Balanced Versus Unbalanced Fluid in Critically Ill Children: Systematic Review and Meta-Analysis

Fluid Management in Critically Ill Children: Single-Center Retrospective Comparison of Trauma and Postoperative Patients, 2020-2022

OBJECTIVE

Injury and surgery both represent well-defined starting points of a predictable inflammatory response, but the consequent response to IV fluids has not been studied. We aimed to review and compare our single-center fluid management strategies in these two populations.

DESIGN

Retrospective cohort study from January 2020 to July 2022. The primary outcome was total IV fluid volume administered. Net fluid balances and select clinical outcomes were also evaluated.

SETTING

Single tertiary academic center and level 1 pediatric trauma center in New York.

PATIENTS

A dataset of critically ill trauma and surgical patients aged 0-18 years who were admitted to the PICU, 2020-2022. Trauma patients had at least moderate traumatic injuries (Injury Severity Score ≥ 9) and surgical patients had at least a 1-hour operation time.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We identified 25 trauma and 115 surgical patients. During the first 5 days of hospitalization, we did not identify an association between grouping and total IV fluids administered and fluid balance in the prehospital, emergency department, and operating room ( p = 0.90 and p = 0.79), even when adjusted for weight ( p = 0.96). Time trend graphs of net fluid balance and IV fluid administered illustrated analogous fluid requirement and response with the transition from net positive to net negative fluid balance between 48 and 72 hours. There was an association between total IV fluid and ventilator requirement ( p = 0.003).

CONCLUSIONS

Critically ill pediatric trauma and postoperative patients seem to have similar fluid management and balance after injury or surgery. In our opinion, these two critically ill populations could be combined in large prospective studies on optimal fluid therapy in critically ill children.

Fluid bolus resuscitation with hypertonic saline albumin solution in critically ill children: a prospective observational pilot study

To evaluate the hemodynamic effects and the safety profile of fluid bolus resuscitation with hypertonic saline albumin (HSA) in critically ill children, we performed a prospective observational pilot study between October 2018 and May 2021 in the pediatric intensive care unit (PICU) in a tertiary hospital in Madrid, Spain. Sixty-four HSA boluses were analyzed in 23 patients. A mean volume of 5.7 ml/kg (Standard Deviation, SD 2.3 ml/kg) per bolus was infused. Acute hypotension was the main indication. 91% of the patients had a cardiac disease, 56% of them had undergone cardiac surgery in the previous 72 h, and 47.8% associated right ventricular dysfunction. A significant increase in systolic, mean, and diastolic blood pressure and a decrease in the vasoactive index was observed after the infusion of HSA. This effect lasted for twenty-four hours (p < 0.05). Moreover, the amount of fluid requirements decreased significantly in the 6 h following HSA infusion [8.7 ml/kg (SD 9.6) vs. 15.1 ml/kg (SD 13.6) in the previous 6 h (p < 0.05)]. Serum levels of sodium and chloride increased after the infusion, reaching their peak concentration after one hour (143 mEq/L (SD 3.5) and 109.7 mEq/L (SD 6) respectively). HSA-related metabolic acidosis or acute kidney injury were not observed in this study. Hypertonic saline albumin is safe and effective when infused at a dose of 5 ml/kg in critically ill children. However, further research is required to confirm our findings.

Fluid resuscitation in children with severe infection and septic shock: a systematic review and meta-analysis

This study aimed to evaluate the current evidence on various aspects of fluid therapy such as type, volume, and timing of fluid bolus administration in children with septic shock. Systematic review and meta-analysis of clinical trials including children less than 18 years of age admitted to the pediatric emergency and intensive care unit with severe infection and shock requiring fluid resuscitation. The intervention included balanced crystalloids (BC) vs normal saline (NS), colloids vs NS, restricted vs liberal fluid bolus, and slow vs fast fluid bolus. The primary outcome was mortality rate. Of the 219 citations retrieved, 12 trials (3526 children with severe infection with or without malaria and shock) were included. The pooled results found no significant difference in the mortality rate between groups comparing balanced crystalloids (BC) vs normal saline (NS), colloids vs NS, restricted vs liberal fluid bolus, and slow vs fast fluid bolus. The risk of acute kidney injury (AKI) was significantly less in the BC group compared to the NS group. The certainty of evidence for mortality was of "moderate certainty" in the BC vs NS group, and was of "very low certainty" for the other two groups.

CONCLUSIONS

The current meta-analysis found no significant difference in the mortality rate between the types of resuscitation fluid, and their speed or volume of administration. However, a significantly decreased risk of AKI was found in the BC group. More evidence is needed regarding the speed and volume of administration of fluid boluses in critically ill children.Prospero registration: CRD42020209066.

