Elevated Venous to Arterial Carbon Dioxide Gap and Anion Gap Are Associated with Poor Outcome in Cardiogenic Shock Requiring Extracorporeal Membrane Oxygenation Support

Which cardiovascular monitoring on veno-arterial extracorporeal membrane oxygenation

PURPOSE REVIEW

To discuss the hemodynamic monitoring techniques to quantify cardiac output, to assess the adequacy of perfusion, and to evaluate cardiac as well as pump preload and fluid responsiveness in patients supported by veno-arterial extracorporeal membrane oxygenation (VA-ECMO). Echocardiography is essential in the hemodynamic assessment of VA-ECMO patients. However, intermittent echocardiography should be complemented by continuous, potentially nurse driven, monitoring techniques. We will focus on invasive and noninvasive hemodynamic monitoring methods beyond echocardiography.

RECENT FINDINGS

Despite the importance of comprehensive hemodynamic monitoring in the provision of safe, adequate, and well balanced VA-ECMO support, limited data are currently available in this specific patient population. While some measurements (intravascular pressures, oxygen saturation) remain valid and provide important information on the hemodynamic state, measurements of cardiac output are invalid with many of the hemodynamic monitoring methods. Many of the routinely used monitoring methods must be interpreted with caution during VA-ECMO support.

SUMMARY

A thorough understanding of the various hemodynamic monitoring methods and the physiological interactions between VA-ECMO and patients is essential for selecting the optimal hemodynamic monitoring strategy and correctly interpreting the resulting hemodynamic measurements.

Optimising fluid therapy during venoarterial extracorporeal membrane oxygenation: current evidence and future directions

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) offers an immediate and effective mechanical cardio-circulatory support for critically ill patients with refractory cardiogenic shock or selected refractory cardiac arrest. As fluid therapy is routinely performed as a component of initial hemodynamic resuscitation of ECMO supported patients, this narrative review intends to summarize the rationale and the evidence on the fluid resuscitation strategy in terms of fluid type and dosing, the impact of fluid balance on outcomes and fluid responsiveness assessment in VA-ECMO patients. Several observational studies have shown a deleterious impact of positive fluid balance on survival and renal outcomes. With regard to the type of crystalloids, further studies are needed to evaluate the safety and efficacy of saline versus balanced solutions in terms of hemodynamic stability, renal outcomes and survival in VA-ECMO setting. The place and the impact of albumin replacement, as a second-line option, should be investigated. During VA-ECMO run, the fluid management approach could be divided into four phases: rescue or salvage, optimization, stabilization, and evacuation or de-escalation. Echocardiographic assessment of stroke volume changes following a fluid challenge or provocative tests is the most used tool in clinical practice to predict fluid responsiveness. This review underscores the need for high-quality evidence regarding the optimal fluid strategy and the choice of fluid type in ECMO supported patients. Pending specific data, fluid therapy needs to be personalized and guided by dynamic hemodynamic approach coupled to close monitoring of daily weight and fluid balance in order to provide adequate ECMO flow and tissue perfusion while avoiding harmful effects of fluid overload.

Can utilization of the venous-to-arterial carbon dioxide difference improve patient outcomes in cardiogenic shock? A narrative review

Cardiogenic shock (CS) is a critical condition with high mortality, characterized by reduced cardiac output (CO) and tissue hypoperfusion, despite advancements in treatment. Traditional hemodynamic markers like CO measurements, monitoring of mixed venous oxygen saturation (SvO₂) and lactate levels have limitations, particularly in detecting microcirculatory dysfunction. The venous-to-arterial carbon dioxide tension difference (V-A PCO₂ gap, also known as P(V-A)CO2 and delta PCO2 or ∆PCO2) has been established as a sensitive marker of tissue perfusion and CO adequacy in septic shock but lacks extensive exploration in CS. This narrative review evaluates the possible uses of V-A PCO₂ gap in contemporary management of CS. Based on the available literature, it elucidates how the V-A PCO2 gap may offer valuable insight into tissue perfusion and CO adequacy in patients with CS. Elevated V-A PCO₂ gaps may reflect impaired clearance of CO₂ due to reduced CO and tissue hypoxia, serving as a reliable early indicator of circulatory failure. Integrating V-A PCO₂ gap monitoring into contemporary hemodynamic assessments holds potential to improve clinical decision-making, enabling more timely interventions and better stratification of patients at risk of deterioration. The sparse evidence suggests an association between elevated V-A PCO₂ gaps and poor outcomes in cardiac patients, including increased mortality and prolonged ventilation needs. Further research is needed to validate the use of this marker in CS and explore its potential to enhance treatment protocols by providing a more nuanced understanding of tissue-level perfusion, especially when macrocirculatory function appears normalized.

