A randomized clinical trial comparing the effect of rapidly infused crystalloids on acid-base status in dehydrated patients in the emergency department

Balanced Crystalloid versus Saline in Adults with Traumatic Brain Injury: Secondary Analysis of a Clinical Trial

Balanced crystalloids may improve outcomes compared with saline for some critically ill adults. Lower tonicity of balanced crystalloids could worsen cerebral edema in patients with intracranial pathology. The effect of balanced crystalloids versus saline on clinical outcomes in patients with traumatic brain injury (TBI) requires further study. We planned an a priori subgroup analysis of TBI patients enrolled in the pragmatic, cluster-randomized, multiple-crossover Isotonic Solutions and Major Adverse Renal Events Trial (SMART) (ClinicalTrials.gov: NCT02444988, NCT02547779). Primary outcome was 30-day in-hospital mortality. Secondary outcomes included hospital discharge disposition (home, facility, death). Regression models adjusted for pre-specified baseline covariates compared outcomes. TBI patients assigned to balanced crystalloids (n = 588) and saline (n = 569) had similar baseline characteristics including Injury Severity Score 19 (10); mean maximum head/neck Abbreviated Injury Score, 3.4 (1.0). Isotonic crystalloid volume administered between intensive care unit admission and first of hospital discharge or 30 days was 2037 (3470) mL and 1723 (2923) mL in the balanced crystalloids and saline groups, respectively (p = 0.18). During the study period, 94 (16%) and 82 (14%) patients (16%) died in the balanced crystalloid and saline groups, respectively (adjusted odds ratio [aOR], 1.03; 95% confidence interval [CI], 0.60 to 1.75; p = 0.913). Patients in the balanced crystalloid group were more likely to die or be discharged to another medical facility (aOR 1.38 [1.02-1.86]; p = 0.04). Overall, balanced crystalloids were associated with worse discharge disposition in critically injured patients with TBI compared with saline. The confidence intervals cannot exclude a clinically relevant increase in mortality when balanced crystalloids are used for patients with TBI.

Recommendation document on rapid intravenous rehydration in acute gastroenteritis

INTRODUCTION

The efficacy and safety of the Rapid Intravenous Rehydration (RIR) guidelines in children affected by dehydration secondary to acute gastroenteritis is supported by current scientific evidence, but there is also great variability in its use in clinical practice.

OBJECTIVE

To prepare a document with evidence-based recommendations about RIR in paediatric population.

METHODS

The project was developed based on GRADE methodology, according to the following work schedule: Working Group training; creation of a catalogue of questions about research and definition of "relevant outcomes"; score and selection criteria for each item; bibliographic review; scientific evidence evaluation and synthesis (GRADE); review, discussion and creation of recommendations. 10 clinical questions and 15 relevant outcomes were created (7 about efficacy and 8 about security).

RESULTS

16 recommendations were set up, from which we can highlight as the main ones: 1) RIR is safe for children affected by mild-moderate dehydration secondary to acute gastroenteritis, unless expressly contraindicated or acute severe comorbidity (strong recommendation, moderate evidence). 2) Its use is recommended in this situation when oral rehydration has failed or due to contraindication (strong, high). 3) Isotonic fluids are recommended (strong, high), suggesting saline fluid as the first option (light, low), supplemented by glucose (2.5%) in those patients showing normoglycemia and ketosis (strong, moderate). 4) A rhythm of 20cc/kg/h is recommended (strong, high) during 1-4 h (strong, moderate).

CONCLUSIONS

This document establishes consensus recommendations, based on the available scientific evidence, which could contribute to the standardisation of the use of RIR in our setting.

Density Functional Theory Investigation of the Biocatalytic Mechanisms of pH-Driven Biomimetic Behavior in CeO2

There is considerable interest in the pH-dependent, switchable, biocatalytic properties of cerium oxide (CeO₂) nanoparticles in biomedicine, where these materials exhibit beneficial antioxidant activity against reactive oxygen species (ROS) at a basic physiological pH but cytotoxic prooxidant activity in an acidic cancer cell pH microenvironment. While the general characteristics of the role of oxygen vacancies are known, the mechanism of their action at the atomic scale under different pH conditions has yet to be elucidated. The present work applies density functional theory (DFT) calculations to interpret, at the atomic scale, the pH-induced behavior of the stable {111} surface of CeO₂ containing oxygen vacancies. Analysis of the surface-adsorbed media species reveals the critical role of pH on the interaction between ROS (^•O₂^- and H₂O₂) and the defective CeO₂ {111} surface. Under basic conditions, the superoxide dismutase (SOD) and catalase (CAT) biomimetic reactions can be performed cyclically, scavenging and decomposing ROS to harmless products, making CeO₂ an excellent antioxidant. However, under acidic conditions, the CAT biomimetic reaction is hindered owing to the limited reversibility of Ce³⁺ ↔ Ce⁴⁺ and formation ↔ annihilation of oxygen vacancies. A Fenton biomimetic reaction (H₂O₂ + Ce³⁺ → Ce⁴⁺ + OH^- + ^•OH) is predicted to occur simultaneously with the SOD and CAT biomimetic reactions, resulting in the formation of hydroxyl radicals, making CeO₂ a cytotoxic prooxidant.

