154 compared to 54 mmol per liter of sodium in intravenous maintenance fluid therapy for adult patients undergoing major thoracic surgery (TOPMAST): a single-center randomized controlled double-blind trial

Capillary Filtration of Plasma Is Accelerated During General Anesthesia: A Secondary Population Volume Kinetic Analysis

How infusion fluids are distributed and eliminated is of importance to how much and how fast they should be administered. This manuscript applies population pharmacokinetic modeling to intravenous infusions of crystalloid fluid, which is a common therapy in hospital care and mandatory during surgery. The analysis was based on the hemodilution and urine output measured during and after 262 infusions of 1647 ± 461 mL (mean ± SD) of fluid over 30 min in adults. The result shows that distribution of fluid from the plasma to the interstitial fluid space occurred twice as fast during general anesthesia as compared to the conscious state. The increased rate ensures adequate nutritional flow to the cells despite decreased flow in the macrocirculation, which is a characteristic of general anesthesia. This increased capillary leakage of fluid was coupled with an even greater reduction of the urinary output and accumulation of fluid in both the fast-exchange interstitial fluid space and a remote "third fluid space," the latter of which apparently serves as an overflow reservoir. During the first hour of the experiments, 88% more fluid resided extravascularly in the presence of general anesthesia than in the awake state. General anesthesia increased the half-life from 1.8 to 16.6 h, showing marked impairment in the handling of infused crystalloid fluid.

Unlocking new frontiers: DNA nanotechnology's impact on acute kidney injury diagnosis and treatment

Acute kidney injury (AKI) serves as an independent risk factor for chronic kidney disease (CKD) and hastens its progression. However, effective early diagnosis and treatment methods for AKI are still limited in clinical practice. There is a pressing need to develop fast, effective, and noninvasive diagnostic methods for AKI, as well as treatments that reduce nephrotoxicity. DNA nanotechnology, utilizing the programmable properties of DNA to engineer nanostructures and nanodevices, has achieved significant advancements in disease diagnosis and treatment. The application of DNA nanotechnology for kidney disease, particularly AKI, has been increasingly explored. This review encompasses the advancement of rapid and highly sensitive detection methods for AKI biomarkers, alongside the development of targeted drug delivery systems to the kidneys. These innovations facilitate precise treatment while minimizing adverse drug effects. The review underscores the progress in employing DNA nanotechnology for AKI diagnosis and treatment. Initially, we examine DNA nanotechnology-based strategies for AKI diagnosis, with an emphasis on biomarker detection. Subsequently, we delve into the therapeutic applications of DNA nanotechnology in AKI, highlighting targeted drug delivery and reduced toxicity. Finally, we offer insights into the challenges and opportunities associated with the clinical application of DNA nanotechnology in AKI management.

Intraoperative isotonic balanced versus hypotonic crystalloids on postoperative sodium homeostasis in small children undergoing major neurosurgery: a randomized controlled trial

BACKGROUND

Whether intraoperative isotonic balanced maintenance fluid is associated with less variation in sodium homeostasis in small children undergoing major neurosurgery remains unknown.

METHODS

Patients aged up to 6 years undergoing major neurosurgery were randomly assigned to receive either isotonic balanced solution (IB) or 0.2% hypotonic solution (H) as intraoperative maintenance fluid. Serum electrolyte levels were measured from preoperative baseline to 6 d following surgery.

RESULTS

Eighty patients were included in the primary analysis. Serum sodium change was significantly less in the IB patients from the end of surgery continuing to 24 h following surgery (at the end of surgery: -1.4 ± 3.6 versus - 4.6 ± 3.5 mmol/l, P < 0.001; 24 h post: -1.2 ± 4.8 versus - 3.4 ± 2.5 mmol/l, P = 0.028). Twenty (50%) of the IB patients and 25 (63%) of the H patients had serum sodium change > 2.5 mmol/l 24 h following surgery (6.0 ± 3.4 versus 4.8 ± 2.1 mmol/l), with 13 (33%) of the IB patients and 25 (63%) of the H patients having sodium decrease > 2.5 mmol/l (6.4 ± 3.7 versus 4.8 ± 2.1 mmol/l) (P = 0.007). Seven patients in group IB experienced an increase in blood sodium levels exceeding 2.5 mmol/l (median, 4.1 [range 2.7 ∼ 9.2] mmol/l). Notably, 10 (25%) of the IB patients and 6 (15%) of the H patients had sodium variation > 5 mmol/l (median, 8.5 [range 5.1 ∼ 14.6] versus 7.2 [range 5.5 ∼ 11.1] mmol/l). Immediately following surgery till 24 h postoperatively, hyponatremia was less observed in the IB patients compared with that in the H patients. The IB patients had higher hemoglobin levels and less diuresis 48 h postoperatively. No symptoms including altered mental status, seizure, and circulatory overload were observed in all patients.

CONCLUSION

Intraoperative isotonic balanced solution infusion resulted in statistically but not clinically minimal variation of sodium homeostasis and hemoglobin level postoperatively in small children undergoing major neurosurgery, compared to the use hypotonic solution. Potentially excessive sodium fluctuation following isotonic balanced maintenance fluid infusion should be cautioned, even for a brief period of infusion.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ( http://www.chictr.org.cn/ ).