Management of cardiogenic shock: state-of-the-art

The management of cardiogenic shock is an ongoing challenge. Despite all efforts and tremendous use of resources, mortality remains high. Whilst reversing the underlying cause, restoring/maintaining organ perfusion and function are cornerstones of management. The presence of comorbidities and preexisting organ dysfunction increases management complexity, aiming to integrate the needs of vital organs in each individual patient. This review provides a comprehensive overview of contemporary literature regarding the definition and classification of cardiogenic shock, its pathophysiology, diagnosis, laboratory evaluation, and monitoring. Further, we distill the latest evidence in pharmacologic therapy and the use of mechanical circulatory support including recently published randomized-controlled trials as well as future directions of research, integrating this within an international group of authors to provide a global perspective. Finally, we explore the need for individualization, especially in the face of neutral randomized trials which may be related to a dilution of a potential benefit of an intervention (i.e., average effect) in this heterogeneous clinical syndrome, including the use of novel biomarkers, artificial intelligence, and machine learning approaches to identify specific endotypes of cardiogenic shock (i.e., subclasses with distinct underlying biological/molecular mechanisms) to support a more personalized medicine beyond the syndromic approach of cardiogenic shock.

Hemodynamic monitoring and echocardiographic evaluation in cardiogenic shock

Cardiogenic shock (CS) is characterized by the presence of a state of tissue hypoperfusion secondary to ventricular dysfunction. Hemodynamic monitoring allows us to obtain information about cardiovascular pathophysiology that will help us make the diagnosis and guide therapy in CS situations. The most used monitoring system in CS is the pulmonary artery catheter since it provides key hemodynamic variables in CS, such as cardiac output, pulmonary artery pressure, and pulmonary artery occlusion pressure. On the other hand, echocardiography makes it possible to obtain, at the bedside, anatomical and hemodynamic data that complement the information obtained through continuous monitoring devices. CS monitoring can be considered multimodal and integrative by including hemodynamic, metabolic, and echocardiographic parameters that allow describing the characteristics of CS and guiding therapeutic interventions during hemodynamic resuscitation.

Serum Anion Gap at Admission Predicts All-Cause Mortality in Critically Ill Patients With Cirrhosis: A Retrospective Cohort Study

INTRODUCTION

The primary objective of this study was to evaluate admission serum anion gap (AG) as a predictor of all-cause mortality in critically ill patients with cirrhosis.

METHODS

A total of 3,084 cirrhotic patients were included and randomly divided into training and validation cohorts (n = 2,159 and 925, respectively). Patients were categorized into high and normal AG groups based on their AG values. Cox regression and Kaplan-Meier survival analysis were used to assess the relationships between AG levels and outcomes.

RESULTS

Both cohorts showed strong parameter similarity ( P > 0.05). High AG was associated with significantly lower survival probabilities. Cox models confirmed elevated AG as a risk factor, even after adjusting for covariates (hazard ratio: 1.920, 1.793, and 1.764 for 30-day, 60-day, and hospital mortality, respectively). Subgroup analyses, especially regarding chronic kidney disease, revealed complex interactions. Serum AG displayed predictive power comparable with established scoring systems.

DISCUSSION

Elevated AG at admission is a valuable predictor of poor outcomes and increased mortality risk in critically ill cirrhotic patients. Serum AG can serve as an easily accessible tool for risk assessment and prognosis evaluation in this population.

