The ideal crystalloid - what is ‘balanced’? Curr Opin Crit Care. 2013;19:299-307. [PMID: 23743589 DOI: 10.1097/mcc.0b013e3283632d46]

Plasma-lyte solution versus saline in kidney transplantation: A systematic review and meta-analysis of randomized controlled trials

INTRODUCTION

The optimal intravenous fluid for kidney transplantation (KT) is still controversial. This meta-analysis aimed to compare the efficacy and safety of plasma-lyte solution (PL) versus saline (NS) in kidney transplantation.

MATERIALS AND METHODS

A comprehensive search was conducted across four databases (PubMed, Embase, Web of Science, and the Cochrane Library) to identify relevant randomized controlled trials (RCTs) comparing plasma-lyte and saline in kidney transplantation. Risk of bias was assessed using the Cochrane RoB 2.0 tool. Meta-analyses of delayed graft function (DGF), creatinine levels, urine output, blood pH, bicarbonate, base excess, electrolytes, serum chloride, potassium and sodium immediately post-surgery were performed.

RESULTS

Totally six randomized controlled studies with 1197 patients were included. In comparison to the NS group, the PL group exhibited a significantly lower incidence of DGF (OR: 0.66, 95% CI: 0.51 to 0.86, P =  0.002) and reduced serum chloride (MD: -8.87, 95% CI: -13.50 to -4.25, P = 0.0002) as well as serum sodium(MD: -1.08, 95% CI: -1.54 to -0.61, P <  0.00001), while blood pH(MD: 0.05, 95% CI: 0.03 to 0.07, P <  0.00001), bicarbonate (MD: 2.09, 95% CI: 1.21 to 2.97, P = 0.005), and base excess levels (MD: 2.42, 95% CI: 0.72 to 4.11, P <  0.00001) were significantly elevated. No statistically significant differences were observed in creatinine, urine output, or potassium concentrations between two groups.

CONCLUSIONS

This meta-analysis compared the efficacy and safety between plasma-lyte and saline in kidney transplantation. Plasma-lyte reduced delayed graft function in kidney transplant compared to saline.

TRIAL REGISTRATION

PROSPERO (CRD42024588701).

Risk of medication-induced lactic acidosis and hyperlactatemia: a pharmacovigilance study of the United States Food and Drug Administration's Adverse Event Reporting System database

Objective

Lactic acidosis and hyperlactatemia (LAHL) are predictors of poor clinical outcomes in critically ill patients. This research aimed to specify medications reported in association with LAHL, thus providing valuable insights into medication safety.

Methods

Spontaneous reports were excavated from the United States Food and Drug Administration's Adverse Event Reporting System (FAERS) database from Q1 2004 to Q2 2024. Adverse reaction signals of medication-induced lactic acidosis and hyperlactatemia (MILAHL) were detected by reporting odds ratio (ROR) and proportional reporting ratio (PRR).

Results

1,055 medications were identified as primary suspect medications of LAHL from Q1 2004 to Q2 2024, of which 180 were considered to have risk signals by ROR and 160 by PRR. Metformin (16,439 cases), linezolid (815 cases), amlodipine (646 cases), salbutamol (531 cases), and paracetamol (417 cases) were the top 5 medications with the most cases of LAHL. Among the top 50 medications with the strongest ROR and PRR signal, 16 were systemic antivirals, and 13 were antidiabetics (9 containing metformin). 23 of the top 50 medications with the strongest ROR and PRR signal did not indicate the risk of LAHL in the Summary of Product Characteristics (SmPC).

Conclusion

This study listed high-risk medications by ROR and PRR analysis, especially those without an LAHL warning in SmPC, to help health professionals identify MILAHL in case of elevated lactate and enhance medication safety monitoring.

Balanced crystalloid versus saline for resuscitation in pediatric septic shock: a systematic review and meta-analysis

BACKGROUND

Fluid resuscitation is a cornerstone of septic shock management in pediatric patients, with normal saline (NS) being the traditional choice. However, balanced solutions (BS) have gained attention due to their potential to mitigate acid-base and electrolyte disturbances. Despite this, the optimal choice between BS and NS for pediatric sepsis remains unclear. Therefore, we aimed to conduct a meta-analysis comparing the clinical outcomes of BS versus NS in pediatric patients with sepsis.

METHODS

We systematically searched PubMed, EMBASE, and Cochrane Central Register of Controlled Trials, along with reference lists of retrieved publications, for studies comparing clinical outcomes in pediatric patients with sepsis treated with BS versus NS. Our outcomes of interest included acute kidney injury (AKI), hospital mortality, hospital length of stay, pediatric intensive care unit (PICU) length of stay, need for renal replacement therapy, hyperchloremia and mechanical ventilation. We performed statistical analysis using Review Manager Web 8.0.0 and Rstudio.

RESULTS

We included 12,231 patients from 8 studies, of which 4 were randomized clinical trials (RCTs). BS was used to treat septic shock in 2,460 (20.1%) patients. The mean age was 5.98 ± 3.08 years, with 43.82% female patients. Follow-up ranged from 3 to 90 days. We found no statistically significant difference between groups in AKI, hospital mortality, mechanical ventilation, need for renal replacement therapy, and PICU length of stay. Hospital length of stay in days was significantly longer with BS compared to NS (MD 3.38; 95% CI 1.13 to 5.64; p = 0.003; I² = 0%) and the occurrence of hyperchloremia was lower in the BS compared to NS (RR 0.70; 95% CI 0.59 to 0.82; p = 0.0001; I² = 0%). In a subgroup analysis of RCTs only, AKI occurrence was not significantly different between BS and NS groups (RR 0.81; 95% CI 0.48 to 1.38; p = 0.44; I² = 18%). However, the need for renal replacement therapy was significantly less frequent in patients treated with BS compared to NS (RR 0.58; 95% CI 0.39 to 0.87; p = 0.008; I² = 0%).

CONCLUSION

In pediatric septic shock patients, treatment with balanced solutions (BS) was associated with a lower need for renal replacement therapy and a reduced occurrence of hyperchloremia. However, hospital length of stay was longer in patients treated with BS compared to those receiving normal saline (NS). These results underscore the complexity of fluid management in pediatric septic shock and emphasize the need for further research.

Effect of isotonic sodium bicarbonate infusion on perioperative acid-base status among patients undergoing emergency laparotomy for perforation peritonitis (ISABEL trial): a randomized controlled trial

PURPOSE

Perioperative metabolic acidosis negatively affects patient outcomes. Perioperative fluid therapy has a clinically significant effect on acid-base balance. This study was conducted to evaluate the effects of isotonic sodium bicarbonate infusion (ISB) versus balanced crystalloid solution (BCS) on perioperative acid-base balance, in terms of postoperative base excess, among patients undergoing emergency laparotomy for perforation peritonitis.

