The effect of liver disease on lactate normalization in severe sepsis and septic shock: a cohort study

Comparing the Prognostic Value of Lactate to the Neutrophil to Lymphocyte Ratio Among Sepsis Patients: A Prospective Cohort Study

Background

Lactate has long been recognized as a key prognostic biomarker in sepsis. Similarly, the prognostic role of the neutrophil-to-lymphocyte ratio (NLR) has been investigated in various conditions, including sepsis. Previous studies have explored the optimal NLR cutoff to differentiate sepsis survivors from nonsurvivors, predict bacteremia, diagnose sepsis, and assess mortality. This study compares the prognostic value of lactate and NLR in septic patients.

Methods

This prospective cohort study included 874 adult septic or septic shock patients presenting to a tertiary care center's Emergency Department between September 2018 and February 2021. The primary outcome was to compare the prognostic value of NLR and lactate regarding in-hospital mortality. Secondary outcomes compared their prognostic value in different septic subgroups.

Results

Stepwise logistic regression showed NLR was not associated with in-hospital mortality (OR=1.003, p=0.544), while lactate was significantly associated with in-hospital mortality (OR=1.188, p<0.0001). There was no significant difference in the AUCs of NLR and lactate (0.552 vs 0.591, p=0.22). Lactate outperformed NLR in patients with albumin <30, those <65 years old, and those with sepsis from a urinary tract infection. No significant differences were found in AUCs between lactate and NLR in patients with septic shock, Lactate<2, Lactate≥2, diabetes, malignancy, chronic kidney diseases, other sources of infection, albumin ≥30 and age ≥ 65.

Conclusion

In this study, lactate but not NLR was associated with in-hospital mortality. There was no significant difference in the AUCs between lactate and NLR among sepsis patients and among most of the subgroups. However, lactate outperformed NLR in the following subgroups: albumin<30 g/L, patients <65 years old and patients with sepsis due to a urinary tract infection. Our results advocate for the continued use of serum lactate rather than NLR, despite its limitations, as a predictor of mortality among septic patients and the different subgroups in this study.

Evaluation of Hypoxia Markers in Critically Ill Patients Categorized by Their Burden of Organ Dysfunction: A Novel Approach to Detect Pathophysiological and Clinical Relevance in a Secondary Analysis of a Prospective Observational Study

In critically ill patients, compromised microcirculation causes tissue hypoxia, organ failure, and death. These pathophysiological processes occur particularly in patients with high illness severity, so reliable hypoxia biomarkers should reflect this in their occurrence. This secondary analysis of a prospective study categorized patients by their burden of organ dysfunction (BOD) using the cohort's median initial sequential organ failure assessment (SOFA) score of 8 as a cutoff. The kinetic parameters of the hypoxia markers lactate and S-adenosylhomocysteine (SAH) were analyzed for correlation with organ dysfunction severity and mortality prediction. In low BOD patients, neither marker correlated with SOFA. In high BOD patients, lactate showed a moderate correlation and SAH showed a strong correlation. Lactate correlated with organ dysfunction in survivors but not in non-survivors, while SAH correlated strongly in non-survivors but not in survivors. In univariate logistic regression, lactate predicted mortality moderately in low BOD (areas under the receiver operating characteristic curves (AUROCs) 0.7-0.8) but poorly in high BOD patients (AUROCs 0.5-0.7). SAH's prediction improved from poor to excellent (AUROCs 0.8-0.9) with higher BOD. Thus, SAH appears superior to lactate in the detection of organ dysfunction severity and mortality prediction in high BOD patients.

The prognostic utility of Lactate/Albumin*Age score in septic patient with normal lactate level

Background

A previous study has shown that the lactate/albumin*age (LAA) score is useful for predicting mortality in patients with sepsis admitted to the ICU. We aimed to evaluate the clinical significance of the LAA score in patients with sepsis who presented to the emergency department (ED).

Methods

This retrospective observational study used data from the Korean Shock Society Registry collected between January 2017 and December 2021. The prognostic performance of the LAA score for predicting the 28-day mortality was evaluated. Lactate and albumin levels were measured immediately after arrival to the ED.

Results

Of the 5346 patients with sepsis, data from 3240 were analyzed. The area under the receiver operating characteristic curve (AUROC) of the LAA score (0.737, 95 % confidence interval (CI) 0.716-0.757), was higher than that of lactate (0.699, 95 % CI 0.677-0.720, p < 0.001), lactate/albumin (LA) ratio (0.730, 95 % CI 0.709-0.751, p = 0.016), and Sequential Organ Failure Assessment (SOFA) score (0.698, 95 % confidence interval 0.676-0.720, p = 0. 004), and Acute Physiology and Chronic Health Evaluation (APACHE) II scores (0.672; 95 % confidence interval 0.649-0.694, p < 0.001). The optimal cut-off value for the LAA score was 119.9. In the Kaplan-Meier analysis according to the optimal cutoff value, the 28-day mortality rates were higher in the high LAA score group (log-rank test, p < 0.001). The LAA score was independently associated with 28-day mortality in the multivariate Cox proportional hazards model (adjusted hazard ratio 2.07, 95 % CI 1.76-2.43, p < 0.001). In the normal (<2 mmol/L) lactate group, the AUROC value for LAA score was higher than LA ratio (normal group 0.674 vs 0.634, p < 0.004). In patients over 65 years old, LAA score (0.731) showed a higher AUROC value than LA ratio (0.725). (p < 0.001).

Conclusion

The LAA score may be used as an independent predictor of mortality in patients with sepsis in the emergency department. Our results show that it performs better than serum lactate alone, LA ratio, and SOFA and APACHE II scores. While this suggests that the LAA could provide clinicians with a useful tool for timely early intervention and care planning in patients with a poor prognosis, further validation in large multicenter prospective studies are necessary to confirm its reliability and practicality as a readily available and objective biomarker.

The Correlation Between the Lactate/Albumin Ratio and Sequential Organ Failure Assessment (SOFA) Score in Patients With Sepsis and Septic Shock

Background Sepsis is defined as a life-threatening organ dysfunction caused by a dysregulated host response to infection, often resulting in severe outcomes such as septic shock and death. Globally, sepsis ranks among the most common causes of illness and death. The Sequential Organ Failure Assessment (SOFA) score is an established marker used to assess and predict the extent of organ failure in septic patients. The introduction of novel markers, such as the lactate/albumin (L/A) ratio, serves as a prognostic indicator in critical care settings, particularly for patients with sepsis. In this context, a higher L/A ratio upon admission aids in assessing disease severity and improving clinical decision-making to reduce mortality and adverse outcomes, which we aim to correlate through our study. Materials and methods This was an observational cross-sectional analysis conducted on 100 patients aged over 18 years who met the "Sepsis-3" guidelines and were admitted to the medical intensive care unit of Dr. D. Y. Patil Hospital, Pune, Maharashtra, India, between October 2022 and May 2024. Patients with chronic liver disease classified as Child-Pugh class C were excluded, as were those with chronic kidney disease (CKD). Written informed consent was obtained from each participant before the study. Data were collected through physical examination, routine laboratory investigations, and radiological assessments. Statistical analysis was performed using IBM SPSS version 20 (IBM Corp., Armonk, NY). Descriptive statistical analyses were conducted using the SPSS data editor. Statistical significance was considered at a p-value of less than 0.05 for all analyses. Results In the study population, 78 patients survived, while 22 patients died. The L/A ratio and SOFA score were significantly higher in non-survivors compared to survivors, both upon admission and thereafter, with statistical significance (p < 0.05). The correlation between the L/A ratio and the SOFA score was examined upon admission at 24 hours, 48 hours, day 7, and day 28. Pearson correlation analysis revealed statistically significant results (p < 0.05) throughout the entire study period. Conclusion A high L/A ratio, along with the SOFA score at ICU admission, was associated with a grave prognosis and poor outcomes, serving as independent risk factors for ICU admission. Therefore, patients with a high L/A ratio and SOFA score should be identified early and managed aggressively to avoid poor outcomes. Our study demonstrates that combining serum lactate and serum albumin levels into the L/A ratio significantly enhances prognostic accuracy compared to using serum lactate alone.

Mortality Prediction by Kinetic Parameters of Lactate and S-Adenosylhomocysteine in a Cohort of Critically Ill Patients

Tissue hypoxia is associated with the development of organ dysfunction and death in critically ill patients commonly captured using blood lactate. The kinetic parameters of serial lactate evaluations are superior at predicting mortality compared with single values. S-adenosylhomocysteine (SAH), which is also associated with hypoxia, was recently established as a useful predictor of septic organ dysfunction and death. We evaluated the performance of kinetic SAH parameters for mortality prediction compared with lactate parameters in a cohort of critically ill patients. For lactate and SAH, maxima and means as well as the normalized area scores were calculated for two periods: the first 24 h and the total study period of up to five days following ICU admission. Their performance in predicting in-hospital mortality were compared in 99 patients. All evaluated parameters of lactate and SAH were significantly higher in non-survivors compared with survivors. In univariate analysis, the predictive power for mortality of SAH was higher compared with lactate in all forms of application. Multivariable models containing SAH parameters demonstrated higher predictive values for mortality than models based on lactate parameters. The optimal models for mortality prediction incorporated both lactate and SAH parameters. Compared with lactate, SAH displayed stronger predictive power for mortality in static and dynamic application in critically ill patients.