The relationship between serum anion gap levels and short-, medium-, and long-term all-cause mortality in ICU patients with congestive heart failure: a retrospective cohort study

BACKGROUND

There hasn't been research done on the connection between serum anion gap (AG) levels and long-, medium-, and short-term all-cause mortality in congestive heart failure (CHF) patients. This study aims to investigate the association between serum anion gap levels and all-cause mortality in CHF patients after adjusting for other covariates.

METHODS

For each patient, we gather demographic information, comorbidities, laboratory results, vital signs, and scoring data using the ICU (Intensive Care Unit) Admission Scoring System from the MIMIC-III database. The connection between baseline AG and long-, medium-, and short-term all-cause mortality in critically ill congestive heart failure patients was investigated using Kaplan-Meier survival curves, subgroup analysis, restricted cubic spline, and Cox proportional risk analysis.

RESULTS

4840 patients with congestive heart failure in total were included in this study. With a mean age of 72.5 years, these patients had a gender split of 2567 males and 2273 females. After adjusting for other covariates, a multiple regression analysis revealed that, in critically ill patients with congestive heart failure, all-cause mortality increased significantly with rising AG levels. In the fully adjusted model, we discovered that AG levels were strongly correlated with 4-year, 365-day, 90-day, and 30-day all-cause mortality in congestive heart failure patients with HRs (95% CI) of 1.06 (1.04, 1.08); 1.08 (1.05, 1.10); and 1.08 (1.05, 1.11) (p-value < 0.05). Our subgroup analysis's findings demonstrated a high level of consistency and reliability. K-M survival curves demonstrate that high serum AG levels are associated with a lower survival probability.

CONCLUSION

Our research showed the association between CHF patients' all-cause mortality and anion gap levels was non-linear. Elevated anion gap levels are associated with an increased risk of long-, medium-, and short-term all-cause death in patients with congestive heart failure. Continuous monitoring of changes in AG levels may have a clinical predictive role.

Cardiogenic shock trajectories: is the Society for Cardiovascular Angiography and Interventions definition the right one?

PURPOSE OF REVIEW

We review the current Society for Cardiovascular Angiography and Interventions (SCAI) cardiogenic shock classification system and consider alternatives or iterations that may enhance our current descriptions of cardiogenic shock trajectory.

RECENT FINDINGS

Several studies have identified the potential prognostic value of serial SCAI stage re-assessment, usually within the first 24 h of shock onset, to predict deterioration and clinical outcomes across shock causes. In parallel, numerous registry-based analyses support the utility of a more precise assessment of the macrocirculation and microcirculation, leveraging invasive haemodynamics, imaging and additional laboratory and clinical markers. The emergence of machine learning and artificial intelligence capabilities offers the opportunity to integrate multimodal data into high fidelity, real-time metrics to more precisely define trajectory and inform our therapeutic decision making.

SUMMARY

Whilst the SCAI staging system remains a pivotal tool in cardiogenic shock assessment, communication and reassessment, it is vital that the sophistication with which we measure and assess shock trajectory evolves in parallel our understanding of the complexity and variability of clinical course and clinical outcomes.

Relationship between the mixed venous-to-arterial carbon dioxide gradient and the cardiac index in acute pulmonary embolism

AIMS

Among patients with acute pulmonary embolism (PE) undergoing mechanical thrombectomy, the cardiac index (CI) is frequently reduced even among those without a clinically apparent shock. The purpose of this study is to describe the mixed venous-to-arterial carbon dioxide gradient (CO2 gap), a surrogate of perfusion adequacy, among patients with acute PE undergoing mechanical thrombectomy.

