Prognostic Value of Hypochloremia in Critically Ill Patients With Decompensated Cirrhosis

Chloride ions in health and disease

Chloride is a key anion involved in cellular physiology by regulating its homeostasis and rheostatic processes. Changes in cellular Cl- concentration result in differential regulation of cellular functions such as transcription and translation, post-translation modifications, cell cycle and proliferation, cell volume, and pH levels. In intracellular compartments, Cl- modulates the function of lysosomes, mitochondria, endosomes, phagosomes, the nucleus, and the endoplasmic reticulum. In extracellular fluid (ECF), Cl- is present in blood/plasma and interstitial fluid compartments. A reduction in Cl- levels in ECF can result in cell volume contraction. Cl- is the key physiological anion and is a principal compensatory ion for the movement of the major cations such as Na+, K+, and Ca2+. Over the past 25 years, we have increased our understanding of cellular signaling mediated by Cl-, which has helped in understanding the molecular and metabolic changes observed in pathologies with altered Cl- levels. Here, we review the concentration of Cl- in various organs and cellular compartments, ion channels responsible for its transportation, and recent information on its physiological roles.

Dietary salt in liver cirrhosis: With a pinch of salt!

Patients with liver cirrhosis are advised to limit their sodium consumption to control excessive fluid accumulation. Salt is the most common form in which sodium is consumed daily. Consequently, various recommendations urge patients to limit salt intake. However, there is a lack of consistency regarding salt restriction across the guidelines. Moreover, there is conflicting evidence regarding the efficacy of salt restriction in the treatment of ascites. Numerous studies have shown that there is no difference in ascites control between patients with restriction of salt intake and those without restriction. Moreover, patients with cirrhosis may have several negative effects from consuming too little salt, although there are no recommendations on the lower limit of salt intake. Sodium is necessary to maintain the extracellular fluid volume; hence, excessive salt restriction can result in volume contraction, which could negatively impact kidney function in a cirrhotic patient. Salt restriction in cirrhotic patients can also compromise nutrient intake, which can have a negative impact on the overall outcome. There is insufficient evidence to recommend restricted salt intake for all patients with cirrhosis, including those with severe hyponatremia. The existing guidelines on salt restriction do not consider the salt sensitivity of patients; their nutritional state, volume status and sodium storage sites; and the risk of hypochloremia. This opinion article aims to critically analyze the existing literature with regard to salt recommendations for patients with liver cirrhosis and identify potential knowledge gaps that call for further research.

Prognosis value of serum chloride on 1-year mortality in cirrhotic patients receiving transjugular intrahepatic portosystemic shunt

BACKGROUND AND PURPOSE

Emerging researches have regarded serum chloride as a capable predictor of mortality in liver cirrhosis. We aim to investigate the clinical role of admission chloride in cirrhotic patients with esophagogastric varices receiving transjugular intrahepatic portosystemic shunt (TIPS), which is unclear.

METHODS

We retrospectively analyzed data of cirrhotic patients with esophagogastric varices undergoing TIPS in Zhongnan Hospital of Wuhan University. Mortality outcome was obtained by following up for 1-year after TIPS. Univariate and multivariate Cox regression were used to identify independent predictors of 1-year mortality post-TIPS. The receiver operating characteristic (ROC) curves were adopted to assess the predictive ability of the predictors. In addition, log-rank test and Kaplan-Meier (KM) analyses were employed to evaluate the prognostic value of predictors in the survival probability.

RESULTS

A total of 182 patients were included ultimately. Age, fever symptom, platelet-to lymphocyte-ratio (PLR), lymphocyte-to-monocyte ratio (LMR), total bilirubin, serum sodium, chloride, and Child-Pugh score were related to 1-year follow-up mortality. In multivariate Cox regression analysis, serum chloride (HR = 0.823, 95%CI = 0.757-0.894, p < 0.001) and Child-Pugh score (HR = 1.401, 95%CI = 1.151-1.704, p = 0.001) were identified as independent predictors of 1-year mortality. Patients with serum chloride <107.35 mmol/L showed worse survival probability than those with serum chloride ≥107.35 mmol/L no matter with or without ascites (p < 0.05).