Timing of endoscopy in patients with elevated lactate levels and acute upper gastrointestinal bleeding; a retrospective comparative study

BACKGROUND/AIMS

While current guidelines recommend performing endoscopy within 24 h in case of acute upper gastrointestinal bleeding (AUGIB), the precise timing remains an issue of debate. Lactate is an established parameter for risk stratification in a variety of medical emergencies. This study evaluated the predictive ability of elevated lactate levels in identifying patients with UGIB, who may benefit from emergent endoscopy.

METHODS

We retrospectively analyzed all patients with elevated lactate levels, who presented to our emergency department between 01 January 2015 and 31 December 2019 due to suspected AUGIB.

RESULTS

Of 134 included cases, 81.3% had an Charlson comorbidity index of ≥3 and 50.4% presented with shock. Fifteen (11.2%) patients died and mortality rates rose with increasing lactate levels. Emergent endoscopy within 6 h (EE) and non-EE were performed in 64 (47.8%) and 70 (52.2%) patients, respectively. Patients who underwent EE had lower systolic blood pressure (107.6 mmHg vs. 123.2 mmHg; p = 0.001) and received blood transfusions more frequently (79.7% vs 64.3%; p = 0.048), but interestingly need for endoscopic intervention (26.6% vs 20.0%; p = 0.37), rebleeding (17.2% vs. 15.7%; p = 0.82) and mortality (9.4% vs. 11.4%; p = 0.7) did not differ significantly.

CONCLUSION

In conclusion, our findings support the recommendations of current guidelines to perform non-EE after sufficient resuscitation and management of comorbid illnesses.

Serum lactate and mean arterial pressure thresholds in patients with cirrhosis and septic shock

BACKGROUND

The Sepsis-3 guidelines have incorporated serum lactate levels of >2 mmol/L in septic shock definition to account for higher observed mortality. Further evidence is needed to support this threshold in cirrhosis, as well as target mean arterial pressure (MAP) during resuscitation.

METHODS

This observational cohort study investigated the association between initial serum lactate and resuscitation MAP levels on in-hospital mortality in patients with and without cirrhosis. Patients admitted to the intensive care unit for the treatment of septic shock between 2006 and 2021 in a quaternary academic center were included. Patients with cirrhosis documented on imaging and International Classification of Disease codes (n=595) were compared to patients without cirrhosis (n=575). The association of intensive care unit admission lactate levels and median 2-hour MAP with in-hospital mortality and the need for continuous renal replacement therapy was assessed. The association between median 24-hour MAP and in-hospital mortality was analyzed post hoc.

RESULTS

Within the cirrhosis group, admission lactate levels of 2-4 and >4 mmol/L were associated with increased in-hospital mortality compared to lactate <2 mmol/L [adjusted odds ratio (aOR): 1.69, CI: 1.03-2.81, aOR: 4.02, CI: 2.53-6.52]. Median 24-hour MAP 60-65 and <60 mm Hg were also associated with increased in-hospital mortality compared with MAP >65 mm Hg (aOR: 2.84, CI: 1.64-4.92 and aOR: 7.34, CI: 3.17-18.76). In the noncirrhosis group, associations with in-hospital mortality were weaker for lactate 2-4 and >4 mmol/L (aOR: 1.32, CI: 0.77-2.27 and aOR: 2.25, CI: 1.40-3.67) and median 24-hour MAP 60-65 and <60 mm Hg (aOR: 1.70, CI: 0.65-4.14 and aOR: 4.41, CI: 0.79-29.38).

CONCLUSIONS

These findings support utilizing lactate >2 mmol/L in the definition of septic shock, as well as a target MAP of >65 mm Hg during resuscitation in patients with cirrhosis.

Association of lactate/albumin ratio with in-hospital mortality in ICU patients with acute respiratory failure: A retrospective analysis based on MIMIC-IV database

We aimed to investigate the association between the lactate/albumin ratio (LAR), and in-hospital mortality in critically ill patients with acute respiratory failure. This retrospective cohort study was conducted based on the medical information mart for intensive care-IV database, which included critically ill adult patients with acute respiratory failure whose primary endpoint was in-hospital death. The analyses included curve fitting, a logistic multivariate regression model, and subgroup analysis. In this study, 6028 intensive care unit patients with acute respiratory failure were analyzed. Of these, 1843 (30.57%) died. After adjusting for confounding factors, a nonlinear relationship between LAR and in-hospital mortality was observed, and the risk of death was found to decrease by 81% with a reduction of 1 unit of LAR when it was < 4.46. The association between LAR and in-hospital mortality was not statistically significant when LAR was > 4.46. Hence, the relationship between LAR and in-hospital mortality could only be observed when the LAR was < 4.46. There is a nonlinear relationship between LAR and the risk of in-hospital death in intensive care unit patients with acute respiratory failure, and there is a saturation effect.

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

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

S-Adenosylhomocysteine Is a Useful Metabolic Factor in the Early Prediction of Septic Disease Progression and Death in Critically Ill Patients: A Prospective Cohort Study

A common final pathway of pathogenetic mechanisms in septic organ dysfunction and death is a lack or non-utilization of oxygen. Plasma concentrations of lactate serve as surrogates for the oxygen-deficiency-induced imbalance between energy supply and demand. As S-adenosylhomocysteine (SAH) was shown to reflect tissue hypoxia, we compared the ability of SAH versus lactate to predict the progression of inflammatory and septic disease to septic organ dysfunction and death. Using univariate and multiple logistic regression, we found that SAH but not lactate, taken upon patients' inclusion in the study close to ICU admission, significantly and independently contributed to the prediction of disease progression and death. Due to the stronger increase in SAH in relation to S-adenosylmethionine (SAM), the ratio of SAM to SAH, representing methylation potential, was significantly decreased in patients with septic organ dysfunction and non-survivors compared with SIRS/sepsis patients (2.8 (IQR 2.3-3.9) vs. 8.8 (4.9-13.8); p = 0.003) or survivors (4.9 (2.8-9.5) vs. 8.9 (5.1-14.3); p = 0.026), respectively. Thus, SAH appears to be a better contributor to the prediction of septic organ dysfunction and death than lactate in critically ill patients. As SAH is a potent inhibitor of SAM-dependent methyltransferases involved in numerous vital biochemical processes, the impairment of the SAM-to-SAH ratio in severely critically ill septic patients and non-survivors warrants further studies on the pathogenetic role of SAH in septic multiple organ failure.

Acid Base Disorders in Cirrhosis

Metabolic and respiratory acid-base disorders are common in individuals with liver disease and cirrhosis. The most common disorder is respiratory alkalosis, which may be related to dyspnea or respiratory stimulation. Primary metabolic disorders are less common. Although the liver plays a role in metabolism of amino acids and generation of acid from dietary sources, it does not play a role in the regulation of pH. Instead, metabolic disorders may arise from alterations in normal metabolism or from medications, particularly diuretics and osmotic laxatives, used in the treatment of these complex patients. Understanding the mechanistic underpinnings of these disorders can aid in the management of individuals with liver disease in the hospital and in outpatient settings.

Association between lactate/albumin ratio and mortality in patients with heart failure after myocardial infarction

AIMS

Lactate/albumin ratio (L/A) is a recognized prognostic index of patients with heart failure (HF) after myocardial infarction (MI). We aim to evaluate the prognostic value of L/A ratio in predicting in-hospital mortality for those patients.

METHODS AND RESULTS

We enrolled qualified patients from Medical Information Mart for Intensive Care IV database for retrospective study. A receiver operating characteristic (ROC) curve of the subjects was applied to determine the predicted value and the best cut-off value of L/A on admission. Univariate/multivariate Cox regression analysis and restricted cubic splines (RCS) were performed to identify the association between hospital admission and hospital mortality. The Kaplan-Meier (KM) method was used to draw the survival curve of the two groups with different L/A levels at admission. L/A values at admission were significantly higher in the death groups than the survival groups [1.36 (1.20) vs. 0.62 (0.36), P < 0.05], and area under the ROC curve [0.780 (95% confidence interval, 0.772-0.827)] was better than other indicators, and the best the cut-off value was 0.671. Data of Cox regression analysis showed that higher L/A value supposed to be an independent risk factor for in-hospital mortality. RCS analysis showed evidence of an increasing trend and a non-linear relationship between L/A and in-hospital mortality (P value was non-linear <0.05). KM survival curves were significantly lower in the high L/A group than the low L/A group (P < 0.001), and the former group had an increased risk of in-hospital mortality compared with the latter one (log rank P < 0.001).

CONCLUSIONS

Elevated L/A ratio on admission is an independent predictor of high in-hospital mortality in post-MI heart failure patients, which proved to be better than lactate, Sequential Organ Failure Assessment score and other related indicators.

Comparison of Lactate Clearance with Established Risk Assessment Tools in Predicting Outcomes in Acute Upper Gastrointestinal Bleeding

Early risk stratification is mandatory in acute upper gastrointestinal bleeding (AUGIB) to guide optimal treatment. Numerous risk scores were introduced, but lack of practicability led to limited use in daily clinical practice. Lactate clearance is an established risk assessment tool in a variety of diseases, such as trauma and sepsis. Therefore, this study compares the predictive ability of pre-endoscopic lactate clearance and established risk scores in patients with AUGIB at the University Hospital of Cologne. Active bleeding was detected in 27 (25.2%) patients, and hemostatic intervention was performed in 35 (32.7%). In total, 16 patients (15%) experienced rebleeding and 12 (11.2%) died. Initially, lactate levels were elevated in 64 cases (59.8%), and the median lactate clearance was 18.7% (2.7-48.2%). Regarding the need for endoscopic intervention, the predictive ability of Glasgow Blatchford Score, pre-endoscopic Rockall score, initial lactate and lactate clearance did not differ significantly, and their area under the receiver operating characteristic curves were 0.658 (0.560-0.747), 0.572 (0.473-0.667), 0.572 (0.473-0.667) and 0.583 (0.483-0.677), respectively. Similar results were observed in relation to rebleeding and mortality. In conclusion, lactate clearance had comparable predictive ability compared to established risk scores. Further prospective research is necessary to clarify the potential role of lactate clearance as a reliable risk assessment tool in AUGIB.

