of China. A total of 648 patients were included in the study, including 491 (75.8%) males. There were 11 ECPR centers in 2017, and the number increased to 42 in 2020. The number of patients received ECPR increased from 33 in 2017 to 274 in 2020, and the survival rate increased from 24.2% to 33.6%. Neurological complications, renal replacement therapy, epinephrine dosage after ECMO, recovery of spontaneous circulation before ECMO, lactate clearance and shockable rhythm were risk factors independently associated with outcomes of whole process. Sex, recovery of spontaneous circulation before ECMO, lactate, shockable rhythm and causes of arrest were pre-ECMO risk factors independently affecting outcomes.

CONCLUSIONS

From January 2017 to March 2021, the numbers of ECPR centers and cases in mainland China increased gradually over time, as well as the survival rate. Pre-ECMO risk factors, especially recovery of spontaneous circulation before ECMO, shockable rhythm and lactate, are as important as post-ECMO management,. Neurological complications are vital risk factors after ECMO that deserved close attention.

TRIAL REGISTRATION

NCT04158479, registered on 2019/11/08. https://clinicaltrials.gov/NCT04158479.

Elevated lactate/albumin ratio is associated with poor prognosis in sepsis patients: A systematic review and meta-analysis

Background

The aim of this study was to explore the association between lactate/albumin ratio and the prognosis of sepsis patients.

Methods

A computerized search was performed in Pubmed, EMbase, Ovid, Medline, and Google Scholar to collate relevant studies. The results were compared using standardized mean differences (SMD)/odds ratio (OR) and 95% confidence intervals (CI). Prospective and retrospective cohort studies were both included in this study.

Emerging Multi-omic Approaches to the Molecular Diagnosis of Mitochondrial Disease and Available Strategies for Treatment and Prevention

Mitochondria are semi-autonomous organelles present in several copies within most cells in the human body that are controlled by the precise collaboration of mitochondrial DNA (mtDNA) and nuclear DNA (nDNA) encoding mitochondrial proteins. They play important roles in numerous metabolic pathways, such as the synthesis of adenosine triphosphate (ATP), the predominant energy substrate of the cell generated through oxidative phosphorylation (OXPHOS), intracellular calcium homeostasis, metabolite biosynthesis, aging, cell cycles, and so forth. Previous studies revealed that dysfunction of these multi-functional organelles, which may arise due to mutations in either the nuclear or mitochondrial genome, leads to a diverse group of clinically and genetically heterogeneous disorders. These diseases include neurodegenerative and metabolic disorders as well as cardiac and skeletal myopathies in both adults and newborns. The plethora of phenotypes and defects displayed leads to challenges in the diagnosis and treatment of mitochondrial diseases. In this regard, the related literature proposed several diagnostic options, such as high throughput mitochondrial genomics and omics technologies, as well as numerous therapeutic options, such as pharmacological approaches, manipulating the mitochondrial genome, increasing the mitochondria content of the affected cells, and recently mitochondrial diseases transmission prevention. Therefore, the present article attempted to review the latest advances and challenges in diagnostic and therapeutic options for mitochondrial diseases.

From Bronchodilation to Lactic Acidosis: A Case Report on Salbutamol's Adverse Effect

Asthma is one of the most prevalent chronic respiratory diseases, characterized by bronchial hyper-responsiveness and intermittent airflow obstruction. Short-acting β2 agonists (SABA) remain the cornerstone of acute asthma management due to its properties in smooth muscle relaxation and bronchodilatation. Rarely, these drugs might be associated with adverse effects, including the development of metabolic and hydro-electrolytic imbalances. We report a case of lactic acidosis secondary to β2 agonists in a young female patient admitted with severe acute asthma. After initial management and significant improvement of the respiratory distress with nebulized and subcutaneous salbutamol, the patient developed high anion gap metabolic acidosis due to hyperlactacidemia and hypokalemia. Alternative causes of lactic acidosis were discarded, such as severe hypoxemia, systemic hypoperfusion, sepsis, and organ dysfunction, and SABA-related lactic acidosis was suspected. This treatment was halted, and tachypnea, metabolic acidosis, and lactate levels rapidly resolved. The remainder of the hospital stay was uneventful, and the patient was discharged after a period of five days. Although rare, the development of unexplained lactic acidosis in a SABA-treated patient should alert the treating physician to this β2 agonist side-effect.