METHODS

This prospective, randomized, single-center, double-blinded study was conducted in a tertiary hospital from October 2021 to November 2022. A total of 90 patients undergoing emergency laparotomy for perforation peritonitis were randomly assigned to receive either isotonic sodium bicarbonate (ISB) or Ringer's Lactate as a balanced crystalloid solution (BCS) for perioperative maintenance fluid therapy. The primary outcome was to compare the base excess (BE) at the end of surgery. The secondary outcomes were to compare the postoperative clinical outcomes, including the requirement of vasopressors, duration of mechanical ventilation, HDU/ICU stay, the incidence of AKI within seven days, the incidence of re-exploration, and in-hospital mortality. Additionally, pH, PaCO2, HCO3, BE, and lactates intraoperatively and up to 24 h postoperatively were also compared.

RESULTS

The median base excess (BE) values at the end of surgery were significantly better in the ISB group - 4.80 [- 6.80, - 4.10] as compared to the BCS group - 7.30 [- 8.50, - 6.30]. The ISB group had a lower incidence of postoperative AKI (9% ISB versus 24% BCS) and requirement of vasopressors (18% ISB versus 44% BCS). However, there was no major difference between the incidence of re-exploration, length of ICU/HDU stay, and in-hospital mortality.

CONCLUSION

Infusing isotonic sodium bicarbonate (ISB) for intraoperative maintenance fluid therapy in patients undergoing emergency laparotomy for perforation peritonitis significantly improves perioperative acid-base balance with better postoperative clinical outcomes compared to a balanced crystalloid solution (BCS).

A brief history of crystalloids: the origin of the controversy

Fluid resuscitation with crystalloids has been used in humans for more than 100 years. In patients with trauma, sepsis or shock of any etiology, they can help modify the clinical course of the illness. However, these solutions are medications which are not side-effect free. Recently, they have been questioned in terms of quantity (fluid overload) and their composition. The most frequently used crystalloids, both in high and low-income countries, are 0.9% normal saline (NS) and Ringer's lactate. The first descriptions of the use of sodium and water solutions in humans date from the cholera epidemic which spread throughout Europe in 1831. The composition of the fluids used by medical pioneers at that time differs greatly from the 0.9% NS used routinely today. The term "physiological solution" referred to fluids which did not cause red blood cell hemolysis in amphibians in in vitro studies years later. 0.9% NS has an acid pH, a more than 40% higher chloride concentration than plasma and a strong ion difference of zero, leading many researchers to consider it an unbalanced solution. In many observational studies and clinical trials, this 0.9% NS composition has been associated with multiple microcirculation and immune response complications, acute kidney injury, and worse clinical outcomes. Ringer's lactate has less sodium than plasma, as well as other electrolytes which can cause problems in patients with traumatic brain injury. This review provides a brief summary of the most important historical aspects of the origin of the most frequently used intravenous crystalloids today.

New Insights into the Fluid Management in Patients with Septic Shock

The importance of fluid resuscitation therapy during the early stages of sepsis management is a well-established principle. Current Surviving Sepsis Campaign (SSC) guidelines recommend the early administration of intravenous crystalloid fluids for sepsis-related hypotension or hyperlactatemia due to tissue hypoperfusion, within the first 3 h of resuscitation and suggest using balanced solutions (BSs) instead of normal saline (NS) for the management of patients with sepsis or septic shock. Studies comparing BS versus NS administration in septic patients have demonstrated that BSs are associated with better outcomes including decreased mortality. After initial resuscitation, fluid administration has to be judicious in order to avoid fluid overload, which has been associated with increased mortality, prolonged mechanical ventilation, and worsening of acute kidney injury. The "one size fits all" approach may be "convenient" but it should be avoided. Personalized fluid management, based on patient-specific hemodynamic indices, provides the foundations for better patient outcomes in the future. Although there is a consensus on the need for adequate fluid therapy in sepsis, the type, the amount of administered fluids, and the ideal fluid resuscitation strategy remain elusive. Well-designed large randomized controlled trials are certainly needed to compare fluid choices specifically in the septic patient, as there is currently limited evidence of low quality. This review aims to summarize the physiologic principles and current scientific evidence regarding fluid management in patients with sepsis, as well as to provide a comprehensive overview of the latest data on the optimal fluid administration strategy in sepsis.

A retrospective analysis of normal saline and lactated ringers as resuscitation fluid in sepsis

Background

The Surviving Sepsis Campaign suggested preferential resuscitation with balanced crystalloids, such as Lactated Ringer's (LR), although the level of recommendation was weak, and the quality of evidence was low. Past studies reported an association of unbalanced solutions, such as normal saline (NS), with increased AKI risks, metabolic acidosis, and prolonged ICU stay, although some of the findings are conflicting. We have compared the outcomes with the preferential use of normal saline vs. ringer's lactate in a cohort of sepsis patients.

Method

We performed a retrospective cohort analysis of patients visiting the ED of 19 different Mayo Clinic sites between August 2018 to November 2020 with sepsis and receiving at least 30 mL/kg fluid in the first 6 h. Patients were divided into two cohorts based on the type of resuscitation fluid (LR vs. NS) and propensity-matching was done based on clinical characteristics as well as fluid amount (with 5 ml/kg). Single variable logistic regression (categorical outcomes) and Cox proportional hazards regression models were used to compare the primary and secondary outcomes between the 2 groups.

Results

Out of 2022 patients meeting our inclusion criteria; 1,428 (70.6%) received NS, and 594 (29.4%) received LR as the predominant fluid (>30 mL/kg). Patients receiving predominantly NS were more likely to be male and older in age. The LR cohort had a higher BMI, lactate level and incidence of septic shock. Propensity-matched analysis did not show a difference in 30-day and in-hospital mortality rate, mechanical ventilation, oxygen therapy, or CRRT requirement. We did observe longer hospital LOS in the LR group (median 5 vs. 4 days, p = 0.047 and higher requirement for ICU post-admission (OR: 0.70; 95% CI: 0.51-0.96; p = 0.026) in the NS group. However, these did not remain statistically significant after adjustment for multiple testing.

Conclusion

In our matched cohort, we did not show any statistically significant difference in mortality rates, hospital LOS, ICU admission after diagnosis, mechanical ventilation, oxygen therapy and RRT between sepsis patients receiving lactated ringers and normal saline as predominant resuscitation fluid. Further large-scale prospective studies are needed to solidify the current guidelines on the use of balanced crystalloids.

Interventions for preventing and treating acute kidney injury in children

This is a protocol for a Cochrane Review (intervention). The objectives are as follows:

This review aims to look at the benefits and harms of all pharmacological interventions except dialysis for the prevention and treatment of AKI.

