Effect of molecular weight and substitution on tissue uptake of hydroxyethyl starch: a meta-analysis of clinical studies

Fluids in the ICU: which is the right one?

The administration of fluids is one of the most common interventions in the intensive care unit. The effects and side effects of intravenous fluids depend on the amount administered and their specific composition. Intravenous fluid solutions are either considered crystalloids (for example 0.9% saline, lactated Ringer's solution) or colloids (artificial colloids such as gelatins, and albumin). This narrative review summarizes the physiological principles of fluid therapy and reviews the most important studies on crystalloids, artificial colloids and albumin in the context of critically ill patients.

Low-Fouling Zwitterionic Polymeric Colloids as Resuscitation Fluids for Hemorrhagic Shock

Colloids, known as volume expanders, have been used as resuscitation fluids for hypovolemic shock for decades, as they increase plasma oncotic pressure and expand intravascular volume. However, recent studies show that commonly used synthetic colloids have adverse interactions with human biological systems. In this work, a low-fouling amine(N)-oxide-based zwitterionic polymer as an alternative volume expander with improved biocompatibility and efficacy is designed. It is demonstrated that the polymer possesses antifouling ability, resisting cell interaction and deposition in major organs, and is rapidly cleared via renal filtration and hepatic circulation, reducing the risk of long-term side effects. Furthermore, in vitro and in vivo studies show an absence of adverse effects on hemostasis or any acute safety risks. Finally, it is shown that, in a head-to-head comparison with existing colloids and plasma, the zwitterionic polymer serves as a more potent oncotic agent for restoring intravascular volume in a hemorrhagic shock model. The design of N-oxide-based zwitterionic polymers may lead to the development of alternative fluid therapies to treat hypovolemic shock and to improve fluid management in general.

Assessment of Hydroxyethyl Starch (6% HES 130/0.4) Kidney Storage in Critically Ill Dogs: A Post-mortem Prospective Study

Objective: Intravenous hydroxyethyl starch (HES) solutions are potentially nephrotoxic due to rapid renal tissue uptake, subsequent osmotic nephrosis, and long-lasting intracellular storage. This study aimed to investigate the severity of intracellular storage of HES in renal tissue samples from critically ill dogs receiving 6% HES 130/0.4.

Materials and Methods: Fresh, post-mortem (<2 h after death) renal tissue samples were analyzed through histology, immunohistochemistry (HES 130/0.4-specific antibodies), and electron microscopy for the severity of renal tubular vacuolization (VAC), intravacuolar HES accumulation (ACC), and ultra-structure impairment. Moreover, we investigated the relationship between VAC or ACC grade and HES dose (mL/kg), duration of HES administration (h), and pre-HES plasma creatinine concentrations.

Results: Histology revealed that 2/20 dogs (10%) had no, 11/20 dogs (55%) had mild, 5/20 dogs (25%) had moderate, and 2/20 dogs (10%) had severe VAC. Immunohistochemistry revealed that 5/20 dogs (25%) had no, 6/20 dogs (30%) had mild, 7/20 dogs (35%) had moderate, and 2/20 dogs (10%) had severe ACC. Both changes were predominantly found in the distal tubular epithelium of mild and moderate cases, and all tubular segments were affected in severe cases. Seven of 20 dogs (35%) had osmotic nephrosis (ON). On electron microscopy, large granules with an electron-dense content were repeatedly detected in individual cells, mainly in the distal tubules. No correlation was found between cumulative HES dose or duration of HES administration and VAC grade, ACC grade, or presence/absence of ON.

Conclusion: A high percentage of dogs had renal tubular HES storage and one-third of dogs showed HES-induced ON. Short-term HES administration caused VAC and ACC, regardless of the dose or duration of administration. In contrast to previous studies, HES 130/0.4 deposits were mainly located in the renal distal tubule.

Granulocyte transfusions made with modified fluid gelatin in pediatric and adolescent patients with prolonged neutropenia

BACKGROUND

Granulocyte transfusions (GT) are used to treat progressive systemic or local infections in prolonged neutropenic patients with antibiotic or antifungal resistance. Granulocytes are most commonly collected from whole blood by apheresis using hydroxyethyl starch (HES) as the red blood cell (RBC) sedimentation agent. This is the first study on the safety and efficacy of transfusing granulocytes collected with modified fluid gelatin (MFG) instead of HES to pediatric patients.

METHODS

Clinical data from 46 pediatric and adolescent patients receiving at least one MFG-based granulocyte transfusion and in total 295 granulocyte concentrates from July 2013 to August 2019 at our local university medical center were evaluated retrospectively.

RESULTS

Forty-one patients (89%) survived at least 21 days after their last granulocyte transfusion. These survivors had lower CRP values and higher leukocyte counts after GT than non-survivors (mean delta of -5.34 mg/dl vs. -11.99 mg/dl and + 0.62 × 10³ /μl vs. +0.18 × 10³ /μl of all GT, respectively). The neutrophil corrected count increment (CCI) was 68.72 mm² /ml in survivors versus 28.00 mm² /ml in non-survivors. There were no major or severe adverse events.

CONCLUSION

This study suggests that modified fluid gelatin is a safe and effective alternative to hydroxyethyl starch for the collection of granulocytes for transfusion to prolonged neutropenic patients with progressive systemic or local infections refractory to antibiotic or antifungal therapy.

Use of hydroxyethyl starch in sepsis research: A systematic review with meta-analysis

BACKGROUND

After being used for more than a decade the use of hydroxyethyl starch (HES) 130/0.38-0.45 in clinical practice was discouraged because of serious adverse events including bleeding, acute kidney injury and death. But could these adverse effects have been discovered sooner? By comparing the summary effect estimates of the adverse effects of HES 130/0.38-0.45 in different study designs we aimed to disclose any signal of this.

