Balanced crystalloids versus isotonic saline in critically ill patients: systematic review and meta-analysis

Comparison of balanced crystalloids versus normal saline in patients with diabetic ketoacidosis: a meta-analysis of randomized controlled trials

Purpose

The optimal resuscitative fluid for patients with diabetic ketoacidosis (DKA) remains controversial. Therefore, our objective was to assess the effect of balanced crystalloids in contrast to normal saline on clinical outcomes among patients with DKA.

Methods

We searched electronic databases for randomized controlled trials comparing balanced crystalloids versus normal saline in patients with DKA, the search period was from inception through October 20th, 2023. The outcomes were the time to resolution of DKA, major adverse kidney events, post-resuscitation chloride, and incidence of hypokalemia.

Results

Our meta-analysis encompassed 11 trials, incorporating a total of 753 patients with DKA. There was no significant difference between balanced crystalloids and normal saline group for the time to resolution of DKA (MD -1.49, 95%CI -4.29 to 1.31, P=0.30, I2 = 65%), major adverse kidney events (RR 0.88, 95%CI 0.58 to 1.34, P=0.56, I2 = 0%), and incidence of hypokalemia (RR 0.80, 95%CI 0.43 to 1.46, P=0.46, I2 = 56%). However, there was a significant reduction in the post-resuscitation chloride (MD -3.16, 95%CI -5.82 to -0.49, P=0.02, I2 = 73%) among patients received balanced crystalloids.

Conclusion

Among patients with DKA, the use of balanced crystalloids as compared to normal saline has no effect on the time to resolution of DKA, major adverse kidney events, and incidence of hypokalemia. However, the use of balanced crystalloids could reduce the post-resuscitation chloride.

Systematic review registration

https://osf.io, identifier c8f3d.

Critical Care Management of Patients After Cardiac Arrest: A Scientific Statement from the American Heart Association and Neurocritical Care Society

The critical care management of patients after cardiac arrest is burdened by a lack of high-quality clinical studies and the resultant lack of high-certainty evidence. This results in limited practice guideline recommendations, which may lead to uncertainty and variability in management. Critical care management is crucial in patients after cardiac arrest and affects outcome. Although guidelines address some relevant topics (including temperature control and neurological prognostication of comatose survivors, 2 topics for which there are more robust clinical studies), many important subject areas have limited or nonexistent clinical studies, leading to the absence of guidelines or low-certainty evidence. The American Heart Association Emergency Cardiovascular Care Committee and the Neurocritical Care Society collaborated to address this gap by organizing an expert consensus panel and conference. Twenty-four experienced practitioners (including physicians, nurses, pharmacists, and a respiratory therapist) from multiple medical specialties, levels, institutions, and countries made up the panel. Topics were identified and prioritized by the panel and arranged by organ system to facilitate discussion, debate, and consensus building. Statements related to postarrest management were generated, and 80% agreement was required to approve a statement. Voting was anonymous and web based. Topics addressed include neurological, cardiac, pulmonary, hematological, infectious, gastrointestinal, endocrine, and general critical care management. Areas of uncertainty, areas for which no consensus was reached, and future research directions are also included. Until high-quality studies that inform practice guidelines in these areas are available, the expert panel consensus statements that are provided can advise clinicians on the critical care management of patients after cardiac arrest.

Critical Care Management of Patients After Cardiac Arrest: A Scientific Statement From the American Heart Association and Neurocritical Care Society