METHODS AND RESULTS

This was a single-centre retrospective study of consecutive patients with PE undergoing mechanical thrombectomy and simultaneous pulmonary artery catheterization over a 3-year period. Of 107 patients, 97 had simultaneous mixed venous and arterial blood gas measurements available. The CO2 gap was elevated (>6 mmHg) in 51% of the cohort and in 49% of patients with intermediate-risk PE. A reduced CI (≤2.2 L/min/m2) was associated with an increased odds [odds ratio = 7.9; 95% confidence interval (CI) 3.49-18.1, P < 0.001] for an elevated CO2 gap. There was an inverse relationship between the CI and the CO2 gap. For every 1 L/min/m2 decrease in the CI, the CO2 gap increased by 1.3 mmHg (P = 0.001). Among patients with an elevated baseline CO2 gap >6 mmHg, thrombectomy improved the CO2 gap, CI, and mixed venous oxygen saturation. When the CO2 gap was dichotomized above and below 6, there was no difference in the in-hospital mortality rate (9 vs. 0%; P = 0.10; hazard ratio: 1.24; 95% CI 0.97-1.60; P = 0.085).

CONCLUSION

Among patients with acute PE undergoing mechanical thrombectomy, the CO2 gap is abnormal in nearly 50% of patients and inversely related to the CI. Further studies should examine the relationship between markers of perfusion and outcomes in this population to refine risk stratification.

The association between serum anion gap and acute kidney injury after coronary artery bypass grafting in patients with acute coronary syndrome

BACKGROUND

The purpose of this study was to explore the association between serum anion gap (SAG) and acute kidney injury (AKI) after coronary artery bypass grafting (CABG) in patients with acute coronary syndrome (ACS) in the Intensive Care Unit (ICU).

METHODS

We retrospectively analyzed the clinical data of 2,428 ACS patients who underwent CABG in the Medical Information Mart for Intensive Care IV (Mimic-IV) database. The endpoint of this study was AKI after CABG. The baseline data of the two groups (non-AKI group vs. AKI group) was compared, and the restricted cubic spline (RCS) plot, multivariable logistic regression model, and subgroup analysis were used to explore the relationship between SAG and the risk of AKI after CABG.

RESULTS

In the adjusted multivariate logistic regression model, SAG was an independent predictor of AKI after CABG (OR = 1.12, 95% CI: 1.02-1.23, P = 0.015). The RCS revealed that the relationship between SAG levels and risk of AKI was J-shaped. When the SAG was ≥ 11.58 mmol/L, the risk of AKI increased by 26% for each unit increase in SAG. Additionally, we further divided the SAG into quartiles. In the fully adjusted model, compared with the first quartile of SAG, the odds ratios (ORs) and 95% confidence intervals (CIs) for AKI risk across the SAG quartiles were 0.729 (0.311, 1.600), 1.308 (0.688-2.478), and 2.221 (1.072, 4.576).

CONCLUSIONS

The SAG level was associated with the risk of AKI after CABG in a J-shaped curve in the ICU. However, the underlying causes of the problem need to be investigated.

The ∆Pv-aCO2/∆Ca-vO2 ratio as a predictor of mortality in patients with severe acute respiratory distress syndrome related to COVID-19

OBJECTIVE

To evaluate the central venous-to-arterial carbon dioxide difference combined with arterial-to-venous oxygen content difference (∆Pv-aCO2/∆Ca-vO2 ratio) as a predictor of mortality in patients with COVID-19-related severe acute respiratory distress syndrome (ARDS).

METHODS

Patients admitted to the intensive care unit with severe ARDS secondary to SARS-CoV-2, and invasive mechanical ventilation were included in this single-center and retrospective cohort study performed between April 18, 2020, and January 18, 2022. The tissue perfusion indexes (lactate, central venous oxygen saturation [ScvO2], and venous-to-arterial carbon dioxide pressure difference [∆Pv-aCO2]), anaerobic metabolism index (∆Pv-aCO2/∆Ca-vO2 ratio), and severity index (Simplified Acute Physiology Score II [SAPSII]) were evaluated to determine its association with the mortality through Cox regression analysis, Kaplan-Meier curve and receiver operating characteristic (ROC) curve.

