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

Preferences and attitudes on acetate- versus lactate-buffered crystalloid solutions for intravenous fluid therapy-An international survey

BACKGROUND

Clinical practice guidelines recommend use of buffered crystalloid solutions in critically ill patients but do not distinguish between solutions based on different buffering anions, that is, acetate- versus lactate-buffered solutions. We therefore surveyed relevant physicians about their preferences and attitudes toward each solution.

METHODS

We conducted an international online survey of anesthesiologists (within perioperative care) and intensive care unit (ICU) physicians. The survey comprised 13 questions on respondents' attitudes and preferences regarding the use of acetate- and/or lactate-buffered crystalloid solutions, including their opinions on a potential clinical trial comparing these solutions and the clinical importance of such a trial.

RESULTS

A total of 1321 respondents participated, with a response rate of 34%, ranging from 14% to 96% across 18 countries. Most surveyed physicians reported using buffered crystalloid solutions "very often" (76%) or "often" (16%). Availability of acetate- and lactate-buffered solutions varied, as 35% of respondents reported having both types available, 35% reported having only acetate-, and 24% reported having only lactate-buffered solutions available. Most respondents (87%) would support a randomized trial in adult emergency surgical patients and ICU patients comparing an acetate- versus lactate-buffered crystalloid solution. The median rating of the clinical importance of this question was 5 (interquartile range 4-6) on a scale from 1 to 9.

CONCLUSIONS

In this international survey, the reported use of buffered crystalloid solutions was high. Availability of the different solutions varied widely. The support for a potential randomized trial was high, with the clinical importance rated important but not critical by most respondents.

Efficacy of compound sodium acetate Ringer's solution in early fluid resuscitation for children with septic shock: a preliminary retrospective cohort study

BACKGROUND

The effectiveness of acetated Ringer's solution in pediatric shock has received little attention. This study aimed to assess the clinical outcomes of using compound sodium acetate Ringer's solution (AR) for fluid resuscitation in children with septic shock.

METHODS

We retrospectively analyzed the clinical data of children with septic shock admitted to the pediatric intensive care unit of the Affiliated Hospital of Southwest Medical University from December 2019 to January 2023. Based on the resuscitation fluid administered, the participants were categorized into the compound AR and normal saline (NS) groups. We compared blood circulation conditions, internal environment parameters (arterial blood pH, lactic acid, serum sodium, chloride, calcium, magnesium, potassium, and blood glucose), and 28-day clinical outcomes between the two groups.

RESULTS

This study included 40 children, with 13 and 27 in the compound AR and NS groups, respectively. The two groups showed no significant differences in sex, age, body weight, body mass index, primary inflammation level, or Pediatric Sequential Organ Failure Assessment on admission. Similarly, no significant difference was observed in resuscitation fluid volume administered during the first hour (compound AR group: 250.00 mL [100.00, 390.00]; NS group: 250.00 mL [100.00, 500.00]). The total amount of crystalloid and colloid fluids administered within 24 h, vasoactive drug use, and blood pressure recovery post-resuscitation did not significantly differ between the groups. However, at 6 h post-resuscitation, the compound AR had considerably lower lactate level than the NS group (1.12 vs. 2.20 mmol/L). There were no significant differences in arterial blood pH, serum sodium, chloride, calcium, magnesium, potassium, and blood glucose levels between the groups. After treatment, in the compound AR group, 3 patients died, 2 improved, and 8 were cured. In the NS group, 7 patients died, 8 improved, and 12 were cured. The 28-day treatment outcomes (mortality rate, improvement rate, cure rate, or side effects) showed no significant differences between the groups.

CONCLUSIONS

Compound AR was as effective as NS as a resuscitation fluid in pediatric septic shock, demonstrating similar intravascular volume restoration and hemodynamic stability maintenance. However, it caused a faster decline in arterial lactate levels without obvious side effects.