Fluid bolus therapy in pediatric sepsis: a narrative review

Leading cause of death in children under five, pediatric sepsis remains a significant global health threat. The 2020 Surviving Sepsis Campaign guidelines revised the management of septic shock and sepsis-associated organ dysfunction in children. In addition to empiric broad-spectrum antibiotics, fluid bolus therapy is one of the cornerstones of management, due to theoretical improvement of cardiac output, oxygen delivery and organ perfusion. Despite a very low level of evidence, the possible benefit of balanced crystalloids in sepsis resuscitation has led to discussion on their position as the ideal fluid. However, the latest adult data are not consistent with this, and the debate is still ongoing in pediatrics. We provide here the current state of knowledge on fluid bolus therapy in pediatric sepsis with emphasis on balanced crystalloids.

Acetate- versus lactate-buffered crystalloid solutions: A systematic review with meta-analysis and trial sequential analysis

OBJECTIVE

There is a widespread use of buffered crystalloid solutions in clinical practice. However, guidelines do not distinguish between specific types of buffered solutions and clinical equipoise exists. We aimed to assess the desirable and undesirable effects of acetate- versus lactate-buffered solutions in hospitalised patients.

METHODS

We conducted a systematic review with meta-analysis and trial sequential analysis of randomised clinical trials assessing the use of acetate- versus lactate-buffered solutions for intravenous administration in hospitalised adults and children. The primary outcome was all-cause short-term mortality. We adhered to our published protocol, the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement, the Cochrane Handbook and the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology.

RESULTS

We included five RCTs enrolling 390 patients. We found no statistically significant difference in short-term mortality (random effects, risk ratio [RR] 0.29; 95% confidence interval [CI] 0.06-1.51, p = .14, I2  = 0%) or hospital length of stay (LOS) (random effects, mean difference [MD]-1.31, 95% CI -3.66 to 1.05, p = .28, I2  = 0%) between acetate- versus lactate-buffered solutions. The quality of evidence was very low. Data regarding intensive care unit LOS were reported by three trials and duration of vasopressor treatment by one trial; none of these data allowed for pooling in meta-analyses. No trials reported data on long-term mortality, health-related quality of life, adverse events, duration of mechanical ventilation or renal replacement therapy.

CONCLUSION

In this systematic review, we found very low quantity and quality of evidence on the use of acetate- versus lactate-buffered solutions in hospitalised patients.

Fluid management in hospitalized pediatric patients

The proper use of intravenous fluids has likely been responsible for saving more lives than any other group of substances. Proper use includes prescribing an appropriate electrolyte and carbohydrate solution, at a calculated rate or volume, for the right child, at the right time. Forming intravenous fluid plans for hospitalized children requires an understanding of water and electrolyte physiology in healthy children and how different pathology deviates from the norm. This review highlights fluid management in several disease types, including liver disease, diabetic ketoacidosis, syndrome of inappropriate antidiuretic hormone, diabetes insipidus, kidney disease, and intestinal failure as well as in those with nonphysiologic fluid losses. For each disease, the review discusses specific considerations, evaluations, and management strategies to consider when customizing intravenous fluid plans. Ultimately, all hospitalized children should receive an individualized fluid plan with recurrent evaluations and fluid modifications to provide optimal care.

Battle of the Crystalloids in the Operating Room: A Literature Review

PURPOSE

The purpose of this article is to synthesize the evidence regarding the commonalities and differences between the three most common crystalloid solutions used in the operating room (normal saline [NS], lactated Ringer's [LR], and Plasmalyte [PL]) in order to determine best practice.

DESIGN

This study is an integrative review of literature.

METHODS

A review of the literature was conducted using the PubMed, CINAHL Plus, and Cochrane Library databases. The inclusion criteria included adult patients undergoing surgery who received either NS, LR, and/or PL (or similar solutions) for fluid maintenance therapy.

FINDINGS

A total of 15 articles from 2008 to 2020 conducted in a surgical setting were selected for the review; eleven randomized controlled studies, three observational studies, and one cohort-controlled trial.

CONCLUSIONS

The findings suggest balanced crystalloid solutions are superior to NS in the operating room in terms of maintaining a stable acid-base balance. PL is preferable to LR because it most closely resembles plasma concentration. Future research is needed to determine the cost-effectiveness of the solutions.

Desenlaces asociados con solución salina normal versus lactato de ringer en sepsis y choque séptico o hipovolémico

Objetivo: los cristaloides son medicamentos usados en pacientes críticamente enfermos, con resultados ambiguos cuando se utilizan soluciones balanceadas versus solución salina normal. El objetivo de este estudio es conocer si existen diferencias al usar solución salina 0.9% vs. lactato de Ringer en pacientes críticamente enfermos con sepsis y choque séptico o hipovolémico, en cuanto a mortalidad, lesión renal aguda y tiempo de estancia hospitalaria. Métodos: estudio observacional de tipo cohorte retrospectiva en mayores de 18 años con diagnóstico de sepsis, choque séptico o hipovolémico. Se excluyeron aquellos con enfermedad renal crónica en diálisis, las hospitalizadas por ginecología/obstetricia y aquellos con diagnóstico de muerte encefálica o donantes de órganos. Se evaluaron los desenlaces primarios de mortalidad, lesión renal aguda y estancia hospitalaria. Resultados: se incluyeron 314 pacientes, 158 en el grupo expuesto a solución salina al 0.9% y 156 con lactato de Ringer. Se presentó lesión renal aguda en 22.7% con solución salina y 25.8% con lactato de Ringer (OR 1.18 IC 95%:0.7-2). La mortalidad con solución salina fue de 49%, y en lactato 49% (OR 1.01 IC 95%:0.63-1.63). Los factores de riesgo identificados para mortalidad fueron uso de soporte vasopresor (OR 35 IC 95% 12-83) y lesión renal aguda (1.3 IC 95% 1.01-1.69). Conclusiones: en el paciente críticamente enfermo con sepsis, choque séptico o hipovolémico el uso de solución salina 0.9% no representa diferencias al compararlo con lactato de Ringer en cuanto a mortalidad, lesión renal aguda o estancia hospitalaria. La elección de un cristaloide debe ser individualizada, teniendo en cuenta las comorbilidades, la presencia de hipercloremia o hiperpotasemia.

Comparison of ringer's lactate and plasmalyt-a as cardiopulmonary bypass prime for bypass associated acidosis in valve replacement surgeries

Introduction:

A wide range of acid base fluctuations are seen during Cardiopulmonary bypass (CPB) and the development of metabolic acidosis is well recognized. We conducted a study tocompare the metabolic effects of Ringer lactate and Plasmalyte-A as CPB prime in causing bypass associated acidosis in valve replacement surgeries.