METHODS

We systematically searched MEDLINE, EMBASE and Cochrane Library and hand-searched the reference lists of relevant studies to identify studies for inclusion. Eligible trials were randomised clinical trials (RCTs) and observational studies in patients with sepsis and randomised trials in animals with induced sepsis comparing HES 130/0.38-0.45 to any type of crystalloid. Relevant outcomes were all-cause mortality at longest follow-up, renal replacement therapy (RRT), acute kidney injury (AKI) and bleeding. We extracted data, conducted conventional meta-analyses and assessed the risk of bias and the quality of evidence.

RESULTS

We included 8 RCTs including 3,273 patients, 1 observational study including 379 patients and 5 randomised animal trials including 94 test animals. There was no suggestion of interaction in subgroup analyses comparing the different study designs for any outcomes (all-cause mortality at longest follow-up p = .33; RRT p = .70; AKI p = .63; bleeding p = .20).

CONCLUSIONS

We observed no interaction between the summary effect estimates of RCTs, observational studies in patients and randomised animal trials for any of the outcomes. Accordingly, we found no evidence indicating that the adverse effects of HES 130/0.38-0.45 could have been discovered sooner.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO ID: CRD42018103422.

PROTOCOL

Johansen JR, Perner A, Brodtkorb JH, Møller MH. Use of hydroxyethyl starch in sepsis research: Protocol for a systematic review. Acta Anaesthesiol Scand. 2019;63:814-818. https://doi.org/10.1111/aas.13345.

Analysis of Molar Substitution of Hydroxybutyl Group by Zeisel Reaction in Starch Ethers

A new etherified starch, δ-hydroxybutyl starch (δ-HBS), was prepared by utilising 4-chlorobutan-1-ol as the etherifying reagent. The method of Zeisel gas chromatography for the determination of the molar substitution was described. This technique offers a simple and rapid method for quantitative analysis with reproducible results. Meanwhile, the mechanism of the Zeisel reaction was also investigated.

Effects of hydroxyethyl starch and gelatin on the risk of acute kidney injury following orthotopic liver transplantation: A multicenter retrospective comparative clinical study

Objectives

This multicenter retrospective study aimed to compare the effects of HES and gelatin (GEL) on the risk of post-OLT AKI.

Method

A total of 1,672 patients undergoing OLT were enrolled from major transplant centers in China between 2005 and 2013. These patients were divided into three groups: GEL, hydroxyethyl starch (HES), and GEL + HES group.

Results

There was no significant difference in the incidence of post-OLT AKI among the GEL, HES, and GEL + HES groups. The GEL + HES group had a lower incidence of stage II post-OLT AKI than the other two groups. Compared with patients receiving GEL, patients receiving HES did not harbor an increased risk of AKI. Our results showed that MELD score (adjusted odds ratio [OR], 1.579; 95% confidence interval [CI], 1.123–2.219; P = 0.009) and preoperative anemia (adjusted OR, 1.533; 95% CI, 1.212–1.939; P < 0.001) were independent risk factors for post-OLT AKI, and normal preoperative Scr level (vs abnormal; adjusted OR, 0.402; 95% CI, 0.222–0.729; P = 0.003) was independent protective factors for post-OLT AKI.

Conclusion

This large-scale multicenter retrospective study found that the intraoperative use of HES did not increase the overall incidence of post-OLT AKI in patients when compared with GEL, and whether to increase the risk of post-OLT AKI needs to be further explored.

Hydroxyethyl starches in equine medicine

OBJECTIVE

To review and discuss the use of hydroxyethyl starches (HES) in equine veterinary medicine, and to provide recommendations for its use.

DATA SOURCES

Veterinary and human peer-reviewed medical literature including scientific reviews, meta-analyses, and original research articles.

HUMAN DATA SYNTHESIS

Increasing evidences on adverse effects after HES use and decreasing support for beneficial effects with regards to volume expansion and colloid osmotic pressure (COP) support in critically ill subjects have led to a recent guideline to limit the use of HES in critically ill people.

EQUINE VETERINARY DATA SYNTHESIS

The rationale for HES use in horses is mainly extrapolated from human medicine, and very limited studies in horses are available. There is limited evidence suggesting a superiority of volume expansion effects of HES over crystalloids. The potential for HES to increase and maintain COP is well supported, but there is no evidence that maintaining or increasing plasma COP influences outcome, tissue edema formation, or rates of complications that potentially relate to edema formation. HES induce dose-dependent changes in coagulopathic parameters, but there is no evidence that HES causes clinical coagulopathies. Insufficient data are available on other adverse effects such as acute kidney injury, or mortality in horses. The use of HES should be restricted in septic patients, but may still have some use in cases of hemorrhagic shock resuscitation, hypoalbuminemia, or perioperative fluid replacement.

CONCLUSION

The evidence supporting the use of HES in horses is weak due to lack of species-specific investigations. Acknowledging species differences, the use of HES should be judicious, yet with some recognition of its benefits in particular cases. More research is necessary to improve knowledge on use of HES in horses and to establish better future recommendations.

Postoperative Blood Loss and Coagulation Changes After Balanced 6% Hydroxyethyl Starch 130/0.4 Administration During Spine Surgery: A Retrospective Study

STUDY DESIGN

Retrospective analysis.

OBJECTIVE

The objective of this study was to investigate the effects of intraoperative balanced 6% hydroxyethyl starch (HES) 130/0.4 on postoperative blood loss and the coagulation profile.

SUMMARY OF BACKGROUND DATA

The safety of colloid versus crystalloid transfusion for bleeding and coagulation during major spine surgery remains controversial and only a few studies exist. Thus, we compared the effects of balanced 6% HES 130/0.4 and crystalloid on postoperative bleeding and coagulation.

