Low Molecular Weight Hydroxyethyl Starch Research Articles

Спосіб інтенсивної терапії загального переохолодження

Актуальність. Загальне переохолодження є однією з найбільш складних проблем сучасної інтенсивної терапії критичних станів. Метою роботи були вивчення ефективності розробленого способу інтенсивної терапії загального переохолодження, оцінка його впливу на швидкість корекції патофізіологічних зрушень і рівень летальності пацієнтів у критичному або термінальному стані. Матеріали та методи. Обстежено 50 пацієнтів (середній вік — 43,00 ± 3,62 року), стан яких був оцінений відповідно до класифікації стадій загального переохолодження Швейцарського товариства гірської медицини. Пацієнти були розподілені на 2 групи: I група (n = 25) — з активним зігріванням системою конвекційного обігріву Warm Air 135 (CSZ, США) та інфузією 37 °С кристалоїдних розчинів у таких дозах: при легкому ступені — 20–30 мл/кг; помірного та тяжкого ступеня — 50–70 мл/кг, із включенням колоїдних розчинів. II група (n = 25) — із пасивним зігріванням і стандартним комплексом інтенсивної терапії, що включав інфузію кристалоїдних і колоїдних розчинів кімнатної температури в дозі 20–30 мл/кг. Вивчалися езофагальна і тімпанітна температури, показники гемодинаміки (артеріальний тиск, частота серцевих скорочень, середній артеріальний тиск), ступінь неврологічного дефіциту за шкалою коми Глазго, швидкість зігрівання. Результати. Вихідна температура ядра тіла у I групі становила 29,03 ± 2,76 °С, у II групі — 31,50 ± 1,97 °С. Мінімальне та максимальне значення температури ядра тіла в I групі становили 24,3 і 33,6 °С; у II — 27,2 і 34,5 °С відповідно. Початковий рівень середнього артеріального тиску становив у I групі 49,86 ± 20,71 мм рт.ст., у II — 70,45 ± 11,72 мм рт.ст.; через 48 годин — 76,65 ± 12,27 мм рт.ст. та 60,82 ± 36,39 мм рт.ст. відповідно. Швидкість досягнення нормотермії (36,0 °С) у I і II групах становила 6,48 ± 3,47 години та 9,20 ± 6,52 години відповідно. Рівень летальності в I групі — 12 %, у II — 48 %, указані відмінності були вірогідними. Висновки. Використання вказаного вище способу інтенсивної терапії загального переохолодження дозволяє знизити летальність на 25 %.

Resuscitation fluid types in sepsis, surgical, and trauma patients: a systematic review and sequential network meta-analyses

BackgroundCrystalloids and different component colloids, used for volume resuscitation, are sometimes associated with various adverse effects. Clinical trial findings for such fluid types in different patients’ conditions are conflicting. Whether the mortality benefit of balanced crystalloid than saline can be inferred from sepsis to other patient group is uncertain, and adverse effect profile is not comprehensive. This study aims to compare the survival benefits and adverse effects of seven fluid types with network meta-analysis in sepsis, surgical, trauma, and traumatic brain injury patients.MethodsSearched databases (PubMed, EMBASE, and Cochrane CENTRAL) and reference lists of relevant articles occurred from inception until January 2020. Studies on critically ill adults requiring fluid resuscitation were included. Intervention studies reported on balanced crystalloid, saline, iso-oncotic albumin, hyperoncotic albumin, low molecular weight hydroxyethyl starch (L-HES), high molecular weight HES, and gelatin. Network meta-analyses were conducted using random-effects model to calculate odds ratio (OR) and mean difference. Risk of Bias tool 2.0 was used to assess bias. Confidence in Network Meta-Analysis (CINeMA) web application was used to rate confidence in synthetic evidence.ResultsFifty-eight trials (n = 26,351 patients) were identified. Seven fluid types were evaluated. Among patients with sepsis and surgery, balanced crystalloids and albumin achieved better survival, fewer acute kidney injury, and smaller blood transfusion volumes than saline and L-HES. In those with sepsis, balanced crystalloids significantly reduced mortality more than saline (OR 0.84; 95% CI 0.74–0.95) and L-HES (OR 0.81; 95% CI 0.69–0.95) and reduced acute kidney injury more than L-HES (OR 0.80; 95% CI 0.65–0.99). However, they required the greatest resuscitation volume among all fluid types, especially in trauma patients. In patients with traumatic brain injury, saline and L-HES achieved lower mortality than albumin and balanced crystalloids; especially saline was significantly superior to iso-oncotic albumin (OR 0.55; 95% CI 0.35–0.87).ConclusionsOur network meta-analysis found that balanced crystalloids and albumin decreased mortality more than L-HES and saline in sepsis patients; however, saline or L-HES was better than iso-oncotic albumin or balanced crystalloids in traumatic brain injury patients.Trial registrationPROSPERO website, registration number: CRD42018115641).