Methods:

We performed a prospective, randomized controlled study on a total of 80 adult patients undergoing CPB for valvular heart surgeries. The patients were randomized into two groups: Group I (Ringer Lactate) and Group II (Plasmalyte-A). Arterial blood samples were taken before initiating CPB, 30 minutes after starting CPB, then every half hourly till termination of CPB and after half an hour stay in the ICU post operatively to analyze primarily H+ ions, bicarbonates, lactate and strong ion difference.

Results and Discussion:

The results were analyzed in a quantitative manner. In Ringer Lactate group, during CPB, there was reduction in pH from 7.428 ± 0.029 at T1 to 7.335 ± 0.06 (P < 0.01) and 7.358 ± 0.06 (P < 0.01) at T2 and T3 respectively. Mean bicarbonates decreased in Ringer Lactate group during CPB from 24.28 ± 1.65 mEq/L at T1 to 20.98 ± 2.97 mEq/L at T2 (P < 0.01). In Plasmalyte-A group, mean pH, bicarbonate, strong ion difference (SID) were comparable at all time intervals (P > 0.05). In Ringer Lactate group, maximum surge in mean blood lactate levels was seen from 0.85 ± 0.35 mmol/l at T1 to 4.29 ± 1.78 mmol/L (P < 0.01) and 4.17 ± 1.28 mmol/L (P < 0.01) at T2 and T3, respectively. Such surge was not seen in Plasmalyte-A group. The mean SID decreased during the CPB in Ringer Lactate group from 41.102 mEq/L at T1 to 35.66 mEq/L (P = 0.033) at T2 implying metabolic acidosis. Numbered patients having hypotension and arrhythmias were also higher in Ringer Lactate group again indicating higher acidosis.

Conclusion:

The different composition of Plasmalyte-A and Ringer Lactate have different metabolic implications for patients undergoing cardiac surgery. Patients who received Plasmalyte-A as cardiopulmonary bypass prime developed less metabolic acidosis. Hence we conclude that Plasmalyte-A is the preferred cardiopulmonary bypass prime in adult patients undergoing valve replacement surgeries.

Acetate- vs lactate-buffered crystalloid solutions: Protocol for a systematic review with meta-analysis and trial sequential analysis

BACKGROUND

Buffered crystalloid solutions are increasingly recommended as first-line resuscitation fluids. However, guidelines do not distinguish between different types of buffered solutions. The aim of the outlined systematic review is to summarize and assess the effects of acetate- vs lactate-buffered crystalloid solutions on patient-important outcomes.

METHODS

We will conduct a systematic review of randomized clinical trials (RCTs) with meta-analysis and trial sequential analysis comparing the use of acetate- vs lactate-buffered crystalloid solutions in hospitalized patients. We will systematically search the Cochrane Library, MEDLINE, EMBASE, and Epistemonikos for relevant literature. We will follow the recommendations set by the Cochrane Collaboration and the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statement. The risk of systematic errors (bias) and random errors will be assessed, and the overall quality of evidence will be evaluated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.

DISCUSSION

The outlined systematic review will provide important data on how patient-important outcomes are affected by intravenous administration of acetate- vs lactate-buffered crystalloid solutions in hospitalized patients.

Fluids in ARDS: more pros than cons

In acute respiratory distress syndrome (ARDS), increased pulmonary vascular permeability makes the lung vulnerable to edema. The use of conservative as compared to liberal fluid strategies may increase the number of ventilator-free days and survival, as well as reduce organ dysfunction. Monitoring the effects of fluid administration is of the utmost importance; dynamic indexes, such as stroke volume and pulse pressure variations, outperform static ones, such as the central venous pressure. The passive leg raise and end-expiratory occlusion tests are recommended for guiding fluid management decisions. The type of intravenous fluids should also be taken into consideration: crystalloids, colloids, and human albumin have all been used for fluid resuscitation. Recent studies have also shown differences in outcome between balanced and non-balanced intravenous solutions. In preclinical studies, infusion of albumin promotes maintenance of the glycocalyx layer, reduces inflammation, and improves alveolar-capillary membrane permeability. Fluids in ARDS must be administered cautiously, considering hemodynamic and perfusion status, oncotic and hydrostatic pressures, ARDS severity, fluid type, volume and infusion rate, and cardiac and renal function. Of note, no guideline to date has recommended a specific fluid composition for use in ARDS; most physicians currently follow recommendations for sepsis.

The Impact of Intravenous Fluid Therapy on Acid-Base Status of Critically Ill Adults: A Stewart Approach-Based Perspective

One of the most important tasks of physicians working in intensive care units (ICUs) is to arrange intravenous fluid therapy. The primary indications of the need for intravenous fluid therapy in ICUs are in cases of resuscitation, maintenance, or replacement, but we also load intravenous fluid for purposes such as fluid creep (including drug dilution and keeping venous lines patent) as well as nutrition. However, in doing so, some facts are ignored or overlooked, resulting in an acid-base disturbance. Regardless of the type and content of the fluid entering the body through an intravenous route, it may impair the acid-base balance depending on the rate, volume, and duration of the administration. The mechanism involved in acid-base disturbances induced by intravenous fluid therapy is easier to understand with the help of the physical-chemical approach proposed by Canadian physiologist, Peter Stewart. It is possible to establish a quantitative link between fluid therapy and acid–base disturbance using the Stewart principles. However, it is not possible to accomplish this with the traditional approach; moreover, it may not be noticed sometimes due to the normalization of pH or standard base excess induced by compensatory mechanisms. The clinical significance of fluid-induced acid-base disturbances has not been completely clarified yet. Nevertheless, as fluid therapy may be the cause of unexplained acid-base disorders that may lead to confusion and elicit unnecessary investigation, more attention must be paid to understand this issue. Therefore, the aim of this paper is to address the effects of different types of fluid therapies on acid-base balance using the simplified perspective of Stewart principles. Overall, the paper intends to help recognize fluid-induced acid-base disturbance through bedside evaluation and choose an appropriate fluid by considering the acid-base status of a patient.

Quantitative Investigation into the influence of intravenous fluids on human immune and cancer cell lines

The effect of intravenous fluids (IVF) has been investigated clinically through the assessment of post-treatment reactions. However, the responses to IVF vary from patient-to-patient. It is important to understand the response of IVF treatment to be able to provide optimal IVF care. Herein, we investigated the impact of commonly used IVFs, Dextrose, NaCl and Ringer on different human cancer (HepG2 (liver hepatocellular carcinoma) and MCF7 (breast adenocarcinoma)) and immune cell lines (U937 (lymphoma) monocyte and macrophages). The effect of IVF exposure on single cells was characterized using hemocytometer, fluorescence microscopy and flow cytometry. Quantitative data on the viability and morphology of the cells were obtained. Our results emphasize that different IVFs demonstrate important differences in how they influence distinct cell lines. Particularly, we observed that the lactated ringer and dextrose solutions altered the viability and nuclear size of cancer and immune cells differently. Our findings present valuable information to the knowledge of cellular-level IVF effects for further investigations in IVF usage on diverse patient populations and support the importance and necessity of developing optimal diluents not only for drug stability but also for patient benefits.