CONCLUSION

Admission hypochloremia and increasing Child-Pugh score are independent predictors of 1-year mortality in cirrhotic patients with esophagogastric varices receiving TIPS.

A clinically applicable prediction model for the risk of in-hospital mortality in solid cancer patients admitted to intensive care units with sepsis

PURPOSE

To develop and validate a user-friendly model to predict the risk of in-hospital mortality in solid cancer patients admitted to the ICU with sepsis.

METHODS

Clinical data of critically ill patients with solid cancer and sepsis were obtained from Medical Information Mart for Intensive Care-IV database and randomly assigned to the training cohort and validation cohort. The primary outcome was in-hospital mortality. The least absolute shrinkage and selection operator (LASSO) regression and logistic regression analysis were used to feature selection and model development. The performance of the model was validated and a dynamic nomogram was developed to visualize the model.

RESULTS

A total of 1584 patients were included in this study, of whom 1108 were assigned to the training cohort and 476 to the validation cohort. The LASSO regression and logistic multivariable analysis showed that nine clinical features were associated with in-hospital mortality and enrolled in the model. The area under the curve of the model was 0.809 (95% CI 0.782-0.837) in the training cohort and 0.770 (95% CI 0.722-0.819) in the validation cohort. The model exhibited satisfactory calibration curves and Brier scores in the training set and validation set were 0.149 and 0.152, respectively. The decision curve analysis and clinical impact curve of the model presented good clinical practicability in both the two cohorts.

CONCLUSION

This predictive model could be used to assess the in-hospital mortality of solid cancer patients with sepsis in the ICU, and a dynamic online nomogram could facilitate the sharing of the model.

Lower serum chloride concentrations are associated with an increased risk of death in ICU patients with acute kidney injury: an analysis of the MIMIC-IV database

BACKGROUND

The association between baseline serum chloride levels and mortality in patients with severe acute kidney injury (AKI) is unknown. Our aim was to investigate the relationship between baseline blood chloride levels and 28-day mortality in patients with AKI admitted to the ICU and to detect possible effect modifiers in this population.

METHODS

AKI patients with severe critical illness were extracted from the MIMIC-IV. During ICU admission, chloride levels were measured for the first time. Our primary outcome was 28-day mortality in patients with AKI after 24 hours in the ICU. Multivariable logistic regression was used to examine the association between three groups of chloride levels and 28-day mortality, and logistic regression with restricted cubic spline was applied to detect the non-linear trendy.

RESULTS

A total of 24,166 patients with critically ill AKI were included in this retrospective cohort study. The total 28-day mortality rate in the ICU was 15.9%. Overall, there was a U-shaped relationship between baseline serum chloride levels and 28-day mortality (non-linear P<0.001). Accordingly, patients with low serum chloride (<96 mEq/L) had a significantly increased risk of death compared to patients with normal serum chloride (96-108 meq/L) (adjusted OR=1.94, 95% CI: 1.68-2.24, P<0.001). None of the variables, including age, gender, 24-hour fluid intake, continuous renal replacement therapy, ventilation, Atrial fibrillation, Sequential Organ Failure Assessment score, whether to measure lactate and AKI stage, significantly modified the association between lower chloride levels and 28-day mortality.

CONCLUSIONS

Low serum chloride levels at baseline were associated with death at 28 days in intensive illnesses with AKI.

Hypochloremia as a novel adverse prognostic factor in acute liver failure

BACKGROUND AND AIMS

Emerging evidence has identified hypochloremia as an independent predictor for mortality in multiple conditions including cirrhosis. Acute liver failure (ALF) is frequently complicated by electrolyte abnormalities. We investigated the prognostic value of hypochloremia in a large cohort of ALF patients from North America.

METHODS

The Acute Liver Failure Study Group (ALFSG) registry is a longitudinal cohort study involving 2588 ALF patients enrolled prospectively from 32 North American academic centres. The primary outcome was a composite of 21-day all-cause mortality or requirement for liver transplantation (death/LT).