Modern opportunities for the burn shock resuscitation

Burn shock is characterized by significant disturbances of central hemodynamic, the presence of microcirculatory disorders due to primary hypovolemia, stress reaction, mass release of inflammatory response mediators, the development of all types of hypoxia, sharp changes in the acid-base state, blood coagulation, dysproteinaemic changes, electrolyte imbalance and quickly leads to the organ dysfunction and multiple organ failure. In this regard, infusion therapy is important in the treatment of burn patients, aimed at blood rheology improving, tissues microcirculation, acidosis correction. Significant homeostatic disturbances during the burn shock acutely determine the infusion solutions choice problem for the hemodynamic disturbance’s correction. The infusion solutions characteristics of for the correction of hemodynamic disturbances during burn shock have been given. Volume deficit recovery for tissue perfusion support and metabolic acidosis correction can be achieved with crystalloid and colloid solutions. Among plasma substitutes, these are low molecular weight hydroxyethyl starch which replaced dextran and native proteins (albumin, plasma). But crystalloids cause swelling. Dextran are not applied now. Albumin transfusion is indicated only for hypoproteinaemia, and plasma for the coagulation factors deficiency. The role of Rheosorbilact in the correction of hypovolemia and metabolic acidosis in patients with burn disease is shown. The presence in clinical practice of domestic polyionic multifunctional solutions of Rheosorbilact gives a positive impetus to the development of new infusion therapy methods.

Safety and efficacy of peri-operative administration of hydroxyethyl starch in children undergoing surgery: A systematic review and meta-analysis.

Hydroxyethyl starch (HES) solutions have shown their efficiency for intravascular volume expansion. A safety recommendation limiting their use in adult patients has recently been made. To assess the efficacy and adverse effects of HES when administered intra-operatively to paediatric patients. Systematic review with meta-analyses. Data were analysed using classical mean differences [and their 95% confidence intervals (CIs)] and trial sequential analysis. A Grading of Recommendations Assessment, Development and Evaluation (GRADE) classification was performed for all outcomes. Reviewers extracted valid data, including perioperative total fluid intakes, mortality, renal function, coagulation tests, blood loss and length of hospital and ICU stay. Searches were performed in databases (Pubmed, Embase, Cochrane central register of controlled trials), clinical trials register, and open access journals not indexed in major databases. Randomised controlled trials (RCTs) published before December 2016 involving paediatric patients who received 6% low molecular weight HES. Nine RCTs involving 530 peri-operative paediatric patients were analysed. Compared with other fluids, HES did not significantly modify the amount of peri-operative fluid administered [mean difference 0.04; 95% CI (-1.76 to 1.84) ml kg], urine output [mean difference -33; 95% CI (-104 to 38) ml kg] or blood loss [mean difference -0.09; (-0.32 to 0.15) ml kg]. Trial sequential analysis determined that the outcomes for peri-operative fluid and urine output were underpowered. All results were graded as very low quality of evidence. Intravascular volume expansion with low molecular weight 6% HES did not appear to modify renal function, blood loss or transfusion when administered to children during the peri-operative period. However, given the lack of statistical power and the very low GRADE quality of evidence, more high-quality RCTs are needed to explore these outcomes.

Perioperative clinical and economic outcomes associated with replacing first-generation high molecular weight hydroxyethyl starch (Hextend®) with low molecular weight hydroxyethyl starch (Voluven®) at a large medical center

BackgroundSeveral plasma volume expander alternatives exist to enhance intravascular volume status in patients undergoing surgery. The optimal intravascular volume expander in the perioperative setting is currently unknown. Low molecular weight hetastarch, Voluven® (130/0.4), may have a better safety profile than high molecular weight hetastarch, Hextend® (450/0.7). We examined the clinical and cost outcomes of converting from Hextend® to Voluven® in a large tertiary medical center.MethodsUsing a large electronic database, we retrospectively compared two different time periods (2009 and 2010) where the availability of semisynthetic colloids changed. Perioperative and postoperative outcomes including the use of red blood cells (RBC), platelets and coagulation factors, length of stay in the postoperative acute care unit (PACU), intensive care unit and hospital, as well as 30-day and 1-year mortality were compared. In addition, direct acquisition costs of all intraoperative and PACU colloids and crystalloid use were determined.ResultsA total of 4,888 adult subjects were compared of which 1,878 received Hextend® (pre-conversion) and 2,759 received Voluven® (post-conversion) during two separate 7-month periods within 1 year apart, with the remainder receiving Plasmanate. The patients were similar in terms of patient demographics, preoperative comorbidities, ASA status, emergency surgery, types of surgery, intraoperative, and PACU times. In unadjusted outcomes, patients in the Hextend® group received more lactated Ringer’s than in the Voluven® group (2,220 + 1,312 vs. 1,946 ± 1,097 ml; P < 0.0001). The use of albumin (Plasmanate) was reduced from 10.5% of patients to 1.1% when Voluven® was substituted for Hextend®. Unadjusted outcomes were similar in each group including hospital LOS, percent change from baseline creatinine and receipt of intraoperative and PACU blood product administration. However, overall unadjusted total fluid costs were greater in the Voluven® compared to Hextend® group ($116.7 compared to $59.3; P < 0.001).ConclusionsConversion from Hextend® to Voluven® in the perioperative period resulted in decreased albumin use and was not associated with changes in clinical outcomes and short- and long-term mortality. The conversion was associated with decreases in crystalloid use and an increase in colloid use and hence IV fluid acquisition costs in the Voluven® group.