WHAT IS KNOWN

• Balanced crystalloids (BC) may be better than normal saline (NS) for fluid resuscitation in critically ill children.

WHAT IS NEW

• BC are better than NS for fluid resuscitation in critically ill children as they decrease AKI and hyperchloremia.

Management of Pediatric Parenteral Fluids

Parenteral fluid therapy in children requires careful consideration of patient-specific factors such as weight, hydration status, and concomitant disease states. Recent literature has changed the standard of care for maintenance fluids for children in the past decade and brought to light more questions. Concentrations of electrolytes in fluids and the use of balanced fluids are still controversial. This article will review the use of parenteral fluids in children, including fluid content, maintenance fluid rate, treatment of dehydration, and the basics of parenteral fluid ingredients. All pediatric patients should have a plan for fluid therapy that includes careful consideration of hydration status and individual response to therapy.

A balancing act: drifting away from the reflexive use of "ab"normal saline

Maintenance intravenous fluids are the most frequently ordered medications for hospitalized children. Since the American Association of Pediatrics published national guidelines, there has been an increased reflexive use of isotonic solutions, especially 0.9% saline, as a prophylaxis against hyponatremia. In this educational review, we discuss the potential deleterious effects of using 0.9% saline, including the development of hyperchloremia, metabolic acidosis, acute kidney injury, hyperkalemia, and a proinflammatory state. Balanced solutions with anion buffers cause relatively minimal harm when used in most children. While the literature supporting one fluid choice over the other is variable, we highlight the benefits of balanced solutions over saline and the importance of prescribing fluid therapy that is individualized for each patient.

Fluids in the treatment of diabetic ketoacidosis in children: A systematic review

AIM

To determine the comparative effectiveness of fluid schemes for children with diabetic ketoacidosis (DKA).

METHODS

We conducted a systematic review with an attempt to conduct network meta-analysis (NMA). We searched MEDLINE, EMBASE, CENTRAL, Epistemonikos, Virtual Health Library, and gray literature from inception to July 31, 2022. We included randomized controlled trials (RCTs) in children with DKA evaluating any intravenous fluid schemes. We planned to conduct NMA to compare all fluid schemes if heterogeneity was deemed acceptable.

RESULTS

Twelve RCTs were included. Studies were heterogeneous in the population (patients and DKA episodes), interventions with different fluids (saline, Ringer's lactate (RL), and polyelectrolyte solution-PlasmaLyte®), tonicity, volume, and administration systems. We identified 47 outcomes that measured clinical manifestations and metabolic control, including single and composite outcomes and substantial heterogeneity preventing statistical combination. No evidence was found of differences in neurological deterioration (main outcome), but differences were found among interventions in some comparisons to normalize acid-base status (∼2 h less with low vs. high volume); time to receive subcutaneous insulin (∼1 h less with low vs. high fluid rate); length of stay (∼6 h less with RL vs. saline); and resolution of the DKA (∼3 h less with two-bag vs. one-bag scheme). However, available evidence is scarce and poor.

CONCLUSIONS

There is not enough evidence to determine the best fluid therapy in terms of fluid type, tonicity, volume, or administration time for DKA treatment. There is an urgent need for more RCTs, and the development of a core outcome set on DKA in children.

A severe pediatric life-threatening metabolic ketoacidosis

This case report presents a 9-year-old child without underlying pathology, with a severe life-threatening non-diabetic metabolic ketoacidosis occurring less than 48 h after the onset of fasting and vomiting. The patient was admitted to the pediatric intensive care unit. He received volume expansion and maintenance fluid therapy which allowed a favorable evolution. Because of the unusual rapid onset of intense ketonemia and acidosis, a hereditary metabolic disease was investigated. The association between short fasting period and severe metabolic ketoacidosis has never been described in children outside of the neonatal period. This clinical case emphasizes urgent recognition, rigorous diagnostic and appropriate management in clinical practice.

Update on perioperative fluids

Adequate fluid management in the perioperative period in paediatric patients is essential for restoring and maintaining homeostasis and ensuring adequate tissue perfusion. A well-designed infusion regimen is crucial for preventing severe complications such as hyponatraemic encephalopathies. The composition of perioperative fluid solutions is now guided by an understanding of extracellular fluid physiology. Various crystalloid and colloidal products are available for use, but a comprehensive approach requires careful consideration of their drawbacks and limitations. Additionally, the unique characteristics of different patient groups must be taken into account. This review will provide the reader with physiological considerations for perioperative fluids and describe indications for perioperative intravenous fluid therapy in paediatric patients. The current evidence on perioperative fluid therapy is finally summarised in practical recommendations.