REGISTRATION NUMBER

ChiCTR2100046539. Registration date: May 21, 2021. Principal investigator: Lin-Lin Song.

Is the NICE Guideline for maintenance fluid therapy in adults in hospital appropriate?

BACKGROUND AND AIMS

The National Institute for Health and Care Excellence's (NICE) Guideline for Maintenance Fluid Therapy in Adults in Hospital is widely used, but the recommendations have not been evaluated properly. In this study, we investigated whether the recommendation of providing 25-30 mL/kg/day of fluid and 1 mmol/kg each of sodium and potassium is sufficient for human needs.

METHODS

First, we calculated the distribution of fluid between the extracellular fluid volume (ECV) and intracellular fluid volume (ICV) during a cross-over infusion experiment where 12 volunteers received 25 mL/kg/day of either a high-sodium (154 mmol/L) or low-sodium (54 mmol/L) solution over 48 h. Second, urine samples from 719 volunteers and clinical patients were used to quantify their renal water conservation and excretion of sodium and potassium. Third, retrospective analysis of a diet study was used to extrapolate how large the fluid intake and the electrolyte excretion likely had been in the 719 volunteers and hospital patients who delivered urine.

RESULTS

The high-sodium fluid maintained the ECV but the ICV had decreased by 1.3 L after 48 h. The low-sodium fluid resulted in a volume deficit of 1.7 L that equally affected the ECV and the ICV. Regression equations based on the diet study suggested that the daily intake of water in the 719 subjects averaged 2.6 L and that 2 mmol/kg of sodium and 1 mmol/kg of potassium was excreted.

CONCLUSION

The NICE guideline recommends too little water and sodium for a human to adequately maintain the ECV and ICV.

CLINICAL TRIAL REGISTRATIONS

EudraCT 2016-001846-24 and ISRCTN 12215472.

A Slow-Exchange Interstitial Fluid Compartment in Volunteers and Anesthetized Patients: Kinetic Analysis and Physiology

BACKGROUND

Physiological studies suggest that the interstitial space contains 2 fluid compartments, but no analysis has been performed to quantify their sizes and turnover rates.

METHODS

Retrospective data were retrieved from 270 experiments where Ringer's solution of between 238 and 2750 mL (mean, 1487 mL) had been administered by intravenous infusion to awake and anesthetized humans (mean age 39 years, 47% females). Urinary excretion and hemoglobin-derived plasma dilution served as input variables in a volume kinetic analysis using mixed-models software.

RESULTS

The kinetic analysis successfully separated 2 interstitial fluid compartments. One equilibrated rapidly with the plasma and the other equilibrated slowly. General anesthesia doubled the rate constants for fluid entering these 2 compartments (from 0.072 to 0.155 and from 0.026 to 0.080 min -1 , respectively). The return flows to the plasma were impeded by intensive fluid therapy; the rate constant for the fast-exchange compartment decreased from 0.251 to 0.050 when the infusion time increased from 15 to 60 minutes, and the rate constant for the slow-exchange compartment decreased from 0.019 to 0.005 when the infused volume increased from 500 to 1500 mL. The slow-exchange compartment became disproportionately expanded when larger fluid volumes were infused and even attained an unphysiologically large size when general anesthesia was added, suggesting that the flow of fluid was restrained and not solely determined by hydrostatic and oncotic forces. The dependence of the slow-exchange compartment on general anesthesia, crystalloid infusion rate, and infusion volume all suggest a causal physiological process.

CONCLUSIONS

Kinetic analysis supported that Ringer's solution distributes in 2 interstitial compartments with different turnover times. The slow compartment became dominant when large amounts of fluid were infused and during general anesthesia. These findings may explain why fluid accumulates in peripheral tissues during surgery and why infused fluid can remain in the body for several days after general anesthesia.

Fluid accumulation syndrome in sepsis and septic shock: pathophysiology, relevance and treatment-a comprehensive review

In this review, we aimed to comprehensively summarize current literature on pathophysiology, relevance, diagnosis and treatment of fluid accumulation in patients with sepsis/septic shock. Fluid accumulation syndrome (FAS) is defined as fluid accumulation (any degree, expressed as percentage from baseline body weight) with new onset organ-failure. Over the years, many studies have described the negative impact of FAS on clinically relevant outcomes. While the relationship between FAS and ICU outcomes is well described, uncertainty exists regarding its diagnosis, monitoring and treatment. A stepwise approach is suggested to prevent and treat FAS in patients with septic shock, including minimizing fluid intake (e.g., by limiting intravenous fluid administration and employing de-escalation whenever possible), limiting sodium and chloride administration, and maximizing fluid output (e.g., with diuretics, or renal replacement therapy). Current literature implies the need for a multi-tier, multi-modal approach to de-resuscitation, combining a restrictive fluid management regime with a standardized early active de-resuscitation, maintenance fluid reduction (avoiding fluid creep) and potentially using physical measures such as compression stockings.Trial registration: Not applicable.

