Chloride toxicity in critically ill patients: What's the evidence?

Fluid management strategies in critically ill patients with ARDS: a narrative review

Hypervolemia is associated with worse outcomes in critically ill patients with acute respiratory distress syndrome (ARDS), with early positive fluid balance linked to longer intensive care unit (ICU) stays, prolonged ventilatory support, and increased mortality risk due to cardiopulmonary complications, lung edema, and extrapulmonary organ dysfunction. However, a restrictive fluid management strategy is associated with hypoperfusion and distal organ dysfunction, including acute renal failure and cognitive impairment. Indeed, fluid administration in patients with ARDS represents a challenge, as it must take into account the underlying condition, such as sepsis or acute brain injury (ABI), where optimal fluid management is a major determinant of disease outcome. In such cases, the approach to fluid administration should be individualized based on hemodynamic and clinical parameters according to the course of the disease. The strategy of "salvage, optimization, stabilization, and de-escalation" can guide fluid administration in the initial therapeutic approach, whereas negative fluid balance with the use of diuretics or renal replacement therapy (RRT) should be the goal once hemodynamic stabilization has been achieved.

Trimatch comparison of the prognosis of hypochloremia, normolchloremia and hyperchloremia in patients with septic shock

BACKGROUND

Septic shock is a lethal disease, and identifying high-risk patients through noninvasive and widely available biomarkers can help improve global outcomes. While the clinical impact of chloride levels on critically ill patients remains unclear, this study aims to investigate the association between hypochloremia and mortality following ICU admission among septic shock patients.

METHODS

This is an analysis of data stored in the databases of Medical Information Mart for Intensive Care IV (MIMIC-IV). The initial chloride levels were classified ashypochloremia, normal chloraemia, and hyperchloraemia. A multivariate logistic regression model was applied, adjusting for age, lactate, pH, PO2, urine volume, RDW, creatinine, and liver disease, to assess the association between the three categories of chloride levels and mortality.

RESULTS

Of 3726 patients included in the study, 470 patients (12.6%) had hypochloremia on ICU admission. During the follow-up period, 1120 (33.5%) patients died. Hypochloremia was significantly associated with increased mortality and the incidence of AKI after adjusting for several variables.

CONCLUSION

Hypochloremia is independently associated with higher hospital mortality, AKI incidence among septic shock patients. However, further high-quality research is necessary to establish the precise relationship between hypochloremia and septic shock prognosis.

Prevalence and Prognostic Significance of Chloride Levels in Patients with Acute Medical Conditions: A Prospective Observational Study

Chloride plays a considerable role in physiology. This study aimed to assess the association between serum chloride and prognosis in the population of adults with acute medical conditions. A prospective cohort study was conducted in an acute medical unit. Chloride levels at admission were the main exposure factor, categorized into hypochloremia, normochloremia, and hyperchloremia. The outcomes were in-hospital mortality and length of hospital stay (LOHS). A total of 798 patients were included. The mean age was 57.3 ± 18.3 years. The prevalence of dyschloremia was 40.9%. Restricted cubic splines revealed a linear association between hypochloremia and in-hospital mortality, as well as between hypochloremia and LOHS. After adjusting for age, sex, heart failure, diabetes, sodium, bicarbonates, creatinine, and diuretic use, hypochloremia was significantly associated with in-hospital mortality (OR = 2.23; 95% CI: 1.29, 3.86, p = 0.006), but not hyperchloremia (p = 0.57). Similarly, it was associated with a longer LOHS (β = 2.19; 95% CI: 0.01, 4.39, p = 0.05), but not hyperchloremia (p = 0.8). The interaction between chloride and sodium levels was not significant (p = 0.61). Subgroup analysis showed that the effect of hypochloremia on in-hospital mortality was consistent across subgroups. The prevalence of dyschloremia in this study was high at 40.9%. Hypochloremia increased the risk of in-hospital mortality and extended the LOHS. Differentiating the effects of chloride levels from those of sodium can enhance clinical risk stratification and enable a more targeted management approach for acutely ill patients. Recognizing this distinction is essential for optimizing prognostic assessment and tailoring treatment strategies accordingly.