Parahydrogen-enhanced pH measurements using [1-13C]bicarbonate derived from non-enzymatic decarboxylation of [1-13C]pyruvate-d3

Alterations in pH are a hallmark in several pathologies including cancer, ischemia, and inflammation. Non-invasive magnetic resonance methods to measure pH offer a new approach for early diagnosis of diseases characterized by acid-base imbalances. The hyperpolarization with parahydrogen-induced polarization (PHIP) enhances inherently low signals in magnetic resonance experiments by several orders of magnitude and offers a suitable platform to obtain biocompatible markers in less than one minute. Here, we present an optimized preparation of an hyperpolarized H13CO3-/13CO2 pH sensor via non-enzymatic decarboxylation with H2O2 of [1-13C]pyruvate-d3 obtained by PHIP at 7 T. An improved 13C polarization of purified [1-13C]pyruvate-d3 in water with 36.65 ± 0.06% polarization was obtained starting from 50 mM precursor. Subsequent decarboxylation, H13CO3-/13CO2 exhibited 12.46 ± 0.01% of polarization at physiological pH, 45 seconds after the reaction start. Considering the dilution factor that [1-13C]pyruvate-d3 exhibits in vivo, we optimized our methodology to test the accuracy of the pH sensor at single digit millimolar concentration. In vitro pH estimations on phantoms and cell culture media demonstrated accurate pH calculations with uncertainties of less than 0.08 units. These promising results highlight the efficiency of a pH sensor generated via PHIP in less than one minute, with remarkable polarization, and biocompatibility suitable for future in vivo studies.

Role of Crystalloids in the Perioperative Setting: From Basics to Clinical Applications and Enhanced Recovery Protocols

Perioperative fluid management, a critical aspect of major surgeries, is characterized by pronounced stress responses, altered capillary permeability, and significant fluid shifts. Recognized as a cornerstone of enhanced recovery protocols, effective perioperative fluid management is crucial for optimizing patient recovery and preventing postoperative complications, especially in high-risk patients. The scientific literature has extensively investigated various fluid infusion regimens, but recent publications indicate that not only the volume but also the type of fluid infused significantly influences surgical outcomes. Adequate fluid therapy prescription requires a thorough understanding of the physiological and biochemical principles that govern the body's internal environment and the potential perioperative alterations that may arise. Recently published clinical trials have questioned the safety of synthetic colloids, widely used in the surgical field. A new clinical scenario has arisen in which crystalloids could play a pivotal role in perioperative fluid therapy. This review aims to offer evidence-based clinical principles for prescribing fluid therapy tailored to the patient's physiology during the perioperative period. The approach combines these principles with current recommendations for enhanced recovery programs for surgical patients, grounded in physiological and biochemical principles.

Influence of acetate- vs. lactate-containing fluid bolus therapy on acid-base status, electrolytes, and plasma lactate in dogs

Objective

Acetate- and lactate-containing fluids influence the acid-base and electrolyte status. This prospective, randomized, clinical study compared two balanced crystalloid solutions regarding their influence on acid-base status, electrolytes, and lactate values, when given to dogs as a resuscitation bolus of 30 mL/kg.

Material and methods

One hundred client-owned dogs presenting to the emergency service with signs of fluid deficits were randomly assigned to receive an intravenous bolus of 30 mL/kg of either a lactate- (LAC), or an acetate-containing solution (ACET). Before and after the bolus, vital parameters were assessed, and a venous blood gas analysis was performed.

Results

Both solutions performed equally well in decreasing the heart rate (ACET: −10 ± 27 bpm, LAC: −12 ± 30 bpm; p = 0.737). The acetate-containing solution caused a significant decrease in plasma lactate levels (p = 0.016), anion gap (p < 0.001), and potassium (p < 0.001), and a significant increase in chloride (p < 0.001), and ionized calcium (p = 0.014). The lactate-containing solution caused a significant decrease in anion gap (p < 0.001), sodium (p = 0.016), and potassium (p = 0.001), and a significant increase in chloride (p < 0.001). ACET causes a stronger decrease in plasma lactate (p = 0.015), sodium (p = 0.039), potassium (p = 0.006), and an increase in chloride (p < 0.001), and ionized calcium (p = 0.016) compared to LAC.