Balanced Crystalloid Solutions

Intravenous fluid therapy is the most common intervention received by acutely ill patients. Historically, saline (0.9% sodium chloride) has been the most frequently administered intravenous fluid, especially in North America. Balanced crystalloid solutions (e.g., lactated Ringer's, Plasma-Lyte) are an increasingly used alternative to saline. Balanced crystalloids have a sodium, potassium, and chloride content closer to that of extracellular fluid and, when given intravenously, have fewer adverse effects on acid-base balance. Preclinical research has demonstrated that saline may cause hyperchloremic metabolic acidosis, inflammation, hypotension, acute kidney injury, and death. Studies of patients and healthy human volunteers suggest that even relatively small volumes of saline may exert physiological effects. Randomized trials in the operating room have demonstrated that using balanced crystalloids rather than saline prevents the development of hyperchloremic metabolic acidosis and may reduce the need for vasopressors. Observational studies among critically ill adults have associated receipt of balanced crystalloids with lower rates of complications, including acute kidney injury and death. Most recently, large randomized trials among critically ill adults have examined whether balanced crystalloids result in less death or severe renal dysfunction than saline. Although some of these trials are still ongoing, a growing body of evidence raises fundamental concerns regarding saline as the primary intravenous crystalloid for critically ill adults and highlights fundamental unanswered questions for future research about fluid therapy in critical illness.

Hypotonic versus isotonic maintenance fluid administration in the pediatric surgical patient. Semin Pediatr Surg 2019;28:43-46. [PMID: 30824133 DOI: 10.1053/j.sempedsurg.2019.01.007]

Intravenous fluid administration has been occurring for well over one hundred years for a variety of pediatric disease processes. Surprisingly, clinicians have yet to agree upon a standardized intravenous solution. There is ongoing debate regarding the administration of isotonic versus hypotonic fluids as maintenance solutions. In this article, we will review what is known about different maintenance solutions, discuss the potential complications with their use, and summarize the available evidence to help guide clinicians in their choice of maintenance fluids for their patients.

Meta-analysis of the effects of normal saline on mortality in intensive care

INTRODUCTION AND OBJECTIVE

To evaluate, by means of a meta-analysis, the effect of normal saline on mortality in intensive care patients, when compared with the use of balanced crystalloids.

MATERIAL AND METHOD

Published controlled clinical trials, randomised and sequential prospective studies in time, evaluating the mortality when physiological saline was used in patients admitted to intensive care units. Electronic search was performed in Medline, Embase, Cochrane Library, ISI Proceedings, and Web of Science, as well as a manual search of selected references. An independent evaluation was performed by 2 investigators. Discrepancies were resolved by consensus in the working group. Contingency tables were performed, and the OR with confidence intervals of each study were obtained. Heterogeneity was assessed by I². Publication bias was assessed using funnel plot and Egger test.

RESULTS

A total of 8 articles were selected for the meta-analysis of mortality, which included a total of 20,684 patients. A significant association was observed between the use of saline and mortality in intensive care patients (OR 1.0972; 95% CI 1.0049-1.1979), when compared to the use of balanced crystalloids. No statistical evidence of publication bias (Egger, P=.5349) was found. In the sensitivity analysis, none of the studies substantially modified the overall outcome if it was eliminated from the meta-analysis.

CONCLUSIONS

There may be an increase in mortality associated with the use of saline in patients admitted to intensive care when comparing with the use of balanced crystalloids.

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.

Choice of Fluid Therapy in the Initial Management of Sepsis, Severe Sepsis, and Septic Shock

Sepsis results in disruption of the endothelial glycocalyx layer and damage to the microvasculature, resulting in interstitial accumulation of fluid and subsequently edema. Fluid resuscitation is a mainstay in the initial treatment of sepsis, but the choice of fluid is unclear. The ideal resuscitative fluid is one that restores intravascular volume while minimizing edema; unfortunately, edema and edema-related complications are common consequences of current resuscitation strategies. Crystalloids are recommended as first-line therapy, but the type of crystalloid is not specified. There is increasing evidence that normal saline is associated with increased mortality and kidney injury; balanced crystalloids may be a safer alternative. Albumin is similar to crystalloids in terms of outcomes in the septic population but is costlier. Hydroxyethyl starches appear to increase mortality and kidney injury in the critically ill and are no longer indicated in these patients. In the trauma population, the shift to plasma-based resuscitation with decreased use of crystalloid and colloid in the treatment of hemorrhagic shock has led to decreased inflammatory and edema-mediated complications. Studies are needed to determine if these benefits also occur with a similar resuscitation strategy in the setting of sepsis.

Preoperative hydration with 0.9% normal saline to prevent acute kidney injury after major elective open abdominal surgery: A randomised controlled trial

BACKGROUND

Postoperative acute kidney injury (AKI) is the second leading cause of hospital-acquired AKI. Although many preventive strategies have been tested, none of them has been totally effective.

OBJECTIVE

We investigated whether preoperative intravenous hydration with 0.9% normal saline could prevent postoperative AKI.

DESIGN

Randomised controlled trial.

SETTING

University Ramón y Cajal Hospital, Spain, from June 2006 to February 2011.

PATIENTS

Total 328 inpatients scheduled for major elective open abdominal surgery.

INTERVENTION

0.9% normal saline at a dose of 1.5 ml kg h for 12 h before surgery.

MAIN OUTCOME MEASURES

The primary outcome was the overall postoperative AKI incidence during the first week after surgery defined by risk, injury, failure, loss, end-stage kidney disease (RIFLE) and AKI network (AKIN) creatinine criteria. Secondary endpoints were the need for ICU admission, renal replacement therapy during the study period and adverse events and hospital mortality during hospital admission.

RESULTS

There was no difference in the incidence of AKI between groups: 4.7% in the normal saline group versus 5.0% in the control group and 11.4% in the 0.9% normal saline group versus 7.9% in the control group as assessed by the RIFLE and AKIN creatinine criteria, respectively. Absolute risk reductions (95% confidence interval) were -0.3% (-5.3 to 4.7%) for RIFLE and 3.5% (-10.2 to 3.6%) for AKIN. ICU admission after surgery was required in 44.5% of all participants. Only 2 (0.7%) patients required renal replacement therapy during the first week after surgery. The analysis of adverse events did not show statistically significant differences between the groups except for pain. In our population, 8 (2.4%) patients died during their hospital admission.