Hypochloremia is an underutilised prognostic marker in patients with advanced liver cirrhosis and liver failure

Patients with advanced liver cirrhosis and liver failure frequently experience abnormalities in their serum electrolyte levels. In such patients, hyponatremia has been identified as a predictor of poor outcomes. However, emerging evidence suggests that serum chloride may provide even better prognostic information in similar situations. Hypochloremia, characterised by low serum chloride levels, has been linked to increased mortality, exacerbated organ dysfunction, and higher requirements for renal replacement therapy and vasopressors in various critical conditions, including advanced liver diseases. The pathophysiological mechanisms underlying the association between low serum chloride levels and poor outcomes in liver disease appear to involve complex interactions among electrolyte imbalances, renal function, and systemic hemodynamics. Chloride dysregulation can influence renal salt-sensing mechanisms, disrupt acid-base homeostasis, and exacerbate complications such as hepatic encephalopathy and hepatorenal syndrome. This article aims to elucidate the prognostic significance of lower serum chloride levels in patients with advanced liver disease. By reviewing recent literature and analysing clinical data, we seek to establish serum chloride as an underutilised but valuable prognostic marker. Understanding the role of serum chloride in liver disease could enhance prognostic accuracy, refine treatment strategies, and ultimately improve patient outcomes.

Serum chloride concentration and outcomes in adults receiving intravenous fluid therapy with a balanced crystalloid solution or 0.9% sodium chloride

PURPOSE

To determine whether there is an interaction between baseline serum chloride concentration and pH and treatment effects in Intensive Care Unit (ICU) patients receiving intravenous fluid therapy with balanced solution versus 0.9% sodium chloride (saline).

METHODS

A secondary analysis of a randomized controlled trial in which patients were divided into cohorts according to quartiles of baseline serum chloride concentration and pH. The primary outcome was day-90 mortality.

RESULTS

From 4846 patients with outcome data available, 4823 with relevant baseline data were included in this analysis, with 1347, 1333, 993 and 1150 patients in the chloride quartiles of < 102, 102-106, 107-109 and > 109 mmol/L, respectively. Data were also analysed in pH quartiles of ≤ 7.27, 7.27-7.34, 7.34-7.39 and > 7.39. The risk-adjusted odds ratio (95% confidence interval [CI]) for day-90 mortality for patients assigned balanced solution compared to saline was 1.23 (0.95-1.58), 0.95 (0.73-1.25), 0.88 (0.64-1.21), and 0.76 (0.57-1.01) for lowest to highest chloride subgroups, respectively (P value for interaction = 0.10), and 0.89 (95% CI 0.69-1.15), 0.94 (0.70-1.27), 0.96 (0.67-1.38) and 1.15 (0.82-1.60) for pH quartiles from lowest to highest, respectively (P value for interaction = 0.63).

CONCLUSIONS

There were no significant differences in the treatment effect of balanced solutions compared to saline according to baseline serum chloride concentration or pH.

European Society of Intensive Care Medicine clinical practice guideline on fluid therapy in adult critically ill patients. Part 1: the choice of resuscitation fluids

PURPOSE

This is the first of three parts of the clinical practice guideline from the European Society of Intensive Care Medicine (ESICM) on resuscitation fluids in adult critically ill patients. This part addresses fluid choice and the other two will separately address fluid amount and fluid removal.

METHODS

This guideline was formulated by an international panel of clinical experts and methodologists. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology was applied to evaluate the certainty of evidence and to move from evidence to decision.

RESULTS

For volume expansion, the guideline provides conditional recommendations for using crystalloids rather than albumin in critically ill patients in general (moderate certainty of evidence), in patients with sepsis (moderate certainty of evidence), in patients with acute respiratory failure (very low certainty of evidence) and in patients in the perioperative period and patients at risk for bleeding (very low certainty of evidence). There is a conditional recommendation for using isotonic saline rather than albumin in patients with traumatic brain injury (very low certainty of evidence). There is a conditional recommendation for using albumin rather than crystalloids in patients with cirrhosis (very low certainty of evidence). The guideline provides conditional recommendations for using balanced crystalloids rather than isotonic saline in critically ill patients in general (low certainty of evidence), in patients with sepsis (low certainty of evidence) and in patients with kidney injury (very low certainty of evidence). There is a conditional recommendation for using isotonic saline rather than balanced crystalloids in patients with traumatic brain injury (very low certainty of evidence). There is a conditional recommendation for using isotonic crystalloids rather than small-volume hypertonic crystalloids in critically ill patients in general (very low certainty of evidence).

CONCLUSIONS

This guideline provides eleven recommendations to inform clinicians on resuscitation fluid choice in critically ill patients.