The critical care management of patients after cardiac arrest is burdened by a lack of high-quality clinical studies and the resultant lack of high-certainty evidence. This results in limited practice guideline recommendations, which may lead to uncertainty and variability in management. Critical care management is crucial in patients after cardiac arrest and affects outcome. Although guidelines address some relevant topics (including temperature control and neurological prognostication of comatose survivors, 2 topics for which there are more robust clinical studies), many important subject areas have limited or nonexistent clinical studies, leading to the absence of guidelines or low-certainty evidence. The American Heart Association Emergency Cardiovascular Care Committee and the Neurocritical Care Society collaborated to address this gap by organizing an expert consensus panel and conference. Twenty-four experienced practitioners (including physicians, nurses, pharmacists, and a respiratory therapist) from multiple medical specialties, levels, institutions, and countries made up the panel. Topics were identified and prioritized by the panel and arranged by organ system to facilitate discussion, debate, and consensus building. Statements related to postarrest management were generated, and 80% agreement was required to approve a statement. Voting was anonymous and web based. Topics addressed include neurological, cardiac, pulmonary, hematological, infectious, gastrointestinal, endocrine, and general critical care management. Areas of uncertainty, areas for which no consensus was reached, and future research directions are also included. Until high-quality studies that inform practice guidelines in these areas are available, the expert panel consensus statements that are provided can advise clinicians on the critical care management of patients after cardiac arrest.

Comparing the clinical effects of balanced electrolyte solutions versus normal saline in managing diabetic ketoacidosis: A systematic review and meta-analyses

The first-line treatment of diabetes ketoacidosis (DKA) involves fluid resuscitation with normal saline infusion to correct hypovolemia. Hyperchloremic metabolic acidosis from aggressive normal saline administration was associated with worse clinical outcomes in managing DKA. Other choices for normal saline include balanced electrolyte solutions (BESs). This study aimed to compare the clinical effects between BESs and normal saline in managing DKA. This study was a systematic review of probing articles published from inception to October 2021 in Cochrane Central Register of Controlled Trials, Medical Literature Analysis and Retrieval System Online, Google Scholar, and Scopus. Eight randomized controlled trials with a total of 595 individuals were included. The data were analyzed at 95% confidence level using random-effects models. For the primary outcomes, there was no difference in the duration of DKA resolution. (Mean difference [MD] -4.73, 95% confidence interval [CI] -2.72-4.92; I² = 92%; P = 0.180). However, there was a significantly lower postresuscitation chloride concentration in the BES (MD 2.96 95% CI - 4.86 to - 1.06; I² = 59%; P = 0.002). For the secondary outcomes, there was a significant reduction in duration for normalization of bicarbonate in the BES group (MD 3.11 95% CI - 3.98-2.23; I² = 5%; P = 0.0004). There were no significant differences between groups in duration for recovery of pH, intensive unit admission, and adverse events (mortality and acute renal failure). Resuscitation with BES was associated with decreased chloride and increased bicarbonate values in DKA patients. It suggests that BES prevents DKA patients from hyperchloremic metabolic acidosis.

A randomized controlled trial to assess the effect of isotonic normal saline versus water post-Ryles Tube feeding for correcting hyponatremia among ICU patients at tertiary care hospital: a pilot study

OBJECTIVES

To assess the effect of isotonic normal saline (NS) versus water post-Ryles Tube (RT) feeding upon hyponatremia and blood parameters in Intensive Care Units (ICU) admitted patients.

METHODS

A parallel group randomized controlled trial design. The total sample size taken for this pilot trial was N = 50 as a thumb rule (n = 25 in each arm) selected by using a simple random sampling method. The sample was ICU-admitted patients with mild and moderate hyponatremia.at tertiary care hospital, Rishikesh. Intervention-20 mL Isotonic 0.9% normal saline (NS) among the experimental group vs. 20 mL water in the control group after each 9 am Ryles tube feeding respectively for three continuous days. At baseline and follow-up electrolytes, blood parameters, Glasgow Coma Scale (GCS), and blood pressures were assessed post-one hour of intervention daily for day-1, 2, 3 & 5. Data were analyzed by using descriptive & inferential statistics in the SPSS software 23.0 version.

RESULTS

There was a significant difference found between the experimental and control groups for the post-test value of serum sodium levels, GCS, Systolic Blood Pressure, and Diastolic Blood Pressure (DBP) at day 1 of administration of normal saline intervention with p-value < 0.0001. However, it was found significant at day 5 between both groups for the above-mentioned variables.