Intravenous maintenance fluid therapy in acutely and critically ill children: state of the evidence

Intravenous maintenance fluid therapy (IV-MFT) is one of the most prescribed, yet one of the least studied, interventions in paediatric acute and critical care settings. IV-MFT is not typically treated in the same way as drugs with specific indications, contraindications, compositions, and associated adverse effects. In the last decade, societies in both paediatric and adult medicine have issued evidence-based practice guidelines for the use of intravenous fluids in clinical practice. The main objective of this Viewpoint is to summarise and compare the rationales on which these international expert guidelines were based and how these recommendations affect IV-MFT practices in paediatric acute and critical care. Although these guidelines recommend the use of isotonic fluids as a standard in IV-MFT, some discrepancies and uncertainties remain regarding the systematic use of balanced fluids, glucose and electrolyte requirements, and appropriate fluid volume. IV-MFT should be considered in the same way as any other prescription drug and none of the components of IV-MFT prescription should be overlooked (ie, choice of drug, dosing rate, duration of treatment, and de-escalation). Furthermore, most evidence that was used to inform the guidelines comes from high-income countries. Although some principles of IV-MFT are universal, the direct relevance to and feasibility of implementing the guidelines in low-income and middle-income countries is uncertain.

A Logical Prescription of Intravenous Fluids

This chapter guides clinicians through the assessment and management of patients requiring intravenous (IV) fluids during hospitalization in the regular ward and ICU. It aims to aid in the determination of the patient’s actual fluid or volume status and guides the prescription and management of electrolyte replacement whilst avoiding potential harm to patients from fluid mismanagement leading to electrolyte disturbances, fluid accumulation, and organ impairment (or a combination). This is referred to as IV Fluid Stewardship, and it incorporates much of the National Institute for Health and Care Excellence (NICE) guidance published.

Choice of creep or maintenance fluid type and their impact on total daily ICU sodium burden in critically ill patients: A systematic review and meta-analysis

PURPOSE

Maintenance and hidden/creep fluids are a major source of fluid and sodium intake in intensive care unit (ICU) patients. Recent research indicates that low versus high sodium content maintenance fluids could decrease fluid and sodium burden. We conducted a systematic review (SR) with meta-analysis to summarize the impact of maintenance fluid choice on total daily sodium in ICU patients.

MATERIALS AND METHODS

Systematic literature search in Pubmed, Embase, the Cochrane Library and the.

CLINICAL TRIALS REGISTRY

Only controlled clinical trials were included.

EXCLUSION CRITERIA

trials on resuscitation fluids, performed in the emergency department only and in pediatric patients. Primary objective was the reduction in mean total sodium intake with low versus high sodium content maintenance/creep fluids.

RESULTS

Five studies (1105 patients) were included. Heterogeneity was high.Risk of bias was moderate. Mean daily sodium reduction was 117 mmol (95%Confidence Interval [CI] -174; -59; p < 0.001) with low versus high sodium content maintenance/creep fluids. Incidence of hyperchloremia was lower (OR 0.26; 95%CI 0.1; 0.64) with low sodium. There were no differences in the incidences of hyper-/hyponatremia and fluid balances.

CONCLUSION

Using low sodium content maintenance/creep fluids substantially reduces daily sodium burden in adult ICU patients. Significant knowledge/research gaps exist regarding relevance and safety.

TRIAL REGISTRATION

PROSPERO 2022 CRD42022300577 (February 2022).

Comparison of Fluid Replacement with Sterofundin ISO® vs. Deltajonin® in Infants Undergoing Craniofacial Surgery-A Retrospective Study

In recent decades, infusion solutions such as NaCl 0.9% and lactate Ringer's solution have been replaced in clinical practice. Since 2017, the national guidelines for perioperative infusion therapy in children recommend balanced isotonic solutions to maintain fluid balance. The composition of balanced infusion solutions varies with respect to their electrolyte content. Hyperchloremia may be mistaken for hypovolemia and may interfere with volume therapy in pediatric patients. Sterofundin ISO® balanced solution contains 127 mmol/L chloride and may cause hyperchloremic acidosis if administered in large volumes.

OBJECTIVES

The purpose of this study was to compare the effects of Sterofundin ISO® (SF) therapy with the balanced isochloremic solution Deltajonin® (DJ) (106 mmol/L chloride) on the acid-base status in infants undergoing craniofacial surgery.

METHODS

This retrospective, non-blinded study included 100 infants undergoing craniectomy due to isolated nonsyndromic sagittal craniosynostosis. The first 50 infants received Sterofundin ISO®. Due to changes in national guidelines, the infusion was changed to the isoionic Deltajonin® in an additional 50 infants in 2017. Pre- and postoperative values of chloride, pH, base excess, bicarbonate, and albumin and phosphate were determined, and the strong-ion difference, strong-ion gap, anion gap, and weak acids were calculated.