[Complications from normal saline in thulium laser enucleation of the prostate]

Systemic fluid absorption frequently occurs during endoscopic prostatic surgery. The introduction of lasers allowed the use of normal saline (0.9% sodium chloride). We report 2 patients who developed hyperchloremic metabolic acidosis and isotonic hypervolemia during thulium laser enucleation of the prostate (ThuLEP) and required prolonged ventilation time, catecholamines, intensive care and prolonged hospitalization. A change to balanced electrolyte solutions in urology-as is already established in infusion and volume therapy-would be desirable, especially to avoid hyperchloremic metabolic acidosis.

[Recommendation document on rapid intravenous rehydration in acute gastroenteritis]

INTRODUCTION

The efficacy and safety of the rapid intravenous rehydration (RIR) guidelines in children affected by dehydration secondary to acute gastroenteritis is supported by current scientific evidence, but there is also great variability in its use in clinical practice.

OBJECTIVE

To prepare a document with evidence-based recommendations about RIR in paediatric population.

METHODS

The project was developed based on GRADE methodology, according to the following work schedule: Working Group training; creation of a catalogue of questions about research and definition of «relevant outcomes»; score and selection criteria for each item; bibliographic review; scientific evidence evaluation and synthesis (GRADE); review, discussion and creation of recommendations. 10 clinical questions and 15 relevant outcomes were created (7 about efficacy and 8 about security).

RESULTS

Sixteen recommendations were set up, from which we can highlight as the main ones: (1) RIR is safe for children affected by mild-moderate dehydration secondary to acute gastroenteritis, unless expressly contraindicated or acute severe comorbidity (strong recommendation and moderate evidence). (2) Its use is recommended in this situation when oral rehydration has failed or due to contraindication (strong and high). (3) Isotonic fluids are recommended (strong and high), suggesting saline fluid as the first option (light and low), supplemented by glucose (2.5%) in those patients showing normoglycemia and ketosis (strong and moderate). (4) A rhythm of 20 cc/kg/h is recommended (strong and high) during 1-4 h (strong and moderate).

CONCLUSIONS

This document establishes consensus recommendations, based on the available scientific evidence, which could contribute to the standardisation of the use of RIR in our setting.

Comparison of Balanced Crystalloid Solutions: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Supplemental Digital Content is available in the text.

OBJECTIVE:

To summarize the evidence comparing various balanced crystalloid solutions.

DATA SOURCES:

We searched MEDLINE, EMBASE, PUBMED, and CENTRAL databases.

STUDY SELECTION:

We included randomized controlled trials that directly compared the IV administration of one balanced crystalloid solution with another.

DATA EXTRACTION AND ANALYSIS:

We examined metabolic and patient-important outcomes and conducted meta-analysis using random effects model. For comparisons or outcomes with insufficient data to allow for pooling, we describe results narratively. We assessed risk of bias for individual trials using the Cochrane risk of bias tool and certainty of evidence using Grading of Recommendations, Assessment, Development and Evaluations methodology.

DATA SYNTHESIS:

We included 24 randomized controlled trials comparing Plasmalyte, Ringer’s Lactate, Ringerfundin, Hartmann’s solution, Ringer’s Bicarbonate, Sterofundin, Kabilyte, Normosol, and novel balanced solutions. Of the included studies, 16 were performed in the perioperative setting, six in the ICU, one in the emergency department, and one in healthy volunteers. Administration of Plasmalyte resulted in a lower postinfusion serum chloride concentration (mean difference, 0.83 mmol/L lower; 95% CI, 0.03–1.64 mmol/L lower, low certainty), higher postinfusion base excess (mean difference, 0.65 mmol/L higher, 95% CI, 0.25–1.05 mmol/L higher, low certainty), and lower postinfusion serum lactate levels (mean difference, 0.46 mmol/L lower; 95% CI, 0.05–0.87 mmol/L lower, low certainty) compared with administration of any other balanced crystalloid. There were no important differences in postinfusion serum pH or potassium when comparing Plasmalyte with other balanced crystalloids. Data addressing other comparisons or examining the impact of different balanced crystalloids on patient-important outcomes were sparsely reported and too heterogeneous to allow for pooling.