Factors predicting mortality in patients with alcoholic liver cirrhosis visiting the emergency department

Liver cirrhosis (LC) is a major cause of morbidity and mortality worldwide and is becoming a regional and healthcare burden. South Korea is one of the 10 countries with the highest age standardized prevalence of decompensated LC. Moreover, the proportion of patients with alcoholic LC is increasing and there has been no decrease in the incidence of decompensated alcoholic LC. Patients with decompensated LC frequently visit the emergency department (ED). Several studies focused on patients with LC who visited the ED, but the studies about alcoholic LC were limited. This study aimed to identify predicting factors for mortality in alcoholic LC patients visiting the ED. This was a retrospective study of alcoholic LC patients who visited an ED between November 2017 and June 2021. The baseline characteristics, complications of LC, model for end-stage liver disease (MELD) score, and laboratory values including lactate were assessed. The primary outcome was in-hospital mortality. In total, 433 patients with alcoholic LC were included for analysis and the in hospital mortality rate was 15.9% (n = 69). Univariate regression analyses identified that MELD score, lactate, platelet, international normalized ratio, bilirubin, creatinine, albumin, and C-reactive protein (CRP) predicted in-hospital mortality. Multivariate regression analysis showed that MELD score, lactate, albumin, and CRP were significantly associated with in-hospital mortality. MELD score, lactate, albumin, and CRP predicted the mortality in alcoholic LC patients visiting the ED.

Lactate/albumin ratio as a predictor of in-hospital mortality in critically ill children

OBJECTIVE

Managing critically ill patients with high mortality can be difficult for clinicians in pediatric intensive care units (PICU), which need to identify appropriate predictive biomarkers. The lactate/albumin (L/A) ratio can precisely stratify critically ill adults. However, the role of the L/A ratio in predicting the outcomes of critically ill children remains unclear. Therefore, this study aimed to evaluate the prognostic performance of the L/A ratio in predicting in-hospital mortality in unselected critically ill patients in the PICU.

METHODS

This was a single-center retrospective study. Clinical data of 8,832 critical patients aged between 28 days and 18 years were collected from the pediatric intensive care (PIC) database from 2010 to 2018. The primary outcome was the in-hospital mortality rate.

RESULTS

There was a higher level of L/A ratio in non-survivors than survivors (P < 0.001). Logistic regression indicated that the association between the L/A ratio and in-hospital mortality was statistically significant (OR 1.44, 95% CI 1.31-1.59, P < 0.001). The AUROC of the L/A ratio for predicting in-hospital mortality was higher than lactate level alone (0.74 vs 0.70, P < 0.001). Stratification analysis showed a significant association between the L/A ratio and in-hospital mortality in the age and primary disease groups (P < 0.05).

CONCLUSIONS

Our study suggested that the L/A ratio was a clinical tool to predict in-hospital mortality in critically ill children better than lactate level alone. However, given that the study was retrospective, more prospective studies should be conducted to test the predictive value of the L/A ratio in critical illness.

Association of lactate to albumin ratio and bicarbonate with short-term mortality risk in patients with acute myocardial infarction

BACKGROUND

Previous studies have indicated that the ratio of lactate/albumin (L/A) has predictive value for the prognosis of critically ill patients with heart failure. Some studies have also indicated that a low serum bicarbonate concentration is inversely related to the mortality risk of patients with cardiogenic shock. However, the value of bicarbonate and the L/A ratio for predicting the mortality risk of patients with acute myocardial infarction (AMI) is still unclear. We therefore conducted a retrospective study to research this problem.

METHODS

The subjects of this study were patients with AMI, and the data source was the Medical Information Mart for Intensive Care III database. The primary endpoint was 30-day all-cause mortality after admission. The Receiver operating characteristic (ROC) curve was used to compare the predictive value of L/A ratio, lactate and albumin for end-point events. The effects of different L/A ratio levels and different bicarbonate concentrations on 7-day and 30-day all-cause mortality were compared using Kaplan-Meier (K-M) curves. Hazard ratios for different L/A ratio and different bicarbonate concentrations were investigated using COX proportional hazards models.

RESULTS

The Area Under Curve (AUC) of L/A ratio, lactate, and albumin were 0.736, 0.718, and 0.620, respectively. (1) L/A ratio: The patients were divided into three groups according to their L/A ratio: tertile T1 (L/A ratio ≤ 0.47), tertile T2 (L/A ratio ≤ 0.97), and tertile T3 (L/A ratio > 0.97). The T2 and T3 groups had higher 30-day all-cause mortality risks than the T1 group. The restricted cubic spline (RCS) model indicated that there was a nonlinear relationship between L/A ratio and 30-day mortality (P < 0.05). (2) Bicarbonate concentration: The patients were also divided into three groups based on their bicarbonate concentration: G1 (22-27 mmol/L), G2 (< 22 mmol/L), and G3 (> 27 mmol/L). The G2 and G3 groups had higher 30-day all-cause mortality risks than the G1 group. The RCS model indicated that there was a nonlinear relationship between bicarbonate concentration and 30-day mortality (P < 0.05). The RCS model indicated that there was a nonlinear relationship between hemoglobin level and 30-day all-cause mortality (P < 0.05).

CONCLUSION

L/A ratio and bicarbonate concentration and hemoglobin level have predictive value for predicting 30-day mortality in patients with acute myocardial infarction.

Admission Lactate Concentration, Base Excess, and Alactic Base Excess Predict the 28-Day Inward Mortality in Shock Patients

Base excess (BE) and lactate concentration may predict mortality in critically ill patients. However, the predictive values of alactic BE (aBE; the sum of BE and lactate), or a combination of BE and lactate are unknown. The study aimed to investigate whether BE, lactate, and aBE measured on admission to ICU may predict the 28-day mortality for patients undergoing any form of shock. In 143 consecutive adults, arterial BE, lactate, and aBE were measured upon ICU admission. Receiver Operating Curve (ROC) characteristics and Cox proportional hazard regression models (adjusted to age, gender, forms of shock, and presence of severe renal failure) were then used to investigate any association between these parameters and 28-day mortality. aBE < −3.63 mmol/L was found to be associated with a hazard ratio of 3.19 (HR; 95% confidence interval (CI): 1.62−6.27) for mortality. Risk of death was higher for BE < −9.5 mmol/L (HR: 4.22; 95% CI: 2.21−8.05), particularly at lactate concentrations > 4.5 mmol/L (HR: 4.62; 95% CI: 2.56−8.33). A 15.71% mortality rate was found for the combined condition of BE > cut-off and lactate < cut-off. When BE was below but lactate above their respective cut-offs, the mortality rate increased to 78.91%. The Cox regression model demonstrated that the predictive values of BE and lactate were mutually independent and additive. The 28-day mortality in shock patients admitted to ICU can be predicted by aBE, but BE and lactate deliver greater prognostic value, particularly when combined. The clinical value of our findings deserves further prospective evaluation.

Comparison of lactate/albumin ratio to lactate and lactate clearance for predicting outcomes in patients with septic shock admitted to intensive care unit: an observational study

The aim of this study was to evaluate the prognostic value of the Lactate to Albumin (L/A) ratio compared to that of lactate and lactate clearance in predicting outcomes in patients with septic shock. This was a multi-center observational study of adult patients with septic shock, who admitted to intensive care units (ICUs) at Shohada and Imam Reza Hospitals, Tabriz, Iran, between Sept 2018 and Jan 2021. The area under the curve (AUC) of receiver operating characteristic (ROC) curve and multivariate logistic regression analyses were used to explore associations of the L/A ratio, lactate and lactate clearance on the primary (mortality) and secondary outcomes [ICU length of stay (LOS), duration of mechanical ventilation (MV), need of renal replacement therapy (RRT) and duration of using vasopressors] at baseline, 6 h and 24 h of septic shock recognition. Best performing predictive value for mortality were related to lactate clearance at 24 h, L/A ratio at 6 h and lactate levels at 24 h with (AUC 0.963, 95% CI 0.918-0.987, P < 0.001), (AUC 0.917, 95% CI 0.861-0.956, P < 0.001), and (AUC 0.904, 95% CI 0.845-0.946, P < 0.001), respectively. Generally, the lactate clearance at 24 h had better prognostic performance for mortality and duration of using vasopressor. However, the L/A ratio had better prognostic performance than serum lactate and lactate clearance for RRT, ICU LOS and MV duration.