METHODS

Patients undergoing spine surgery between February 1, 2015 and February 28, 2017 were divided into 2 groups: patients receiving intraoperative balanced 6% HES 130/0.4 and patients receiving crystalloid. We compared the postoperative bleeding volume with changes in the coagulation profile and length of hospital stay between these 2 groups. Propensity score (PS)-matching and multivariate stepwise linear regression were performed.

RESULTS

A total of 169 patients who met the inclusion criteria were analyzed. The quantity of total colloid per patient was 10-15 mL/kg. A significant difference was observed in the total intraoperative transfused crystalloid volume between the 2 groups (colloid group, 1.394.6±1.414.0 mL; crystalloid group, 2.027.3±1.114.1 mL; P<0.001). Postoperative blood loss and coagulation profile changes were not significantly different in the 60 PS-matched paired patients. Furthermore, no differences in either postoperative transfusion requirement or length of hospital stay were observed between the groups. Multivariate stepwise linear regression revealed that operation time (β=0.549; P<0.001) and intraoperative transfusion of packed red blood cells (β=0.466; P=0.003) or fresh frozen plasma (β=-0.263; P=0.041) were independently associated with postoperative blood loss. However, intraoperative colloid administration was not a predictive factor.

CONCLUSIONS

Intraoperative infusion of balanced 6% HES 130/0.4 in patients undergoing spine surgery presented clinically insignificant changes in postoperative blood loss and coagulation compared to crystalloid.

LEVEL OF EVIDENCE

Level III.

Understanding the Harms of HES: A Review of the Evidence to Date

Intravenous (IV) fluid resuscitation is one of the most common interventions in intensive care medicine. Despite clear guidelines, the choice of IV fluid is largely dependent on physician preference instead of high-quality evidence of efficacy and safety. This is particularly the case for synthetic colloids, such as hydroxyethyl starch (HES). The use of HES in critical care has been associated with increased rates of acute kidney injury (AKI), renal replacement therapy and mortality. In light of this, current guidelines and scientific and regulatory bodies do not recommend the use of HES for fluid therapy in critical illness and caution against its use in many other settings. Despite this, HES products are still debated and used. Awareness of the indications, contraindications, doses, benefits and adverse effects for IV fluids, as well as recommendations from scientific and regulatory bodies, is essential to guarantee patients' safety. Poor awareness of optimal IV fluid therapy has recently been revealed in some countries including Turkey. Therefore, we provide a review of fluids used for resuscitation, discuss safety data and adverse effects of HES, such as increased AKI and mortality, and discuss recent updates from scientific and regulatory bodies in order to raise awareness of fluid therapy. We conclude that given the lack of a clear benefit of HES in any clinical setting and the availability of safer alternatives, such as crystalloids and albumin, HES should be avoided.

Undisclosed conflicts of interest in German-language textbooks of anesthesiology, critical care, and emergency medicine

BACKGROUND

Medical textbooks are important throughout postgraduate internship, residency and fellowship programs but authors' conflicts of interest (COI) are rarely disclosed. In anesthesiology, two high-profile cases of research fraud/unethical publishing have previously been identified. This study evaluated whether anesthesiology textbooks in German include controversial recommendations on hydroxyethyl starch (HES) and whether authors had undisclosed COI.

METHODS

Forty-five anesthesiology, critical care, and emergency medicine electronic textbooks (January 2015-August 2017) were identified on the websites of German, Austrian, and Swiss publishers. Six textbooks were excluded (irrelevant content; compilation of peer-reviewed articles). Content on HES ('Kolloid', 'Hydroxyäthylstärke', 'Hydroxyethylstärke', 'HES', 'HAES') and COI ('Interessenkonflikt') was electronically searched; subject lists were manually searched. Recommendations on HES were analyzed in the context of indications/warnings/international guidelines. Potential COI for authors of controversial recommendations were searched on PubMed/EMBASE (January 2016-May 2018).

RESULTS

COI statements were absent in 38/39 textbooks (present for 1/553 authors; 0.2 %). Twelve textbooks did not discuss HES for volume resuscitation. HES was recommended in 13 textbooks; many recommendations were controversial (10/39 textbooks, 26 %; 25/553 authors, 5 %). Journal COI statements were available for 18/25 authors; 7 authors had financial/other COI, including 4/18 (22 %) with ties to HES manufacturers.

CONCLUSIONS

Recommendations on volume resuscitation with HES are highly controversial in German-language electronic textbooks; about one-quarter of relevant textbooks are inconsistent with regulatory authority or international guideline criteria. Undisclosed potential COI of textbook authors making controversial recommendations of HES were frequent, linking roughly one in five authors to the HES-producing industry. Against this background, COI statements must become part of standard textbook publication ethics.

Synthetic colloid resuscitation in severely injured patients: analysis of a nationwide trauma registry (TraumaRegister DGU)

The purpose of this study was to investigate the efficacy and safety of synthetic colloid resuscitation among severely injured patients. Fluid resuscitation of trauma patients of a nationwide trauma registry was analysed between 2002 and 2015. Effects of synthetic colloid resuscitation in the pre-hospital setting and emergency department on renal failure, renal replacement therapy and multiple organ failure were analysed among patients with ≥2 days intensive care unit stay, and in-hospital mortality was analysed among all patients. 48,484 patients with mean age of 49 years and mean injury severity score of 23 points were included; 72.3% were male and 95.5% had blunt trauma. Risk-adjusted analyses revealed that patients receiving >1,000 ml synthetic colloids experienced an increase of renal failure and renal replacement therapy rates (OR 1.42 and 1.32, respectively, both p ≤ 0.006). Any synthetic colloid use was associated with an increased risk of multiple organ failure (p < 0.001), but there was no effect on hospital mortality (p = 0.594). Between 2002 and 2015 usage of synthetic colloids dropped, likewise did total fluid intake and usage of blood products. The data from this analysis suggests that synthetic colloid resuscitation provides no beneficial effects and might be harmful in patients with severe trauma.