CONCLUSIONS:

Administration of Plasmalyte results in lower serum concentrations of chloride and lactate, and higher base excess than other balanced crystalloids. The certainty of evidence is low and requires further study in large randomized controlled trials to inform the choice of balanced crystalloid in patients requiring volume replacement.

Resuscitation With Ringer's Lactate Compared With Normal Saline for Pediatric Diabetic Ketoacidosis

OBJECTIVE

The aims of this study were to describe the use of Ringer's lactate (LR) or normal saline (NS) for resuscitation among children with diabetic ketoacidosis (DKA) and compare the effect of fluid type on cost, length of stay, and rate of cerebral edema (CE).

METHODS

This is a retrospective study of 49,737 children aged 0 to 17 years with DKA between January 1, 2005, and September 30, 2015, using data from the Pediatric Health Information System. Treatment with LR or NS was identified. Our primary outcomes were total adjusted cost and length of stay. Our secondary outcome was CE rate per 1000 episodes.

RESULTS

The majority of patients were treated with NS (n = 43,841 [88%]) compared with LR (n = 1762 [4%]) or both NS and LR (n = 4134 [8%]). Hospital-year-specific practice patterns were used to investigate the effect of fluid type across resuscitation fluid groups. Total adjusted cost was $1160 less (95% confidence interval, -1468 to -852), or -14.2%, for cases with any episode of LR compared with NS only. Length of stay was not different across groups. The rate of cerebral edema per 1000 episodes was 12.7 for cases with any episode of LR compared with 34.6 NS only (difference, -21.9; 95% confidence interval, -30.4 to -13.3).

CONCLUSIONS

Ringer's lactate was infrequently used for resuscitation of pediatric DKA patients. However, resuscitation with LR compared with NS was associated with lower total cost and rates of CE. Further investigation using patient-level clinical and laboratory data is needed to evaluate factors that drive cost and risk of CE development with each fluid.

Prevention and Therapy of AKI in Asia: A Big Challenge

Asia is the largest and most populous continent and has huge differences in socioeconomic status, development, and health care between the different countries and regions within each country. This manifests in the varied causes of acute kidney injury (AKI), particularly higher rates of community-acquired AKI and in the differential access to health care for the population. Because of resource limitations, prevention and treatment of AKI is a difficult challenge. This review highlights the differences in AKI in Asia compared with the developed world and discusses prevention and treatment of AKI within the context of resource limitations.

Balanced Crystalloids versus Saline in Sepsis. A Secondary Analysis of the SMART Clinical Trial

Rationale: Administration of intravenous crystalloid solutions is a fundamental therapy for sepsis, but the effect of crystalloid composition on patient outcomes remains unknown.Objectives: To compare the effect of balanced crystalloids versus saline on 30-day in-hospital mortality among critically ill adults with sepsis.Methods: Secondary analysis of patients from SMART (Isotonic Solutions and Major Adverse Renal Events Trial) admitted to the medical ICU with an International Classification of Diseases, 10th Edition, Clinical Modification System code for sepsis, using multivariable regression to control for potential confounders.Measurements and Main Results: Of 15,802 patients enrolled in SMART, 1,641 patients were admitted to the medical ICU with a diagnosis of sepsis. A total of 217 patients (26.3%) in the balanced crystalloids group experienced 30-day in-hospital morality compared with 255 patients (31.2%) in the saline group (adjusted odds ratio [aOR], 0.74; 95% confidence interval [CI], 0.59-0.93; P = 0.01). Patients in the balanced group experienced a lower incidence of major adverse kidney events within 30 days (35.4% vs. 40.1%; aOR, 0.78; 95% CI, 0.63-0.97) and a greater number of vasopressor-free days (20 ± 12 vs. 19 ± 13; aOR, 1.25; 95% CI, 1.02-1.54) and renal replacement therapy-free days (20 ± 12 vs. 19 ± 13; aOR, 1.35; 95% CI, 1.08-1.69) compared with the saline group.Conclusions: Among patients with sepsis in a large randomized trial, use of balanced crystalloids was associated with a lower 30-day in-hospital mortality compared with use of saline.Clinical trial registered with www.clinicaltrials.gov (NCT02444988).

Buffered solutions versus 0.9% saline for resuscitation in critically ill adults and children

BACKGROUND

Fluid therapy is one of the main interventions provided for critically ill patients, although there is no general consensus regarding the type of solution. Among crystalloid solutions, 0.9% saline is the most commonly administered. Buffered solutions may offer some theoretical advantages (less metabolic acidosis, less electrolyte disturbance), but the clinical relevance of these remains unknown.