Lactate induces vascular permeability via disruption of VE-cadherin in endothelial cells during sepsis

Circulating lactate levels are a critical biomarker for sepsis and are positively correlated with sepsis-associated mortality. We investigated whether lactate plays a biological role in causing endothelial barrier dysfunction in sepsis. We showed that lactate causes vascular permeability and worsens organ dysfunction in CLP sepsis. Mechanistically, lactate induces ERK-dependent activation of calpain1/2 for VE-cadherin proteolytic cleavage, leading to the enhanced endocytosis of VE-cadherin in endothelial cells. In addition, we found that ERK2 interacts with VE-cadherin and stabilizes VE-cadherin complex in resting endothelial cells. Lactate-induced ERK2 phosphorylation promotes ERK2 disassociation from VE-cadherin. In vivo suppression of lactate production or genetic depletion of lactate receptor GPR81 mitigates vascular permeability and multiple organ injury and improves survival outcome in polymicrobial sepsis. Our study reveals that metabolic cross-talk between glycolysis-derived lactate and the endothelium plays a critical role in the pathophysiology of sepsis.

Serum Lactate and Mortality during Pediatric Admissions: Is 2 Really the Magic Number?

The primary objective of this study was to determine if serum lactate level at the time of hospital admission can predict mortality in pediatric patients. A systematic review was conducted to identify studies that assessed the utility of serum lactate at the time of admission to predict mortality in pediatric patients. The areas under the curve from the receiver operator curve analyses were utilized to determine the pooled area under the curve. Additionally, standardized mean difference was compared between those who survived to discharge and those who did not. A total of 12 studies with 2,099 patients were included. Out of these, 357 (17%) experienced mortality. The pooled area under the curve for all patients was 0.74 (0.67-0.80, p  < 0.01). The pooled analyses for all admissions were higher in those who experienced mortality (6.5 vs. 3.3 mmol/L) with a standardized mean difference of 2.60 (1.74-3.51, p  < 0.01). The pooled area under the curve for cardiac surgery patients was 0.63 (0.53-0.72, p  < 0.01). The levels for cardiac surgery patients were higher in those who experienced mortality (5.5 vs. 4.1 mmol/L) with a standardized mean difference of 1.80 (0.05-3.56, p  = 0.04). Serum lactate at the time of admission can be valuable in identifying pediatric patients at greater risk for inpatient mortality. This remained the case when only cardiac surgery patients were included.

Impact of Comorbidities on Beneficial Effect of Lactated Ringers vs. Saline in Sepsis Patients

Background: Lactated Ringers reduced mortality more than saline in sepsis patients but increased mortality more than saline in traumatic brain injury patients.

Method: This prospective cohort study was conducted in a medical intensive care unit (ICU) in central Taiwan. We applied standard sepsis evaluation protocol and identified heart, lung, liver, kidney, and endocrine comorbidities. We also evaluated resuscitation response with central venous pressure, central venous oxygen saturation, and serum lactate level simultaneously. Propensity-score matching and Cox regression were used to estimate mortality. The competing risk model compared the lengths of hospital stays with the subdistribution hazard ratio (SHR).

Results: Overall, 938 patients were included in the analysis. The lactated Ringers group had a lower mortality rate (adjusted hazard ratio, 0.59; 95% CI 0.43-0.81) and shorter lengths of hospital stay (SHR, 1.39; 95% C.I. 1.15-1.67) than the saline group; the differences were greater in patients with chronic pulmonary disease and small and non-significant in those with chronic kidney disease, moderate to severe liver disease and cerebral vascular disease. The resuscitation efficacy was the same between fluid types, but serum lactate levels were significantly higher in the lactated Ringers group than in the saline group (0.12 mg/dl/h; 95% C.I.: 0.03, 0.21), especially in chronic liver disease patients. Compared to the saline group, the lactated Ringers group achieved target glucose level earlier in both diabetes and non-diabetes patients.

Conclusion: Lactate Ringer's solution provides greater benefits to patients with chronic pulmonary disease than to those with chronic kidney disease, or with moderate to severe liver disease. Comorbidities are important in choosing resuscitation fluid types.

Hepatorenal syndrome in acute-on-chronic liver failure with acute kidney injury: more questions requiring discussion

In cirrhosis with ascites, hepatorenal syndrome (HRS) is a specific prerenal dysfunction unresponsive to fluid volume expansion. Acute-on-chronic liver failure (ACLF) comprises a group of clinical syndromes with multiple organ failure and early high mortality. There are differences in the characterization of ACLF between the Eastern and Western medical communities. Patients with ACLF and acute kidney injury (AKI) have more structural injuries, contributing to confusion in diagnosing HRS-AKI. In this review, we discuss progress in the pathogenesis, diagnosis, and management of HRS-AKI, especially in patients with ACLF. Controversy regarding HRS-AKI in ACLF and acute liver failure, hepatic carcinoma, shock, sepsis, and chronic kidney disease is also discussed. Research on the treatment of HRS-AKI with ACLF needs to be more actively pursued to improve disease prognosis.

The prognostic value of the lactate/albumin ratio for predicting mortality in septic patients presenting to the emergency department: a prospective study

OBJECTIVES

Lactate/albumin (L/A) ratio is a biomarker in sepsis that has been shown to outperform lactate. This prospective study aims to validate the superior prognostic value of the L/A ratio to lactate in sepsis and septic shock.

METHODS

Prospective cohort conducted from September 2018 till February 2021 on adult patients presenting to the Emergency Department (ED) at a tertiary care centre with sepsis or septic shock. The primary outcome was the prognostic value of the L/A ratio compared to lactate with regards to mortality.

RESULTS

A total of 939 septic patients were included throughout the study period. A total of 236 patients developed septic shock. The AUC value of the L/A ratio in septic patients was 0.65 (95% CI 0.61-0.70) and was higher than that of lactate alone 0.60 (95% CI 0.55-0.64) with a p < .0001. The optimal L/A ratio cut-off threshold that separated survivors from non-survivors was found to be 0.115 for all septic patients. The AUC of the L/A ratio was significantly higher for patients with a lactate ≥2 mmol/L: 0.69 (95% CI 0.64-0.74) versus 0.60 (95% CI 0.54-0.66) with a p < .0001 as well as for patients with an albumin level less than 30 g/L (AUC = 0.69 95% CI= 0.62-0.75 vs AUC= 0.66 95% CI= 0.59-0.73, p = .04). Among septic shock patients there was no statically significant difference in the AUC value of the L/A ratio compared to lactate (0.53 95% CI 0.45-0.61 vs 0.50 95% CI 0.43-0.58 respectively with a p-value = .11).

CONCLUSIONS

The L/A ratio is a better predictor of in-patient mortality than lactate in sepsis patients. This superiority was not found in the septic shock subgroup. Our results encourage the use of the ratio early in the ED as a superior prognostic tool in sepsis patients.Key messagesWe aimed to assess the prognostic usefulness of the Lactate/Albumin ratio compared to lactate alone in septic and septic shock patients.The L/A ratio proved to be a better predictor of in-patient mortality than lactate alone in sepsis patients. This pattern also applies across various subgroups in our study (malignancy, diabetics, age above 65, lactate level less than 2 mmol/L, albumin less than 30 g/L). Our results favour the use of the L/A ratio over lactate alone in patients with sepsis and the previously mentioned subgroups.Our results do not favour the use of the ratio instead of lactate in septic shock patients as there was no statistically significant difference between the AUCs of the ratio and lactate alone.

Serum lactate levels in cirrhosis and non-cirrhosis patients with septic shock

Background

In septic shock patients with cirrhosis, impaired liver function might decrease lactate elimination and produce a higher lactate level. This study investigated differences in initial lactate, lactate clearance, and lactate utility between cirrhotic and non-cirrhotic septic shock patients.

Methods

This is a retrospective cohort study conducted at a referral, university-affiliated medical center. We enrolled adults admitted during 2012-2018 who satisfied the septic shock diagnostic criteria of the Surviving Sepsis Campaign: 2012. Patients previously diagnosed with cirrhosis by an imaging modality were classified into the cirrhosis group. The initial lactate levels and levels 6 hours after resuscitation were measured and used to calculate lactate clearance. We compared initial lactate, lactate at 6 hours, and lactate clearance between the cirrhosis and non-cirrhosis groups. The primary outcome was in-hospital mortality.

Results

Overall 777 patients were enrolled, of whom 91 had previously been diagnosed with cirrhosis. Initial lactate and lactate at 6 hours were both significantly higher in cirrhosis patients, but there was no difference between the groups in lactate clearance. A receiver operating characteristic curve analysis for predictors of in-hospital mortality revealed cut-off values for initial lactate, lactate at 6 hours, and lactate clearance of >4 mmol/L, >2 mmol/L, and <10%, respectively, among non-cirrhosis patients. Among patients with cirrhosis, the cut-off values predicting in-hospital mortality were >5 mmol/L, >5 mmol/L, and <20%, respectively. Neither lactate level nor lactate clearance was an independent risk factor for in-hospital mortality among cirrhotic and non-cirrhotic septic shock patients.

Conclusion

The initial lactate level and lactate at 6 hours were significantly higher in cirrhosis patients than in non-cirrhosis patients.

Liver cirrhosis affects serum lactate level measurement while assessing disease severity in patients with sepsis

BACKGROUND

Elevated serum lactate is associated with higher mortality in sepsis, whereas liver dysfunction is associated with higher serum lactate levels. We assessed the predictive ability of serum lactate in patients with liver cirrhosis and sepsis.

METHODS

This retrospective study included 12 281 cases of suspected infection with initial serum blood lactate drawn during January 2007-December 2013.