Pediatric perioperative fluid management

The purpose of perioperative fluid management in children is to maintain adequate volume status, electrolyte level, and endocrine system homeostasis during the perioperative period. Although hypotonic solutions containing glucose have traditionally been used as pediatric maintenance fluids, recent studies have shown that isotonic balanced crystalloid solutions lower the risk of hyponatremia and metabolic acidosis perioperatively. Isotonic balanced solutions have been found to exhibit safer and more physiologically appropriate characteristics for perioperative fluid maintenance and replacement. Additionally, adding 1-2.5% glucose to the maintenance fluid can help prevent children from developing hypoglycemia as well as lipid mobilization, ketosis, and hyperglycemia. The fasting time should be as short as possible without compromising safety; recent guidelines have recommended that the duration of clear fluid fasting be reduced to 1 h. The ongoing loss of fluid and blood as well as the free water retention induced by antidiuretic hormone secretion are unique characteristics of postoperative fluid management that must be considered. Reducing the infusion rate of the isotonic balanced solution may be necessary to avoid dilutional hyponatremia during the postoperative period. In summary, perioperative fluid management in pediatric patients requires careful attention because of the limited reserve capacity in this population. Isotonic balanced solutions appear to be the safest and most beneficial choice for most pediatric patients, considering their physiology and safety concerns.

Haemodynamic support for paediatric septic shock: a global perspective

Septic shock is a leading cause of hospitalisation, morbidity, and mortality for children worldwide. In 2020, the paediatric Surviving Sepsis Campaign (SSC) issued evidence-based recommendations for clinicians caring for children with septic shock and sepsis-associated organ dysfunction based on the evidence available at the time. There are now more trials from multiple settings, including low-income and middle-income countries (LMICs), addressing optimal fluid choice and amount, selection and timing of vasoactive infusions, and optimal monitoring and therapeutic endpoints. In response to developments in adult critical care to trial personalised haemodynamic management algorithms, it is timely to critically reassess the current state of applying SSC guidelines in LMIC settings. In this Viewpoint, we briefly outline the challenges to improve sepsis care in LMICs and then discuss three key concepts that are relevant to management of children with septic shock around the world, especially in LMICs. These concepts include uncertainties surrounding the early recognition of paediatric septic shock, choices for initial haemodynamic support, and titration of ongoing resuscitation to therapeutic endpoints. Specifically, given the evolving understanding of clinical phenotypes, we focus on the controversies surrounding the concepts of early fluid resuscitation and vasoactive agent use, including insights gained from experience in LMICs and high-income countries. We outline the key components of sepsis management that are both globally relevant and translatable to low-resource settings, with a view to open the conversation to the large variety of treatment pathways, especially in LMICs. We emphasise the role of simple and easily available monitoring tools to apply the SSC guidelines and to tailor individualised support to the patient's cardiovascular physiology.

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.

Balanced crystalloid solutions versus 0.9% saline for treating acute diarrhoea and severe dehydration in children

BACKGROUND

Although acute diarrhoea is a self-limiting disease, dehydration may occur in some children. Dehydration is the consequence of an increased loss of water and electrolytes (sodium, chloride, potassium, and bicarbonate) in liquid stools. When these losses are high and not replaced adequately, severe dehydration appears. Severe dehydration is corrected with intravenous solutions. The most frequently used solution for this purpose is 0.9% saline. Balanced solutions (e.g. Ringer's lactate) are alternatives to 0.9% saline and have been associated with fewer days of hospitalization and better biochemical outcomes. Available guidelines provide conflicting recommendations. It is unclear whether 0.9% saline or balanced intravenous fluids are most effective for rehydrating children with severe dehydration due to diarrhoea.

OBJECTIVES

To evaluate the benefits and harms of balanced solutions for the rapid rehydration of children with severe dehydration due to acute diarrhoea, in terms of time in hospital and mortality compared to 0.9% saline.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was 4 May 2022.

SELECTION CRITERIA

We included randomized controlled trials in children with severe dehydration due to acute diarrhoea comparing balanced solutions, such as Ringer's lactate or Plasma-Lyte with 0.9% saline solution, for rapid rehydration.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were 1. time in hospital and 2.

MORTALITY

Our secondary outcomes were 3. need for additional fluids, 4. total amount of fluids received, 5. time to resolution of metabolic acidosis, 6. change in and the final values of biochemical measures (pH, bicarbonate, sodium, chloride, potassium, and creatinine), 7. incidence of acute kidney injury, and 8.