OBJECTIVES

To assess the effects of buffered solutions versus 0.9% saline for resuscitation in critically ill adults and children.

SEARCH METHODS

We searched the following databases to July 2018: CENTRAL, MEDLINE, Embase, CINAHL, and four trials registers. We checked references, conducted backward and forward citation searching of relevant articles, and contacted study authors to identify additional studies. We imposed no language restrictions.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) with parallel or cross-over design examining buffered solutions versus intravenous 0.9% saline in a critical care setting (resuscitation or maintenance). We included studies on participants with critical illness (including trauma and burns) or undergoing emergency surgery during critical illness who required intravenous fluid therapy. We included studies of adults and children. We included studies with more than two arms if they fulfilled all of our inclusion criteria. We excluded studies performed in persons undergoing elective surgery and studies with multiple interventions in the same arm.

DATA COLLECTION AND ANALYSIS

We used Cochrane's standard methodological procedures. We assessed our intervention effects using random-effects models, but when one or two trials contributed to 75% of randomized participants, we used fixed-effect models. We reported outcomes with 95% confidence intervals (CIs).

MAIN RESULTS

We included 21 RCTs (20,213 participants) and identified three ongoing studies. Three RCTs contributed 19,054 participants (94.2%). Four RCTs (402 participants) were conducted among children with severe dehydration and dengue shock syndrome. Fourteen trials reported results on mortality, and nine reported on acute renal injury. Sixteen included trials were conducted in adults, four in the paediatric population, and one trial limited neither minimum or maximum age as an inclusion criterion. Eight studies involving 19,218 participants were rated as high methodological quality (trials with overall low risk of bias according to the domains: allocation concealment, blinding of participants/assessors, incomplete outcome data, and selective reporting), and in the remaining trials, some form of bias was introduced or could not be ruled out.We found no evidence of an effect of buffered solutions on in-hospital mortality (odds ratio (OR) 0.91, 95% CI 0.83 to 1.01; 19,664 participants; 14 studies; high-certainty evidence). Based on a mortality rate of 119 per 1000, buffered solutions could reduce mortality by 21 per 1000 or could increase mortality by 1 per 1000. Similarly, we found no evidence of an effect of buffered solutions on acute renal injury (OR 0.92, 95% CI 0.84 to 1.00; 18,701 participants; 9 studies; low-certainty evidence). Based on a rate of 121 per 1000, buffered solutions could reduce the rate of acute renal injury by 19 per 1000, or result in no difference in the rate of acute renal injury. Buffered solutions did not show an effect on organ system dysfunction (OR 0.80, 95% CI 0.40 to 1.61; 266 participants; 5 studies; very low-certainty evidence). Evidence on the effects of buffered solutions on electrolyte disturbances varied: potassium (mean difference (MD) 0.09, 95% CI -0.10 to 0.27; 158 participants; 4 studies; very low-certainty evidence); chloride (MD -3.02, 95% CI -5.24 to -0.80; 351 participants; 7 studies; very low-certainty evidence); pH (MD 0.04, 95% CI 0.02 to 0.06; 200 participants; 3 studies; very low-certainty evidence); and bicarbonate (MD 2.26, 95% CI 1.25 to 3.27; 344 participants; 6 studies; very low-certainty evidence).

AUTHORS' CONCLUSIONS

We found no effect of buffered solutions on preventing in-hospital mortality compared to 0.9% saline solutions in critically ill patients. The certainty of evidence for this finding was high, indicating that further research would detect little or no difference in mortality. The effects of buffered solutions and 0.9% saline solutions on preventing acute kidney injury were similar in this setting. The certainty of evidence for this finding was low, and further research could change this conclusion. Patients treated with buffered solutions showed lower chloride levels, higher levels of bicarbonate, and higher pH. The certainty of evidence for these findings was very low. Future research should further examine patient-centred outcomes such as quality of life. The three ongoing studies once published and assessed may alter the conclusions of the review.