The effects of hydroxyethyl starch and gelatine on pulmonary cytokine production and oedema formation

Recently, side effects of plasma expanders like hydroxyethyl starch and gelatine gained considerable attention. Most studies have focused on the kidneys; lungs remain unconsidered. Isolated mouse lungs were perfused for 4 hours with buffer solutions based on hydroxyethyl starch (HES) 130/0.4, HES 200/0.5 or gelatine and ventilated with low or high pressure under physiological pH and alkalosis. Outcome parameters were cytokine levels and the wet-to-dry ratio. For cytokine release, murine and human PCLS were incubated in three different buffers and time points.In lungs perfused with the gelatine based buffer IL-6, MIP-2 and KC increased when ventilated with high pressure. Wet-to-dry ratios increased stronger in lungs perfused with gelatine - compared to HES 130/0.4. Alkalotic perfusion resulted in higher cytokine levels but normal wet-to-dry ratio. Murine PCLS supernatants showed increased IL-6 and KC when incubated in gelatine based buffer, whereas in human PCLS IL-8 was elevated. In murine IPL HES 130/0.4 has lung protective effects in comparison to gelatine based infusion solutions, especially in the presence of high-pressure ventilation. Gelatine perfusion resulted in increased cytokine production. Our findings suggest that gelatine based solutions may have side effects in patients with lung injury or lung oedema.

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

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

Effects of hydroxyethyl starch 130/0.42 vs. Ringer's acetate on cytokine levels in severe sepsis

BACKGROUND

The Scandinavian Starch for Severe Sepsis/Septic Shock (6S) trial showed increased 90-day mortality with hydroxyethyl starch (HES) 130/0.42 vs. Ringer's acetate. To explore the underlying pathophysiology, we compared early changes in plasma cytokine concentrations between patients resuscitated with HES vs. Ringer's acetate.

METHODS

In a subgroup of 226 patients from the 6S trial, we calculated delta plasma concentrations of tumour necrosis factor alpha (TNF-α), interleukin (IL)-6 and IL-10 from randomization to day 2. We used multiple linear and logistic regression analyses to assess differences between the groups and associations between delta cytokine concentrations and 90-day mortality, respectively.

RESULTS

Baseline characteristics and day 2 mortality were comparable between the groups. We observed similar delta cytokine concentrations in the HES vs. Ringer's group (mean difference in delta TNF-α: -1.5 pg/ml (95% CI, -4.9 to 1.9), P = 0.39; IL-6: 36.0 pg/ml (-24.1 to 96.1), P = 0.24; IL-10: -3.9 pg/ml (-21.1 to 28.9), P = 0.76). In all included patients, we observed a linear relationship between increases in TNF-α and 90-day mortality (P = 0.005).

CONCLUSION

Resuscitation with HES 130/0.42 vs. Ringer's acetate did not appear to affect plasma concentrations of TNF-α, IL-6 or IL-10 differently during the first days after randomization into the 6S trial. In the overall cohort, increases in TNF-α were associated with increased 90-day mortality. Although interpretation should be done with caution, it seems unlikely that the increased mortality observed with the use HES in the 6S trial is signalled by early changes in three biomarkers of systemic inflammation.

Use of intravenous fluids/solutions: a narrative review

OBJECTIVE

Intravenous fluids are broadly categorized into colloids and crystalloids. The aim of this review is to present under a clinical point of view the characteristics of intravenous fluids that make them more or less appropriate either for maintaining hydration when enteral intake is contraindicated or for treating hypovolemia.

METHODS

We considered randomized trials and meta-analyses as well as narrative reviews evaluating the effects of colloids or crystalloids in patients with hypovolemia or as maintenance fluids published in the PubMed and Cochrane databases.

RESULTS

Clinical studies have not shown a greater clinical benefit of albumin solutions compared with crystalloid solutions. Furthermore, albumin and colloid solutions may impair renal function, while there is no evidence that the administration of colloids reduces the risk of death compared with resuscitation with crystalloids in patients with trauma, burns or following surgery. Among crystalloids, normal saline is associated with the development of hyperchloremia-induced impairment of kidney function and metabolic acidosis. On the other hand, the other commonly used crystalloid solution, the Ringer's Lactate, has certain indications and contraindications. These matters, along with the basic principles of the administration of potassium chloride and bicarbonate, are meticulously discussed in the review.

CONCLUSIONS

Intravenous fluids should be dealt with as drugs, as they have specific clinical indications, contraindications and adverse effects.

Administration of HES in elderly patients undergoing hip arthroplasty under spinal anesthesia is not associated with an increase in renal injury

Background

Hydroxyethyl starch (HES) is applied to achieve volume expansion during surgery; however, nephrotoxicity may be induced in patients with sepsis. Simultaneously, neutrophil gelatinase-associated lipocalin (NGAL) and IL-18 have been illustrated as pivotal indicators to diagnose the acute kidney injury (AKI) early. This multi-center, randomized, double-blinded, placebo-controlled study aimed to investigate whether 6% HES 130/0.4 administration caused postoperative AKI, which can be revealed by urinary and plasma NGAL and IL-18 estimations in elderly patients with normal renal function undergoing hip arthroplasty under spinal anesthesia.

Methods

120 ASA I–III, patients aged >65 y undergoing hip arthroplasty under spinal anesthesia randomly received 6% HES 130/0.4 or sodium lactate Ringer’s solution 7.5 mL/kg during the first hour of surgery. 118 patients completed the study. Blood pressure, NGAL concentrations, IL18, β₂ micro-albumin and albumin in urine and creatinine, NGAL and IL-18 in plasma were repeatedly measured before, during, and after surgery.

Results

The groups were balanced in mean arterial pressure, urine and plasma NGAL, plasma IL-18 and creatinine, urine β₂ microalbumin and albumin (P > 0.05). Urine IL-18 was dramatically elevated in both groups after surgery (P < 0.05), but did not vary significantly between the groups (P > 0.05).