Forecasting acute kidney injury and resource utilization in ICU patients using longitudinal, multimodal models

BACKGROUND

Advances in artificial intelligence (AI) have realized the potential of revolutionizing healthcare, such as predicting disease progression via longitudinal inspection of Electronic Health Records (EHRs) and lab tests from patients admitted to Intensive Care Units (ICU). Although substantial literature exists addressing broad subjects, including the prediction of mortality, length-of-stay, and readmission, studies focusing on forecasting Acute Kidney Injury (AKI), specifically dialysis anticipation like Continuous Renal Replacement Therapy (CRRT) are scarce. The technicality of how to implement AI remains elusive.

OBJECTIVE

This study aims to elucidate the important factors and methods that are required to develop effective predictive models of AKI and CRRT for patients admitted to ICU, using EHRs in the Medical Information Mart for Intensive Care (MIMIC) database.

METHODS

We conducted a comprehensive comparative analysis of established predictive models, considering both time-series measurements and clinical notes from MIMIC-IV databases. Subsequently, we proposed a novel multi-modal model which integrates embeddings of top-performing unimodal models, including Long Short-Term Memory (LSTM) and BioMedBERT, and leverages both unstructured clinical notes and structured time series measurements derived from EHRs to enable the early prediction of AKI and CRRT.

RESULTS

Our multimodal model achieved a lead time of at least 12 h ahead of clinical manifestation, with an Area Under the Receiver Operating Characteristic Curve (AUROC) of 0.888 for AKI and 0.997 for CRRT, as well as an Area Under the Precision Recall Curve (AUPRC) of 0.727 for AKI and 0.840 for CRRT, respectively, which significantly outperformed the baseline models. Additionally, we performed a SHapley Additive exPlanation (SHAP) analysis using the expected gradients algorithm, which highlighted important, previously underappreciated predictive features for AKI and CRRT.

CONCLUSION

Our study revealed the importance and the technicality of applying longitudinal, multimodal modeling to improve early prediction of AKI and CRRT, offering insights for timely interventions. The performance and interpretability of our model indicate its potential for further assessment towards clinical applications, to ultimately optimize AKI management and enhance patient outcomes.

A Case Report of Refractory Hyperlactatemia Secondary to Thiamine Deficiency

Thiamine is an essential water-soluble vitamin that must be obtained through diet. This vitamin is crucial for various biochemical reactions and is vital for aerobic metabolism. When individuals are deficient in thiamine, which can be due to hypermetabolism (such as in inflammation, ischemia, or malnutrition, among other reasons), anaerobic metabolism may be utilized to maintain energy needs. Such chemical processes produce lactic acid. Excess lactic acid can cause various clinical signs and symptoms, though lactate dehydrogenase (LDH) can typically break down this compound. The following case presents a very unusual instance where a 51-year-old Caucasian woman presented with the chief complaint of ongoing and severe abdominal pain. After an extensive work-up ruling out numerous diagnoses and an eight-day hospital stay, it was believed that she may be suffering from hyperlactatemia secondary to thiamine deficiency, as she improved significantly after administration of this vitamin. It was thought that this was likely due to her previous systemic lupus erythematosus (SLE) diagnosis, vasculitis, chronic inflammation, and a hypermetabolic state, in addition to concurrent LDH malfunction.