Fluid Management in Sepsis

Among critically ill adults, sepsis remains both common and lethal. In addition to antibiotics and source control, fluid resuscitation is a fundamental sepsis therapy. The physiology of fluid resuscitation for sepsis, however, is complex. A landmark trial found early goal-directed sepsis resuscitation reduced mortality, but 3 recent multicenter trials did not confirm this benefit. Multiple trials in resource-limited settings have found increased mortality with early fluid bolus administration in sepsis, and the optimal approach to early sepsis resuscitation across settings remains unknown. After initial resuscitation, excessive fluid administration may contribute to edema and organ dysfunction. Using dynamic variables such as passive leg raise testing can predict a patient's hemodynamic response to fluid administration better than static variables such as central venous pressure. Whether using measures of "fluid responsiveness" to guide fluid administration improves patient outcomes, however, remains unknown. New evidence suggests improved patient outcomes with the use of balanced crystalloids compared to saline in sepsis. Albumin may be beneficial in septic shock, but other colloids such as starches, dextrans, and gelatins appear to increase the risk of death and acute kidney injury. For the clinician caring for patients with sepsis today, the initial administration of 20 mL/kg of intravenous balanced crystalloid, followed by consideration of the risks and benefits of subsequent fluid administration represents a reasonable approach. Additional research is urgently needed to define the optimal dose, rate, and composition of intravenous fluid during the management of patients with sepsis and septic shock.

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.

Balanced crystalloids for septic shock resuscitation

Timely fluid administration is crucial to maintain tissue perfusion in septic shock patients. However, the question concerning which fluid should be used for septic shock resuscitation remains a matter of debate. A growing body of evidence suggests that the type, amount and timing of fluid administration during the course of sepsis may affect patient outcomes. Crystalloids have been recommended as the first-line fluids for septic shock resuscitation. Nevertheless, given the inconclusive nature of the available literature, no definitive recommendations about the most appropriate crystalloid solution can be made. Resuscitation of septic and non-septic critically ill patients with unbalanced crystalloids, mainly 0.9% saline, has been associated with a higher incidence of acid-base balance and electrolyte disorders and might be associated with a higher incidence of acute kidney injury. This can result in greater demand for renal replacement therapy and increased mortality. Balanced crystalloids have been proposed as an alternative to unbalanced solutions in order to mitigate their detrimental effects. Nevertheless, the safety and effectiveness of balanced crystalloids for septic shock resuscitation need to be further addressed in a well-designed, multicenter, pragmatic, randomized controlled trial.

Prevention and Therapy of Acute Kidney Injury in the Developing World

Timely recognition of patients at risk or with possible acute kidney injury (AKI) is essential for early intervention to minimize further damage and improve outcome. Initial management of patients with suspected and persistent AKI should include thorough clinical assessment of all patients with AKI to identify reversible factors, including fluid volume status, potential nephrotoxins, and an assessment of the underlying health of the kidney. Based on these assessments, early interventions to provide appropriate and adequate fluid resuscitation while avoiding fluid overload, removal of nephrotoxins, and adjustment of drug doses according to the level of kidney function derangement are important. The judicious use of diuretics for fluid overload and/or in cardiac decompensated patients and introduction of early enteral nutritional support need to be considered to improve outcomes in AKI. Although these basic principles are well recognized, their application in clinical practice in low resource settings is often limited due to lack of education, availability of resources, and lack of trained personnel, which limits access to care. We report the consensus recommendations of the 18th Acute Dialysis Quality Initiative meeting in Hyderabad, India, on strategies to evaluate patients with suspected AKI and initiate measures for prevention and management to improve outcomes, particularly in low resource settings. These recomendations provide a framework for caregivers, who are often primary care physicians, nurses, and other allied healthcare personnel, to manage patients with AKI in resource poor countries.

Use of intravenous fluids/solutions: a narrative review

OBJECTIVE

Intravenous fluids are broadly categorized into colloids and crystalloids. The aim of this review is to present under a clinical point of view the characteristics of intravenous fluids that make them more or less appropriate either for maintaining hydration when enteral intake is contraindicated or for treating hypovolemia.

METHODS

We considered randomized trials and meta-analyses as well as narrative reviews evaluating the effects of colloids or crystalloids in patients with hypovolemia or as maintenance fluids published in the PubMed and Cochrane databases.

RESULTS

Clinical studies have not shown a greater clinical benefit of albumin solutions compared with crystalloid solutions. Furthermore, albumin and colloid solutions may impair renal function, while there is no evidence that the administration of colloids reduces the risk of death compared with resuscitation with crystalloids in patients with trauma, burns or following surgery. Among crystalloids, normal saline is associated with the development of hyperchloremia-induced impairment of kidney function and metabolic acidosis. On the other hand, the other commonly used crystalloid solution, the Ringer's Lactate, has certain indications and contraindications. These matters, along with the basic principles of the administration of potassium chloride and bicarbonate, are meticulously discussed in the review.

CONCLUSIONS

Intravenous fluids should be dealt with as drugs, as they have specific clinical indications, contraindications and adverse effects.