Conclusion

Both solutions caused mild changes in electrolyte concentrations and had minor influence on acid-base status when used for bolus therapy in dogs with fluid deficits. Further studies are needed to evaluate their influence on acid-base status, lactate, and electrolytes when used in larger volumes and for a longer time span.

The Efficacy and Safety of Sodium Bicarbonate Ringer's Solution in Critically Ill Patients: A Retrospective Cohort Study

Background: Sodium bicarbonate Ringer’s solution has been widely used in clinical practice in recent years. There are few clinical studies on the efficacy and safety of this fluid among critically ill patients until now.

Method: This retrospective cohort study included critically ill adult patients in the intensive care unit (ICU) of Tongji Hospital from 1 January 2019 to 31 December 2020. By reviewing exclusively the use of either sodium bicarbonate Ringer’s solution or saline for resuscitation or maintenance, the patients were included into two groups, respectively. The primary outcome was the major adverse kidney event within 30 days (MAKE30), including death, new receipt of renal replacement therapy, or persistent renal dysfunction. Safety outcomes were focused on arterial blood gas and plasma biochemical alterations, which might potentially be induced by the administration of bicarbonate Ringer’s solution.

Result: A total of 662 patients were included in the cohort. Compared to the saline group, the bicarbonate Ringer’s group had a significantly lower rate of the new receipt of renal replacement therapy [adjusted odds ratio (OR) = 0.591, 95% confidence interval (CI), 0.406 to 0.861; p = 0.006]. There was no significant difference between the two groups in 30-day mortality, final creatinine level ≥200% of baseline, and major adverse kidney event within 30 days. In subgroup analysis, the incidence of MAKE30 was higher in the bicarbonate Ringer’s group than that of the saline group among patients with cardiovascular disease. The patients in the bicarbonate Ringer’s group had a longer length of intensive care unit stay than patients in the saline group, but their new renal replacement therapy days were shorter. No major alterations were found in arterial blood gas and plasma biochemical during the follow-up period.

Conclusion: Compared to saline, sodium bicarbonate Ringer’s solution exhibited a potential renal function protective effect while causing no major alterations in arterial blood gas and plasma biochemistry. However, the application in patients with cardiovascular disease diagnosis at ICU admission should be cautious.

Observational study on fluid therapy management in surgical adult patients

Background

Perioperative fluid therapy management is changing due to the incorporation of different fluids, surgical techniques, and minimally invasive monitoring systems. The objective of this study was to explore fluid therapy management during the perioperative period in our country.

Methods

We designed the Fluid Day study as a cross-sectional, multicentre, observational study. The study was performed in 131 Spanish hospitals in February 2019. We included adult patients undergoing general anaesthesia for either elective or non-elective surgery. Demographic variables were recorded, as well as the type and total volume of fluid administered during the perioperative period and the monitorization used. To perform the analysis, patients were categorized by risk group.

Results

We recruited 7291 patients, 6314 of which were included in the analysis; 1541 (24.4%) patients underwent high-risk surgery, 1497 (23. 7%) were high risk patients, and 554 (8.7%) were high-risk patients and underwent high-risk surgery; 98% patients received crystalloids (80% balanced solutions); intraoperative colloids were used in 466 patients (7.51%). The hourly intraoperative volume in mL/kg/h and the median [Q1; Q3] administered volume (mL/kg) were, respectively, 6.67 [3.83; 8.17] ml/Kg/h and 13.9 [9.52;5.20] ml/Kg in low-risk patients undergoing low- or intermediate-risk surgery, 6 [4.04; 9.08] ml/Kg/h and 15.7 [10.4;24.5] ml/Kg in high- risk patients undergoing low or intermediate-risk surgery, 6.41 [4.36; 9.33] ml/Kg/h and 20.2 [13.3;32.4] ml/Kg in low-risk patients undergoing high-risk surgery, and 5.46 [3.83; 8.17] ml/Kg/h and 22.7[14.1;40.9] ml/Kg in high-risk patients undergoing high- risk surgery . We used advanced fluid monitoring strategies in 5% of patients in the intraoperative period and in 10% in the postoperative period.