Association between serum chloride and in-hospital mortality in congestive heart failure with diabetes: Data from the MIMIC-IV database

Background

Congestive heart failure (CHF) demonstrates a heightened prevalence in individuals with diabetes mellitus within Intensive Care Units. The occurrence of abnormal chloride levels is frequently observed in critically ill patients, yet its clinical significance remains subject to debate. This study endeavors to explore the relationship between serum chloride levels and in-hospital mortality among patients affected by both congestive heart failure and diabetes.

Methods

A retrospective cohort study was conducted, utilizing data from the Medical Information Mart for Intensive Care-IV (MIMIC-IV) database, focusing on adult patients in the United States. The impact of serum chloride levels upon ICU admission on in-hospital mortality was analyzed using multivariable logistic regression models, generalized additive models and subgroup analysis.

Results

The study encompassed 7,063 patients with coexisting diabetes and congestive heart failure. The fully adjusted model revealed an inverse association between serum chloride levels and in-hospital mortality. As a tertile variable (Q3 vs Q1), the odds ratio (OR) was 0.73 with a 95% confidence interval (CI) of 0.54-0.98 (p = 0.039). As a continuous variable, per 1 mmol/L increment, the OR (95% CI) was 0.97 (0.96-0.99, p = 0.01). The relationship between serum chloride and in-hospital mortality demonstrated linearity (non-linear p = 0.958). Stratified analyses further validated the robustness of this correlation.

Conclusions

Serum chloride levels exhibited a negative association with in-hospital mortality in patients with both congestive heart failure and diabetes. Nevertheless, prospective, randomized, controlled studies are warranted to corroborate and validate the findings presented in this investigation.

Comparison of Balanced Crystalloids versus Normal Saline in Critically Ill Patients: A Systematic Review with Meta-Analysis and Trial Sequential Analysis of Randomized Controlled Trials

Background

Fluid resuscitation is routinely needed for critically ill patients. However, the optimal choice between crystalloids and normal saline is in heat debate.

Objective

To conduct a meta-analysis comparing normal saline and balanced crystalloids in the treatment of critically ill patients with composite mortality as the primary outcome.

Methods

PubMed, Embase, Medline, Web of Science, and Cochrane Library were searched from inception up to March 2022. Studies of critically ill adult patients assigned to receive normal saline or balanced crystalloids were included. We conducted a meta-analysis using an inverse variance, random-effects model in addition to trial sequential analysis (TSA). The primary outcome was composite mortality. Subgroup analyses were also conducted.

Results

Eighteen full-text studies (n=36,224) were included. Balanced crystalloids were associated with lower mortality compared with normal saline (risk ratio [RR]=0.96; 95% confidential interval [CI] 0.93, 1; p=0.03; I2=0) and lower incidence of acute kidney injury/acute renal failure (RR =0.93; 95% CI = 0.87, 0.99; p=0.03). No significant difference was observed in other outcomes. In the sepsis patients, the balanced crystalloid showed a lower composite mortality rate compared with normal saline (RR =0.91; 95% CI = 0.85, 0.99; p=0.02). TSA analysis demonstrated that, with 80% power, the effect of balanced crystalloid is not larger than a 10% relative decrease in composite mortality compared with normal saline.

Conclusion and Relevance

This study demonstrated that balanced crystalloids could be an optimal choice over normal saline in critically ill patients to a reduced composite mortality rate. In patients with sepsis, the difference is especially significant. Nonetheless, the optimal resuscitation fluid option between saline and balanced crystalloid solutions should be investigated further with more evidence.

[Improved quality of stored packed red blood cells by mechanical rinsing]

BACKGROUND

The transfusion of packed red blood cells (PRBC) is associated with various side effects, including storage damage to PRBCs. The cells change their structure, releasing potassium as well as lactate. Mechanical rinsing, available in many hospitals, is able to remove toxic substances and possibly minimizes the negative side effects of transfusion.

OBJECTIVE

The primary aim of our study was to improve the quality of PRBCs before transfusion. The effects of different washing solutions on PRBC quality were analyzed.