RESULTS

Using one-to-two propensity score matching analysis, 1053 and 2106 septic patients with and without underlying liver cirrhosis, respectively, were successfully matched. Lactate levels of survivors and nonsurvivors were 2.58 and 5.93 mmol/L, respectively, in patients without liver cirrhosis (WLC), 2.96 and 7.29 mmol/L, respectively, in patients with nondecompensated liver cirrhosis (NDLC), and 4.08 and 7.16 mmol/L, respectively, in patients with decompensated liver cirrhosis (DLC). In receiver operating characteristic curve analysis, the sensitivity and specificity for predicting mortality were 0.81 and 0.55, respectively, in the WLC group, 0.85 and 0.45, respectively, in the NDLC group, and 0.86 and 0.33, respectively, in the DLC group, using serum lactate levels >2.0 mmol/L.

CONCLUSIONS

The serum lactate level can be used to predict the severity of sepsis in patients with liver cirrhosis; however, its specificity would be lower at a cutoff of 2.0 mmol/L.

Exaggerated Microvascular Vasodilating Responses in Cirrhotic Patients With Septic Shock

OBJECTIVES

Cirrhosis is associated with hemodynamic and vascular disorders. However, microvascular reactivity of cirrhotic patients in the context of sepsis has poorly been investigated.

DESIGN

Prospective observational study.

SETTING

Medical ICU in a tertiary teaching hospital.

PATIENTS

We prospectively included adult patients admitted in the ICU for septic shock with and without cirrhosis. After initial resuscitation, global hemodynamic parameters were recorded and skin microvascular reactivity to local acetylcholine iontophoresis was measured.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Thirty patients with septic shock were included (60% male), 10 with cirrhosis and 20 without, with a median age of 61 years (54-74 yr). Cirrhotic patients were mainly classed as Child-Pugh C (80%) and all of them had ascites. Sequential Organ Failure Assessment score and ICU mortality of cirrhotic patients were higher than the noncirrhotic patients, respectively (6.5 [5.0-8.3] vs 11.5 [9.0-14.0]; p < 0.01; 15% vs 70%; p < 0.01). Peripheral tissue perfusion and global hemodynamic parameters were not different between the cirrhotic and noncirrhotic patients but arterial lactate level was three times higher in patients with cirrhosis (6.0 mmol/L [3.9-8.0 mmol/L] vs 2.0 mmol/L [0.9-3.5 mmol/L]; p < 0.01). Basal skin microvascular blood flow was not statistically different between the groups (4.94 perfusion units [3.45-8.73 perfusion units] vs 6.95 perfusion units [5.24-8.38 perfusion units]; p = 0.29). After acetylcholine simulation, skin microvascular blood flow increased more in cirrhotic patients than in noncirrhotic patients (644% [217-966%] vs 169% [73-505%], p = 0.03). Global microvascular reactivity was seven times higher in cirrhotic patients (area under the curve, 16,412 perfusion units [13,898-19,041 perfusion units] vs 2,664 perfusion units [969-4,604 perfusion units]; p < 0.001).

CONCLUSIONS

We identified an exaggerated vasodilating microvascular response in cirrhotic patients with septic shock. Such a result may explain vasopressor resistance and paves the way for future therapeutic trials, targeting nitric oxide pathway specifically in this population.

Can Lactate Clearance Predict Mortality in Critically Ill Children?

Serial evaluation of blood lactate, including lactate clearance, may have greater value over single measurement at the time of presentation. The rationale of the current study was to evaluate the use of lactate clearance after 6 hours of admission to pediatric intensive care unit (PICU) as a predictor of mortality in critically ill children. A prospective observational study was conducted in a nine-bed PICU of a tertiary care teaching hospital over a period of 6 months. Lactate levels were measured in arterial blood samples of 76 patients at the time of admission and 6 hours later. According to calculated lactate clearance, patients were divided into group A (lactate clearance more than 0) which included 71% of patients and group B (lactate clearance ≤0) which included 29% of patients. Lactate level at admission was a poor predictor of mortality (area under receiver operating characteristic curve [AUC] = 0.519, p = 0.789). Lactate clearance after 6 hours of admission was a significant predictor of mortality (AUC = 0.766, p < 0.001). Using Kaplan–Meier survival curve, overall survival was significantly better among group A (p < 0.001). Using multivariate logistic regression model, lactate clearance after 6 hours (odds ratio = 0.98, 95% confidence interval [CI]: 0.96–0.99) and The Pediatric Index of Mortality 2 (PIM2) score (odds ratio = 4.7, 95% CI: 1.85–12.28) had independent prognostic significance as regard to mortality (p = 0.030, 0.001 respectively). We conclude that lactate clearance after 6 hours of admission can predict mortality in critically ill children.

Significance of lactate clearance in septic shock patients with high bilirubin levels

Lactate clearance is affected by hepatic function. However, it is unclear whether the association between hepatic dysfunction and lactate clearance can act as a prognostic marker of clinical outcomes in patients with septic shock. We aimed to evaluate the association between lactate clearance and mortality in two cohorts of septic shock patient who had hepatic dysfunction based on their total serum bilirubin levels (TBIL). Lactate clearance at 24 h after the onset of septic shock was analyzed using two cohorts, sub-categorized into two groups based on TBIL: < 2 mg/dL and ≥ 2 mg/dL. In the derivation cohort, lactate clearance was lower in non-survivors than in survivors with TBIL ≥ 2 mg/dL, while there was no significant difference in lactate clearance between non-survivors and survivors with TBIL < 2 mg/dL. Multivariate logistic regression analysis revealed that increased lactate clearance was significantly associated with decreased 28-day mortality in the TBIL ≥ 2 mg/dL group (10% lactate clearance, adjusted odds ratio [OR]: 0.88, 95% confidence interval (CI): 0.80-0.97, P = 0.0075), Creatinine level ≥ 2 mg/dL group (adjusted OR: 0.88, 95% CI: 0.81-0.95, P = 0.00069) and APACHE II score ≥ 35 group (adjusted OR: 0.93, 95% CI: 0.87-0.98, P = 0.013). In the validation cohort, lactate clearance was lower in non-survivors than in survivors with TBIL ≥ 2 mg/dL, while no significant difference in lactate clearance was observed between non-survivors and survivors with TBIL < 2 mg/dL. Increased lactate clearance was significantly associated with decreased 28-day mortality in the TBIL ≥ 2 mg/dL group (10% lactate clearance, adjusted OR: 0.89, 95% CI: 0.83-0.96, P = 0.0038) and the association was just about significant in APACHE II score ≥ 35 group (adjusted OR: 0.86, 95% CI: 0.74-1.00, P = 0.051). In conclusion, increased lactate clearance in septic shock patients with hepatic dysfunction (TBIL ≥ 2 mg/dL) or high severity (APACHE II score ≥ 35) was associated with decreased 28-day mortality.

Lactate/Albumin Ratio as a Predictor of In-Hospital Mortality in Septic Patients Presenting to the Emergency Department

Background: The aim of this study is to evaluate the prognostic value of the Lactate to Albumin (L/A) ratio compared to that of lactate only in predicting morbidity and mortality in sepsis patients.

Methods: This was a single-center retrospective cohort study. All adult patients above the age of 18 with a diagnosis of sepsis who presented between January 1, 2014 and June 30, 2019 were included. The primary outcome was in-hospital mortality.

Results: A total of 1,381 patients were included, 44% were female. Overall in-hospital mortality was 58.4% with the mortalities of sepsis and septic shock being 45.8 and 67%, respectively. 55.5% of patients were admitted to the intensive care unit. The area under the curve value for lactate was 0.61 (95% CI 0.57–0.65, p < 0.001) and for the L/A ratio was 0.67 (95% CI 0.63–0.70, p < 0.001). The cutoff generated was 1.22 (sensitivity 59%, specificity 62%) for the L/A ratio in all septic patients and 1.47 (sensitivity 60%, specificity 67%) in patients with septic shock. The L/A ratio was a predictor of in-hospital mortality (OR 1.53, CI 1.32–1.78, p < 0.001).

Conclusion: The L/A ratio has better prognostic performance than initial serum lactate for in-hospital mortality in adult septic patients.

Update on diagnosis and management of sepsis in cirrhosis: Current advances

Sepsis and septic shock are catastrophic disease entities that portend high mortality in patients with cirrhosis. In cirrhosis, hemodynamic perturbations, immune dysregulation, and persistent systemic inflammation with altered gut microbiota in the background of portal hypertension enhance the risk of infections and resistance to antimicrobials. Patients with cirrhosis develop recurrent life-threatening infections that progress to multiple organ failure. The definition, pathophysiology, and treatment options for sepsis have been ever evolving. In this exhaustive review, we discuss novel advances in the understanding of sepsis, describe current and future biomarkers and scoring systems for sepsis, and delineate newer modalities and adjuvant therapies for the treatment of sepsis from existing literature to extrapolate the same concerning the management of sepsis in cirrhosis. We also provide insights into the role of gut microbiota in initiation and progression of sepsis and finally, propose a treatment algorithm for management of sepsis in patients with cirrhosis.

LIV-4: A novel model for predicting transplant-free survival in critically ill cirrhotics

BACKGROUND

Critically ill patients with cirrhosis, particularly those with acute decompensation, have higher mortality rates in the intensive care unit (ICU) than patients without chronic liver disease. Prognostication of short-term mortality is important in order to identify patients at highest risk of death. None of the currently available prognostic models have been widely accepted for use in cirrhotic patients in the ICU, perhaps due to complexity of calculation, or lack of universal variables readily available for these patients. We believe a survival model meeting these requirements can be developed, to guide therapeutic decision-making and contribute to cost-effective healthcare resource utilization.