Hyperchloremia and moderate increase in serum chloride are associated with acute kidney injury in severe sepsis and septic shock patients

Background

Acute kidney injury and hyperchloremia are commonly present in critically ill septic patients. Our study goal was to evaluate the association of hyperchloremia and acute kidney injury in severe sepsis and septic shock patients.

Methods

In this retrospective cohort study in a provincial tertiary care hospital, adult patients with severe sepsis or septic shock and serum chloride measurements were included. Serum chloride was measured on a daily basis for 48 hours. Primary outcome was development of acute kidney injury (AKI) and association of AKI and serum chloride parameters was analyzed.

Results

A total of 240 patients were included in the study, 98 patients (40.8 %) had hyperchloremia. The incidence of acute kidney injury (AKI) was significantly higher in the hyperchloremia group (85.7 % vs 47.9 %; p < 0.001). Maximal chloride concentration in the first 48 hours ([Cl^-]_max) was significantly associated with AKI. In multivariate analysis, [Cl^-]_max was independently associated with AKI [adjusted odds ratio (OR) for AKI = 1.28 (1.02–1.62); p = 0.037]. The increase in serum chloride (Δ[Cl^-] = [Cl^-]_max – initial chloride concentration) demonstrated a dose-dependent relationship with severity of AKI. The mean Δ[Cl^-] in patients without AKI was 2.1 mmol/L while in the patients with AKI stage 1, 2 and 3 the mean Δ[Cl^-] was 5.1, 5.9 and 6.7 mmol/L, respectively. A moderate increase in serum chloride (Δ[Cl^-] ≥ 5 mmol/L) was associated with AKI [OR = 5.70 (3.00–10.82); p < 0.001], even in patients without hyperchloremia [OR = 8.25 (3.44–19.78); p < 0.001].

Conclusions

Hyperchloremia is common in severe sepsis and septic shock and independently associated with AKI. A moderate increase in serum chloride (Δ[Cl^-] ≥5 mmol/L) is associated with AKI even in patients without hyperchloremia.

Acetate-buffered crystalloid fluids: Current knowledge, a systematic review

INTRODUCTION

The concept of fluid resuscitation with balanced solutions containing acetate is relatively new. The knowledge about acetate mostly originates from nephrological research, as acetate was primarily used as a dialysis buffer where much higher doses of acetate are infused. The aim of this review is to give an overview of the advantages and disadvantages of an acetate-buffered crystalloid fluid when compared with other crystalloid infusates.

METHODS

We report trials with the primary object of comparing an acetate-buffered infusion solute to another crystalloid infusate. A systematic literature search of MEDLINE and the Cochrane Controlled Clinical trials register was conducted to identify suitable studies.

RESULTS

The search strategy used produced 1205 potential titles. After eliminating doubles, 312 titles and abstracts were screened, and 31 references were retrieved for full-text analysis. A total of 27 scientific studies were included in the study.

CONCLUSION

Acetate-buffered crystalloid solutes do have a favorable influence on microcirculation. To what extent the acetate-buffered crystalloids influence kidney function is controversially discussed and not yet clear. Metabolic alkalosis did not occur in a single study in humans after an acetate-buffered infusate; potassium levels stayed stable in all studies. Cardiac output and contractility seem to be positively influenced; nonetheless, data on maintenance of a target blood pressure remain inconclusive. Whether acetate-buffered crystalloid fluids lead to lower rates of acute kidney injury and increased survival when compared with normal saline is yet unclear and may depend on the amount of fluid administered.

Impact of common crystalloid solutions on resuscitation markers following Class I hemorrhage: A randomized control trial

BACKGROUND

Resuscitation after hemorrhage with crystalloid solutions can lead to marked acidosis and iatrogenically worsen the lethal triad. The effect of differing solutions on base deficit and lactate has been sparsely prospectively studied in humans. We sought to quantify the effect of normal saline (NS) and lactated Ringer's (LR) resuscitation in voluntary blood donors as a model for Class I hemorrhage.

METHODS

A prospective randomized control trial was conducted in conjunction with blood drives. Donors were randomized to receive no intravenous fluid (noIVF), 2-L NS, or 2-L LR after blood donation of 500 mL. Lactate and base deficit were measured before and after fluid administration using an iSTAT. The mean laboratory values were compared between groups first using a global test followed by pairwise testing between groups using the Wilcoxon rank-sum and Kruskal-Wallis tests. The Bonferroni correction was used and a statistical significance of p < 0.0167 was set.