Unmasking the Rarity: A Case Report on Type B Lactic Acidosis in Pediatric Acute Lymphoblastic Leukemia

Acute lymphoblastic leukemia (ALL) is the most prevalent pediatric malignancy, accounting for approximately 25% of childhood cancers. Despite significant advancements in treatment protocols, ALL remains a complex disease, often presenting with various complications, including the rare metabolic disturbance of type B lactic acidosis. This case report details the clinical journey of a 14-year-old female with ALL who developed type B lactic acidosis during treatment. The patient presented with intermittent fever, abdominal pain, jaundice, and hepatosplenomegaly, accompanied by severe anemia and thrombocytopenia. Initial management included supportive care and chemotherapy initiation. Despite aggressive interventions, the patient's condition deteriorated, with escalating lactic acidosis and respiratory distress, leading to a critical need for tailored management strategies. This report underscores the importance of early recognition and comprehensive management of type B lactic acidosis in pediatric ALL, highlighting its multifactorial etiology and potentially life-threatening consequences. Enhanced clinical awareness and a multidisciplinary approach are crucial for improving outcomes in such complex cases.

Cardiogenic shock as a health issue. Physiology, classification, and detection

Cardiogenic shock (CS) is a heterogeneous syndrome with high mortality and a growing incidence. It is characterized by an imbalance between the tissue oxygen demands and the capacity of the cardiovascular system to meet these demands, due to acute cardiac dysfunction. Historically, acute coronary syndromes have been the primary cause of CS. However, non-ischemic cases have seen a rise in incidence. The pathophysiology involves ischemic damage of the myocardium and a sympathetic, renin-angiotensin-aldosterone system and inflammatory response, perpetuating the situation of tissue hypoperfusion and ultimately leading to multiorgan dysfunction. The characterization of CS patients through a triaxial assessment and the widespread use of the Society for Cardiovascular Angiography and Interventions (SCAI) scale has allowed standardization of the severity stratification of CS; this, coupled with early detection and the "hub and spoke" approach, could contribute to improving the prognosis of these patients.

The lactate-to-albumin ratio relationship with all-cause mortality in cerebral infarction patients: analysis from the MIMIC-IV database

Objective

To examine the association of lactate-to-albumin ratio (LAR) with 30-day and 90-day mortality in patients with cerebral infarction admitted to the intensive care unit (ICU).

Methods

In this retrospective observational study, 1,089 patients with cerebral infarction were recruited. The concentration of blood lactate and serum albumin on the first day of ICU admission were recorded. The relationship between LAR levels and mortality was evaluated through univariate and multivariate Cox regression analyses, four-knot multivariate restricted cubic spline regression, and Kaplan-Meier (KM) curves.

Results

The overall 30-day and 90-day mortality rates in the entire cohort were 27.3 and 35.8%, respectively. KM analysis revealed a significant relationship between high LAR index and the risk of all-cause mortality (log-rank p < 0.001). Furthermore, multivariate Cox proportional risk analysis showed that the LAR index independently predicted the risk of 30-day mortality (HR: 1.38, 95% CI 1.15-1.64, p = 0.004) and 90-day mortality (HR: 1.53, 95% CI 1.32-1.77, p < 0.001) in the study population. Furthermore, a higher LAR exceeding 0.53 was positively correlated with the risk of 30-day and 90-day mortalities. Subsequent subgroup analyses demonstrated that LAR could predict the primary outcome.

Conclusion

In summary, the LAR index is a reliable and independent predictor of increased mortality among critically ill patients suffering from cerebral infarction. Nonetheless, there is a need for additional comprehensive prospective studies to validate these findings.

Vitamin B1 Deficiency Identified from Incidental Detection of Hyperlactatemia: A Case Report