CONCLUSION

The intervention of normal saline was found to be a cheaper and more effective remedy to treat hyponatremia and reduce mortality among ICU-admitted patients due to deterioration in bio-physiological parameters.

Early Recognition and Risk Stratification in Cardiogenic Shock: Well Begun Is Half Done

Cardiogenic shock is a complex syndrome manifesting with distinct phenotypes depending on the severity of the primary cardiac insult and the underlying status. As long as therapeutic interventions fail to divert its unopposed rapid evolution, poor outcomes will continue challenging health care systems. Thus, early recognition in the emergency setting is a priority, in order to avoid delays in appropriate management and to ensure immediate initial stabilization. Since advanced therapeutic strategies and specialized shock centers may provide beneficial support, it seems that directing patients towards the recently described shock network may improve survival rates. A multidisciplinary approach strategy commands the interconnections between the strategic role of the ED in affiliation with cardiac shock centers. This review outlines critical features of early recognition and initial therapeutic management, as well as the utility of diagnostic tools and risk stratification models regarding the facilitation of patient trajectories through the shock network. Further, it proposes the implementation of precise criteria for shock team activation and the establishment of definite exclusion criteria for streaming the right patient to the right place at the right time.

The Future of Cardiothoracic Surgical Critical Care Medicine as a Medical Science: A Call to Action

Cardiothoracic surgical critical care medicine (CT-CCM) is a medical discipline centered on the perioperative care of diverse groups of patients. With an aging demographic and an increase in burden of chronic diseases the utilization of cardiothoracic surgical critical care units is likely to escalate in the coming decades. Given these projections, it is important to assess the state of cardiothoracic surgical intensive care, to develop goals and objectives for the future, and to identify knowledge gaps in need of scientific inquiry. This two-part review concentrates on CT-CCM as its own subspeciality of critical care and cardiothoracic surgery and provides aspirational goals for its practitioners and scientists. In part one, a list of guiding principles and a call-to-action agenda geared towards growth and promotion of CT-CCM are offered. In part two, an evaluation of selected scientific data is performed, identifying gaps in CT-CCM knowledge, and recommending direction to future scientific endeavors.

Balanced electrolyte solutions versus isotonic saline in adult patients with diabetic ketoacidosis: A systematic review and meta-analysis

BACKGROUND

Current guidelines suggest the use of isotonic saline (IS) infusion as the preferred resuscitation fluid in the management of diabetic ketoacidosis (DKA). However, balanced electrolyte solutions (BES) have been proposed as an alternative due to a lower propensity to cause hyperchloremic metabolic acidosis. Evidence regarding the use of BES in DKA remains limited.

OBJECTIVES

To determine if the use of BES in fluid resuscitation leads to faster resolution of DKA compared to IS.

METHODS

The study involves a comprehensive search of literature from PubMed, Cochrane CENTRAL, Google Scholar, and Science Direct of clinical trials addressing the use of BES vs IS in fluid resuscitation in DKA. The time to resolution of DKA was examined as the primary endpoint. Pooled hazard ratios (HR) and Mean Difference (MD) in hours with their 95% confidence intervals (CI) were calculated using a random-effects model.

RESULTS

The literature search included 464 studies that were screened individually. A total of 9 studies were identified but 6 studies were excluded due to irrelevance in the outcome of interest and target population. The pooled hazard ratio HR significantly revealed 1.46 [1.10 to 1.94] (p = 0.009) with 12% heterogeneity while MD was -3.02 (95% CI -6.78-0.74; p = 0.12) with heterogeneity of 85%.

CONCLUSION

Considering the evidence from pooled small randomized trials with moderate overall certainty of evidence, the use of BES in DKA was associated with faster rates of DKA resolution compared to IS.

Order Substitutions and Education for Balanced Crystalloid Solution Use in an Integrated Health Care System and Association With Major Adverse Kidney Events

Importance

Trials comparing balanced crystalloids with normal saline have yielded mixed results regarding reductions in kidney complications and mortality for hospitalized patients receiving intravenous fluids.