AIM

To identify markers that best identify likelihood of survival and to determine the performance of existing survival models.

METHODS

Consecutive cirrhotic patients admitted to a United States quaternary care center ICU between 2008-2014 were included and comprised the training cohort. Demographic data and clinical laboratory test collected on admission to ICU were analyzed. Area under the curve receiver operator characteristics (AUROC) analysis was performed to assess the value of various scores in predicting in-hospital mortality. A new predictive model, the LIV-4 score, was developed using logistic regression analysis and validated in a cohort of patients admitted to the same institution between 2015-2017.

RESULTS

Of 436 patients, 119 (27.3%) died in the hospital. In multivariate analysis, a combination of the natural logarithm of the bilirubin, prothrombin time, white blood cell count, and mean arterial pressure was found to most accurately predict in-hospital mortality. Derived from the regression coefficients of the independent variables, a novel model to predict inpatient mortality was developed (the LIV-4 score) and performed with an AUROC of 0.86, compared to the Model for End-Stage Liver Disease, Chronic Liver Failure-Sequential Organ Failure Assessment, and Royal Free Hospital Score, which performed with AUROCs of 0.81, 0.80, and 0.77, respectively. Patients in the internal validation cohort were substantially sicker, as evidenced by higher Model for End-Stage Liver Disease, Model for End-Stage Liver Disease-Sodium, Acute Physiology and Chronic Health Evaluation III, SOFA and LIV-4 scores. Despite these differences, the LIV-4 score remained significantly higher in subjects who expired during the hospital stay and exhibited good prognostic values in the validation cohort with an AUROC of 0.80.

CONCLUSION

LIV-4, a validated model for predicting mortality in cirrhotic patients on admission to the ICU, performs better than alternative liver and ICU-specific survival scores.

Lactate/albumin ratio: An early prognostic marker in critically ill patients

OBJECTIVES

We investigate the clinical utility of the lactate/albumin (L/A) ratio as an early prognostic marker of ICU mortality in a large cohort of unselected critically ill patients.

METHODS

A retrospective single-center study using data from the Multiparameter Intelligent Monitoring Intensive Care III (MIMIC-III) database collected between 2001 and 2012. We screened adult patients (age ≥ 15) with measured lactate and albumin on the first day of ICU stay to evaluate the prognostic performance of the lactate and lactate/albumin (L/A) ratio for ICU mortality prediction.

RESULTS

The overall ICU mortality in the 6414 eligible ICU patients was 16.4%. L/A showed a receiver-operating characteristics area under the curve (ROC-AUC) value of 0.69 (95% CI: 0.67, 0.70) to predict ICU mortality, higher than lactate 0.67 (95%CI: 0.65, 0.69). Regardless of the lactate level, L/A yielded better ROC-AUC compared to the lactate level [normal lactate (<2.0 mmol/L): 0.63 vs 0.60; intermediate lactate (2.0 mmol/L ≤ lactate <4.0 mmol/L): 0.58 vs 0.56; high lactate (≥4.0 mmol/L): 0.67 vs 0.66]. L/A was a better prognostic marker for ICU mortality in patients with decreased lactate elimination [hepatic dysfunction: 0.72 vs 0.70; renal dysfunction 0.70 vs 0.68]. The L/A ratio ROC-AUC was better in patients with sepsis (0.68 vs 0.66) and those who developed severe sepsis or septic shock (0.68 vs 0.66).

CONCLUSIONS

The performance of L/A and lactate were equivalent in predicting ICU mortality and can be used as early prognostic markers for ICU patients with different initial lactate level and the presence of hepatic or renal dysfunction.

Acute-on-chronic liver failure syndrome - clinical results from an intensive care unit in a liver transplant center

OBJECTIVE

To characterize a cohort of acute-on-chronic liver failure patients in Intensive Care and to analyze the all-cause 28-day mortality risk factors assessed at ICU admission and day 3.

METHODS

This was a retrospective cohort study of consecutive patients admitted to the intensive care unit between March 2013 and December 2016.

RESULTS

Seventy-one patients were included. The median age was 59 (51 - 64) years, and 81.7% of patients were male. Alcohol consumption alone (53.5%) was the most frequent etiology of cirrhosis and infection (53.5%) was the most common acute-on-chronic liver failure precipitating event. At intensive care unit admission, the clinical severity scores were APACHE II 21 (16 - 23), CLIF-SOFA 13 (11 - 15), Child-Pugh 12 (10 - 13) and MELD 27 (20 - 32). The acute-on-chronic liver failure scores were no-acute-on-chronic liver failure: 11.3%; one: 14.1%; two: 28.2% and three: 46.5%; and the number of organ failures was one: 4.2%; two: 42.3%; three: 32.4%; four: 16.9%; and five: 4.2%. Liver transplantation was performed in 15.5% of patients. The twenty-eight-day mortality rate was 56.3%, and the in-ICU mortality rate was 49.3%. Organ failure at intensive care unit admission (p = 0.02; OR 2.1; 95%CI 1.2 - 3.9), lactate concentration on day 3 (p = 0.02; OR 6.3; 95%CI 1.4 - 28.6) and the international normalized ratio on day 3 (p = 0.03; OR 10.2; 95%CI 1.3 - 82.8) were independent risk factors.

CONCLUSION

Acute-on-chronic liver failure patients presented with high clinical severity and mortality rates. The number of organ failures at intensive care unit admission and the lactate and international normalized ratio on day 3 were independent risk factors for 28-day mortality. We consider intensive care essential for acute-on-chronic liver failure patients and timely liver transplant was vital for selected patients.

Assessment of microcirculation in cardiogenic shock

PURPOSE OF REVIEW

Adequate tissue perfusion is of utmost importance to avoid organ failure in patients with cardiogenic shock. Within the recent years, the microcirculation, defined as the perfusion of the smallest vessels, has been identified to play a crucial role. Microcirculatory changes may include capillary flow disturbances as well as changes in the density of perfused vessels. Due to the availability of new technologies to assess the microcirculation, interesting new data came up and it is the purpose of this review to summarize recent studies in the field.

RECENT FINDINGS

Nowadays, an increasing number of studies confirm parameters of the microcirculation, derived by intravital microscopy, to represent strong outcome predictors in cardiogenic shock. In addition, microcirculation as read-out parameter in innovative clinical studies has meanwhile been accepted as serious endpoint. Treatment strategies such as mechanical assist devices, blood pressure regulating agents or fluids use tissue perfusion and microcirculatory network density as targets in addition to clinical perfusion evaluation and decreasing serum lactate levels.

SUMMARY

The parameter most frequently used to detect tissue malperfusion is serum lactate. Novel, noninvasive methods to quantify microvascular perfusion have the potential to guide treatment in terms of optimizing organ perfusion and oxygenation probably paving the way for an individualized therapy.

Prognostic Value of The Lactate/Albumin Ratio for Predicting 28-Day Mortality in Critically ILL Sepsis Patients

AIM

The aim of this study was to evaluate the clinical utility of the lactate/albumin (L/A) ratio as a predictive factor of 28-day mortality in critically ill sepsis patients.

METHODS

This is a retrospective observational study from a prospectively collected multicenter registry of 10 emergency departments (EDs) in teaching hospitals that participated in the Korean Shock Society. It enrolled patients who were 19 years of age or older who had a suspected or confirmed infection and evidence of refractory hypotension or hypoperfusion. The prognostic performance of the L/A ratio and lactate level for predicting 28-day mortality was assessed. Lactate and albumin levels were measured immediately after ED arrival.

RESULTS

A total of 946 patients were included, with 22.5% overall 28-day mortality. The area under the receiver operating characteristic curve (AUROC) value of the L/A ratio (0.69, 95% confidence interval [CI] 0.64-0.73, P < 0.01) was higher than that of lactate (0.65, 95% CI 0.61-0.70, P < 0.01) for predicting 28-day mortality. The optimal cutoff of the L/A ratio was 1.32. The AUROC value of the L/A ratio was better than that of lactate regardless of lactate level (normal [<2.0 mmol/L]: 0.68 vs. 0.55; intermediate [≥2.0, < 4.0 mmol/L]: 0.65 vs. 0.50; high [≥4.0 mmol/L]: 0.66 vs. 0.62). In the subgroup with decreased lactate elimination, the AUROC value of the L/A ratio was also significantly higher than that of lactate (hepatic dysfunction: 0.70 vs. 0.66; renal dysfunction: 0.71 vs. 0.67). The L/A ratio cut-off and hypoalbminemia showed further discriminative value for 28-day mortality even in patients with normal or intermediate lactate levels.

CONCLUSIONS

The prognostic performance of the L/A ratio was superior to that of a single lactate measurement for predicting 28-day mortality of critically ill sepsis patients. L/A ratio can be a useful prognostic factor regardless of initial lactate level and the presence of hepatic or renal dysfunction.

Lactate and number of organ failures predict intensive care unit mortality in patients with acute-on-chronic liver failure

BACKGROUND AND AIMS

Patients with acute-on-chronic liver failure (ACLF) have high mortality rates. Most prognostic scores were not developed for the intensive care unit (ICU) setting. We aimed to improve risk stratification for patients with ACLF in the ICU.

METHODS

A training set with 240 patients with cirrhosis and organ failures (Chronic Liver Failure Sequential Organ Failure Assessment score [CLIF-SOFA]) from Curry Cabral Hospital (Portugal) and University of Alberta Hospital (Canada) in 2010-2016 was used to derive a prognostic model for ICU mortality. A validation set with 237 patients with cirrhosis and organ failures from Vancouver General Hospital (Canada) in 2000-2011 was used to evaluate its performance.