RESULTS

A total of 157 patients completed the study. The mean (SD) age was 39.2 (12.7), and 65.0% were female. Patients in each group lost equivalent amounts of total blood volume, and a similar amount was replaced in the crystalloid group (p > 0.0167). Donors had comparable increases in lactate and base deficit after donation regardless of the group (p > 0.0167). After resuscitation with 2-L crystalloid, the lactate level increased higher in the LR group than in the noIVF or the NS group (1.36 mmol/L vs. 1.00 mmol/L vs. 1.54 mmol/L, p < 0.0001). In addition, the resuscitation base deficit increased in the NS group more than in the noIVF or LR group (-0.65 vs. -3.06 vs. -0.34, p < 0.0001).

CONCLUSION

This study is one of the first human studies to prospectively demonstrate quantifiable differences in base deficit and lactate by type of crystalloid resuscitation. LR resuscitation elevated lactate levels, and NS negatively affected the base deficit. These findings are critical to the interpretation of trauma patient resuscitation with crystalloid solutions.

LEVEL OF EVIDENCE

Therapeutic study, level II.

[NaCl 0.9 % for volume substitution : blessing or curse?]

The nonphysiological high chloride content of 0.9 % saline causes hyperchloremic acidosis and rapidly reduces renal perfusion in healthy volunteers-negative affects not seen with balanced crystalloids with low chloride content. Evidence from recently published studies strongly suggests that 0.9 % saline negatively effects outcome in surgical and critically ill patients. Major complications are the increased incidence of acute kidney injury and need for renal replacement therapy, as well as higher postoperative in-hospital mortality. Although implemented as the gold standard in many clinical guidelines, there are currently no data supporting the use of 0.9 % saline instead of modern balanced crystalloids. This is also and even particularly true for patients with hypokalemia and acute or chronic kidney injury. In-house training is an effective tool for sustainably raising the awareness of this issue among nursing and medical staff, and identifying alternative strategies to the use of NaCl 0.9 % in clinical practice.

Crystalloid fluid therapy

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency medicine 2016. Other selected articles can be found online at http://www.biomedcentral.com/collections/annualupdate2016. Further information about the Annual Update in Intensive Care and Emergency Medicine is available from http://www.springer.com/series/8901.

What is the ideal crystalloid?

PURPOSE OF REVIEW

We discuss the importance of the composition of intravenous crystalloid solutions. On the basis of current physiologic principles, evidence from basic science and clinical experiments, recent observational studies, and clinical trials, we conclude that the 'ideal crystalloid' depends on clinical context. We make recommendations on solutions that may be used during critical illness, major surgery, and certain clinical situations.

RECENT FINDINGS

The routine use of solutions with a supraphysiologic chloride content and a low strong ion difference (SID), such as isotonic saline solution, may be associated with adverse outcomes, especially among critically ill patients. On the contrary, solutions with a physiologic chloride content and a 'balanced' electrolyte composition (SID closer to plasma) may improve the likelihood of survival. The distribution of different types of crystalloids across traditional 'body compartments' is a function of osmolality of the fluid infused relative to plasma, integrity of the glycocalyx, and the hemodynamic/'volume' state of the patient. During critical illness, the routine administration of colloids may offer no clinical benefits compared with the use of crystalloids.

SUMMARY

Crystalloids, like other types of intravenous fluids, are drugs with important effects on clinical outcomes that may be mediated by osmolality, chloride content, and SID.

Meta-analysis of high- versus low-chloride content in perioperative and critical care fluid resuscitation

Background

The objective of this systematic review and meta-analysis was to assess the relationship between the chloride content of intravenous resuscitation fluids and patient outcomes in the perioperative or intensive care setting.

Methods

Systematic searches were performed of PubMed/MEDLINE, Embase and Cochrane Library (CENTRAL) databases in accordance with PRISMA guidelines. Randomized clinical trials, controlled clinical trials and observational studies were included if they compared outcomes in acutely ill or surgical patients receiving either high-chloride (ion concentration greater than 111 mmol/l up to and including 154 mmol/l) or lower-chloride (concentration 111 mmol/l or less) crystalloids for resuscitation. Endpoints examined were mortality, measures of kidney function, serum chloride, hyperchloraemia/metabolic acidosis, blood transfusion volume, mechanical ventilation time, and length of hospital and intensive care unit stay. Risk ratios (RRs), mean differences (MDs) or standardized mean differences (SMDs) and confidence intervals were calculated using fixed-effect modelling.