CONCLUSION

Intravenous hydration with 0.9% normal saline before major open abdominal surgery was not effective in preventing postoperative AKI. No safety concerns were identified during the trial.

TRIAL REGISTRATIONS

Clinical trials.gov: NCT00953940 and EUDRA CT: 2005-004755-35.

Choice of Fluids for Resuscitation of the Critically Ill: What Nurses Need to Know

Fluid administration is one of the most universal interventions in the intensive care unit; however, there remains a lack of optimal fluid choice in clinical practice. With increasing evidence suggesting that the choice and dose of fluid may influence patient outcomes, it is important to have an understanding of the differences between the various fluid products and these potential effects in order for nurses to navigate the critically ill patient. This article reviews properties, adverse effects, and monitoring of commonly used colloid and crystalloid fluids, providing information that may aid in fluid selection in the intensive care unit.

Contemporary Approaches to Perioperative IV Fluid Therapy

BACKGROUND

Intravenous fluid therapy is required for most surgical patients, but inappropriate regimens are commonly prescribed. The aim of this narrative review was to provide evidence-based guidance on appropriate perioperative fluid management.

METHOD

We did a systematic literature search of the literature to identify relevant studies and meta-analyses to develop recommendations.

RESULTS

Of 275 retrieved articles, we identified 25 articles to inform this review. "Normal" saline (0.9% sodium chloride) is not physiological and can result in sodium overload and hyperchloremic acidosis. Starch colloid solutions are not recommended in surgical patients at-risk of sepsis or renal failure. Most surgical patients can have clear fluids and/or administration of carbohydrate-rich drinks up to 2 h before surgery. An intraoperative goal-directed fluid strategy may reduce postoperative complications and reduce hospital length of stay. Regular postoperative assessment of the patient's fluid status and requirements should include looking for physical signs of dehydration or hypovolemia, or fluid overload. Both hypovolemia and salt and water overload lead to adverse events, complications and prolonged hospital stay. Urine output can be an unreliable indicator of hydration status in the postoperative surgical patient. Excess fluid administration has been linked to acute kidney injury, gastrointestinal dysfunction, and cardiac and pulmonary complications.

CONCLUSION

There is good evidence supporting the avoidance of unnecessary fasting and the value of an individualized perioperative IV fluid regimen, with transition to oral fluids as soon as possible, to help patients recover from major surgery.

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.

Resuscitation With Balanced Fluids Is Associated With Improved Survival in Pediatric Severe Sepsis

OBJECTIVE

To evaluate outcomes in patients receiving balanced fluids for resuscitation in pediatric severe sepsis.

DESIGN

Observational cohort review of prospectively collected data from a large administrative database.

SETTING

PICUs from 43 children's hospitals.

PATIENTS

PICU patients diagnosed with severe sepsis.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We reviewed data from the Pediatric Health Information System database from 2004 to 2012. Children with pediatric severe sepsis receiving balanced fluids for resuscitation in the first 24 and 72 hours of treatment were compared to those receiving unbalanced fluids. Thirty-six thousand nine hundred eight patients met entry criteria for analysis. Two thousand three hundred ninety-eight patients received exclusively balanced fluids at 24 hours and 1,641 at 72 hours. After propensity matching, the 72-hour balanced fluids group had lower mortality (12.5% vs 15.9%; p = 0.007; odds ratio, 0.76; 95% CI, 0.62-0.93), lower prevalence of acute kidney injury (16.0% vs 19.2%; p = 0.028; odds ratio, 0.82; 95% CI, 0.68-0.98), and fewer vasoactive infusion days (3.0 vs 3.3 d; p < 0.001) when compared with the unbalanced fluids group.

CONCLUSIONS

In this retrospective analysis carried out by propensity matching, exclusive use of balanced fluids in pediatric severe sepsis patients for the first 72 hours of resuscitation was associated with improved survival, decreased prevalence of acute kidney injury, and shorter duration of vasoactive infusions when compared with exclusive use of unbalanced fluids.

Fluids in Sepsis and Septic Shock (FISSH): protocol for a pilot randomised controlled trial

INTRODUCTION

Observational evidence suggests physiological benefits and lower mortality with lower chloride solutions; however, 0.9% saline remains the most widely used fluid worldwide. Given uncertainty regarding the association of lower chloride on mortality, it is unlikely that practice will change without direct randomised clinical trial (RCT) evidence. This pilot RCT will investigate the feasibility of a large-scale trial directly comparing low chloride with high chloride fluids in patients with septic shock.

METHODS AND ANALYSIS

This is a randomised, concealed, blinded parallel-group multicentre pilot trial. We will include adult critically ill patients with septic shock, defined as ongoing hypotension despite 1 L of fluid, or a serum lactate >4 mmol/L, who are within 6 hours of hospital presentation or rapid response team activation. We will exclude patients if they have an aetiology of shock other than sepsis, if they have acute burn injury, elevated intracranial pressure, intent to withdraw life support or previous enrolment in this or a competing trial. Following informed consent, patients will be randomised to a low chloride fluid strategy or a high chloride fluid strategy for the duration of their ICU stay or until 30 days postrandomisation. Clinicians, patients, families and research staff will be blinded. The primary outcome for this trial will be feasibility, assessed by consent rate, recruitment success and protocol adherence. Patient-important clinical outcomes include mortality, receipt of renal replacement therapy, intensive care unit and hospital lengths of stay and surrogate outcomes of incidence of acidosis, hyperkalaemia and acute kidney injury.

ETHICS AND DISSEMINATION

This pilot trial will test the feasibility of conducting the main trial, which will examine the effect of high versus low chloride fluids in patients with septic shock on patient-important outcomes.

TRIAL REGISTRATION NUMBER

NCT02748382, registered 8 April 2016.

PROTOCOL DATE

1 July 2016.

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.

Fluid Resuscitation: Principles of Therapy and "Kidney Safe" Considerations

Fluid resuscitation in the acutely ill must take into consideration numerous elements, including the intravenous solution itself, the phase of resuscitation, and the strategies toward volume management which are paramount. With the advancement in the understanding and implementation of aggressive fluid resuscitation has also come a greater awareness of the resultant fluid toxicity, especially in those that suffer acute kidney injury, and the realization that there is continued ambiguity with regard to volume mitigation and removal in the resuscitated patient. As such, the discussion regarding intravenous solutions continues to evolve especially as it pertains to their effect on kidney and metabolic function, electrolytes, and ultimately patient outcome. In the section below, we review the foundations of fluid resuscitation in the critically ill patient and the different solutions available in this context, including their composition, physiologic properties, and safety and efficacy including the available data regarding "renal-safe" options.