Introduction: Vitamin B1 deficiency poses a significant risk of impaired consciousness, with manifestations ranging from anorexia and fatigue to severe neurological and cardiovascular disturbances. Wernicke's encephalopathy, a neurological disorder stemming from vitamin B1 deficiency, presents as the triad of ophthalmoplegia, altered mental state, and cerebellar ataxia. However, these symptoms are not consistently present, complicating the diagnosis. In addition, subclinical vitamin B1 deficiency can progress unnoticed until severe complications arise. Studies indicate a high rate of undiagnosed cases, emphasizing the need for early detection and intervention. Case presentation: We present the case of a 65-year-old man in whom hyperlactatemia was incidentally detected, leading to the diagnosis of vitamin B1 deficiency. The patient, presenting with vertigo and vomiting, had been eating boxed lunches bought from convenience stores following the death of his wife 3 years earlier. Vertigo gradually improved with rest, but the persistence of hyperlactatemia prompted further investigation, revealing low vitamin B1 levels and high pyruvate levels. Treatment with dietary adjustments and supplements significantly improved his symptoms. Discussion: In this case, hyperlactatemia was found in a vertigo patient, revealing asymptomatic vitamin B1 deficiency. Elevated lactate is often linked with conditions like sepsis but can also stem from overlooked factors such as low vitamin B1 levels due to poor diet habits like consuming fried foods. Conclusion: This case highlights the importance of considering vitamin B1 deficiency in patients with unexplained hyperlactatemia, even in high-income countries. Early detection can prevent progression to the severe complications associated with Wernicke's encephalopathy. Proactive measurement of lactate levels in at-risk populations may facilitate early diagnosis and intervention, ultimately improving patient outcomes.

Comparison of bicarbonate Ringer's solution with lactated Ringer's solution among postoperative outcomes in patients with laparoscopic right hemihepatectomy: a single-centre randomised controlled trial

The study was aimed to investigate the positive impact of bicarbonate Ringer's solution on postoperative outcomes in patients who underwent laparoscopic right hemihepatectomy. Patients in the two groups were infused with lactated Ringer's solution (LRS, n = 38) and the bicarbonate Ringer's solution (BRS, n = 38) at a rate of 5 ml·kg-1·h-1. The stroke volume was monitored and 200 ml of hydroxyethyl starch with 130/0.4 sodium chloride injection (Hes) of a bolus was given in the first 5-10 min. The main outcome was to test lactic acid (LAC) concentration before and after surgery. The concentrations of LAC in the LRS group were higher than in the BRS group at 2 h after operation began, at the end of the operation and 2 h after the operation. Overall, the parameters including pH, base excess (BE), HCO3-, aspartate transaminase (AST) and alanine transaminase (ALT) were improved. The values of bilirubin in the LRS group were higher and albumin were lower than in the BRS group at post-operation 1st and 2nd day (P<0.05). The time of prothrombin time (PT) and activated partial thromboplastin time (APTT) in the LRS group were longer than that in the BRS group at post-operation 1st and 2nd day (P<0.05). Likewise, the concentrations of Mg2+, Na+ and K+ also varied significantly. The length of hospital was reduced, and the incidence of premature ventricular contractions (P = 0.042) and total complications (P = 0.016) were lower in group BRS. TRIAL REGISTRATION: The study was registered at clinicalTrials.gov with the number ChiCTR2000038077 on 09/09/2020.

Effects of different types of Ringer's solution on patients with traumatic haemorrhagic shock: a prospective cohort study

OBJECTIVE

To compare the fluid resuscitation effect of sodium acetate Ringer's solution and sodium bicarbonate Ringer's solution on patients with traumatic haemorrhagic shock.

METHOD

We conducted a prospective cohort study in our emergency department on a total of 71 patients with traumatic haemorrhagic shock admitted between 1 December 2020 and 28 February 2022. Based on the time of admission, patients were randomly divided into a sodium bicarbonate Ringer's solution group and sodium acetate Ringer's solution group, and a limited rehydration resuscitation strategy was adopted in both groups. General data were collected separately, and the patients' vital signs (body temperature, respiration, blood pressure and mean arterial pressure (MAP)), blood gas indices (pH, calculated bicarbonate (cHCO3-), partial pressure of oxygen (PaO2), partial pressure of carbon dioxide (pCO2) and clearance of lactate (CLac)), shock indices, peripheral platelet counts, prothrombin times and plasma fibrinogen levels were measured and compared before and 1 h after resuscitation.

RESULTS

The post-resuscitation heart rate of the sodium bicarbonate Ringer's solution group was significantly lower than that of the sodium acetate Ringer's solution group (p < 0.05), and the MAP was also significantly lower (p < 0.05). The patients in the sodium bicarbonate Ringer's solution group had significantly higher pH, cHCO3- and PaO2 values and lower pCO2 and CLac values (p < 0.05) than those in the sodium acetate Ringer's solution group, and the post-resuscitation peripheral platelet counts and fibrinogen levels were significantly higher, with shorter plasma prothrombin times and smaller shock indices (p < 0.001).