RESULTS

Both groups were comparable in terms of their age, sex, underlying disease, preoperative electrolytes (except K at 3.9 ± 0.3 mmol/L (SF) vs. 4.1 ± 0.3 mmol/L (DJ) and lactate 8.7 ± 2.1 (SF) vs. 9.6 ± 2.6 mmol/L (DJ)). In the Sterofundin ISO® group, hyperchloremic metabolic acidosis was observed in 19 patients, whereas only 2 infants in the Deltajonin® group had hyperchloremic metabolic acidosis. The postoperative chloride level was 111 ± 2.7 mmol/L (SF) vs. 108 ± 2.4 mmol/L (DJ). The difference in anion gap was 12.5 ± 3.0 mmol/L (SF) vs. 14.6 ± 2.8 mmol/L (DJ), and the difference in SIDa (apparent strong-ion difference) was 30.9 mmol/L (SF) vs. 33.8 mmol/L (DJ).

CONCLUSIONS

Hyperchloremic acidosis can be induced by the volume replacement with high-chloride-concentration crystalloids such as Sterofundin ISO®. This can be detected using the Stewart model.

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.

Intravenous fluid therapy in patients with severe acute pancreatitis admitted to the intensive care unit: a narrative review

Patients with acute pancreatitis (AP) often require ICU admission, especially when signs of multiorgan failure are present, a condition that defines AP as severe. This disease is characterized by a massive pancreatic release of pro-inflammatory cytokines that causes a systemic inflammatory response syndrome and a profound intravascular fluid loss. This leads to a mixed hypovolemic and distributive shock and ultimately to multiorgan failure. Aggressive fluid resuscitation is traditionally considered the mainstay treatment of AP. In fact, all available guidelines underline the importance of fluid therapy, particularly in the first 24–48 h after disease onset. However, there is currently no consensus neither about the type, nor about the optimal fluid rate, total volume, or goal of fluid administration. In general, a starting fluid rate of 5–10 ml/kg/h of Ringer’s lactate solution for the first 24 h has been recommended. Fluid administration should be aggressive in the first hours, and continued only for the appropriate time frame, being usually discontinued, or significantly reduced after the first 24–48 h after admission. Close clinical and hemodynamic monitoring along with the definition of clear resuscitation goals are fundamental. Generally accepted targets are urinary output, reversal of tachycardia and hypotension, and improvement of laboratory markers. However, the usefulness of different endpoints to guide fluid therapy is highly debated. The importance of close monitoring of fluid infusion and balance is acknowledged by most available guidelines to avoid the deleterious effect of fluid overload. Fluid therapy should be carefully tailored in patients with severe AP, as for other conditions frequently managed in the ICU requiring large fluid amounts, such as septic shock and burn injury. A combination of both noninvasive clinical and invasive hemodynamic parameters, and laboratory markers should guide clinicians in the early phase of severe AP to meet organ perfusion requirements with the proper administration of fluids while avoiding fluid overload. In this narrative review the most recent evidence about fluid therapy in severe AP is discussed and an operative algorithm for fluid administration based on an individualized approach is proposed.

Intravenous maintenance fluid therapy practice in the pediatric acute and critical care settings: a European and Middle Eastern survey

The ideal fluid for intravenous maintenance fluid therapy (IV-MFT) in acutely and critically ill children is controversial, and evidence-based clinical practice guidelines are lacking and current prescribing practices remain unknown. We aimed to describe the current practices in prescribing IV-MFT in the context of acute and critically ill children with regard to the amount, tonicity, composition, use of balanced fluids, and prescribing strategies in various clinical contexts. A cross-sectional electronic 27-item survey was emailed in April-May 2021 to pediatric critical care physicians across European and Middle East countries. The survey instrument was developed by an expert multi-professional panel within the European Society of Pediatric and Neonatal Intensive Care (ESPNIC). A total of 154 respondents from 35 European and Middle East countries participated (response rate 64%). Respondents were physicians in charge of acute or critically ill children. All respondents indicated they routinely use a predefined formula to prescribe the amount of IV-MFT and considered fluid balance monitoring very important in the management of acute and critically ill children. The use of balanced solution was preferred if there were altered serum sodium and chloride levels or metabolic acidosis. Just under half (42%, 65/153) of respondents believed balanced solutions should always be used. Respondents considered the use of isotonic IV solutions as important for acute and critically ill children. In terms of the indication and the composition of IV-MFT prescribed, responses were heterogeneous among centers. Almost 70% (107/154) respondents believed there was a gap between current practice and what they considered ideal IV-MFT due to a lack of guidelines and inadequate training of healthcare professionals.   Conclusions: Our study showed considerable variability in clinical prescribing practice of IV-MFT in acute pediatric settings across Europe and the Middle East. There is an urgent need to develop evidence-based guidelines for IV-MFT prescription in acute and critically ill children. What is Known: • The administration of maintenance intravenous fluid therapy is a standard of care for a lot of hospitalized children • Maintenance intravenous fluid therapy prescriptions are often based on Holliday and Segar's historical guidelines even if this practice has been associated with several complications. What is New: • This study provided information on the prescribing practice regarding fluid restriction, fluid tonicity, and balance. • This study showed considerable variability in clinical prescribing practice of intravenous maintenance fluid therapy across Europe and the Middle East.

Interdisciplinary knowledge gaps on intravenous fluid management in adult patients: Survey among physicians and nurses of a university hospital

RATIONALE

Intravenous (IV) fluids are frequently involved in iatrogenic complications in hospitalized patients. Knowledge of IV fluids seems inadequate and is not covered sufficiently in standard medical education.