Conclusion

Elderly patients undergoing surgery under spinal anesthesia are a high-risk population in AKI. These patients with normal renal function receiving a spinal anesthesia for a short duration surgery would not develop AKI when 500 mL (small volume) HES is infused.

Trial registration

Identifier: NCT02361736. Registration date was 2 February 2015.

An in vitro comparison of the effects of voluven (6% hydroxyethyl starch 130/0.4) and hespan (6% hydroxyethyl starch 670/0.75) on measures of blood coagulation in canine blood

OBJECTIVE

To assess primary and secondary hemostasis following in vitro dilution of canine whole blood (WB) with hydroxyethyl starch (HES) 130/0.4 and HES 670/0.75.

DESIGN

In vitro experimental study.

SETTING

Private practice, teaching hospital.

ANIMALS

Twenty-five healthy dogs.

INTERVENTIONS

Each dog underwent venipuncture and 18 mL of venous blood was sampled once.

MEASUREMENTS AND MAIN RESULTS

Collected blood was separated in 4 aliquots. Aliquot A served as baseline sample. The remaining tubes of WB were diluted with 0.9% saline, HES 670/0.75 and HES 130/0.4 at a ratio of 1:5.5. Dilutional effects were evaluated using prothrombin time (PT), activated partial thromboplastin time (aPTT), packed cell volume (PCV), thromboelastography (TEG), and platelet closure time (Ct), which was measured using a platelet function analyzer (PFA). Clot strength (ie, G value) was calculated from measured TEG values. Significant increases in PT (P < 0.05) and aPTT (P < 0.05) were documented following WB dilution with saline. Dilution of WB with HES 670/0.75 and HES 130/0.4 resulted in significant hypocoagulable changes in K, MA and G (P < 0.05) compared to baseline and saline. When comparing saline to HES 670/0.75, both R and K values were significantly increased (P < 0.05). K value was significantly increased (P < 0.05) when comparing baseline to HES 130/0.4 and HES 670/0.75. Ct (P < 0.05) was significantly prolonged after WB dilution with HES solutions but not after saline.

CONCLUSIONS

Dilution of WB with HES 670/0.75 and HES 130/0.4 resulted in changes in primary and secondary hemostasis. Although there were small differences between saline and HES 670/0.75, no differences between HES solutions were evident in this small study. This may suggest there would be minimal increases in bleeding risk when either solution is administered to dogs at low doses. Clinical relevance of our findings requires further investigation.

Controversies in the use of hydroxyethyl starch solutions in small animal emergency and critical care

OBJECTIVES

To (1) review the development and medical applications of hydroxyethyl starch (HES) solutions with particular emphasis on its physiochemical properties; (2) critically appraise the available evidence in human and veterinary medicine, and (3) evaluate the potential risks and benefits associated with their use in critically ill small animals.

DATA SOURCES

Human and veterinary original research articles, scientific reviews, and textbook sources from 1950 to the present.

HUMAN DATA SYNTHESIS

HES solutions have been used extensively in people for over 30 years and ever since its introduction there has been a great deal of debate over its safety and efficacy. Recently, results of seminal trials and meta-analyses showing increased risks related to kidney dysfunction and mortality in septic and critically ill patients, have led to the restriction of HES use in these patient populations by European regulatory authorities. Although the initial ban on the use of HES in Europe has been eased, proof regarding the benefits and safety profile of HES in trauma and surgical patient populations has been requested by these same European regulatory authorities.

VETERINARY DATA SYNTHESIS

The veterinary literature is limited mostly to experimental studies and clinical investigations with small populations of patients with short-term end points and there is insufficient evidence to generate recommendations.

CONCLUSIONS

Currently, there are no consensus recommendations regarding the use of HES in veterinary medicine. Veterinarians and institutions affected by the HES restrictions have had to critically reassess the risks and benefits related to HES usage based on the available information and sometimes adapt their procedures and policies based on their reassessment. Meanwhile, large, prospective, randomized veterinary studies evaluating HES use are needed to achieve relevant levels of evidence to enable formulation of specific veterinary guidelines.

The effect of 6% hydroxyethyl starch 130/0.4 on renal function, arterial blood pressure, and vasoactive hormones during radical prostatectomy: a randomized controlled trial

BACKGROUND

Although hydroxyethyl starch (HES) is commonly used as an intravascular volume expander in surgical patients, recent studies suggest that it may increase the risk of renal failure in critically ill patients. We hypothesized that patients undergoing radical prostatectomy and receiving HES would be more likely to develop markers of renal failure, such as increasing urinary neutrophil gelatinase-associated lipocalin (u-NGAL), creatinine clearance (C(crea)), and decreasing urine output (UO).

METHODS

In a randomized, double-blinded, placebo-controlled study, 40 patients referred for radical prostatectomy received either 6% HES 130/0.4 or saline 0.9%; 7.5 mL/kg during the first hour of surgery and 5 mL/kg in the following hours; u-NGAL, urine albumin, C(crea), UO, arterial blood pressure, and plasma concentrations of creatinine, renin, angiotensin II, aldosterone, and vasopressin were measured before, during, and after surgery.

RESULTS

Thirty-six patients completed the study. u-NGAL, C(crea), UO, plasma neutrophil gelatinase-associated lipocalin, p-creatinine, urine albumin, and arterial blood pressure were the same in both groups. Blood loss was higher in the HES group (HES 1250 vs saline 750 mL), while p-albumin was reduced to a significantly lower level. P-renin and p-angiotensin-II increased in both groups, whereas p-aldosterone and p-vasopressin increased significantly in the saline group.

CONCLUSIONS

We found no evidence of nephrotoxicity after infusion of 6% HES 130/0.4 in patients undergoing prostatectomy with normal preoperative renal function. Hemodynamic stability and infused fluid volume were the same in both groups. We observed an increased blood loss in the group given 6% HES 130/0.4.