A comparison of balanced and unbalanced crystalloid solutions in surgery patient outcomes

INTRODUCTION

The objective of this study was to evaluate adverse patient outcomes associated with the choice of intravenous fluid administered during general anaesthesia.

METHODS

This study was a retrospective chart review of vascular surgery patients at a Canadian tertiary care hospital. Patients were separated into three groups: those who were intraoperatively administered normal saline (NS), balanced crystalloids, or a combination of both solutions. Multivariate analysis was performed to determine association between volume of each fluid type administered and adverse outcomes including in-hospital mortality, prolonged intensive care unit admission, vasopressor requirement, ventilator requirement, hemodialysis requirement, and a composite endpoint of any of these adverse events occurring.

RESULTS

Overall, 796 vascular surgery patients were included in the analysis. There were 425 patients who received balanced crystalloids, 158 patients who received NS, and 213 patients received both balanced crystalloids and NS. Groups were similar in age (P=0.06), but varied in gender (P<0.001) and overall health (ASA≥2; P=0.027). The most common adverse event was ventilator requirement (NS: 27.9%, balanced: 7.5%, both: 38.0%; P<0.001). Mortality was lowest in the group that received balanced fluids (NS: 12.0%, balanced: 5.9%, both: 10.8%; P=0.018). Patients who were administered NS or both fluids were more likely to reach the composite endpoint than patients receiving balanced crystalloid alone.

CONCLUSION

The administration of an unbalanced crystalloid solution was associated with poor patient outcomes in our study population.

Plasma-Lyte 148: A clinical review

AIM

To outline the physiochemical properties and specific clinical uses of Plasma-Lyte 148 as choice of solution for fluid intervention in critical illness, surgery and perioperative medicine.

METHODS

We performed an electronic literature search from Medline and PubMed (via Ovid), anesthesia and pharmacology textbooks, and online sources including studies that compared Plasma-Lyte 148 to other crystalloid solutions. The following keywords were used: “surgery”, “anaesthesia”, “anesthesia”, “anesthesiology”, “anaesthesiology”, “fluids”, “fluid therapy”, “crystalloid”, “saline”, “plasma-Lyte”, “plasmalyte”, “hartmann’s”, “ringers”“acetate”, “gluconate”, “malate”, “lactate”. All relevant articles were accessed in full. We summarized the data and reported the data in tables and text.

RESULTS

We retrieved 104 articles relevant to the choice of Plasma-Lyte 148 for fluid intervention in critical illness, surgery and perioperative medicine. We analyzed the data and reported the results in tables and text.

CONCLUSION

Plasma-Lyte 148 is an isotonic, buffered intravenous crystalloid solution with a physiochemical composition that closely reflects human plasma. Emerging data supports the use of buffered crystalloid solutions in preference to saline in improving physicochemical outcomes. Further large randomized controlled trials assessing the comparative effectiveness of Plasma-Lyte 148 and other crystalloid solutions in measuring clinically important outcomes such as morbidity and mortality are needed.

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

Crystalloids have become the fluid of choice in critically ill patients and in the operating room both for fluid resuscitation and fluid maintenance. Among crystalloids, NaCl 0.9% has been the most widely used fluid. However, emerging evidence suggests that administration of 0.9% saline could be harmful mainly through high chloride content and that the use of fluid with low chloride content may be preferable in major surgery and intensive care patients. Administration of NaCl 0.9% is the leading cause of metabolic hyperchloraemic acidosis in critically ill patients and side effects might target coagulation, renal function, and ultimately increase mortality. More balanced solutions therefore may be used especially when large amount of fluids are administered in high-risk patients. In this review, we discuss physiological background favouring the use of balanced solutions as well as the most recent clinical data regarding the use of crystalloid solutions in critically ill patients and patients undergoing major surgery.

Key Controversies in Colloid and Crystalloid Fluid Utilization

Nearly 2 centuries have passed since the use of intravenous fluid became a foundational component of clinical practice. Despite a steady stream of published investigations on the topic, questions surrounding the choice, dose, timing, targets, and cost-effectiveness of various fluid options remain insufficiently answered. In recent years, 2 of the most debated topics reference the role of albumin in acute care and the safety of normal saline. Although albumin has a place in therapy for specific patient populations, its high cost relative to other fluids makes it a less desirable option for hospitals and health systems with escalating formulary scrutiny. Pharmacists bear responsibility for reconciling this disparity and supporting the rational use of albumin in acute care through a careful evaluation of recently published literature. In parallel, it has become clear that crystalloids should no longer be considered a homogenous class of fluids. The past reliance on normal saline has been questioned due to recent findings of renal dysfunction attributable to the solution's supraphysiologic chloride concentration. These safety concerns with 0.9% sodium chloride may result in a practice shift toward more routine use of "balanced crystalloids," such as lactated Ringer's or Plasma-Lyte, that mimic the composition of extracellular fluid. The purpose of this review is to summarize the evidence regarding these 2 important fluid controversies that are likely to affect hospital pharmacists in the coming decades - the evidence-based use of human albumin and the rising role of balanced salt solutions in clinical practice.

Fluid therapy for septic shock resuscitation: which fluid should be used?

Early resuscitation of septic shock patients reduces the sepsis-related morbidity and mortality. The main goals of septic shock resuscitation include volemic expansion, maintenance of adequate tissue perfusion and oxygen delivery, guided by central venous pressure, mean arterial pressure, mixed or central venous oxygen saturation and arterial lactate levels. An aggressive fluid resuscitation, possibly in association with vasopressors, inotropes and red blood cell concentrate transfusion may be necessary to achieve those hemodynamic goals. Nonetheless, even though fluid administration is one of the most common interventions offered to critically ill patients, the most appropriate type of fluid to be used remains controversial. According to recently published clinical trials, crystalloid solutions seem to be the most appropriate type of fluids for initial resuscitation of septic shock patients. Balanced crystalloids have theoretical advantages over the classic solutions, but there is not enough evidence to indicate it as first-line treatment. Additionally, when large amounts of fluids are necessary to restore the hemodynamic stability, albumin solutions may be a safe and effective alternative. Hydroxyethyl starches solutions must be avoided in septic patients due to the increased risk of acute renal failure, increased need for renal replacement therapy and increased mortality. Our objective was to present a narrative review of the literature regarding the major types of fluids and their main drawbacks in the initial resuscitation of the septic shock patients.