RESULTS

One hundred fifteen patients were included in the study and classified into two groups, the survivor group (n = 54) and the non-survivor group (n = 61). The lactate, ScvO2, ∆Pv-aCO2, and ∆Pv-aCO2/∆Ca-vO2 ratio medians were 1.6 mEq/L, 75%, 5 mmHg, and 1.56 mmHg/mL, respectively. The ∆Pv-aCO2/∆Ca-vO2 ratio (Hazard Ratio (HR) = 1.17, 95% confidence interval (CI) = 1.06-1.29, p = 0.001) was identified as a mortality biomarker for patients with COVID-19-related severe ARDS. The area under the curve for ∆Pv-aCO2/∆Ca-vO2 ratio was 0.691 (95% CI 0.598-0.774, p = 0.0001). The best cut-off point for ∆Pv-aCO2/∆Ca-vO2 ratio was >2.14 mmHg/mL, with a sensitivity of 49.18%, specificity of 85.19%, a positive likelihood of 3.32, and a negative likelihood of 0.6. The Kaplan-Meier curve showed that survival rates were significantly worse in patients with values greater than this cut-off point.

CONCLUSIONS

The ∆Pv-aCO2/∆Ca-vO2 ratio could be used as a predictor of mortality in patients with severe ARDS secondary to SARS-CoV-2.

Use of CO2-Derived Variables in Cardiac Intensive Care Unit: Pathophysiology and Clinical Implications

Shock is a life-threatening condition, and its timely recognition is essential for adequate management. Pediatric patients with congenital heart disease admitted to a cardiac intensive care unit (CICU) after surgical corrections are particularly at risk of low cardiac output syndrome (LCOS) and shock. Blood lactate levels and venous oxygen saturation (ScVO₂) are usually used as shock biomarkers to monitor the efficacy of resuscitation efforts, but they are plagued by some limitations. Carbon dioxide (CO₂)-derived parameters, namely veno-arterial CO₂ difference (ΔCCO₂) and the VCO₂/VO₂ ratio, may represent a potentially valuable addition as sensitive biomarkers to assess tissue perfusion and cellular oxygenation and may represent a valuable addition in shock monitoring. These variables have been mostly studied in the adult population, with a strong association between ΔCCO₂ or VCO₂/VO₂ ratio and mortality. In children, particularly in CICU, few studies looked at these parameters, while they reported promising results on the use of CO₂-derived indices for patients' management after cardiac surgeries. This review focuses on the physiological and pathophysiological determinants of ΔCCO₂ and VCO₂/VO₂ ratio while summarizing the actual state of knowledge on the use of CO₂-derived indices as hemodynamical markers in CICU.

Hemodynamic monitoring in cardiogenic shock

Cardiogenic shock (CS) is a life-threatening condition characterized by acute end-organ hypoperfusion due to inadequate cardiac output that can result in multiorgan failure, which may lead to death. The diminished cardiac output in CS leads to systemic hypoperfusion and maladaptive cycles of ischemia, inflammation, vasoconstriction, and volume overload. Obviously, the optimal management of CS needs to be readjusted in view of the predominant dysfunction, which may be guided by hemodynamic monitoring. Hemodynamic monitoring enables (1) characterization of the type of cardiac dysfunction and the degree of its severity, (2) very early detection of associated vasoplegia, (3) detection and monitoring of organ dysfunction and tissue oxygenation, and (4) guidance of the introduction and optimization of inotropes and vasopressors as well as the timing of mechanical support. It is now well documented that early recognition, classification, and precise phenotyping via early hemodynamic monitoring (e.g., echocardiography, invasive arterial pressure, and the evaluation of organ dysfunction and parameters derived from central venous catheterization) improve patient outcomes. In more severe disease, advanced hemodynamic monitoring with pulmonary artery catheterization and the use of transpulmonary thermodilution devices is useful to facilitate the right timing of the indication, weaning from mechanical cardiac support, and guidance on inotropic treatments, thus helping to reduce mortality. In this review, we detail the different parameters relevant to each monitoring approach and the way they can be used to support optimal management of these patients.