RESULTS

Amongst patients in the training set, ICU and hospital mortality rates were 39.2% and 54.6% respectively. Median lactate (4.4 vs 2.5 mmol/L) and number of organ failures (3 vs 2) on admission to ICU were associated with higher likelihood of ICU mortality (P < 0.001 for both). The lactate and organ failures predictive model (LacOF) was derived to predict ICU mortality: -2.420 + 0.072 × lactate + 0.569 × number of organ failures (area under-the-curve [AUC], 0.76). In the validation set, the LacOF model discriminative ability (AUC, 0.85) outperformed the CLIF-SOFA (AUC, 0.79), Chronic Liver Failure Consortium Acute-on-Chronic Liver Failure (AUC, 0.73), Model for End-stage Liver Disease score (AUC, 0.78) and Acute Physiology and Chronic Health Evaluation II scores (AUC, 0.74; P < 0.05 for all). The LacOF model calibration was good up to the 25% likelihood of ICU mortality.

CONCLUSIONS

In patients with ACLF, lactate and number of organ failures on admission to ICU are useful to predict ICU mortality. This early prognostic evaluation may help to better stratify the risk of ICU mortality and thus optimize organ support strategies.

Management of Sepsis in Patients With Cirrhosis: Current Evidence and Practical Approach

Sepsis in patients with cirrhosis is associated with high mortality. An impaired immune response accounts for the increased infection risk observed in these patients. Hemodynamic and systemic changes suggestive of sepsis may be observed in patients with cirrhosis in the absence of infection; therefore, diagnosis and treatment of sepsis may be delayed. The optimal management of the critically ill patient with sepsis and cirrhosis has not been well established and is generally extrapolated from consensus guidelines and expert recommendations made for management of patients without cirrhosis with sepsis. Despite the lack of strong evidence, we propose a contemporary pragmatic approach to sepsis management in patients with cirrhosis, including the choice of fluids, vasopressors, and antibiotics.

Lactate normalization within 6 hours of bundle therapy and 24 hours of delayed achievement were associated with 28-day mortality in septic shock patients

This study evaluated the prognostic ability of lactate normalization achieved within 6 and 24 h from septic shock recognition. Data from a septic shock registry from October 2015 to February 2017 were reviewed. The study included 2,102 eligible septic shock patients to analyze the prognostic ability of lactate normalization, defined as a follow-up lactate level <2 mmol/L within six hours of bundle therapy and within 24 hours of delayed normalization. The primary outcome was 28-day mortality. The overall 28-day mortality rate was 21.4%. The rates of lactate normalization within 6 and 24 h were significantly higher in the survivor groups than in the non-survivor group (42.4% vs. 23.4% and 60.2% vs. 31.2%; P<0.001, respectively). Multivariate logistic regression analysis showed that both 6- and 24-h lactate normalization were independent predictors (odds ratio [OR] 0.58, 95% confidence interval [CI] 0.45-0.75, p<0.001 and OR 0.42, 95% CI 0.33-0.54, p<0.001, respectively). When we could not achieve the lactate normalization, the sensitivity, specificity, positive, and negative predictive value to predict mortality were 76.6%, 42.4%, 26.5% and 87.0% respectively for 6-h normalization, and 68.8%, 60.2%, 32.0% and 87.7% respectively for 24-h normalization. Besides 6-h lactate normalization, 24-h delayed lactate normalization was associated with decreasing mortality in septic shock patients. Lactate normalization may have a role in early risk stratification and as a therapeutic target.

Acid-Base Disturbances in Patients with Asthma: A Literature Review and Comments on Their Pathophysiology

Asthma is a common illness throughout the world that affects the respiratory system function, i.e., a system whose operational adequacy determines the respiratory gases exchange. It is therefore expected that acute severe asthma will be associated with respiratory acid-base disorders. In addition, the resulting hypoxemia along with the circulatory compromise due to heart–lung interactions can reduce tissue oxygenation, with a particular impact on respiratory muscles that have increased energy needs due to the increased workload. Thus, anaerobic metabolism may ensue, leading to lactic acidosis. Additionally, chronic hypocapnia in asthma can cause a compensatory drop in plasma bicarbonate concentration, resulting in non-anion gap acidosis. Indeed, studies have shown that in acute severe asthma, metabolic acid-base disorders may occur, i.e., high anion gap or non-anion gap metabolic acidosis. This review briefly presents studies that have investigated acid-base disorders in asthma, with comments on their underlying pathophysiology.

Utility of the early lactate area score as a prognostic marker for septic shock patients in the emergency department

Background

The current Surviving Sepsis Campaign guidelines recommend the remeasurement of lactate levels if the initial lactate level is elevated; however, the prognostic value of lactate kinetics is limited and inconsistent. We attempted to determine the efficacy of the lactate area score (calculated from repeated lactate measurements during initial resuscitation) as a prognostic marker of septic shock in the emergency department (ED).

Methods

We performed a retrospective study of adult patients with septic shock in the ED of a single tertiary medical center. Serial lactate levels were measured five times within 12 hours. We also compared the initial lactate level, maximum lactate level, and lactate area score. The lactate area score was defined as the sum of the area under the curve measured at 2, 4, 6, and 12 hours following the initial measurement.

Results

A total of 362 patients were enrolled in this study, and the overall 28-day mortality was 31.8%. The lactate area score of serial lactate levels as well as the initial (median [interquartile range], 4.9 [3.4 to 10.5]; P=0.003) and maximum (7.3 [4.2 to 13.2]; P<0.001) lactate levels were significantly higher in the non-survivor group. However, in multivariate analysis, only the lactate area score (odds ratio, 1.013; 95% confidence interval, 1.007 to 1.019) was significantly associated with 28-day mortality.

Conclusions

The early lactate area score may be a possible prognostic marker for predicting the 28-day mortality of adult septic shock patients. Further prospective interventional studies should be conducted to validate our results.

Admission characteristics predictive of in-hospital death from hospital-acquired sepsis: A comparison to community-acquired sepsis

PURPOSE

Healthcare associated (HA) sepsis is associated with increased resource utilization and mortality compared with community acquired (CA) sepsis. The purpose of this study was to identify independent predictors of in-hospital mortality from HA-sepsis.

MATERIALS AND METHODS

Retrospective study of adult patients admitted with HA or CA-sepsis. Predictors were identified using logistic regression.

RESULTS

There were 3917 sepsis encounters, of which 3186 were CA and 731 were HA. History of stroke (83/731, 11%) and myocardial infarction (70/731, 10%) were higher in HA than CA-sepsis (stroke: 258/3186, 8%, p = .005; myocardial infarction: 213/3186, 7%, p = .007). HA-sepsis patients required more mechanical ventilation (153/731, 21%) than CA-patients (218/3186, 7%, p < .001) and had a higher rate of vasopressor use (334/731, 46%) than CA patients (832/3186, 26%, p < .001). The HA group had longer ICU lengths of stay (LOS) than CA patients did at 9 days and 2.8 days, respectively (p < .0001). Moderate to severe liver disease (OR = 27, 95%CI 1.4, 513, p = .031) and congestive heart failure (CHF, 5.81, 95% CI 1.3, 26, p = .025) were predictive of in-hospital mortality from HA-sepsis.

CONCLUSIONS

Liver disease and CHF were independent predictors of in-hospital mortality in HA-sepsis. HA-sepsis patients had increased prevalence of previous stroke, myocardial infarction, and liver disease.

Direct-acting antiviral hepatitis C virus treatment perturbation of the metabolic milieu

OBJECTIVE

Hepatitis C virus (HCV), cirrhosis, and HCV medications including direct-acting antivirals (DAAs) ±ribavirin may all influence the metabolic milieu. While interferon-based regimens improve glucose tolerance, evidence is limited on DAAs. Cases of elevated lactate have recently been reported in patients treated with DAAs, and lactic acidosis is a known complication of antivirals used to treat hepatitis B virus and HIV.

PATIENTS AND METHODS

Measures were evaluated at baseline, week 4, end of treatment, and 12-24 weeks after treatment. Mixed-effects modeling was used to determine factors influencing glucose and lactate over time.

RESULTS

In total, 442 patients were treated (mean age 56, 65% male, 72% genotype 1, 48% cirrhotic). Glucose did not change on or after DAA treatment from baseline (P=0.51) aside from those with untreated diabetes, which declined (P=0.02). Overall, there was a decline in lactate following HCV treatment (mean 2.4-2.1 mmol/l; P<0.001). Lactate initially increased on treatment and then decreased after treatment completion in male patients treated with ribavirin. This pattern was not observed in other groups. There was no evidence of lactic acidosis with HCV nucleotide use.

CONCLUSION

Distinct glucose and lactate trajectories were identified without evidence of DAA metabolic toxicity. HCV treatment does not improve random glucose levels aside from perhaps in untreated diabetic patients.

Sequential Organ Failure Assessment Component Score Prediction of In-hospital Mortality From Sepsis

OBJECTIVES

Early organ dysfunction in sepsis confers a high risk of in-hospital mortality, but the relative contribution of specific types of organ failure to overall mortality is unclear. The objective of this study was to assess the predictive ability of individual types of organ failure to in-hospital mortality or prolonged intensive care.