Objective

To evaluate the association of a multifaceted implementation program encouraging the preferential use of lactated Ringer solution with patient outcomes and intravenous fluid-prescribing practices in a large, multilevel health care system.

Design, Setting, and Participants

This type 2 hybrid implementation and comparative effectiveness study enrolled all patients 18 years or older who received 1 L or more of intravenous fluids while admitted to an emergency department and/or inpatient unit at 1 of 22 hospitals in Idaho and Utah between November 1, 2018, and February 29, 2020. An interrupted time series analysis was used to assess study outcomes before and after interventions to encourage use of lactated Ringer solution.

Exposures

Implementation program combining order set modification, electronic order entry alerts, and sequential clinician-targeted education to encourage prescribing of lactated Ringer solution instead of normal saline.

Main Outcomes and Measures

The primary implementation outcome was the patient-level proportion of intravenous fluids that was balanced crystalloids. The primary effectiveness outcome was the incidence of major adverse kidney events (MAKE30)-a composite of new persistent kidney dysfunction, new initiation of dialysis, and death-at 30 days.

Results

Among 148 423 patients (median [IQR] age, 47 [30-67] years; 91 302 women [61%]), the proportion of total fluids received that was lactated Ringer solution increased from 28% to 75% in the first week vs the last week of the study (immediate implementation effect odds ratio [OR], 3.44; 95% CI, 2.79-4.24). The estimated MAKE30 absolute risk reduction was 2.2% (95% CI, 1.3%-3.3%) based on interrupted time series analysis showing a decrease in the week-on-week trend for MAKE30 (OR difference, 0.03; 95% CI, 0.03-0.03, P < .001). The immediate postimplementation OR for MAKE30 was 0.88 (95% CI, 0.76-1.01), with a decrease in persistent kidney dysfunction (OR, 0.80; 95% CI, 0.69-0.93) and mortality (OR, 0.78; 95% CI, 0.65-0.93) but not dialysis (OR, 1.00; 95% CI, 0.76-1.32).

Conclusions and Relevance

In this comparative effectiveness study, an implementation program was associated with an increase in the proportion of fluids administered as lactated Ringer solution compared with normal saline and was associated with a reduction in MAKE30 events among patients treated in a large integrated health care system.

Balanced Crystalloids versus Normal Saline in Adults with Sepsis: A Comprehensive Systematic Review and Meta-Analysis

The crystalloid fluid of choice in sepsis remains debatable. We aimed to perform a comprehensive meta-analysis to compare the effect of balanced crystalloids (BC) vs. normal saline (NS) in adults with sepsis. A systematic search of PubMed, EMBASE, and Web of Sciences databases through 22 January 2022, was performed for studies that compared BC vs. NS in adults with sepsis. Our outcomes included mortality and acute kidney injury (AKI), need for renal replacement therapy (RRT), and ICU length of stay (LOS). Pooled risk ratio (RR) and mean difference (MD) with the corresponding 95% confidence intervals (CIs) were obtained using a random-effect model. Fifteen studies involving 20,329 patients were included. Overall, BC showed a significant reduction in the overall mortality (RR 0.88, 95% CI 0.81-0.96), 28/30-day mortality (RR 0.87, 95% CI 0.79-0.95), and AKI (RR 0.85, 95% CI 0.77-0.93) but similar 90-day mortality (RR 0.96, 95% CI 0.90-1.03), need for RRT (RR 0.91, 95% CI 0.76-1.08), and ICU LOS (MD -0.25 days, 95% CI -3.44, 2.95), were observed between the two groups. However, subgroup analysis of randomized controlled trials (RCTs) showed no statistically significant differences in overall mortality (RR 0.92, 95% CI 0.82-1.02), AKI (RR 0.71, 95% CI 0.47-1.06), and need for RRT (RR 0.71, 95% CI 0.36-1.41). Our meta-analysis demonstrates that overall BC was associated with reduced mortality and AKI in sepsis compared to NS among patients with sepsis. However, subgroup analysis of RCTs showed no significant differences in both overall mortality and AKI between the groups. There was no significant difference in the need for RRT or ICU LOS between BC and NS. Pending further data, our study supports using BC over NS for fluid resuscitation in adults with sepsis. Further large-scale RCTs are necessary to validate our findings.