ADVERSE EVENTS

We used GRADE to assess the certainty of the evidence.

MAIN RESULTS

Characteristics of the included studies We included five studies with 465 children. Data for meta-analysis were available from 441 children. Four studies were conducted in low- and middle-income countries and one study in two high-income countries. Four studies evaluated Ringer's lactate, and one study evaluated Plasma-Lyte. Two studies reported the time in hospital, and only one study reported mortality as an outcome. Four studies reported final pH and five studies reported bicarbonate levels. Adverse events reported were hyponatremia and hypokalaemia in two studies each. Risk of bias All studies had at least one domain at high or unclear risk of bias. The risk of bias assessment informed the GRADE assessments. Primary outcomes Compared to 0.9% saline, the balanced solutions likely result in a slight reduction of the time in hospital (mean difference (MD) -0.35 days, 95% confidence interval (CI) -0.60 to -0.10; 2 studies; moderate-certainty evidence). However, the evidence is very uncertain about the effect of the balanced solutions on mortality during hospitalization in severely dehydrated children (risk ratio (RR) 0.33, 95% CI 0.02 to 7.39; 1 study, 22 children; very low-certainty evidence). Secondary outcomes Balanced solutions probably produce a higher increase in blood pH (MD 0.06, 95% CI 0.03 to 0.09; 4 studies, 366 children; low-certainty evidence) and bicarbonate levels (MD 2.44 mEq/L, 95% CI 0.92 to 3.97; 443 children, four studies; low-certainty evidence). Furthermore, balanced solutions likely reduces the risk of hypokalaemia after the intravenous correction (RR 0.54, 95% CI 0.31 to 0.96; 2 studies, 147 children; moderate-certainty evidence). Nonetheless, the evidence suggests that balanced solutions may result in no difference in the need for additional intravenous fluids after the initial correction; in the amount of fluids administered; or in the mean change of sodium, chloride, potassium, and creatinine levels.

AUTHORS' CONCLUSIONS

The evidence is very uncertain about the effect of balanced solutions on mortality during hospitalization in severely dehydrated children. However, balanced solutions likely result in a slight reduction of the time in the hospital compared to 0.9% saline. Also, balanced solutions likely reduce the risk of hypokalaemia after intravenous correction. Furthermore, the evidence suggests that balanced solutions compared to 0.9% saline probably produce no changes in the need for additional intravenous fluids or in other biochemical measures such as sodium, chloride, potassium, and creatinine levels. Last, there may be no difference between balanced solutions and 0.9% saline in the incidence of hyponatraemia.

Fluid management of the critically Ill child

PURPOSE OF REVIEW

This review summarizes current literature pertaining to fluid management for critically ill children. It includes an overview on crystalloid fluid used throughout the critical illness course, management of fluid output and complications with fluid overload.

RECENT FINDINGS

Observational paediatric studies and adult randomized trials show mixed results regarding risk of mortality and kidney injury with 0.9% saline and crystalloid fluid. A recent adult randomized trial suggests that a fluid restrictive strategy may be well tolerated in critically ill adults with septic shock, but further randomized trials are needed in paediatrics. Fluid overload has been associated with increased morbidity and mortality. Trials exploring ways to decrease fluid accumulation must be done in paediatrics.

SUMMARY

Additional high-quality studies are needed to precisely define the type, timing and rate of intravenous fluid critically ill children should receive throughout their clinical illness course.

Exploring a case of incompatibility in a complex regimen containing Plasma-Lyte 148 in the pediatric intensive care

BACKGROUND

In the local pediatric intensive care unit, precipitation was observed in the intravenous catheter upon co-administration of four drugs together with the buffered electrolyte solution (Plasma-Lyte 148, Baxter). Co-infusion of incompatible combinations represents a safety concern.

AIMS

To reproduce the clinical case of precipitation. To further explore and understand the risk of precipitation, different combinations of the components as well as the corresponding electrolyte solution with 5% glucose (Plasma-Lyte 148 with 5% glucose) should be investigated.

METHODS

Physical compatibility of fentanyl, ketamine, midazolam, and potassium chloride was tested in combination with the buffered electrolyte solutions. The concentrations and infusion rates representative of children 10-40 kg were used to estimate mixing ratios. Analyses detecting visual particles (Tyndall beam) and sub-visual particles (light obscuration technology) were undertaken. Measured turbidity and pH in mixed samples were compared with unmixed controls.