METHODS

Retrospective cohort study of adult emergency department patients with sepsis from October 1, 2013, to November 10, 2015. Multivariable regression was used to assess the odds ratios of individual organ failure types for the outcomes of in-hospital death (primary) and in-hospital death or ICU stay ≥ 3 days (secondary).

RESULTS

Of 2796 patients, 283 (10%) experienced in-hospital mortality, and 748 (27%) experienced in-hospital mortality or an ICU stay ≥ 3 days. The following components of Sequential Organ Failure Assessment (SOFA) score were most predictive of in-hospital mortality (descending order): coagulation (odds ratio [OR]: 1.60, 95% confidence interval [CI]: 1.32-1.93), hepatic (1.58, 95% CI: 1.32-1.90), respiratory (OR: 1.33, 95% CI: 1.21-1.47), neurologic (OR: 1.20, 95% CI: 1.07-1.35), renal (OR: 1.14, 95% CI: 1.02-1.27), and cardiovascular (OR: 1.13, 95% CI: 1.01-1.25). For mortality or ICU stay ≥3 days, the most predictive SOFA components were respiratory (OR: 1.97, 95% CI: 1.79-2.16), neurologic (OR: 1.72, 95% CI: 1.54-1.92), cardiovascular (OR: 1.38, 95% CI: 1.23-1.54), coagulation (OR: 1.31, 95% CI: 1.10-1.55), and renal (OR: 1.19, 95% CI: 1.08-1.30) while hepatic SOFA (OR: 1.16, 95% CI: 0.98-1.37) did not reach statistical significance (P = .092).

CONCLUSION

In this retrospective study, SOFA score components demonstrated varying predictive abilities for mortality in sepsis. Elevated coagulation or hepatic SOFA scores were most predictive of in-hospital death, while an elevated respiratory SOFA was most predictive of death or ICU stay >3 days.

Timing of Repeated Lactate Measurement in Patients With Septic Shock at the Emergency Department

BACKGROUND

The objective of this study was to evaluate the prognostic value of lactate levels during the first 12 hours after shock development and to identify the optimal timing for repeated lactate measurements in patients with septic shock.

METHODS

We conducted a retrospective cohort study using a prospective data registry, and enrolled 2,226 consecutive adult patients with septic shock between January 2010 and December 2015. Blood lactate was measured at shock development, and after 2, 4, 6 and 12 hours (T₀, T₂, T₄, T₆ and T₁₂) during protocol-driven resuscitation bundle therapy. The prognostic value of lactate levels for 28-day mortality was analyzed using logistic regression and receiver operating characteristic curve analysis.

RESULTS

A total of 829 patients with septic shock were included in the study, among whom 211 died during the study period. The lactate levels at each time point were associated with increased 28-day mortality, and the lactate level at 6 hours had the greatest prognostic value (area under the curve of T₀ = 0.61; T₂ = 0.65; T₄ = 0.69; T₆ = 0.72 and T₁₂ = 0.62, and odds ratio (OR) of T₀, 1.17 [95% CI: 1.11-1.23]; T₂, 1.23 [95% CI: 1.17-1.30]; T₄, 1.30 [95% CI: 1.22-1.38]; T₆, 1.33 [95% CI: 1.26-1.42] and T₁₂, 1.24 [95% CI: 1.19-1.30]). Hyperlactatemia over 2mmol/L and 4mmol/L at 6 hours from shock was associated with 4-times higher mortality (≥2mmol/L, OR = 3.89 [95% CI: 2.48-6.09]; ≥4mmol/L, OR = 3.93 [95% CI: 2.83-5.44]).

CONCLUSIONS

During the first 12 hours following shock development, the optimal time point of repeated blood lactate measurement was 6 hours, which was the greatest prognostic value for mortality.

Advances in the design of nanomaterial-based electrochemical affinity and enzymatic biosensors for metabolic biomarkers: A review

This review (with 340 refs) focuses on methods for specific and sensitive detection of metabolites for diagnostic purposes, with particular emphasis on electrochemical nanomaterial-based sensors. It also covers novel candidate metabolites as potential biomarkers for diseases such as neurodegenerative diseases, autism spectrum disorder and hepatitis. Following an introduction into the field of metabolic biomarkers, a first major section classifies electrochemical biosensors according to the bioreceptor type (enzymatic, immuno, apta and peptide based sensors). A next section covers applications of nanomaterials in electrochemical biosensing (with subsections on the classification of nanomaterials, electrochemical approaches for signal generation and amplification using nanomaterials, and on nanomaterials as tags). A next large sections treats candidate metabolic biomarkers for diagnosis of diseases (in the context with metabolomics), with subsections on biomarkers for neurodegenerative diseases, autism spectrum disorder and hepatitis. The Conclusion addresses current challenges and future perspectives. Graphical abstract This review focuses on the recent developments in electrochemical biosensors based on the use of nanomaterials for the detection of metabolic biomarkers. It covers the critical metabolites for some diseases such as neurodegenerative diseases, autism spectrum disorder and hepatitis.

Prognosis of patients excluded by the definition of septic shock based on their lactate levels after initial fluid resuscitation: a prospective multi-center observational study

Background

Septic shock can be defined both by the presence of hyperlactatemia and need of vasopressors. Lactate levels should be measured after volume resuscitation (as per the Sepsis-3 definition). However, currently, no studies have evaluated patients who have been excluded by the new criteria for septic shock. The aim of this study was to determine the clinical characteristics and prognosis of these patients, based on their lactate levels after initial fluid resuscitation.

Methods

This observational study was performed using a prospective, multi-center registry of septic shock, with the participation of 10 hospitals in the Korean Shock Society, between October 2015 and February 2017. We compared the 28-day mortality between patients who were excluded from the new definition (defined as lactate level <2 mmol/L after volume resuscitation) and those who were not (≥2 mmol/L after volume resuscitation), from among a cohort of patients with refractory hypotension, and requiring the use of vasopressors. Other outcome variables such as in-hospital mortality, intensive care unit (ICU) stay (days), Sequential Organ Failure Assessment (SOFA) scores and Acute Physiology and Chronic Health Evaluation (APACHE) II scores were also analyzed.

Results

Of 567 patients with refractory hypotension, requiring the use of vasopressors, 435 had elevated lactate levels, while 83 did not have elevated lactate levels (either initially or after volume resuscitation), and 49 (8.2%) had elevated lactate levels initially, which normalized after fluid resuscitation. Thus, these 49 patients were excluded by the new definition of septic shock. These patients, in whom perfusion was restored, demonstrated significantly lower age, platelet count, and initial and subsequent lactate levels (all p < 0.01). Similarly, significantly lower 28-day mortality was observed in these patients than in those who had not been excluded (8.2% vs 25.5%, p = 0.02). In-hospital mortality and the maximum SOFA score were also significantly lower in the excluded patients group (p = 0.03, both).

Conclusions

It seems reasonable for septic shock to be defined by the lactate levels after volume resuscitation. However, owing to the small number of patients in whom lactate levels were improved, further study is warranted.

Electronic supplementary material

The online version of this article (10.1186/s13054-017-1935-3) contains supplementary material, which is available to authorized users.

Metformin-associated lactic acidosis (MALA): Moving towards a new paradigm

Although metformin has been used for over 60 years, the balance between the drug's beneficial and adverse effects is still subject to debate. Following an analysis of how cases of so-called "metformin-associated lactic acidosis" (MALA) are reported in the literature, the present article reviews the pitfalls to be avoided when assessing the purported association between metformin and lactic acidosis. By starting from pathophysiological considerations, we propose a new paradigm for lactic acidosis in metformin-treated patients. Metformin therapy does not necessarily induce metformin accumulation, just as metformin accumulation does not necessarily induce hyperlactatemia, and hyperlactatemia does not necessarily induce lactic acidosis. In contrast to the conventional view, MALA probably accounts for a smaller proportion of cases than either metformin-unrelated lactic acidosis or metformin-induced lactic acidosis. Lastly, this review highlights the need for substantial improvements in the reporting of cases of lactic acidosis in metformin-treated patients. Accordingly, we propose a check-list as a guide to clinical practice.

Acid-base disorders in liver disease

Alongside the kidneys and lungs, the liver has been recognised as an important regulator of acid-base homeostasis. While respiratory alkalosis is the most common acid-base disorder in chronic liver disease, various complex metabolic acid-base disorders may occur with liver dysfunction. While the standard variables of acid-base equilibrium, such as pH and overall base excess, often fail to unmask the underlying cause of acid-base disorders, the physical-chemical acid-base model provides a more in-depth pathophysiological assessment for clinical judgement of acid-base disorders, in patients with liver diseases. Patients with stable chronic liver disease have several offsetting acidifying and alkalinising metabolic acid-base disorders. Hypoalbuminaemic alkalosis is counteracted by hyperchloraemic and dilutional acidosis, resulting in a normal overall base excess. When patients with liver cirrhosis become critically ill (e.g., because of sepsis or bleeding), this fragile equilibrium often tilts towards metabolic acidosis, which is attributed to lactic acidosis and acidosis due to a rise in unmeasured anions. Interestingly, even though patients with acute liver failure show significantly elevated lactate levels, often, no overt acid-base disorder can be found because of the offsetting hypoalbuminaemic alkalosis. In conclusion, patients with liver diseases may have multiple co-existing metabolic acid-base abnormalities. Thus, knowledge of the pathophysiological and diagnostic concepts of acid-base disturbances in patients with liver disease is critical for therapeutic decision making.