RESULTS

Patients with hypochloremia (<98 mEq/L) had a significantly higher 21-day mortality rate (42.1%) compared with those with normal (27.5%) or high (>107 mEq/L) chloride (28.0%) (p < .001). There was lower transplant-free cumulative survival in the hypochloremic group than in the normo- or hyper-chloremic groups (log-rank, χ2 24.2, p < .001). Serum chloride was inversely associated with the hazard of 21-day death/LT with multivariable adjustment for known prognostic factors (adjusted hazard ratio [aHR]: 0.977; 95% CI: 0.969-0.985; p < .001). Adding chloride to the ALFSG Prognostic Index more accurately predicted risk of death/LT in 19% of patients (net reclassification improvement [NRI] = 0.19, 95% CI: 0.13-0.25) but underestimated the probability of transplant-free survival in 34% of patients (NRI = -0.34, 95% CI: -0.39 to -0.28).

CONCLUSIONS

Hypochloremia is a novel independent adverse prognostic factor in ALF. A new ALFSG-Cl Prognostic Index may improve the sensitivity to identify patients at risk for death without LT.

Association between serum chloride levels with mortality in critically ill patients with acute kidney injury: An observational multicenter study employing the eICU database

Objective

The effect of the serum chloride (Cl) level on mortality in critically ill patients with acute kidney injury (AKI) remains unknown. We sought an association between mortality and serum Cl.

Methods

We identified AKI patients in the eICU Collaborative Research Database from 2014 to 2015 at 208 US hospitals. The outcomes included in-hospital and intensive care unit (ICU) mortality. Time-varying covariates Cox regression models and the Kaplan-Meier (K-M) curves were used to assess the association between serum Cl levels and mortality. Multivariable adjusted restricted cubic spline models were used to analyze the potential nonlinear relationship between mortality and serum Cl.

Results

In total, 4,234 AKI patients were included in the study. Compared with normochloremia (98≤chloride<108mEq/L), hypochloremia (Cl<98mEq/L) was associated with mortality (adjusted hazard ratio [HR] for in-hospital mortality 1.46, 95% confidence interval [CI] 1.20–1.80, P = 0.0003; adjusted HR for ICU mortality 1.37, 95% CI 1.05–1.80, P = 0.0187). Hyperchloremia showed no significant difference in mortality compared to normochloremia (adjusted HR for in-hospital mortality 0.89, 95% CI 0.76–1.04, P = 0.1438; adjusted HR for ICU mortality 0.87, 95% CI 0.72–1.06, P = 0.1712). Smoothing curves revealed continuous non-linear associations between serum Cl levels and mortality. The K-M curve showed that patients with hypochloremia presented with a lower survival rate.

Conclusions

Lower serum Cl levels after ICU admission was associated with increased in-hospital and ICU mortality in critically ill patients with AKI. The results should be verified in well-designed prospective studies.

Association of hyperchloremia with all-cause mortality in patients admitted to the surgical intensive care unit: a retrospective cohort study

Background

Serum chloride (Cl⁻) is one of the most essential extracellular anions. Based on emerging evidence obtained from patients with kidney or heart disease, hypochloremia has been recognized as an independent predictor of mortality. Nevertheless, excessive Cl⁻ can also cause death in severely ill patients. This study aimed to investigate the relationship between hyperchloremia and high mortality rate in patients admitted to the surgical intensive care unit (SICU).

Methods

We enrolled 2131 patients from the Multiparameter Intelligent Monitoring in Intensive Care III database version 1.4 (MIMIC-III v1.4) from 2001 to 2012. Selected SICU patients were more than 18 years old and survived more than 72 h. A serum Cl⁻ level ≥ 108 mEq/L was defined as hyperchloremia. Clinical and laboratory variables were compared between hyperchloremia (n = 664) at 72 h post-ICU admission and no hyperchloremia (n = 1467). The Locally Weighted Scatterplot Smoothing (Lowess) approach was utilized to investigate the correlation between serum Cl- and the thirty-day mortality rate. The Cox proportional-hazards model was employed to investigate whether serum chlorine at 72 h post-ICU admission was independently related to in-hospital, thirty-day and ninety-day mortality from all causes. Kaplan-Meier curve of thirty-day and ninety-day mortality and serum Cl⁻ at 72 h post-ICU admission was further constructed. Furthermore, we performed subgroup analyses to investigate the relationship between serum Cl⁻ at 72 h post-ICU admission and the thirty-day mortality from all causes.