The effects of 0.9% saline versus Plasma-Lyte 148 on renal function as assessed by creatinine concentration in patients undergoing major surgery: A single-centre double-blinded cluster crossover trial

OBJECTIVES

Saline and Plasma-Lyte have different physiochemical contents; consequently, they may differently affect patients' renal function. We compared the effects of fluid therapy with 0.9% saline and with Plasma-Lyte 148 on renal function as assessed by creatinine concentration among patients undergoing major surgery.

METHODS

We conducted a prospective, double-blinded cluster crossover trial comparing the effects of the two fluids on major surgery patients. The primary aim was to establish the pilot feasibility, safety and preliminary efficacy evidence base for a large interventional trial to establish whether saline or Plasma-Lyte is the preferred crystalloid fluid for managing major surgery patients. The primary efficacy outcome was the proportion of patients with changes in renal function as assessed by creatinine concentration during their index hospital admission. We used changes in creatinine to define acute kidney injury (AKI) according to the RIFLE criteria.

RESULTS

The study was feasible with 100% patient and clinician acceptance. There were no deviations from the trial protocol. After screening, we allocated 602 patients to saline and 458 to Plasma-Lyte. The median (IQR) volume of intraoperative fluid received was 2000 mL (1000:2000) in both groups. Forty-nine saline patients (8.1%) and 49 Plasma-Lyte patients (10.7%) developed a postoperative AKI (adjusted incidence rate ratio [aIRR]: 1.34; 95% CI: 0.93-1.95; p = 0.120). No differences were observed in the development of postoperative complications (aIRR: 0.98; 95% CI: 0.89-1.08) or the severity of the worst complication (aIRR: 1.00; 95% CI: 0.78-1.30). The median (IQR) length of hospital stay was six days (3:11) for the saline group and five days (3:10) for the Plasma-Lyte group (aIRR: 0.85; 95% CI: 0.73-0.98). There were no serious adverse events relating to the trial fluids, nor were there fluid crossover or contamination events.

CONCLUSIONS

The study design was feasible to support a future follow-up larger clinical trial. Patients treated with saline did not demonstrate an increased incidence of postoperative AKI (defined as changes in creatinine) compared to those treated with Plasma-Lyte. Our findings imply that clinicians can reasonably use either solution intraoperatively for adult patients undergoing major surgery.

TRIAL REGISTRATION

Registry: Australian New Zealand Clinical Trials Registry; ACTRN12613001042730; URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=364988.

Intravenous Fluid Management in Critically Ill Adults: A Review

TOPIC

This article reviews the management of intravenous fluids and the evaluation of volume status in critically ill adults.

CLINICAL RELEVANCE

Intravenous fluid administration is one of the most common interventions in the intensive care unit. Critically ill patients have dynamic fluid requirements, making the management of fluid therapy challenging. New literature suggests that balanced salt solutions may be preferred in some patient populations.

PURPOSE OF PAPER

The bedside critical care nurse must understand the properties of various intravenous fluids and their corresponding impact on human physiology. The nurse's clinical and laboratory assessments of each patient help define the goals of fluid therapy, which will in turn be used to determine the optimal patient-specific selection and dose of fluid for administration. Nurses serve a vital role in monitoring the safety and efficacy of intravenous fluid therapy. Although this intervention can be lifesaving, inappropriate use of fluids has the potential to yield detrimental effects.