MATERIAL AND METHODS

This in vitro study compares 30 mechanically washed PRBCs. They were either processed with standard normal saline 0.9% (n = 15, N group) or a hemofiltration solution containing 4 mmol/l potassium (n = 15, HF group) by a mechanical rinsing device (Xtra, LivaNova, Munich, Germany). A subgroup analysis was performed based on the storage duration of the processed PRBCs (7, 14, 37 days). Samples were taken before washing (EKprä), immediately after washing (EKpost) and 10 h later (EKpost10h), after storage in the "wash medium" at room temperature. Concentrations of ATP (probability of survival in transfused erythrocytes), lactate, citrate and electrolytes (potassium, sodium, chloride, calcium) were tested.

RESULTS AND CONCLUSION

Mechanical rinsing improves pretransfusion quality of PRBC. Washing with a hemofiltration solution results in a more physiological electrolyte composition. Even 10 h after mechanical rinsing with a hemofiltration solution, the quality of 37-day-old PRBC is comparable to young PRBC that have been stored for 7 days and have not been washed. Washing stored PRBC increases the ATP content, which subsequently leads to an increased probability of survival of red cells after transfusion.

Management of severe thermal burns in the acute phase in adults and children

OBJECTIVES

To provide recommendations to facilitate the management of severe thermal burns during the acute phase in adults and children.

DESIGN

A committee of 20 experts was asked to produce recommendations in six fields of burn management, namely, (1) assessment, admission to specialised burns centres, and telemedicine; (2) haemodynamic management; (3) airway management and smoke inhalation; (4) anaesthesia and analgesia; (5) burn wound treatments; and (6) other treatments. At the start of the recommendation-formulation process, a formal conflict-of-interest policy was developed and enforced throughout the process. The entire process was conducted independently of any industry funding. The experts drew up a list of questions that were formulated according to the PICO model (Population, Intervention, Comparison, and Outcomes). Two bibliography experts per field analysed the literature published from January 2000 onwards using predefined keywords according to PRISMA recommendations. The quality of data from the selected literature was assessed using GRADE® methodology. Due to the current paucity of sufficiently powered studies regarding hard outcomes (i.e. mortality), the recommendations are based on expert opinion.

RESULTS

The SFAR guidelines panel generated 24 statements regarding the management of acute burn injuries in adults and children. After two scoring rounds and one amendment, strong agreement was reached for all recommendations.

CONCLUSION

Substantial agreement was reached among a large cohort of experts regarding numerous strong recommendations to optimise the management of acute burn injuries in adults and children.

Physiological response to fluid resuscitation with Ringer lactate versus Plasmalyte in critically ill burn patients

The metabolic consequences in vivo of various balanced solutions are poorly known in critically ill patients. The main objective of this study was to describe the metabolic consequences of Plasmalyte versus Ringer lactate (RL) in critically ill burn patients, with a special focus on the plasma clearance of buffer anions (i.e., gluconate, acetate, and lactate). We conducted a randomized trial between August 2017 and October 2018 in a tertiary teaching hospital in Paris, France. Patients with burn total body surface area >30% were randomized to receive Plasmalyte or RL. The primary end point was the base excess 24 h after inclusion. The secondary end points were acetate, gluconate, and lactate plasma concentration, the strong ion difference (SID). Twenty-eight patients were randomized. Twenty-four hours after inclusion, plasma BE was not significantly different in the Plasmalyte and RL groups {-0.9 [95% confidence interval (95% CI): -1.8-0.9] vs. -2.1 [95% CI: -4.6-0.6] mmol/L, respectively, P = 0.26}. Plasma gluconate concentration was higher in the Plasmalyte group (P < 0.001), with a maximum level of 1.86 (95% CI: 0.98-4.0) mmol/L versus 0 (95% CI: 0-0.15) mmol/L. Plasma acetate and lactate were not significantly different. Ionized calcium level was lower in the Plasmalyte group (P = 0.002). Hemodynamics did not differ between groups. To conclude, the alkalinizing effect of Plasmalyte was less important than expected with no difference in base excess compared with RL, in part due to gluconate accumulation. Acetate and lactate did not significantly accumulate. Plasmalyte led to significantly lower ionized calcium levels.NEW & NOTEWORTHY During fluid resuscitation in burns the alkalinizing effect of Plasmalyte was less important than expected, with no difference in base excess compared with Ringer lactate (RL), in part due to gluconate accumulation. Acetate and lactate did not significantly accumulate. Plasmalyte led to significantly lower ionized calcium levels.

Association between fluctuations in serum chloride levels and 30-day mortality among critically ill patients: a retrospective analysis

Background

This study investigated the associations of fluctuations in serum chloride (Cl⁻) levels with 30-day mortality after intensive care unit (ICU) admission among critically ill patients.