Conclusions

The most widely used fluid was balanced crystalloids. Colloids were used in a small number of patients. Hourly surgery volume tended to be more restrictive in high-risk patients but confirms a high degree of variation in the perioperatively administered volume. Scarce monitorization was observed in fluid therapy management.

Trial registration

Clinical Trials: NCT03630744.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-021-01518-z.

Influence of acetate containing fluid versus lactate containing fluid on acid-base status, electrolyte level, and blood lactate level in dehydrated dogs

BACKGROUND AND AIM

Acetate or lactate buffered, balanced isotonic rehydration fluids are commonly used for fluid therapy in dogs and may influence acid-base and electrolyte status. This study aimed to assess acid-base status, electrolyte levels, and lactate levels in dehydrated dogs after receiving acetate or lactate-containing intravenous rehydration fluids.

MATERIALS AND METHODS

In this prospective, randomized study, 90 dehydrated dogs were included and randomized to receive acetate [Sterofundin® ISO B. Braun Vet Care (STERO), Germany) or lactate (Ringer-Lactat-Lösung nach Hartmann B. Braun Vet Care (RL), Germany] containing intravenous fluids for rehydration. The exclusion criteria were as follows: Age <6 months, liver failure, congestive heart failure, and extreme electrolyte deviation. Physical examination, venous blood gas, and lactate levels were analyzed before and after rehydration. The two groups were compared using t-test and Chi-square test. The significance level was set at p≤0.05.

RESULTS

Post-rehydration heart rate decreased in the STERO group (p<0.001) but not in the RL group (p=0.090). Lactate levels decreased in both groups STERO (p<0.001) and in group RL (p=0.014). Sodium and chloride levels increased during rehydration in group STERO (p<0.001; p<0.001) and group RL (p=0.002; p<0.001). There was a larger decrease in lactate levels in group STERO compared to group RL (p=0.047).

CONCLUSION

Both solutions led to a mild increase in sodium and chloride levels and decreased lactate levels. The acetate-containing solution had an inferior effect on the decrease in lactate level.

Bicarbonate Ringer's solution for early resuscitation in hemorrhagic shock rabbits

Background

Fluid resuscitation is important for correcting hypovolemia. Isotonic crystalloids are the preferred solution for the initial clinical management of patients with multiple traumas. Bicarbonated Ringer’s solution (BRS), offering physiological levels of bicarbonate ions and electrolyte ions, can be used for supplementing missing extracellular fluid and correcting metabolic acidosis. We here investigated the effects of BRS on the resuscitation of hemorrhagic shock models and compared the resuscitation performance of three crystalloids, including BRS, acetated Ringer’s solution (ARS), and normal saline.

Methods

Thirty adult male New Zealand rabbits were randomly divided into five groups (n=6): a sham operation group (Sham group), an operation without fluid therapy group (Shock group), a BRS group, an ARS group, and a normal saline group (Saline group). The New Zealand rabbits experienced rapid bloodletting to shock status and maintained for 20 minutes except Sham group. The status of shock was maintained in the Shock group. The fluid was infused at a rate of 60 mL/kg per hour for 1.5 hours in three fluid therapy group. Measurement of vital signs, arterial blood gas tests, blood biochemistry, hematoxylin and eosin (HE) staining of lung tissue, TUNEL staining of the liver and kidney tissues, and analysis of intestinal flora were performed.