The role of temporary mechanical circulatory support in de novo heart failure syndromes with cardiogenic shock: A contemporary review

Cardiogenic shock (CS) is a complex clinical syndrome with a high mortality rate. It can occur to due to multiple etiologies of cardiovascular disease and is phenotypically heterogeneous. Acute myocardial infarction-related CS (AMI-CS) has historically been the most prevalent cause, and thus, research and guidance have focused primarily on this. Recent data suggest that the burden of non-ischemic CS is increasing in the population of patents requiring intensive care admission. There is, however, a paucity of data and guidelines to inform the management of these patients who fall into two broad groups: those with existing heart failure and CS and those with no known history of heart failure who present with "de novo" CS. The use of temporary mechanical circulatory support (MCS) has expanded across all etiologies, despite its high cost, resource intensity, complication rates, and lack of high-quality outcome data. Herein, we discuss the currently available evidence on the role of MCS in the management of patients with de novo CS to include fulminant myocarditis, right ventricular (RV) failure, Takotsubo syndrome, post-partum cardiomyopathy, and CS due to valve lesions and other cardiomyopathies.

Influence of Venoarterial Extracorporeal Membrane Oxygenation Integrated Hemoadsorption on the Early Reversal of Multiorgan and Microcirculatory Dysfunction and Outcome of Refractory Cardiogenic Shock

Background: The purpose of this investigation was to evaluate the impact of venoarterial extracorporeal membrane oxygenation (VA−ECMO) integrated hemoadsorption on the reversal of multiorgan and microcirculatory dysfunction, and early mortality of refractory cardiogenic shock patients. Methods: Propensity score−matched cohort study of 29 pairs of patients. Subjects received either VA−ECMO supplemented with hemoadsorption or standard VA−ECMO management. Results: There was a lower mean sequential organ failure assessment score (p = 0.04), lactate concentration (p = 0.015), P(v−a)CO2 gap (p < 0.001), vasoactive inotropic score (p = 0.007), and reduced delta C−reactive protein level (p = 0.005) in the hemoadsorption compared to control groups after 72 h. In−hospital mortality was similar to the predictions in the control group (62.1%) and was much lower than the predicted value in the hemoadsorption group (44.8%). There were less ECMO-associated bleeding complications in the hemoadsorption group compared to controls (p = 0.049). Overall, 90-day survival was better in the hemoadsorption group than in controls without statistical significance. Conclusion: VA−ECMO integrated hemoadsorption treatment was associated with accelerated recovery of multiorgan and microcirculatory dysfunction, mitigated inflammatory response, less bleeding complications, and lower risk for early mortality in comparison with controls.

The value of anion gap for predicting the short-term all-cause mortality of critically ill patients with cardiac diseases, based on MIMIC-III database

BACKGROUND

The association of anion gap (AG) with short-term mortality in the critically ill patients with cardiac diseases is still not well understood.

OBJECTIVE

To evaluate the association of AG with short-term mortality, and the predictive ability of AG for short-term mortality in critically ill patients with cardiac diseases.

METHODS

This retrospective cohort study enrolled 9104 critically ill patients with cardiac diseases from the Medical Information Mart for Intensive Care III (MIMIC III) database. The restricted cubic spline models were used to evaluate the nonlinear relationship between AG and short-term mortality. Cox proportional hazards regression models and subgroup analysis were applied to assess the association of AG with short-term mortality.

RESULTS

The data were divided into three groups by AG tertiles: tertile I (AG <12, n = 2095), tertile II (12 ≤ AG < 15, n = 3195), and tertile III (15 ≤ AG, n = 3814). The restricted cubic spline models revealed continuous AG was non-linearly related to short-term mortality. The elevated AG tertiles were strongly associated with higher in-hospital, 30-day and 90-day mortality (all P for trend < 0.001). After adding AG to traditional severity scores, the area under curves (AUCs) elevated significantly compared to severity scores alone (all DeLong's test: P < 0.001). Subgroup analysis did not indicate significant interaction in most diverse subgroups.