METHODS

Two surveys were developed, based on the 2016 British National Institute for Health and Care Excellence guideline 'IV fluid therapy in adults in hospital', to provide insight on the learning needs and expectations of physicians and nurses. Each survey focused on profession-specific practice and consisted of three parts: demographics, knowledge questions and evaluation of current habits. Physicians and nurses practicing in a Belgian university hospital were invited to complete the survey electronically, respectively, in January and May 2018.

RESULTS

A total of 103 physicians (19%) and 259 nurses (24%) participated. Although every indication for fluid therapy may require a specific fluid and electrolyte mixture, and hence, knowledge of their exact composition, most physicians and nurses did not know the composition of commonly prescribed solutions for IV infusion. Senior physicians did not score better than juniors did on questions concerning the daily needs of a nil-by-mouth patient. The availability of an IV fluid on the ward guides physicians to prescribe IV fluids (17%). Nurses (56%) feel they share responsibility in fluid management as they frequently intervene in urgent situations. More than half of participants (70% of physicians, 79% of nurses) indicated a need for additional information.

CONCLUSIONS

A clear need for more structured information on IV fluids was identified. Both physicians and nurses struggle with fluid therapy. Continuing education on IV fluid management, emphasizing multidisciplinary collaboration, and monitoring evidence-based practice is essential to support the clinical decision process in daily practice.

Introducing NICE guidelines for intravenous fluid therapy into a district general hospital

Background

National Institute for Health and Care Excellence (NICE) guidelines on intravenous fluid prescribing for adults in hospital, issued in 2013, advised less use of 0.9% sodium chloride than current practice, provided a logical system for prescribing and suggested further study of electrolyte abnormalities.

Aims

To describe the steps taken to establish and monitor guideline introduction and to assess effects on clinical biochemistry results, in a general hospital setting.

Methods

We used established principles of change to modify education, teaching, record keeping and audit throughout the hospital, changed the availability of intravenous fluid preparations in the wards and monitored the use of intravenous fluids. We anonymously linked local clinical chemistry records to nationally available patient records (NHS Scotland SMR01). We chose specified medical emergencies, and major emergency and elective general and orthopaedic surgery, where management would require intravenous fluids, for a two-phase cross-sectional study between 2007 and 2017, spanning the change in prescribing. Primary outcomes were abnormal bicarbonate, sodium, potassium and incidence of acute kidney injury (AKI), and secondary outcomes were mortality and length of stay.

Results

Over the study period, sodium chloride 0.9% use decreased by 75%, and overall intravenous fluid use decreased from 0.65 to 0.40 L/occupied bed day. The incidence of acidosis decreased from 7.4% to 4.8% of all admissions (difference −2.7%, 95% CI −2.1 to −3.0). No important changes in other electrolytes were noted; in particular, plasma sodium values showed no adverse effects. Stage 1 AKI increased from 6.7% to 9.0% (difference 2.3%, 95% CI 1.6 to 3.0), but other causes for this cannot be excluded. Mortality and length of stay showed no adverse effects.

Conclusions and implications

Effective implementation of the guidelines required substantial time, effort and resource. NICE suggestions of fluid types for maintenance appear appropriate, but prescribed volumes continue to require careful clinical judgement.

Effect of sodium administration on fluid balance and sodium balance in health and the perioperative setting. Extended summary with additional insights from the MIHMoSA and TOPMAST studies

PURPOSE

We aimed to provide an extended analysis of the physiological handling of of the sodium burden induced by maintenance fluids.

MATERIALS AND METHODS

We revisited two studies that demonstrated, in healthy volunteers and in surgical patients, that maintenance fluids with 154 mmol/L of sodium lead to a more positive fluid balance than a regimen containing 54 mmol/L. We report different unpublished data on the renal handling of the imposed sodium burdens with specific attention to the resulting fluid and sodium balances.

RESULTS

The kidneys adapt to the sodium-rich fluids not only by altering sodium excretion, but also by retaining extra free water by concentrating urine. Realigning urinary sodium excretion with an increased administration takes around one day in health and much longer in the clinical setting. This difference may be explained by the presence of hypovolemia-induced aldosterone secretion in the latter group. Non-osmotic storage of sodium limits an unrestrained fluid retention even when very high amounts of sodium are administered but fluid accumulation will inevitably be further prolonged.

CONCLUSIONS

Sodium administration induced by sodium-rich maintenance fluids leads, especially in the clinical setting, to prolonged fluid retention when compared with a regimen that resembles a healthy dietary sodium intake, even when kidney function is normal.

Improving intravenous fluid prescribing

Intravenous (IV) fluid therapy is integral to the care of patients in hospitals but involves complex decisions. Errors in fluid prescribing are common, leading to significant harm due to inappropriate fluid type, rate or volume. British national guidelines have been developed to improve prescribing, but adherence has been generally poor. The Scottish Government has set up a National IV Fluid Improvement Programme to implement national guidelines throughout Scotland. This article reviews the need for such guidance and discusses how the Scottish National IV Fluid Improvement Programme hopes to achieve its aims across Scotland. This may provide an improvement framework for fluid prescribing in other regions.