Results

A J-shaped correlation was observed, indicating that hyperchloremia was linked to an elevated risk of thirty-day mortality from all causes. In the multivariate analyses, it was established that hyperchloremia remained a valuable predictor of in-hospital, thirty-day and ninety-day mortality from all causes; with adjusted hazard ratios (95% CIs) for hyperchloremia of 1.35 (1.02 ~ 1.77), 1.67 (1.28 ~ 2.19), and 1.39 (1.12 ~ 1.73), respectively. In subgroup analysis, we observed hyperchloremia had a significant interaction with AKI (P for interaction: 0.017), but there were no interactions with coronary heart disease, hypertension, and diabetes mellitus (P for interaction: 0.418, 0.157, 0.103, respectively).

Conclusion

Hyperchloremia at 72 h post-ICU admission and increasing serum Cl⁻ were associated with elevated mortality risk from all causes in severely ill SICU patients.

Severe Symptomatic Hypochloremia Associated with Rare Signet Ring Cell Carcinoma of the Ampulla of Vater: A Case Report

Hypochloremia is an electrolyte disturbance characterized by low serum concentration of chloride ions, often occurring in acute illnesses and characterized by nonspecific signs and symptoms. It rarely results from decreased intake and is predominantly due to either renal or extra-renal losses. We report a case of severely worsening symptomatic hypochloremia resulting from an extra-renal loss of chloride ion in a 58-year-old female patient presenting for prolonged protracted vomiting. Chloremia reached a surprising level of 48 mEq/L, the lowest level reported in the literature. The patient was eventually diagnosed with a rare signet ring cell carcinoma that occurred in the ampulla of Vater, leading to a malignant gastric outlet obstruction and causing extra-renal loss of chloride.

Lower serum chloride concentrations are associated with increased risk of mortality in critically ill cirrhotic patients: an analysis of the MIMIC-III database

Background

Cirrhosis can be complicated by electrolyte abnormalities, but the major focus has been concentrated on the clinical significance of serum sodium levels. Emerging studies have identified hypochloremia as an independent prognostic marker in patients with chronic heart failure and chronic kidney disease. The aim of this study was to investigate whether serum chloride levels were associated with mortality of critically ill cirrhotic patients.

Methods

Critically ill cirrhotic patients were identified from the Multi-parameter Intelligent Monitoring in Intensive Care III Database. The primary outcome was ICU mortality. Logistic regression was used to explore the association between serum chloride levels and ICU mortality. The area under the receiver operating characteristic curves (AUC) was used to assess the performance of serum chloride levels for predicting ICU mortality.

Results

A total of 1216 critically ill cirrhotic patients were enrolled in this study. The overall ICU mortality rate was 18.8%. Patients with hypochloremia had a higher ICU mortality than those with non-hypochloremia (34.2% vs. 15.8%; p < 0.001). After multivariable risk adjustment for age, gender, ethnicity, chloride, sodium, Model for End-stage Liver Disease score, Sequential Organ Failure Assessment score, Elixhauser comorbidity index, mechanical ventilation, vasopressors, renal replacement therapy, acute kidney injury, hemoglobin, platelet, and white blood cell, serum chloride levels remained independently associated with ICU mortality (OR 0.94; 95% CI 0.91–0.98; p = 0.002) in contrast to serum sodium levels, which were no longer significant (OR 1.03; 95% CI 0.99–1.08; p = 0.119). The AUC of serum chloride levels (AUC, 0.600; 95% CI 0.556–0.643) for ICU mortality was statistically higher than that of serum sodium levels (AUC, 0.544; 95% CI 0.499–0.590) (p < 0.001).

Conclusions

In critically ill cirrhotic patients, serum chloride levels are independently and inversely associated with ICU mortality, thus highlighting the prognostic role of serum chloride levels which are largely overlooked.