CONCLUSION

Sodium bicarbonate Ringer's solution is beneficial for maintaining MAP at a low level after resuscitation. The use of sodium bicarbonate Ringer's solution in limited fluid resuscitation has positive results and is of high clinical value.

Lactate combined with SOFA score for improving the predictive efficacy of SOFA score in patients with severe heatstroke

BACKGROUND

The relationship between lactate levels and multiple organ dysfunction in patients with severe heatstroke remains unclear. In this study, we aimed to elucidate the clinical significance of lactate in severe heatstroke prognosis and assess whether incorporating lactate in the SOFA score improves its predictive efficacy.

METHODS

This study was a multicenter retrospective cohort investigation included 275 patients. Logistic regression analysis was performed to examine the relationship between lactate levels and patient outcomes and complications, including acute kidney injury (AKI), disseminated intravascular coagulation (DIC), and myocardial injury. Further, receiver operating characteristic (ROC) curves and clinical decision curve analysis (DCA) were used to evaluate the predictive power of lactate and SOFA scores in severe heatstroke-associated death. Lastly, the Kaplan-Meier survival curve was employed to differentiate the survival rates among the various patient groups.

RESULTS

After adjusting for confounding factors, lactate was demonstrated as an independent risk factor for death (OR = 1.353, 95% CI [1.170, 1.569]), AKI (OR = 1.158, 95% CI [1.007, 1.332]), DIC (OR = 1.426, 95% CI [1.225, 1.659]), and myocardial injury (OR = 2.039, 95% CI [1.553, 2.679]). The area under the curve (AUC) of lactate for predicting death from severe heatstroke was 0.7540, with a cutoff of 3.35. The Kaplan-Meier survival curve analysis showed that patients with elevated lactate levels had higher mortality rates. Additionally, the ROC curves demonstrated that combining lactate with the SOFA score provided better predictive efficacy than the SOFA score alone in patients with severe heatstroke (AUC: 0.9025 vs. 0.8773, DeLong test, P < 0.001). Finally, the DCA curve revealed a higher net clinical benefit rate for lactate combined with the SOFA score.

CONCLUSIONS

Lactate is an independent risk factor for severe heatstroke-related death as well as a risk factor for AKI, DIC, and myocardial injury associated with severe heatstroke. Thus, combining lactate with the SOFA score can significantly improve its predictive efficacy in patients with severe heatstroke.

Outcomes of patients with pneumatosis intestinalis and/or portal venous gas: a study of factors associated with survival and surgical intervention

BACKGROUNDS

This study investigated the incidence of, and mortality and management outcomes following, pneumatosis intestinalis and/or portal venous gas on computed tomography.

METHODS

A retrospective study of patients identified with pneumatosis intestinalis and/or portal venous gas on computed tomography at a quaternary centre (2013-2021) was performed. Data relating to clinical presentation (including quick sequential organ failure assessment score), co-morbidities (Charlson Comorbidity Index), biochemical data (including peak lactate level), and radiological findings, were obtained. Factors associated with these were assessed by logistic regression.

RESULTS

From 16 428 scans, 107 (0.65%) demonstrated pneumatosis intestinalis and/or portal venous gas (mean 65.2 years [SD 15.2]; 60 [56%] male). Overall, 37 patients (35%) had both findings present. Thirty-three deaths (31%) were recorded. Fifty-four patients (51%) underwent surgery. Death was associated with quick sequential organ failure assessment score (score 1: OR 5.71, 95% CI 1.31-24.87; score 2: OR 10.00, 95% CI 1.94-51.54), Charlson Comorbidity Index ≥5 (OR 2.86, 95% CI 1.19-6.84), peak lactate ≥2.6 mmol/L (OR 14.53, 95% CI 4.39-48.14), and concomitant pneumatosis intestinalis and portal venous gas (OR 8.25, 95% CI 3.04-22.38). The presence of free peritoneal fluid (OR 3.23, 95% CI 1.44-7.28) or perforated viscus (OR 5.10, 95% CI 1.05-24.85) were the only predictors for surgery.