CONTENT COVERED

This article discusses fluid physiology and the goals of intravenous fluid therapy, compares the types of intravenous fluids (isotonic crystalloids, including 0.9% sodium chloride and balanced salt solutions; hypotonic and hypertonic crystalloids; and colloids) and their adverse effects and impact on hemodynamics, and describes the critical care nurse's essential role in selecting and monitoring intravenous fluid therapy.

COVID-19-associated acute kidney injury: consensus report of the 25th Acute Disease Quality Initiative (ADQI) Workgroup

Kidney involvement in patients with coronavirus disease 2019 (COVID-19) is common, and can range from the presence of proteinuria and haematuria to acute kidney injury (AKI) requiring renal replacement therapy (RRT; also known as kidney replacement therapy). COVID-19-associated AKI (COVID-19 AKI) is associated with high mortality and serves as an independent risk factor for all-cause in-hospital death in patients with COVID-19. The pathophysiology and mechanisms of AKI in patients with COVID-19 have not been fully elucidated and seem to be multifactorial, in keeping with the pathophysiology of AKI in other patients who are critically ill. Little is known about the prevention and management of COVID-19 AKI. The emergence of regional 'surges' in COVID-19 cases can limit hospital resources, including dialysis availability and supplies; thus, careful daily assessment of available resources is needed. In this Consensus Statement, the Acute Disease Quality Initiative provides recommendations for the diagnosis, prevention and management of COVID-19 AKI based on current literature. We also make recommendations for areas of future research, which are aimed at improving understanding of the underlying processes and improving outcomes for patients with COVID-19 AKI.

COVID-19-associated acute kidney injury: consensus report of the 25th Acute Disease Quality Initiative (ADQI) Workgroup

Kidney involvement in patients with coronavirus disease 2019 (COVID-19) is common, and can range from the presence of proteinuria and haematuria to acute kidney injury (AKI) requiring renal replacement therapy (RRT; also known as kidney replacement therapy). COVID-19-associated AKI (COVID-19 AKI) is associated with high mortality and serves as an independent risk factor for all-cause in-hospital death in patients with COVID-19. The pathophysiology and mechanisms of AKI in patients with COVID-19 have not been fully elucidated and seem to be multifactorial, in keeping with the pathophysiology of AKI in other patients who are critically ill. Little is known about the prevention and management of COVID-19 AKI. The emergence of regional 'surges' in COVID-19 cases can limit hospital resources, including dialysis availability and supplies; thus, careful daily assessment of available resources is needed. In this Consensus Statement, the Acute Disease Quality Initiative provides recommendations for the diagnosis, prevention and management of COVID-19 AKI based on current literature. We also make recommendations for areas of future research, which are aimed at improving understanding of the underlying processes and improving outcomes for patients with COVID-19 AKI.

Chemical and Physical Stability of an Admixture Containing Cefepime and Vancomycin in Lactated Ringer Solution

Purpose: To evaluate the chemical and physical stability of an admixture containing cefepime and vancomycin in a single volume of lactated Ringer solution at refrigerated temperatures. Methods: Cefepime 2000 mg and vancomycin 1000 mg were, respectively, reconstituted with 10 and 20 mL of sterile water for injection (SWFI) per manufacturer instructions. This resulted in cefepime and vancomycin concentrations of 200 and 50 mg/mL, respectively. The resulting cefepime and vancomycin solutions at 10 and 20 mL, respectively, were drawn up and injected into 1000 mL lactated Ringer solution. Aliquot samples were obtained on days 0 to 9, visually inspected for gross incompatibility, and then stored at -80°C. Samples were thawed on the day of the analysis and run through ultraperformance liquid chromatography. Area under the concentration-time curve (AUC) on each day was compared with baseline AUC values. Chemical stability was defined as an AUC more than 93% of the baseline value. Results: No evidence of gross physical incompatibility was observed by visual inspection. Cefepime and vancomycin replicants were more than 94.5% and 98% of baseline AUC values. Therefore, all sample replicants were found to be more than 93% of their baseline AUC value. Conclusion: An admixture containing cefepime 2000 mg and vancomycin 1000 mg in 1000 mL lactated Ringer solution appears to be chemically and physically stable at refrigerated temperatures for up to 9 days.