CONCLUSION

AG was an independent risk factor for short-term all-cause mortality in critically ill patients with cardiac diseases. AG improved significantly the mortality predictive abilities of traditional severity scores when AG was added to these scores.

Optimal Perfusion Targets in Cardiogenic Shock

Cardiology shock is a syndrome of low cardiac output resulting in end-organ dysfunction. Few interventions have demonstrated meaningful clinical benefit, and cardiogenic shock continues to carry significant morbidity with mortality rates that have plateaued at upwards of 40% over the past decade. Clinicians must rely on clinical, biochemical, and hemodynamic parameters to guide resuscitation. Several features, including physical examination, renal function, serum lactate metabolism, venous oxygen saturation, and hemodynamic markers of right ventricular function, may be useful both as prognostic markers and to guide therapy. This article aims to review these targets, their utility in the care of patients with cardiology shock, and their association with outcomes.

A novel nomogram for predicting 3-year mortality in critically ill patients after coronary artery bypass grafting

Background

The long-term outcomes for patients after coronary artery bypass grafting (CABG) have been received more and more concern. The existing prediction models are mostly focused on in-hospital operative mortality after CABG, but there is still little research on long-term mortality prediction model for patients after CABG.

Objective

To develop and validate a novel nomogram for predicting 3-year mortality in critically ill patients after CABG.

Methods

Data for developing novel predictive model were extracted from Medical Information Mart for Intensive cart III (MIMIC-III), of which 2929 critically ill patients who underwent CABG at the first admission were enrolled.

Results

A novel prognostic nomogram for 3-year mortality was constructed with the seven independent prognostic factors, including age, congestive heart failure, white blood cell, creatinine, SpO₂, anion gap, and continuous renal replacement treatment derived from the multivariable logistic regression. The nomogram indicated accurate discrimination in primary (AUC: 0.81) and validation cohort (AUC: 0.802), which were better than traditional severity scores. And good consistency between the predictive and observed outcome was showed by the calibration curve for 3-year mortality. The decision curve analysis also showed higher clinical net benefit than traditional severity scores.

Conclusion

The novel nomogram had well performance to predict 3-year mortality in critically ill patients after CABG. The prediction model provided valuable information for treatment strategy and postdischarge management, which may be helpful in improving the long-term prognosis in critically ill patients after CABG.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12893-021-01408-8.

Association Between Anion Gap and Mortality in Critically Ill Patients with Cardiogenic Shock

Background

No epidemiological study has determined the association between the anion gap (AG) and all-cause mortality in critically ill patients with cardiogenic shock (CS). This study was conducted to clarify the relationship between the AG and mortality in CS.

Methods

We extracted clinical data from the public database, MIMIC-III V1.4, by using a generalized additive model to identify the nonlinear relationship between the AG and the 30-day mortality in 1248 intensive care unit patients. Cox proportional hazard models were used to assess the association between the AG and the 30-day, 90-day, and 365-day mortality in CS.

Results

The AG and 30-day all-cause mortality showed a nonlinear relationship, indicated by a J-shaped curve. In the multivariate analysis, after adjusting for potential confounders, a high AG was associated with an increased risk of 30-day, 90-day, and 365-day all-cause mortality in patients with CS compared with patients who had low AG (hazard ratio [95% confidence interval] 1.62 [1.14-2.30]; 1.35 [1.04-1.84]; and 1.38 [1.03-1.84], respectively). Similar results were shown in Model I (adjusted for age, sex and ethnicity) and in Model II (fully adjusting for age, ethnicity, sex, acute kidney injury stage, CHF, renal disease, stroke, malignancy, respiratory failure, pneumonia, sodium, potassium, chloride, BUN, PT, WBC, pH, creatinine, albumin, glucose, bicarbonate, vasopressor use, diastolic blood pressure, respiration rate, temperature, the Elixhauser Comorbidity Index, SOFA score and SAPSII score).

Conclusion

The relationship between the AG and 30-day all-cause mortality followed a J-shaped curve. Higher AG was associated with an increased risk of 30-day, 90-day, and 365-day all-cause mortality in critically ill patients with CS.