The ideal fluid

PURPOSE OF REVIEW

The characteristics of an ideal intravenous fluid in the critically ill patient are discussed.

RECENT FINDINGS

Intravenous fluids are the most frequent drug administered to patients. Questioning the use of commonly administered intravenous fluids has resulted in an increased focus on their efficacy and safety. Discrimination between fluids currently in use has been the central theme of many recent large studies, and emerging from these findings is an understanding of characteristics that would make for an ideal fluid for critically ill patients. There is increased morbidity and mortality with high chloride-containing crystalloid solutions and hydroxyethyl starch preparations, with resultant international governmental agency warnings regarding hydroxyethyl starch . The ideal fluid is one which achieves the aim of administration while minimizing or negating adverse effects, is inexpensive, and sufficiently stable when stored to be used in a wide range of clinical settings.

SUMMARY

The ideal fluid currently does not exist. Of existing options, use of hydroxyethyl starches and high chloride-containing crystalloid solutions should be discouraged. There is a lack of direct evidence that a balanced crystalloid solution confers benefit, however, the trend of recent data would support future investigation into the advantage of balanced solution over 0.9% saline.

Acute kidney injury with hydroxyethyl starch 130/0.42 in severe sepsis

BACKGROUND

We aimed to detail the effects of hydroxyethyl starch (HES) vs. Ringer's on kidney function including the interaction with mortality in post-hoc analyses as resuscitation with HES 130/0.42 increased mortality in the Scandinavian Starch for Severe Sepsis/Septic Shock (6S) trial.

METHODS

In all 798 randomised patients, we assessed the incidence and effect on mortality of acute kidney injury (AKI) in the HES vs. Ringer's acetate groups using the Kidney Disease: Improving Global Outcome criteria. We also assessed the intervention effect on time to and duration of renal replacement therapy (RRT).

RESULTS

At baseline, the intervention groups were similar. The maximal AKI stage was higher in the HES vs. Ringer's group within the first 5 days after randomisation (P = 0.03), the average difference being 0.2 points (P < 0.01). An increase in AKI stage was associated with mortality (hazard ratio (HR) 1.35; 95% CI 1.22 to 1.49; P < 0.01). Significantly, more patients in the HES group received RRT within the first 5 days (P = 0.01), and the time to initiation of RRT was also shorter compared with the Ringer's group (HR 1.40; 95% CI 1.01-1.93; P = 0.04). The intervention effect of HES on mortality was reduced when adjusting for AKI stage as a time-dependent covariate (P = 0.15).

CONCLUSION

In patients with severe sepsis, HES appeared to increase the rate of severe AKI and use of RRT within the first 5 days. The increased mortality observed with HES may have been partly mediated through acute kidney impairment.

Fluid resuscitation in acute medicine: what is the current situation?

The administration of intravenous fluids for resuscitation is the most common intervention in acute medicine. There is increasing evidence that the type of fluid may directly affect patient-centred outcomes. There is a lack of evidence that colloids confer clinical benefit over crystalloids and they may be associated with harm. Hydroxyethyl starch preparations are associated with increased mortality and use of renal replacement therapy in critically ill patients, particularly those with sepsis; albumin is associated with increased mortality in patients with severe traumatic brain injury. Crystalloids, such as saline or balanced salt solutions, are increasingly recommended as first-line resuscitation fluids for the majority of patients with hypovolaemia. There is emerging evidence that saline may be associated with adverse outcomes due to the development of hyperchloraemic metabolic acidosis, although the safety of balanced salt solutions has not been established. Fluid requirements vary over the course of critical illness. The excessive use of fluids during the resuscitative period is associated with increased cumulative fluid balance and adverse outcomes in critically ill patients. The selection of fluid depends on the clinical context in which it is administered and requires careful consideration of the dose and potential for toxicity. There is an urgent need to conduct further high-quality randomized controlled trials of currently available fluid therapy in patients with critical illness.

Contribution of Raman spectroscopy in nephrology: a candidate technique to detect hydroxyethyl starch of third generation in osmotic renal lesions

Raman spectroscopy, a candidate tool for detection of HES, a volume expander administrated after hemodynamic instability, in the kidney.

Lack of nephrotoxicity by 6% hydroxyethyl starch 130/0.4 during hip arthroplasty: a randomized controlled trial

BACKGROUND

Hydroxyethyl starch (HES) is commonly used as plasma expander during surgery but may be nephrotoxic as seen in studies in patients with sepsis. The authors hypothesized that the possible nephrotoxicity of 6% HES 130/0.4 could be revealed by measurements of urinary excretion of neutrophil gelatinase-associated lipocalin (u-NGAL) in patients with normal renal function during hip arthroplasty.

METHODS

In this randomized, double-blinded, placebo-controlled study, 40 patients referred for hip arthroplasty received either 6% HES 130/0.4 or isotonic saline 0.9%; 7.5 ml/kg during the first hour of surgery and 5 ml/kg during the following hours; 38 patients completed the study. U-NGAL, urine albumin, blood pressure, and plasma concentrations of creatinine, renin, NGAL, albumin, angiotensin-II, and aldosterone were measured before, during, and after surgery. U-NGAL was defined as primary outcome.

RESULTS

There were no significant differences in U-NGAL (mean difference and 95% CI), plasma creatinine, and urine albumin during the study. U-NGAL and urine albumin increased significantly in both groups the morning after surgery but was normalized at follow-up after 10 to 12 days. Mean arterial pressure was significantly higher during the recovery period in the HES group compared with that in the control group (91 [13] and 83 [6] mmHg, mean [SD], P < 0.03). Plasma renin and angiotensin-II were nonsignificantly different in both groups, whereas plasma aldosterone was significantly lower in the HES group. Plasma albumin was reduced in both groups, but to a significantly lower level in the HES group.