Acute Kidney Injury in the Context of Acute Respiratory Distress Syndrome

Acute kidney injury is a heterogeneous syndrome defined by rapid (hours to days) decline in the glomerular filtration rate leading to retention of metabolic waste products including creatinine and urea, resulting in declination of the body's ability to manage fluid status and acid-base regulation. Acute kidney injury is seen commonly in acute respiratory distress syndrome and this article will explore the relationship between the 2 entities.

Why physiology will continue to guide the choice between balanced crystalloids and normal saline: a systematic review and meta-analysis

BACKGROUND

Crystalloids are the most frequently prescribed drugs in intensive care medicine and emergency medicine. Thus, even small differences in outcome may have major implications, and therefore, the choice between balanced crystalloids versus normal saline continues to be debated. We examined to what extent the currently accrued information size from completed and ongoing trials on the subject allow intensivists and emergency physicians to choose the right fluid for their patients.

METHODS

Systematic review and meta-analysis with random effects inverse variance model. Published randomized controlled trials enrolling adult patients to compare balanced crystalloids versus normal saline in the setting of intensive care medicine or emergency medicine were included. The main outcome was mortality at the longest follow-up, and secondary outcomes were moderate to severe acute kidney injury (AKI) and initiation of renal replacement therapy (RRT). Trial sequential analyses (TSA) were performed, and risk of bias and overall quality of evidence were assessed. Additionally, previously published meta-analyses, trial sequential analyses and ongoing large trials were analysed for included studies, required information size calculations and the assumptions underlying those calculations.

RESULTS

Nine studies (n = 32,777) were included. Of those, eight had data available on mortality, seven on AKI and six on RRT. Meta-analysis showed no significant differences between balanced crystalloids versus normal saline for mortality (P = 0.33), the incidence of moderate to severe AKI (P = 0.37) or initiation of RRT (P = 0.29). Quality of evidence was low to very low. Analysis of previous meta-analyses and ongoing trials showed large differences in calculated required versus accrued information sizes and assumptions underlying those. TSA revealed the need for extremely large trials based on our realistic and clinically relevant assumptions on relative risk reduction and baseline mortality.

CONCLUSIONS

Our meta-analysis could not find significant differences between balanced crystalloids and normal saline on mortality at the longest follow-up, moderate to severe AKI or new RRT. Currently accrued information size is smaller, and the required information size is larger than previously anticipated. Therefore, completed and ongoing trials on the topic may fail to provide adequate guidance for choosing the right crystalloid. Thus, physiology will continue to play an important role for individualizing this choice.

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.

Effects of chloride content of intravenous crystalloid solutions in critically ill adult patients: a meta-analysis with trial sequential analysis of randomized trials

BACKGROUND

Intravenous crystalloid solutions are administered commonly for critically ill patients. We performed this meta-analysis of randomized trials with trial sequential analysis (TSA) to evaluate effects of chloride content of intravenous crystalloid solutions on clinical outcomes among critically ill adult patients.

METHODS

Electronic databases were searched up to June 1, 2018, for randomized trials of use of balanced crystalloids versus 0.9% saline solutions in critically ill adult patients. The outcome variables included mortality, renal outcomes, serum content alterations and organ function. Subgroup analysis was conducted according to patient settings, types or volume of crystalloid fluid, or among sepsis versus non-sepsis, TBI versus non-TBI or subpopulations by the categories of baseline kidney function. Random errors were evaluated by trial sequential analysis.