Results

The reduction in both base excess (BE) and bicarbonate ion (HCO₃^-) caused by acidosis in rabbits with hemorrhagic shock was significantly improved in the BRS group when compared with the Saline group at infusion for 30 minutes (T3) and 30 minutes after infusion (T5) (BRS group vs. Saline group, BE: at T3, −4.83±3.60 vs. −12.50±3.27 mmol/L, P<0.01; at T5, −3.67±4.37 vs. −11.00±2.76 mmol/L, P<0.01; HCO₃^-: at T3, 22.15±2.63 vs. 15.42±3.03 mmol/L, P<0.01; at T5, 23.15±2.9 vs. 16.23±3.07 mmol/L, P<0.01). Compared with Shock group, liver cell apoptosis due to hemorrhagic shock was relieved in both the BRS group and ARS group (BRS group vs. Shock group: 19.1±3.3 vs. 28.1±6.1, P<0.05; ARS group vs. Shock group: 19.8±5.4 vs. 28.1±6.1, P<0.05).

Conclusions

During resuscitation of hemorrhagic shock, BRS, a novel perioperative balanced crystalloid, is more effective than normal saline in maintaining acid-base balance and in protecting tissues and organs.

Hypochloremia Secondary to Diuretics in Preterm Infants: Should Clinicians Pay Close Attention?

Diuretic therapy, commonly used in the newborn intensive care unit, is associated with a variety of electrolyte abnormalities such as hyponatremia, hypokalemia, and hypochloremia. Hypochloremia, often ignored, is associated with significant morbidities and increased mortality in infants and adults. Clinicians respond in a reflex manner to hyponatremia than to hypochloremia. Hypochloremia is associated with nephrocalcinosis, hypochloremic alkalosis, and poor growth. Besides, the diuretic resistance associated with hypochloremia makes maintaining chloride levels in the physiological range even more logical. Since sodium supplementation counters the renal absorption of calcium and lack of evidence for spironolactone role in diuretic therapy for bronchopulmonary dysplasia (BPD), alternate chloride supplements such as potassium or arginine chloride may need to be considered in the management of hypochloremia due to diuretic therapy. In this review, we have summarized the current literature on hypochloremia secondary to diuretics and suggested a pragmatic approach to hypochloremia in preterm infants.

N-Acetyl cysteine abrogates silver-induced reactive oxygen species in human cells without altering silver-based antimicrobial activity

Silver-based antimicrobials are widely used topically to treat infections associated with multi-drug resistant (MDR) pathogens. Expanding this topical use to aerosols to treat lung infections requires understanding and preventing silver toxicity in the respiratory tract. A key mechanism resulting in silver-induced toxicity is the production of reactive oxygen species (ROS). In this study, we have verified ROS generation in silver-treated bronchial epithelial cells prompting evaluation of three antioxidants, N-acetyl cysteine (NAC), ascorbic acid, and melatonin, to identify potential prophylactic agents. Among them, NAC was the only candidate that abrogated the ROS generation in response to silver acetate exposure resulting in the rescue of these cells from silver-associated toxicity. Further, this protective effect directly translated to preservation of metabolic activity, as demonstrated by the normal levels of citric acid cycle metabolites in NAC-pretreated silver acetate-exposed cells. Because the citric acid cycle remained functional, silver-exposed cells pre-incubated with NAC demonstrated significantly higher levels of adenosine triphosphate levels compared with NAC-free controls. Moreover, we found that this prodigious capacity of NAC to rescue silver acetate-exposed cells was due not only to its antioxidant activity, but also to its ability to directly bind silver. Despite binding to silver, NAC did not alter the antimicrobial activity of silver acetate.

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 management in patients undergoing cardiac surgery: effects of an acetate- versus lactate-buffered balanced infusion solution on hemodynamic stability (HEMACETAT)

BACKGROUND

Recent evidence suggests that acetate-buffered infusions result in better hemodynamic stabilization than 0.9% saline in patients undergoing major surgery. The choice of buffer in balanced crystalloid solutions may modify their hemodynamic effects. We therefore compared the inopressor requirements of Ringer's acetate and lactate for perioperative fluid management in patients undergoing cardiac surgery.