Fluid-induced harm in the hospital: look beyond volume and start considering sodium. From physiology towards recommendations for daily practice in hospitalized adults

PURPOSE

Iatrogenic fluid overload is a potential side effect of intravenous fluid therapy in the hospital. Little attention has been paid to sodium administration as a separate cause of harm. With this narrative review, we aim to substantiate the hypothesis that a considerable amount of fluid-induced harm is caused not only by fluid volume, but also by the sodium that is administered to hospitalized patients.

METHODS

We show how a regular dietary sodium intake is easily surpassed by the substantial amounts of sodium that are administered during typical hospital stays. The most significant sodium burdens are caused by isotonic maintenance fluid therapy and by fluid creep, defined as the large volume unintentionally administered to patients in the form of dissolved medication. In a section on physiology, we elaborate on the limited renal handling of an acute sodium load. We demonstrate how the subsequent retention of water is an energy-demanding, catabolic process and how free water is needed to excrete large burdens of sodium. We quantify the effect size of sodium-induced fluid retention and discuss its potential clinical impact. Finally, we propose preventive measures, discuss the benefits and risks of low-sodium maintenance fluid therapy, and explore options for reducing the amount of sodium caused by fluid creep.

CONCLUSION

The sodium burdens caused by isotonic maintenance fluids and fluid creep are responsible for an additional and avoidable derailment of fluid balance, with presumed clinical consequences. Moreover, the handling of sodium overload is characterized by increased catabolism. Easy and effective measures for reducing sodium load and fluid retention include choosing a hypotonic rather than isotonic maintenance fluid strategy (or avoiding these fluids when enough free water is provided through other sources) and dissolving as many medications as possible in glucose 5%.

Hidden sources of fluids, sodium and potassium in stabilised Swedish ICU patients: A multicentre retrospective observational study

BACKGROUND

Fluid overload in ICU patients is associated with increased morbidity and mortality. Although studies report on optimisation of resuscitation fluids given to ICU patients, increasing evidence suggests that maintenance fluids and fluids used to administer drugs are important sources of fluid overload.

OBJECTIVES

We aimed to evaluate the volume of maintenance fluids and electrolytes on overall fluid balance and their relation to mortality in stabilised ICU patients.

DESIGN

Multicentre retrospective observational study.

SETTING

Six mixed surgical and medical ICUs in Sweden.

PATIENTS

A total of 241 adult patients who spent at least 7 days in the ICU during 2018.

MAIN OUTCOME MEASURES

The primary endpoint was the volume of maintenance, resuscitation and drug diluent fluids administered on days 3 to 7 in the ICU. Secondary endpoints were to compare dispensed amounts of maintenance fluids and electrolytes with predicted requirements. We also investigated the effects of administered fluids and electrolytes on patient outcomes.

RESULTS

During ICU days 3 to 7, 56.4% of the total fluids given were maintenance fluids, nutritional fluids or both, 25.4% were drug fluids and 18.1% were resuscitation fluids. Patients received fluids 1.29 (95% confidence interval 1.07 to 1.56) times their estimated fluid needs. Despite this, 93% of the cohort was treated with diuretics or renal replacement therapy. Patients were given 2.17 (1.57 to 2.96) times their theoretical sodium needs and 1.22 (0.75 to 1.77) times their potassium needs. The median [IQR] volume of fluid loss during the 5-day study period was 3742 [3156 to 4479] ml day-1, with urine output the main source of fluid loss. Death at 90 days was not associated with fluid or electrolyte balance in this cohort.

CONCLUSION

Maintenance and drug fluids far exceeded resuscitative fluids in ICU patients beyond the resuscitative phase. This excess fluid intake, in conjunction with high urinary output and treatment for fluid offload in almost all patients, suggests that a large volume of the maintenance fluids given was unnecessary.

TRIAL REGISTRATION

ClinicalTrials.org NCT03972475.

The Surviving Sepsis Campaign: Fluid Resuscitation and Vasopressor Therapy Research Priorities in Adult Patients

OBJECTIVE

Expand upon the priorities of fluid resuscitation and vasopressor therapy research priorities identified by a group of experts assigned by the Society of Critical Care Medicine and the European Society of Intensive Care Medicine.

DATA SOURCES

Original article, literature search.

STUDY SELECTION

Several members of the original task force with expertise specific to the area of fluid resuscitation and vasopressor therapy.

DATA EXTRACTION

None.

DATA SYNTHESIS

None.

CONCLUSION

In the second of a series of manuscripts subsequent to the original article, members with expertise in the subjects expound upon the three identified priorities related to fluid resuscitation and vasopressor therapies. This analysis summarizes what is known and what were identified as ongoing and future research.

Crystalloid and Colloid Compositions and Their Impact

This manuscript will review crystalloid (hypo-, iso-, and hyper-tonic) and colloid (synthetic and natural) fluids that are available for intravenous administration with a focus on their electrolyte, acid-base, colligative, and rheological effects as they relate to each solution's efficacy and safety. The goal is for the reader to better understand the differences between each fluid and the influence on plasma composition, key organ systems, and their implications when used therapeutically in animals with critical illness.