CONCLUSION

Pneumatosis intestinalis and portal venous gas are rare findings. Despite traditionally portending a poor prognosis, mortality occurred in only one-third of patients. There were clear indicators of mortality viz. sepsis severity, comorbidities, and concomitant pneumatosis intestinalis and portal venous gas. Factors predicting surgery warrant further investigation.

Usefulness of lactate to albumin ratio for predicting in-hospital mortality in atrial fibrillation patients admitted to the intensive care unit: a retrospective analysis from MIMIC-IV database

BACKGROUND

High lactate to albumin ratio (LAR) has been reported to be associated to with poor prognosis in patients admitted to the intensive care unit (ICU). However, its role in predicting in-hospital mortality in AF patients admitted to ICU has not been explored.

METHODS

The Medical Information Mart for Intensive Care-IV (MIMIC-IV) database was used to retrieve information on patients who had been diagnosed with AF. X-tile software was utilized to determine the optimal cut-off LAR. Area under the receiver operating characteristic curves (AUC), calibration plots, and decision curve analysis (DCA) were conducted to assess the prediction performance of LAR for in-hospital mortality.

RESULTS

Finally, 8,287 AF patients were included and 1,543 death (18.6%) occurred. The optimal cut-off value of LAR is 0.5. Patients in lower LAR (< 0.5) group showed a better in-hospital survival compared to patients in higher LAR (≥ 0.5) group (HR: 2.67, 95%CI:2.39-2.97, P < 0.001). A nomogram for in-hospital mortality in patients with AF was constructed based on multivariate Cox analysis including age, CCI, β blockers usage, APSIII, hemoglobin and LAR. This nomogram exhibited excellent discrimination and calibration abilities in predicting in-hospital mortality for critically ill AF patients.

CONCLUSION

LAR, as a readily available biomarker, can predict in-hospital mortality in AF patients admitted to the ICU. The nomogram that combined LAR with other relevant variables performed exceptionally well in terms of predicting in-hospital mortality.

Effect of early peri-operative arterial lactate concentration level ratios on post-hepatectomy liver failure

BACKGROUND

Post-hepatectomy liver failure (PHLF) is a serious complication after hepatectomy and a major cause of death. The current criteria for PHLF diagnosis (ISGLS consensus) require laboratory data of elevated INR level and hyperbilirubinemia on or after postoperative day 5. This study aims to propose a new indicator for the early clinical prediction of PHLF.

METHODS

The peri-operative arterial lactate concentration level ratios were derived from time points within the 3 days before surgery and within POD1, the patients were divided into two groups: high lactate ratio group (≥ 1) and low lactate ratio group (< 1). We compared the differences in morbidity rates between the two groups. Utilized logistic regression analysis to identify the risk factors associated with PHLF development and ROC curves to compare the predictive value of lactate ratio and other liver function indicators for PHLF.

RESULTS

A total of 203 patients were enrolled in the study. Overall morbidity and severe morbidity occurred in 64.5 and 12.8 per cent of patients respectively. 39 patients (19.2%) met the criteria for PHLF, including 15 patients (7.4%) with clinically relevant Post-hepatectomy liver failure (CR-PHLF). With a significantly higher incidence of PHLF observed in the lactate ratio ≥ 1 group compared to the lactate ratio < 1 group (n = 34, 26.8% vs. n = 5, 6.6%, P < 0.001). Multivariable logistic regression analysis revealed that a lactate ratio ≥ 1 was an independent predictor for PHLF (OR: 3.239, 95% CI 1.097-9.565, P = 0.033). Additionally, lactate ratio demonstrated good predictive efficacy for PHLF (AUC = 0.792).

CONCLUSIONS

Early assessment of peri-operative arterial lactate concentration level ratios may provide experience in early intervention of complications in patients with hepatocellular carcinoma, which can reduce the likelihood of PHLF occurrence and improve patient prognosis.