Methods

We retrospectively analyzed the medical records of adult patients (≥18 years old) admitted to the ICU between January 2012 and December 2017. Positive and negative fluctuations in Cl⁻ were defined as the differences between the Cl⁻ upon ICU admission (baseline Cl⁻) and the maximum and minimum Cl⁻ levels, respectively, measured within 72 h after ICU admission.

Results

The final analysis included 18,825 adult patients. In multivariable Cox regression analyses, the risk of 30-day mortality increased by 8% per 1-mmol L^− 1 positive fluctuation in Cl⁻ within 72 h (hazard ratio = 1.08, 95% confidence interval: 1.04–1.11, P < 0.001). In subgroup analyses, a positive fluctuation in Cl⁻ was associated with increased 30-day mortality among patients with a severe positive cumulative fluid balance (FB, > 10%), normochloremia (97–110 mmol L^− 1) or hyperchloremia (> 110 mmol L^− 1) upon ICU admission. Furthermore, a negative fluctuation in the Cl⁻ level during the first 72 h of an ICU stay was associated with a negative cumulative FB (< 0%) or hypochloremia (< 97 mmol L^− 1) upon ICU admission.

Conclusions

A fluctuation in the Cl⁻ level during the first 72 h of an ICU stay was found to associate independently with increased 30-day mortality among critically ill adult patients. However, the nature of this association differed according to the cumulative FB status or dyschloremia status upon ICU admission.

Electronic supplementary material

The online version of this article (10.1186/s12871-019-0753-3) contains supplementary material, which is available to authorized users.

Early Hemodynamic Management of Critically Ill Burn Patients

The challenge of initial hemodynamic resuscitation of severe burn patients is in avoiding under- and over-resuscitation associated with bad outcome. This review aims to propose strategies for the initial hemodynamic management of severe burns.

Supplemental Digital Content is available in the text.

Crystalloid fluid choice in the critically ill : Current knowledge and critical appraisal

Intravenous infusion of crystalloid solutions is one of the most frequently administered medications worldwide. Available crystalloid infusion solutions have a variety of compositions and have a major impact on body systems; however, administration of crystalloid fluids currently follows a "one fluid for all" approach than a patient-centered fluid prescription. Normal saline is associated with hyperchloremic metabolic acidosis, increased rates of acute kidney injury, increased hemodynamic instability and potentially mortality. Regarding balanced infusates, evidence remains less clear since most studies compared normal saline to buffered infusion solutes.; however, buffered solutes are not homogeneous. The term "buffered solutes" only refers to the concept of acid-buffering in infusion fluids but this does not necessarily imply that the solutes have similar physiological impacts. The currently available data indicate that balanced infusates might have some advantages; however, evidence still is inconclusive. Taking the available evidence together, there is no single fluid that is superior for all patients and settings, because all currently available infusates have distinct differences, advantages and disadvantages; therefore, it seems inevitable to abandon the "one fluid for all" strategy towards a more differentiated and patient-centered approach to fluid therapy in the critically ill.

Effect of Intravenously Administered Crystalloid Solutions on Acid-Base Balance in Domestic Animals

Intravenous fluid therapy can alter plasma acid-base balance. The Stewart approach to acid-base balance is uniquely suited to identify and quantify the effects of the cationic and anionic constituents of crystalloid solutions on plasma pH. The plasma strong ion difference (SID) and weak acid concentrations are similar to those of the administered fluid, more so at higher administration rates and with larger volumes. A crystalloid's in vivo effects on plasma pH are described by 3 general rules: SID > [HCO3-] increases plasma pH (alkalosis); SID < [HCO3-] decreases plasma pH (alkalosis); and SID = [HCO3-] yields no change in plasma pH. The in vitro pH of commercially prepared crystalloid solutions has little to no effect on plasma pH because of their low titratable acidity. Appreciation of IV fluid composition and an understanding of basic physicochemical principles provide therapeutically valuable insights about how and why fluid therapy can produce and correct alterations of plasma acid-base equilibrium. The ideal balanced crystalloid should (1) contain species-specific concentrations of key electrolytes (Na+ , Cl- , K+ , Ca++ , Mg++ ), particularly Na+ and Cl- ; (2) maintain or normalize acid-base balance (provide an appropriate SID); and (3) be isosmotic and isotonic (not induce inappropriate fluid shifts) with normal plasma.