Septic Shock: Advances in Diagnosis and Treatment

IMPORTANCE

Septic shock is a clinical emergency that occurs in more than 230,000 US patients each year. OBSERVATIONS AND ADVANCES: In the setting of suspected or documented infection, septic shock is typically defined in a clinical setting by low systolic (≤90 mm Hg) or mean arterial blood pressure (≤65 mm Hg) accompanied by signs of hypoperfusion (eg, oliguria, hyperlactemia, poor peripheral perfusion, or altered mental status). Focused ultrasonography is recommended for the prompt recognition of complicating physiology (eg, hypovolemia or cardiogenic shock), while invasive hemodynamic monitoring is recommended only for select patients. In septic shock, 3 randomized clinical trials demonstrate that protocolized care offers little advantage compared with management without a protocol. Hydroxyethyl starch is no longer recommended, and debate continues about the role of various crystalloid solutions and albumin.

CONCLUSIONS AND RELEVANCE

The prompt diagnosis of septic shock begins with obtainment of medical history and performance of a physical examination for signs and symptoms of infection and may require focused ultrasonography to recognize more complex physiologic manifestations of shock. Clinicians should understand the importance of prompt administration of intravenous fluids and vasoactive medications aimed at restoring adequate circulation, and the limitations of protocol-based therapy, as guided by recent evidence.

Forum for debate: Safety of allogeneic blood transfusion alternatives in the surgical/critically ill patient

In recent years, several safety alerts have questioned or restricted the use of some pharmacological alternatives to allogeneic blood transfusion in established indications. In contrast, there seems to be a promotion of other alternatives, based on blood products and/or antifibrinolytic drugs, which lack a solid scientific basis. The Multidisciplinary Autotransfusion Study Group and the Anemia Working Group España convened a multidisciplinary panel of 23 experts belonging to different healthcare areas in a forum for debate to: 1) analyze the different safety alerts referred to certain transfusion alternatives; 2) study the background leading to such alternatives, the evidence supporting them, and their consequences for everyday clinical practice, and 3) issue a weighted statement on the safety of each questioned transfusion alternative, according to its clinical use. The members of the forum maintained telematics contact for the exchange of information and the distribution of tasks, and a joint meeting was held where the conclusions on each of the items examined were presented and discussed. A first version of the document was drafted, and subjected to 4 rounds of review and updating until consensus was reached (unanimously in most cases). We present the final version of the document, approved by all panel members, and hope it will be useful for our colleagues.

Fluid type and the use of renal replacement therapy in sepsis: a systematic review and network meta-analysis

Fluid resuscitation, along with the early administration of antibiotics, is the cornerstone of treatment for patients with sepsis. However, whether differences in resuscitation fluids impact on the requirements for renal replacement therapy (RRT) remains unclear. To examine this issue, we performed a network meta-analysis (NMA), including direct and indirect comparisons, that addressed the effect of different resuscitation fluids on the use of RRT in patients with sepsis. The data sources MEDLINE, EMBASE, ACPJC, CINAHL and Cochrane Central Register were searched up to March 2014. Eligible studies included randomized trials reported in any language that enrolled adult patients with sepsis or septic shock and addressed the use of RRT associated with alternative resuscitation fluids. The risk of bias for individual studies and the overall certainty of the evidence were assessed. Ten studies (6664 patients) that included a total of nine direct comparisons were assessed. NMA at the four-node level showed that an increased risk of receiving RRT was associated with fluid resuscitation with starch versus crystalloid [odds ratio (OR) 1.39, 95% credibility interval (CrI) 1.17-1.66, high certainty]. The data suggested no difference between fluid resuscitation with albumin and crystalloid (OR 1.04, 95% CrI 0.78-1.38, moderate certainty) or starch (OR 0.74, 95% CrI 0.53-1.04, low certainty). NMA at the six-node level showed a decreased risk of receiving RRT with balanced crystalloid compared to heavy starch (OR 0.50, 95% CrI 0.34-0.74, moderate certainty) or light starch (OR 0.70, 95% CrI 0.49-0.99, high certainty). There was no significant difference between balanced crystalloid and saline (OR 0.85, 95% CrI 0.56-1.30, low certainty) or albumin (OR 0.82, 95% CrI 0.49-1.37, low certainty). Of note, these trials vary in terms of case mix, fluids evaluated, duration of fluid exposure and risk of bias. Imprecise estimates contributed to low confidence in most estimates of effect. Among the patients with sepsis, fluid resuscitation with crystalloids compared to starch resulted in reduced use of RRT; the same may be true for albumin versus starch.

Balanced versus unbalanced salt solutions: what difference does it make?

BACKGROUND

The infusion of crystalloid solutions is a fundamental part of the management of critically ill patients. These solutions are used to maintain the balance of water and essential electrolytes and replace losses when patients have limited gastrointestinal intake. They also act as carriers for intravenous infusion of medication and red cells. The most commonly used solution, 0.9% saline, has equal concentrations of Na(+) and Cl(-) even though the plasma concentration of Na(+) normally is 40 meq/L higher than that of Cl(-). The use of this fluid thus can produce a hyperchloremic acidosis in a dose-dependent manner, but it is not known whether this has clinical significance.

APPROACH

The first part of this article deals with the significance of Na(+) and Cl(-) in normal physiology. This begins with examination of their roles in the regulation of osmolality, acid-base balance, and generation of electrochemical gradients and why the concentration of Cl(-) normally is considerably lower than that of Na(+). The next part deals with how their concentrations are regulated by the gastrointestinal tract and kidney. Based on the physiology, it would seem that solutions in which the concentration of Na(+) is "balanced" by a substance other than Cl(-) would be advantageous. The final part examines the evidence to support that point.

CONCLUSIONS

There are strong observational data that support the notion that avoiding an elevated Cl(-) concentration or using fluids that reduce the rise in Cl(-) reduces renal dysfunction, infections, and possibly even mortality. However, observational studies only can indicate an association and cannot indicate causality. Unfortunately, randomized trials to date are far too limited to address this crucial issue. What is clear is that appropriate randomized trials will require very large populations. It also is not known whether the important variable is the concentration of Cl(-), the difference in concentrations of Na(+) and Cl(-), or the total body mass of Cl(-).

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.

Update on the management of neonatal sepsis in horses

Despite advances in neonatal intensive care sepsis, severe sepsis and septic shock remain the biggest killers of neonatal foals. Management of this severe syndrome remains difficult, requiring intensive intervention. Key aspects of management include infection control, hemodynamic support, immunomodulatory interventions, and metabolic/endocrine support. Infection control largely consists of early antimicrobial therapy, plasma transfusions, and local therapy for the infected focus. In cases with severe sepsis or septic shock, hemodynamic support with fluids, vasoactive agents, and respiratory support insuring oxygen delivery to vital organs is important. Nutritional support is important, but close monitoring is needed to avoid hyperglycemia and hypoglycemia.