RESULTS

Eight studies with 19,301 patients were analyzed. A trend of in-hospital survival benefit with no statistical difference could be observed with balanced crystalloids compared with 0.9% saline (RR 0.92, 95% CI 0.85-1.0, p = 0.06). The use of balanced crystalloid solutions was associated with longer RRT-free days (SMD 0.09, 95% CI 0.06-0.12, p < 0.001), less risk of increase in serum concentrations of chloride (SMD - 1.23, 95% CI - 1.59 to - 0.87, p < 0.001) and sodium (SMD - 1.28, 95% CI - 1.65 to - 0.92, p < 0.001), less risk of decline in serum base deficit (SMD - 0.58, 95% CI - 0.98 to - 0.18, p = 0.004), longer ventilator-free days (SMD 0.08, 95% CI 0.05-0.11, p < 0.001) and vasopressor-free days (SMD 0.04, 95% CI 0.00-0.07, p = 0.02). Subgroup analysis showed that balanced crystalloid solutions were associated with a reduced in-hospital mortality rate among septic patients (RR 0.86, 95% CI 0.75-0.98; p = 0.02) and non-traumatic brain injury patients (RR 0.90, 95% CI 0.82-0.99, p = 0.02), while the TSA results indicated a larger sample size is still in need.

CONCLUSIONS

Limited evidence supported statistical survival benefit with balanced crystalloid solutions, while it benefited in reducing organ support duration and fluctuations in serum electrolyte and base excess and was associated with decreased in-hospital mortality in subpopulation with sepsis and non-TBI. Large-scale rigorous randomized trials with better designs are needed to provide robust evidence for clinical management. Trial registration The protocol for this meta-analysis was registered on PROSPERO: International prospective register of systematic reviews (CRD42018102661), https://www.crd.york.ac.uk/prospero/#recordDetails.

"I don't get no respect": the role of chloride in acute kidney injury

Acute kidney injury (AKI) is a major public health problem that complicates 10-40% of hospital admissions. Importantly, AKI is independently associated with increased risk of progression to chronic kidney disease, end-stage renal disease, cardiovascular events, and increased risk of in-hospital and long-term mortality. The chloride content of intravenous fluid has garnered much attention over the last decade, as well as its association with excess use and adverse outcomes, including AKI. Numerous studies show that changes in serum chloride concentration, independent of serum sodium and bicarbonate, are associated with increased risk of AKI, morbidity, and mortality. This comprehensive review details the complex renal physiology regarding the role of chloride in regulating renal blood flow, glomerular filtration rate, tubuloglomerular feedback, and tubular injury, as well as the findings of clinical research related to the chloride content of intravenous fluids, changes in serum chloride concentration, and AKI. Chloride is underappreciated in both physiology and pathophysiology. Although the exact mechanism is debated, avoidance of excessive chloride administration is a reasonable treatment option for all patients and especially in those at risk for AKI. Therefore, high-risk patients and those with "incipient" AKI should receive balanced solutions rather than normal saline to minimize the risk of AKI.

Balanced crystalloids for intravenous fluid therapy in critically ill and non-critically ill patients: A protocol for systematic review and network meta-analyses

BACKGROUND

The balanced crystalloids have become a substitute for saline for fluid resuscitation. Some studies have investigated the clinical effect and adverse event of differently balanced crystalloids, but they have no consistent conclusions. This study aims to assess and compare the effect of differently balanced crystalloids for intravenous fluid therapy in critically ill and non-critically ill patients using network meta-analysis (NMA).

METHODS

Electronic databases including PubMed, EMBASE, Cochrane Library, Web of Science, Clinical Trials.gov, and the International Clinical Trials Registry Platform (ICTRP) will be searched from inception to April 2018. We will include randomized controlled trials (RCTs) that reported the effect and adverse event of balanced crystalloids. Risk of bias assessment of the included RCTs will be conducted according to the Cochrane Handbook 5.1.0. A Bayesian NMA will be performed using R software. GRADE will be used to explore the quality of evidence.

RESULTS

The results of this NMA will be published in a peer-reviewed journal.

CONCLUSION

This NMA will summarize the direct and indirect evidence to assess the effect of differently balanced crystalloids.

ETHICS AND DISSEMINATION

Ethics approval and patient consent are not required as this study is an NMA based on published studies.

PROSPERO REGISTRATION NUMBER

CRD42018093818.