Results

The search identified 21 studies involving 6253 patients. High-chloride fluids did not affect mortality but were associated with a significantly higher risk of acute kidney injury (RR 1·64, 95 per cent c.i. 1·27 to 2·13; P < 0·001) and hyperchloraemia/metabolic acidosis (RR 2·87, 1·95 to 4·21; P < 0·001). High-chloride fluids were also associated with greater serum chloride (MD 3·70 (95 per cent c.i. 3·36 to 4·04) mmol/l; P < 0·001), blood transfusion volume (SMD 0·35, 0·07 to 0·63; P = 0·014) and mechanical ventilation time (SMD 0·15, 0·08 to 0·23; P < 0·001). Sensitivity analyses excluding heavily weighted studies resulted in non-statistically significant effects for acute kidney injury and mechanical ventilation time.

Conclusion

A weak but significant association between higher chloride content fluids and unfavourable outcomes was found, but mortality was unaffected by chloride content.

The case for 0.9% NaCl: is the undefendable, defensible?

Although 0.9% NaCl solution is by far the most-used fluid for fluid therapy in resuscitation, it is difficult to find a paper advocating its use over other types of crystalloid solutions. Literature on the deleterious effects of 0.9% NaCl has accumulated over the last decade, but critical appraisal of alternative crystalloid solutions is lacking. As such, the literature seems to suggest that 0.9% NaCl should be avoided at all costs, whereas alternative crystalloid solutions can be used without scrutiny. The basis of this negative evaluation of 0.9% NaCl is almost exclusively its effect on acid-base homeostasis, whereas the potentially deleterious effects present in other types of crystalloids are neglected. We have the challenging task of defending the use of 0.9% NaCl and reviewing its positive attributes, while an accompanying paper will argue against the use of 0.9% NaCl. It is challenging because of the large amount of literature, including our own, showing adverse effects of 0.9% NaCl. We will discuss why 0.9% NaCl solution is the most frequently used resuscitation fluid. Although it has some deleterious effects, all fluids share common features of concern. As such the emphasis on fluid resuscitation should be on volume rather than on composition and should be accompanied by a physiological assessment of the impact of fluids. In this paper, we hope to discuss the context within which fluids, specifically 0.9% NaCl, can be given in a safe and effective manner.

Isotonic crystalloid solutions: a structured review of the literature

BACKGROUND

Several different crystalloid solutions are available for i.v. fluid administration but there is little information about their specific advantages and disadvantages.

METHODS

We performed a systematic search of MEDLINE, EMBASE, and CENTRAL up until May 17, 2012, selecting all prospective human studies that directly compared any near-isotonic crystalloids and reported any outcome.

RESULTS

From the 5060 articles retrieved in the search, only 28 met the selection criteria. There was considerable heterogeneity among the studies. Several articles reported an increased incidence of hyperchloraemic acidosis with the use of normal saline, and others an increase in blood lactate levels when large amounts of Ringer's lactate solutions were infused. From the limited data available, normal saline administration appears to be associated with increased blood loss and greater red blood cell transfusion volumes in high-risk populations compared to Ringer's lactate. Possible effects of the different solutions on renal function, inflammatory response, temperature, hepatic function, glucose metabolism, and splanchnic perfusion are also reported. The haemodynamic profiles of all the solutions were similar.

CONCLUSIONS

Different solutions have different effects on acid-base status, electrolyte levels, coagulation, renal, and hepatic function. Whether these differences have clinical consequences remains unclear.

Should chloride-rich crystalloids remain the mainstay of fluid resuscitation to prevent 'pre-renal' acute kidney injury?: con

The high chloride content of 0.9% saline leads to adverse pathophysiological effects in both animals and healthy human volunteers, changes not seen after balanced crystalloids. Small randomized trials confirm that the hyperchloremic acidosis induced by saline also occurs in patients, but no clinical outcome benefit was demonstrable when compared with balanced crystalloids, perhaps due to a type II error. A strong signal is emerging from recent large propensity-matched and cohort studies for the adverse effects that 0.9% saline has on the clinical outcome in surgical and critically ill patients when compared with balanced crystalloids. Major complications are the increased incidence of acute kidney injury and the need for renal replacement therapy, and that pathological hyperchloremia may increase postoperative mortality. However, there are no large-scale randomized trials comparing 0.9% saline with balanced crystalloids. Some balanced crystalloids are hypo-osmolar and may not be suitable for neurosurgical patients because of their propensity to cause brain edema. Saline may be the solution of choice used for the resuscitation of patients with alkalosis and hypochloremia. Nevertheless, there is evidence to suggest that balanced crystalloids cause less detriment to renal function than 0.9% saline, with perhaps better clinical outcome. Hence, we argue that chloride-rich crystalloids such as 0.9% saline should be replaced with balanced crystalloids as the mainstay of fluid resuscitation to prevent ‘pre-renal' acute kidney injury.