The surviving sepsis campaign: fluid resuscitation and vasopressor therapy research priorities in adult patients

OBJECTIVE

To expand upon the priorities of fluid resuscitation and vasopressor therapy research priorities identified by a group of experts assigned by the Society of Critical Care Medicine and the European Society of Intensive Care Medicine.

DATA SOURCES

Original paper and literature search.

STUDY SELECTION

Several members of the original task force with expertise specific to the area of fluid resuscitation and vasopressor therapy.

DATA EXTRACTION

None.

DATA SYNTHESIS

None.

CONCLUSION

In the second of a series of manuscripts subsequent to the original paper, members with expertise in the subjects expound upon the three identified priorities related to fluid resuscitation and vasopressor therapies. This analysis summarizes what is known and what were identified as ongoing and future research.

Clinical physiology aspects of chloremia in fluid therapy: a systematic review

Background

This systematic review discusses a clinical physiology aspect of chloride in fluid therapy. Crystalloid solutions are one of the most widely used remedies. While generally used in medicine for almost 190 years, studies focused largely on their safety have only been published since the new millennium. The most widely used solution, normal saline, is most often referred to in this context. Its excessive administration results in hyperchloremic metabolic acidosis with other consequences, including higher mortality rates.

Methods

Original papers and review articles eligible for developing the present paper were identified by searching online in the electronic MEDLINE database. The keywords searched for included hyperchloremia, hypochloremia, and compound words containing the word “chloride,” infusion therapy, metabolic acidosis, renal failure, and review.

Results

A total of 21,758 papers published before 31 May 2020 were identified; of this number, 630 duplicates were removed from the list. Upon excluding articles based on their title or abstract, 1850 papers were screened, of which 63 full-text articles were assessed.

Conclusions

According to the latest medical concepts, dyschloremia (both hyperchloremia and hypochloremia) represents a factor indisputably having a negative effect on selected variables of clinical outcome. As infusion therapy can significantly impact chloride homeostasis of the body, the choice of infusion solutions should always take into account the potentially adverse impact of chloride content on chloremia and organ function.

Fluid therapy in mechanically ventilated critically ill children: the sodium, chloride and water burden of fluid creep

Background

Fluid therapy is a cornerstone of pediatric intensive care medicine. We aimed at quantifying the load of water, sodium and chloride due to different fluid indications in our pediatric intensive care unit (PICU). We were particularly interested in the role of fluid creep, i.e. fluid administered mainly as the vehicle for drugs, and the association between sodium load and water balance.

Methods

Critically ill children aged ≤3 years and invasively ventilated for ≥48 h between 2016 and 2019 in a single tertiary center PICU were retrospectively enrolled. Need for renal replacement therapy, plasmapheresis or parenteral nutrition constituted exclusion criteria. Quantity, quality and indication of fluids administered intravenously or enterally, urinary output and fluid balance were recorded for the first 48 h following intubation. Concentrations of sodium and chloride provided by the manufacturers were used to compute the electrolyte load.

Results

Forty-three patients (median 7 months (IQR 3–15)) were enrolled. Patients received 1004 ± 284 ml of water daily (153 ± 36 ml/kg/day), mainly due to enteral (39%), creep (34%) and maintenance (24%) fluids. Patients received 14.4 ± 4.8 mEq/kg/day of sodium and 13.6 ± 4.7 mEq/kg/day of chloride, respectively. The majority of sodium and chloride derived from fluid creep (56 and 58%). Daily fluid balance was 417 ± 221 ml (64 ± 30 ml/kg/day) and was associated with total sodium intake (r² = 0.49, p < 0.001).

Conclusions

Critically ill children are exposed, especially in the acute phase, to extremely high loads of water, sodium and chloride, possibly contributing to edema development. Fluid creep is quantitatively the most relevant fluid in the PICU and future research efforts should address this topic in order to reduce the inadvertent water and electrolyte burden and improve the quality of care of critically ill children.

Effect of Early Balanced Crystalloids Before ICU Admission on Sepsis Outcomes

BACKGROUND

Studies suggest that using balanced crystalloids (lactated Ringer's solution or Plasma-Lyte A) rather than saline (0.9% sodium chloride) may improve outcomes for patients with sepsis in the ED and ICU.

RESEARCH QUESTION

What is the relative impact on sepsis outcomes of fluid composition during early resuscitation in the ED vs after ICU admission?

STUDY DESIGN AND METHODS

We performed a secondary analysis of the Isotonic Solutions and Major Adverse Renal Events Trial (SMART) data set, examining medical ICU patients with a diagnosis of sepsis (n = 1,641). SMART was a cluster-crossover trial comparing balanced crystalloids vs saline among critically ill adults. During the first 7 months of SMART, fluid choice was controlled only in the ICU ("ICU-only period"). In the final 15 months, fluid choice was coordinated between the ED and ICU ("ED and ICU period"). We performed logistic regression modeling for 30-day in-hospital mortality with an interaction term between randomized group (balanced crystalloids vs saline) and study period (ICU-only period vs ED and ICU period).