RESULTS

Both midazolam and ketamine showed formation of visual and sub-visual particles upon mixing with Plasma-Lyte 148, respectively. Particle formation was confirmed by increased turbidity and a distinct Tyndall effect. pH in mixed samples mirrored the pH of the buffered electrolyte, suggesting that the solubility limits of midazolam, and in some ratios also ketamine, were exceeded. Midazolam also precipitated in combination with the glucose-containing product that held a lower pH, more favorable for keeping midazolam dissolved.

CONCLUSIONS

Replication of the case revealed that both midazolam and ketamine contributed to the precipitation. Midazolam and ketamine were both evaluated as incompatible with the buffered electrolyte solution and midazolam also with the buffered electrolyte-glucose solution and should not be co-administered in the same i.v.-catheter line. Fentanyl and potassium chloride were interpreted as compatible with both buffered electrolytes.

Endothelial and Glycocalyx Biomarkers in Children With Sepsis After One Bolus of Unbalanced or Balanced Crystalloids

OBJECTIVES

To assess the disruption of endothelial glycocalyx integrity in children with sepsis receiving fluid resuscitation with either balanced or unbalanced crystalloids. The primary outcome was endothelial glycocalyx disruption (using perfused boundary region >2 µm on sublingual video microscopy and syndecan-1 greater than 80 mg/dL) according to the type of crystalloid. The secondary outcomes were increased vascular permeability (using angiopoietin-2 level), apoptosis (using annexin A5 level), and associated clinical changes.

DESIGN

A single-center prospective cohort study from January to December 2021.

SETTING

Twelve medical-surgical PICU beds at a university hospital.

PATIENTS

Children with sepsis/septic shock before and after receiving fluid resuscitation with crystalloids for hemodynamic instability.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We included 106 patients (3.9 yr [interquartile range, 0.60-13.10 yr]); 58 of 106 (55%) received boluses of unbalanced crystalloid. This group had greater odds of endothelial glycocalyx degradation (84.5% vs 60.4%; adjusted odds ratio, 3.78; 95% CI, 1.49-9.58; p < 0.01) 6 hours after fluid administration, which correlated with increased angiopoietin-2 (rho = 0.4; p < 0.05) and elevated annexin A5 ( p = 0.04). This group also had greater odds of metabolic acidosis associated with elevated syndecan-1 (odds ratio [OR], 4.88; 95% CI, 1.23-28.08) and acute kidney injury (OR, 1.7; 95% CI, 1.12-3.18) associated with endothelial glycocalyx damage. The perfused boundary region returned to baseline 24 hours after receiving the crystalloid boluses.

CONCLUSIONS

Children with sepsis, particularly those who receive unbalanced crystalloid solutions during resuscitation, show loss and worsening of endothelial glycocalyx. The abnormality peaks at around 6 hours after fluid administration and is associated with greater odds of metabolic acidosis and acute kidney injury.

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.

Hyperchloremia and association with acute kidney injury in critically ill children

BACKGROUND

Hyperchloremia has been associated with acute kidney injury (AKI) in critically ill adult patients. Data is limited in pediatric patients. Our study sought to determine if an association exists between hyperchloremia and AKI in pediatric patients admitted to the intensive care unit (PICU).

METHODS

This is a single-center retrospective cohort study of pediatric patients admitted to the PICU for greater than 24 h and who received intravenous fluids. Patients were excluded if they had a diagnosis of kidney disease or required kidney replacement therapy (KRT) within 6 h of admission. Exposures were hyperchloremia (serum chloride ≥ 110 mmol/L) within the first 7 days of PICU admission. The primary outcome was the development of AKI using the Kidney Disease Improving Global Outcomes (KDIGO) criteria. Secondary outcomes included time on mechanical ventilation, new KRT, PICU length of stay, and mortality. Outcomes were analyzed using multivariate logistic regression.

RESULTS

There were 407 patients included in the study, 209 in the hyperchloremic group and 198 in the non-hyperchloremic group. Univariate analysis demonstrated 108 (51.7%) patients in the hyperchloremic group vs. 54 (27.3%) in the non-hyperchloremic group (p =  < .001) with AKI. On multivariate analysis, the odds ratio of AKI with hyperchloremia was 2.24 (95% CI 1.39-3.61) (p = .001). Hyperchloremia was not associated with increased odds of mortality, need for KRT, time on mechanical ventilation, or length of stay.

CONCLUSION

Hyperchloremia was associated with AKI in critically ill pediatric patients. Further pediatric clinical trials are needed to determine the benefit of a chloride restrictive vs. liberal fluid strategy. A higher resolution version of the Graphical abstract is available as Supplementary information.