CONCLUSION

The study showed no evidence of a harmful effect of intraoperative infusion of 6% HES 130/0.4 on renal function in patients during hip arthroplasty.

Hydroxyeyhyl starch: Controversies revisited

Hydroxyethyl starch (HES) family has been one of the cornerstones in fluid management for over four decades. Recent evidence from clinical studies and meta-analyses has raised few concerns about the safety of these fluids, especially in certain subpopulations of patients. High-quality clinical trials and meta-analyses have emphasized nephrotoxic effects, increased risk of bleeding, and a trend toward higher mortality in these patients after the use of HES solutions. Scientific evidence was derived from international guidelines, aggregated research literature, and opinion-based evidence was obtained from surveys and other activities (e.g., internet postings). On critical analysis of the current data available, it can be summarized that further large scale trials are still indicated before HES can be discarded.

Intravenous fluids in sepsis: what to use and what to avoid

PURPOSE OF REVIEW

Septic shock is one of the most common and life-threatening conditions afflicting critically ill patients. Intravenous volume resuscitation is considered an initial and very important step in management. The most suitable fluid for volume expansion during septic shock remains unclear. In this review, we focus on the benefits and adverse effects of the most commonly used intravenous fluids in critically ill septic patients.

RECENT FINDINGS

The debate about the benefits of colloids over crystalloids has been ongoing for the last few decades. With recent literature showing apparent harm from the use of hydroxyethyl starches (HESs), and given the growing concerns of adverse renal and acid-base abnormalities associated with 0.9% saline compared with balanced crystalloid solutions, it may be time to change the nature of the 'fluid debate'.

SUMMARY

Crystalloids should still be considered as the first-choice drug for volume resuscitation in patients with septic shock. Colloids such as albumin can be considered in some clinical settings. HES should be avoided. Balanced crystalloids might have an important role to play in the management of septic shock.

Fluid resuscitation in sepsis: reexamining the paradigm

Sepsis results in widespread inflammatory responses altering homeostasis. Associated circulatory abnormalities (peripheral vasodilation, intravascular volume depletion, increased cellular metabolism, and myocardial depression) lead to an imbalance between oxygen delivery and demand, triggering end organ injury and failure. Fluid resuscitation is a key part of treatment, but there is little agreement on choice, amount, and end points for fluid resuscitation. Over the past few years, the safety of some fluid preparations has been questioned. Our paper highlights current concerns, reviews the science behind current practices, and aims to clarify some of the controversies surrounding fluid resuscitation in sepsis.

Modern resuscitation of hemorrhagic shock: what is on the horizon?

PURPOSE

Mortality rates among the severely injured remain high. The successful treatment of hemorrhagic shock relies on expeditious control of bleeding through surgical ligation, packing, or endovascular techniques. An important secondary concern in hemorrhaging patients is how to respond to the lost blood volume. A single method that is able to adequately address all needs of the exsanguinating patient has not yet been agreed upon, despite a large growth of knowledge regarding the causative factors of traumatic shock.

METHODS

A review of relevent literature was performed.

CONCLUSIONS

Many different trials are currently underway to discriminate ways to improve outcomes in the severely injured and bleeding patient.  This paper will review: (1) recent advances in our understanding of the effects hemorrhagic shock has on the coagulation cascade and vascular endothelium, (2) recent research findings that have changed resuscitation, and (3) resuscitation strategies that are not widely used but under active investigation.

[Limited applications for hydroxyethyl starch : background and alternative concepts]

BACKGROUND

Within the framework of a risk assessment procedure the Committee for Risk Assessment of Pharmacovigilance (PRAC) of the European Medicines Agency (EMA) came to the conclusion that the benefits of hydroxylethyl starch infusion solutions (HES) no longer outweighed the risks and on 14 June 2013 recommended that approval should be suspended. Until the procedure has finally been concluded, which could last several months, the Federal Institute for Drugs and Medical Products (BfArM) has recommended that HES should not be used.

AIM

The aim of this article is to present the data situation in the most objective and compact way and to ultimately give the reader the foundations in order to be able to form a personal opinion. In addition an attempt will be made to describe a concept how infusion therapy can be carried out without using hydroxyethyl starch (HES).

MATERIAL AND METHODS

The background to this decision is given based on a review of the literature and the relevance for intensive care, emergency and perioperative medicine is assessed. Furthermore, a concept of infusion therapy without hydroxyethyl starch is formulated also based on the results of current studies.

RESULTS

For infusion regimens without HES it should be noted that gelatin represents a considerable risk for anaphylactic reactions, that transfer of the new variants of Creutzfeldt-Jacob disease (bovine spongiform encephalopathy BSE) cannot fundamentally be excluded and that some evidence has been found that gelatin can cause kidney injury, probably in a similar way to HES. With respect to the cost-benefit analysis of infusion solutions, blood loss in adults of approximately 1-1.5 l can be substituted by balanced crystalloids (basic therapy 4-5 times compared to the amount of blood lost). For larger blood losses small amounts of hyperoncotic albumin solution (20 %) or alternatively 5 % albumin solution can be used. The 20 % albumin solution seems to have some advantages because it has a higher volume effect (approximately 200 %) and can be more favourable for the fluid balance than 5 % albumin solution. Blood losses greater than 2-3 l normally also require administration of blood products (e.g. fresh frozen plasma FFP and erythrocyte concentrates EC).

CONCLUSIONS

The third generation HES solutions cannot be completely replaced by other colloids and in future crystalloids will more strongly again broadly form the basis for infusion therapy. In this aspect balanced crystalloids have priority with respect to the acid-base equilibrium. The history of HES has impressively shown that infusion therapy must be adjusted on a scientifically founded basis, whether in intensive care medicine, perioperative or emergency medicine. Large prospective studies with clinically relevant endpoints are urgently needed.