RESULTS

Three hundred and sixty-seven patients with sepsis were enrolled during the ICU-only period and 1,274 were enrolled during the ED and ICU period. Thirty-day in-hospital mortality occurred in 47 of 142 patients (33.1%) in the balanced crystalloid group vs 74 of 225 patients (32.9%) in the saline group during the ICU-only period (OR, 1.14; 95% CI, 0.70-1.88) and in 170 of 682 patients (24.9%) in the balanced crystalloid group vs 181 of 592 patients (30.6%) in the saline group in the ED and ICU period (OR, 0.68; 95% CI, 0.52-0.89) (P value for interaction, .07), consistent with a beneficial effect of balanced crystalloid primarily in the ED and ICU period.

INTERPRETATION

Among patients with sepsis, the effect of balanced crystalloids vs saline on mortality was greater among patients for whom fluid choice was controlled starting in the ED compared with starting in the ICU.

Hypertonic saline for fluid resuscitation in ICU patients post-cardiac surgery (HERACLES): a double-blind randomized controlled clinical trial

PURPOSE

Recent evidence questions a liberal approach to fluid resuscitation in intensive care unit (ICU) patients. Here, we assess whether use of hypertonic saline applied as single infusion at ICU admission after cardiac surgery can reduce cumulative perioperative fluid volume.

METHODS

Prospective randomized double-blind single-center clinical trial investigates effects of a single infusion of hypertonic saline (HS) versus normal saline (comparator). Primary endpoint was the cumulative amount of fluid administered in patients in the hypertonic saline versus the 0.9% saline groups (during ICU stay). Upon ICU admission, patients received a single infusion of 5 ml/kg body weight of 7.3% NaCl (or 0.9% NaCl) over 60 min. Patients undergoing cardiac surgery for elective valvular and/or coronary heart disease were included. Patients with advanced organ dysfunction, infection, and/or patients on chronic steroid medication were excluded.

RESULTS

A total of 101 patients were randomized to receive the study intervention (HS n = 53, NS n = 48). Cumulative fluid intake on the ICU (primary endpoint) did not differ between the HS and the NS groups [median 3193 ml (IQR 2052-4333 ml) vs. 3345 ml (IQR 2332-5043 ml)]. Postoperative urinary output until ICU discharge was increased in HS-treated patients [median 2250 ml (IQR 1640-2690 ml) vs. 1545 ml (IQR 1087-1976 ml)], and ICU fluid balance was lower in the HS group when compared to the NS group [296 ml (IQR - 441 to 1412 ml) vs. 1137 ml (IQR 322-2660 ml)].

CONCLUSION

In a monocentric prospective double-blind randomized clinical trial, we observed that hypertonic saline did not reduce the total fluid volume administered on the ICU in critically ill cardiac surgery patients. Hypertonic saline infusion was associated with timely increase in urinary output. Variations in electrolyte and acid-base homeostasis were transient, but substantial in all patients.

Intravenous fluid therapy in the perioperative and critical care setting: Executive summary of the International Fluid Academy (IFA)

Intravenous fluid administration should be considered as any other pharmacological prescription. There are three main indications: resuscitation, replacement, and maintenance. Moreover, the impact of fluid administration as drug diluent or to preserve catheter patency, i.e., fluid creep, should also be considered. As for antibiotics, intravenous fluid administration should follow the four Ds: drug, dosing, duration, de-escalation. Among crystalloids, balanced solutions limit acid-base alterations and chloride load and should be preferred, as this likely prevents renal dysfunction. Among colloids, albumin, the only available natural colloid, may have beneficial effects. The last decade has seen growing interest in the potential harms related to fluid overloading. In the perioperative setting, appropriate fluid management that maintains adequate organ perfusion while limiting fluid administration should represent the standard of care. Protocols including a restrictive continuous fluid administration alongside bolus administration to achieve hemodynamic targets have been proposed. A similar approach should be considered also for critically ill patients, in whom increased endothelial permeability makes this strategy more relevant. Active de-escalation protocols may be necessary in a later phase. The R.O.S.E. conceptual model (Resuscitation, Optimization, Stabilization, Evacuation) summarizes accurately a dynamic approach to fluid therapy, maximizing benefits and minimizing harms. Even in specific categories of critically ill patients, i.e., with trauma or burns, fluid therapy should be carefully applied, considering the importance of their specific aims; maintaining peripheral oxygen delivery, while avoiding the consequences of fluid overload.

Fluid resuscitation in sepsis: the great 30 mL per kg hoax

Large volume fluid resuscitation is currently viewed as the cornerstone of the treatment of septic shock. The surviving sepsis campaign (SSC) guidelines provide a strong recommendation to rapidly administer a minimum of 30 mL/kg crystalloid solution intravenously in all patients with septic shock and those with elevated blood lactate levels. However, there is no credible evidence to support this recommendation. In fact, recent findings from experimental, observational and randomized clinical trials demonstrate improved outcomes with a more restrictive approach to fluid resuscitation. Accumulating evidence suggests that aggressive fluid resuscitation is harmful. Paradoxically, excess fluid administration may worsen shock. In this review, we critically evaluate the scientific evidence for a weight-based fluid resuscitation approach. Furthermore, the potential mechanisms and consequences of harm associated with fluid resuscitation are discussed. Finally, we recommend an individualized, conservative and physiologic guided approach to fluid resuscitation.