METHODS

Using a randomized controlled double-blind design, we compared Ringer's acetate (RA) to Ringer's lactate (RL) with respect to the average rate of inopressor administered until postoperative hemodynamic stabilization was achieved. Secondary outcomes were the cumulative dose of inopressors, the duration of inopressor administration, the total fluid volume administered, and the changes in acid-base homeostasis. Patients undergoing elective valvular cardiac surgery were included. Patients with severe cardiac, renal, or liver disease were excluded from the study.

RESULTS

Seventy-five patients were randomly allocated to the RA arm, 73 to the RL. The hemodynamic profiles were comparable between the groups. The groups did not differ with respect to the average rate of inopressors (RA 2.1 mcg/kg/h, IQR 0.5-8.1 vs. RL 1.7 mcg/kg/h, IQR 0.7-8.2, p = 0.989). Cumulative doses of inopressors and time on individual and combined inopressors did not differ between the groups. No differences were found in acid-base parameters and their evolution over time.

CONCLUSION

In this study, hemodynamic profiles of patients receiving Ringer's lactate and Ringer's acetate were comparable, and the evolution of acid-base parameters was similar. These study findings should be evaluated in larger, multi-center studies.

TRIAL REGISTRATION

Clinicaltrials.gov NCT02895659 . Registered 16 September 2016.

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.

Normal saline versus Normosol™-R in sepsis resuscitation: A retrospective cohort study

Objective

To determine the effect of Normosol™-R as compared to normal saline on the outcomes of acute kidney injury and the need for renal replacement therapy in the resuscitation phase of sepsis.

Design

Our study is a retrospective before-and-after cohort study.

Setting

The study occurred at a 700-bed tertiary academic level 1-trauma center.

Patients

A total of 1218 patients were enrolled through emergency department admissions. The normal saline (before) cohort was defined as the dates between 1 March and 30 September 2014 and the Normosol™-R (after) cohort was assessed from 1 March to 30 September 2015.

Interventions

None.

Measurements and main results

Intravenous fluid volumes received during the first 24 h, 72 h, and total hospital stays were compared. Sodium, chloride, potassium, and bicarbonate levels at 72 h were also compared. The medical coded diagnosis of acute kidney failure, need for renal replacement therapy, hospital LOS, ICU admission, ICU LOS, in-hospital mortality, and need for mechanical ventilation were all compared. There was no significant difference in intravenous fluid volumes between groups. Regression modelling controlling for baseline characteristics and 24-h fluid intake volume found no differences between groups for the primary outcomes of acute kidney injury (P = 0.99) and renal replacement therapy (P = 0.88). Patients in the Normosol™-R cohort were found to have a lower rate of hyperchloremia at 72 h post-admission (28% vs. 13%, P < 0.0001). There was a trend toward a decrease in the hospital and ICU LOS in the Normosol™-R cohort; however, the data were not statistically significant.

Conclusions

This study was unable to detect any difference in outcomes between sepsis patients who received intravenous fluid resuscitation with either a balanced crystalloid (Normosol™-R) or normal saline, except for a decreased rate of hyperchloremia.

Crystalloid fluid choice in the critically ill : Current knowledge and critical appraisal

Intravenous infusion of crystalloid solutions is one of the most frequently administered medications worldwide. Available crystalloid infusion solutions have a variety of compositions and have a major impact on body systems; however, administration of crystalloid fluids currently follows a "one fluid for all" approach than a patient-centered fluid prescription. Normal saline is associated with hyperchloremic metabolic acidosis, increased rates of acute kidney injury, increased hemodynamic instability and potentially mortality. Regarding balanced infusates, evidence remains less clear since most studies compared normal saline to buffered infusion solutes.; however, buffered solutes are not homogeneous. The term "buffered solutes" only refers to the concept of acid-buffering in infusion fluids but this does not necessarily imply that the solutes have similar physiological impacts. The currently available data indicate that balanced infusates might have some advantages; however, evidence still is inconclusive. Taking the available evidence together, there is no single fluid that is superior for all patients and settings, because all currently available infusates have distinct differences, advantages and disadvantages; therefore, it seems inevitable to abandon the "one fluid for all" strategy towards a more differentiated and patient-centered approach to fluid therapy in the critically ill.