Hydroxyethyl starch for resuscitation

PURPOSE OF REVIEW

Resuscitation with hydroxyethyl starch (HES) is controversial. In this review, we will present the current evidence for the use of HES solutions including data from recent high-quality randomized clinical trials.

RECENT FINDINGS

Meta-analyses of HES vs. control fluids show clear signals of harm including adverse effects on kidney and haemostatic function, and trends towards increased mortality. These results are mainly based on recent large randomized clinical trials comparing tetrastarch (HES 130/0.4 and HES 130/0.42) vs. crystalloid in patients in the ICU. Trials in trauma and surgical patients cannot adequately assess safety issues and do not show clear benefit with the use of HES. There is currently no firm evidence that tetrastarch has better safety profile than the former HES solutions.

SUMMARY

There is no evidence for an overall beneficial effect of HES in any subgroup of critically ill patients, but there are clear signs of harm. As safer alternatives exist, we recommend that HES is no longer used in critically ill patients.

Fluids are drugs: type, dose and toxicity

PURPOSE OF REVIEW

We discuss the formulation of a prescription for intravenous (i.v.) fluid therapy (a 'volume prescription') for critically ill patients: pros/cons of different fluid types; accurate dosing; and qualitative and quantitative toxicities. Updated physiologic concepts are invoked and results of recent major clinical trials on i.v. fluid therapy in the acutely ill are interpreted.

RECENT FINDINGS

Context is vital and any fluid can be harmful if dosed incorrectly. When contrasting 'crystalloid versus colloid', differences in efficacy are modest, but differences in safety are significant. Differences in chloride load and strong ion difference appear to be clinically important. Quantitative toxicity is mitigated when dosing is based on dynamic parameters that predict volume responsiveness. Qualitative toxicity for colloids (even with newer hydroxyethyl starch 130/0.4 solutions) and isotonic saline remain a concern.

SUMMARY

Similar to any drug used in acutely ill patients, clinicians ordering a volume prescription must recognize that context is crucial. Physiologically balanced crystalloids may be the 'default' fluid for acutely ill patients, and the role for colloids is unclear. Optimal dosing involves assessment of volume responsiveness.

Accumulation of hydroxyethyl starch in human and animal tissues: a systematic review

PURPOSE

To systematically review clinical and preclinical data on hydroxyethyl starch (HES) tissue storage.

METHODS

MEDLINE (PubMed) was searched and abstracts were screened using defined criteria to identify articles containing original data on HES tissue accumulation.

RESULTS

Forty-eight studies were included: 37 human studies with a total of 635 patients and 11 animal studies. The most frequent indication for fluid infusion was surgery accounting for 282 patients (45.9%). HES localization in skin was shown by 17 studies, in kidney by 12, in liver by 8, and in bone marrow by 5. Additional sites of HES deposition were lymph nodes, spleen, lung, pancreas, intestine, muscle, trophoblast, and placental stroma. Among major organs the highest measured tissue concentration of HES was in the kidney. HES uptake into intracellular vacuoles was observed by 30 min after infusion. Storage was cumulative, increasing in proportion to dose, although in 15% of patients storage and associated symptoms were demonstrated at the lowest cumulative doses (0.4 g kg(-1)). Some HES deposits were extremely long-lasting, persisting for 8 years or more in skin and 10 years in kidney. Pruritus associated with HES storage was described in 17 studies and renal dysfunction in ten studies. In one included randomized trial, HES infusion produced osmotic nephrosis-like lesions indicative of HES storage (p = 0.01) and also increased the need for renal replacement therapy (odds ratio, 9.50; 95% confidence interval, 1.09-82.7; p = 0.02). The tissue distribution of HES was generally similar in animals and humans.

CONCLUSIONS

Tissue storage of HES is widespread, rapid, cumulative, frequently long-lasting, and potentially harmful.

Fluid resuscitation with hydroxyethyl starches in patients with sepsis is associated with an increased incidence of acute kidney injury and use of renal replacement therapy: a systematic review and meta-analysis of the literature

PURPOSE

Fluid resuscitation is a key intervention in sepsis, but the type of fluids used varies widely. The aim of this meta-analysis is to determine whether resuscitation with hydroxyethyl starches (HES) compared with crystalloids affects outcomes in patients with sepsis.

MATERIALS AND METHODS

Search of MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials up to February 2013. Studies that compared resuscitation with HES versus crystalloids in septic patients, and reported incidence of acute kidney injury (AKI), renal replacement therapy (RRT), transfusion of red blood cell (RBC) or fresh frozen plasma and/or mortality. Three investigators independently extracted data into uniform risk ratio measures. The Grading of Recommendations Assessment, Development and Evaluation framework was used to determine the quality of the evidence.

RESULTS

Ten trials (4624 patients) were included. An increased incidence of AKI (risk ratio [RR], 1.24 [95% Confidence Interval {CI}, 1.13-1.36], and need of RRT (RR, 1.36 [95% CI, 1.17-1.57]) was found in patients who received resuscitation with HES. Resuscitation with HES was also associated with increased transfusion of RBC (RR, 1.14 [95% CI, 1.01-1.93]), but not fresh frozen plasma (RR, 1.47 [95% CI, 0.97-2.24]). Furthermore, while intensive care unit mortality (RR, 0.74 [95% CI, 0.43-1.26]), and 28-day mortality (RR, 1.11 [95% CI, 0.96-1.28]) was not different, resuscitation with HES was associated with higher 90-day mortality (RR, 1.14 [95% CI, 1.04-1.26]).

CONCLUSIONS

Fluid resuscitation practice with HES as in the meta-analyzed studies is associated with increased an increase in AKI incidence, need of RRT, RBC transfusion, and 90-day mortality in patients with sepsis. Therefore, we favor the use of crystalloids over HES for resuscitation in patients with sepsis.