0.9% NaCl (Normal Saline) - Perhaps not so normal after all?

Crystalloid infusion is widely employed in patient care for volume replacement and resuscitation. In the United States the crystalloid of choice is often normal saline. Surgeons and anesthesiologists have long preferred buffered solutions such as Ringer's Lactate and Plasma-Lyte A. Normal saline is the solution most widely employed in medical and pediatric care, as well as in hematology and transfusion medicine. However, there is growing concern that normal saline is more toxic than balanced, buffered crystalloids such as Plasma-Lyte and Lactated Ringer's. Normal saline is the only solution recommended for red cell washing, administration and salvage in the USA, but Plasma-Lyte A is also FDA approved for these purposes. Lactated Ringer's has been traditionally avoided in these applications due to concerns over clotting, but existing research suggests this is not likely a problem. In animal models and clinical studies in various settings, normal saline can cause metabolic acidosis, vascular and renal function changes, as well as abdominal pain in comparison with balanced crystalloids. The one extant randomized trial suggests that in very small volumes (2 l or less) normal saline is not more toxic than other crystalloids. Recent evidence suggests that normal saline causes substantially more in vitro hemolysis than Plasma-Lyte A and similar solutions during short term storage (24 hours) after washing or intraoperative salvage. There are now abundant data to raise concerns as to whether normal saline is the safest replacement solution in infusion therapy, red cell washing and salvage, apheresis and similar uses. In the USA, Plasma-Lyte A is also FDA approved for use with blood components and is likely a safer solution for these purposes. Its only disadvantage is a higher cost. Additional studies of the safety of normal saline for virtually all current clinical uses are needed. It seems likely that normal saline will eventually be abandoned in favor of safer, more physiologic crystalloid solutions in the coming years.

Normal saline for intravenous fluid therapy in critically ill patients

The efficacy and safety of normal saline (NS) for fluid therapy in critically ill patients remain controversy. In this review, we summarized the evidence of randomized controlled trials (RCTs) which compared NS with other solutions in critically ill patients. The results showed that when compared with 6% hydroxyethyl starch (HES), NS may reduce the onset of acute kidney injury (AKI). However, there is no significant different in mortality and incidence of AKI when compared with 10% HES, albumin and buffered crystalloid solution. Therefore, it is important to prescribe intravenous fluid for patients according to their individual condition.

Hypertonic saline in critical illness - A systematic review

INTRODUCTION

The optimal approach to fluid management in critically ill patients is highly debated. Fluid resuscitation using hypertonic saline was used in the past for more than thirty years, but has recently disappeared from clinical practice. Here we provide an overview on the currently available literature on effects of hypertonic saline infusion for fluid resuscitation in the critically ill.

METHODS

Systematic analysis of reports of clinical trials comparing effects of hypertonic saline as resuscitation fluid to other available crystalloid solutions. A literature search of MEDLINE and the Cochrane Controlled Clinical trials register (CENTRAL) was conducted to identify suitable studies.

RESULTS

The applied search strategy produced 2284 potential publications. After eliminating doubles, 855 titles and abstracts were screened and 40 references retrieved for full text analysis. At total of 25 scientific studies meet the prespecified inclusion criteria for this study.

CONCLUSION

Fluid resuscitation using hypertonic saline results in volume expansion and less total infusion volume. This may be of interest in oedematous patients with intravascular volume depletion. When such strategies are employed, renal effects may differ markedly according to prior intravascular volume status. Hypertonic saline induced changes in serum osmolality and electrolytes return to baseline within a limited period in time. Sparse evidence indicates that resuscitation with hypertonic saline results in less perioperative complications, ICU days and mortality in selected patients. In conclusion, the use of hypertonic saline may have beneficial features in selected critically ill patients when carefully chosen. Further clinical studies assessing relevant clinical outcomes are warranted.