This Month In: Anesthesiology

This Month In: Anesthesiology

Comparison of low molecular weight hydroxyethyl starch and human albumin as priming solutions in children undergoing cardiac surgery

Human albumin is the conventional cardiopulmonary bypass circuit primer. However, it has high manufacturing costs. Crystalloid and colloid solutions have been developed as alternatives, including a new generation of non-ionic hydroxyethyl starch (HES). The efficacy of hydroxyethyl starch with a 130 molecular weight and substitution degree of 0.4 (hydroxyethyl starch 130/0.4) was compared with human albumin for use in cardiopulmonary bypass surgery in American Society of Anesthesiologists' grade I-II pediatric congenital heart disease patients. Efficacy was evaluated by comparing perioperative hemodynamic parameters, including plasma colloid osmotic pressure, renal function, blood loss, allogeneic blood volumes and plasma volume substitution. The hydroxyethyl starch group exhibited significantly higher preoperative colloid osmotic pressure (p<0.01) and significantly lower operative renal function and postoperative allogeneic blood volumes than the human albumin group. No significant differences were observed in serum creatinine, glucose, hematocrit or lactic acid levels (p>0.05). Our results indicate that hydroxyethyl starch may be a viable alternative to human albumin in pediatric patients undergoing relatively simple cardiopulmonary bypass surgeries.

In vitro evaluation of canine hemostasis following dilution with hydroxyethyl starch (130/0.4) via thromboelastometry

To assess the effects of in vitro hemodilution of canine blood with a low molecular weight hy-droxyethyl starch (HES 130/0.4) by means of thromboelastometry (TEM). In vitro experimental study. University Teaching Hospital. Ten healthy adult staff-owned dogs were sampled for the purposes of the study. Samples were also collected from 45 clinically normal dogs to establish thromboelastometric reference intervals. For each dog whole blood was collected by jugular venipuncture and placed into tubes containing 3.8% trisodium citrate and stored at 37°C. Two standard dilutions (1:4 and 1:10) from canine blood specimens were prepared with HES 130/0.4 and saline 0.9%. The effects of dilution were studied by TEM. No statistically significant differences were observed between the TEM values of the control samples and the samples diluted with saline solution (ratio 1:10 and 1:4). In contrast, hypocoagulability was observed in the samples treated with HES 130/0.4, with more severe effects at 1:4 dilution than at 1:10 dilution. The 1:4 dilution with HES 130/0.4 produced marked alterations: CT (P = 0.035) and CFT (P = 0.0007) on the ex-TEM profile, CT (P = 0.0005) and ML (P = 0.0017) on the fib-TEM profile and CFT (P = 0.0043) on the in-TEM, were all significantly increased (P < 0.05), whereas MCF (P = 0.0042) and alpha angle (P = 0.002) on the in-TEM and MCF (P = 0.011) and alpha angle (P = 0.001) ex-TEM profiles and MCF (P = 0.0001) on the fib-TEM profile were significantly decreased (P < 0.05). Dilution of canine blood with HES 130/0.4 results in a thromboelastometric pattern consistent with hypocoagulation and this effect appears to result from a dose-dependent alteration in fibrinogen concentration and inhibition of platelet function. As this is an in vitro study, further in vivo investigations are necessary to confirm the results.

Effects of fluid resuscitation with synthetic colloids or crystalloids alone on shock reversal, fluid balance, and patient outcomes in patients with severe sepsis

To assess shock reversal and required fluid volumes in patients with septic shock. Prospective before and after study comparing three different treatment periods. Fifty-bed single-center surgical intensive care unit. Consecutive patients with severe sepsis. Fluid therapy directed at preset hemodynamic goals with hydroxyethyl starch (predominantly 6% hydroxyethyl starch 130/0.4) in the first period, 4% gelatin in the second period, and only crystalloids in the third period. Main outcome was time to shock reversal (serum lactate <2.2 mmol/L and discontinuation of vasopressor use). Hemodynamic goals were mean arterial pressure >70 mm Hg; ScvO2 <70%; central venous pressure >8 mm Hg. Safety outcomes were acute kidney injury defined by Risk, Injury, Failure, Loss, and End-stage kidney disease criteria and new need for renal replacement therapy. Hemodynamic measures, serum lactate, and creatinine were comparable at baseline in all study periods (hydroxyethyl starch n = 360, gelatin n = 352, only crystalloids n = 334). Severity scores, hospital length of stay, and intensive care unit or hospital mortality did not differ significantly among groups. All groups showed similar time to shock reversal. More fluid was needed over the first 4 days in the crystalloid group (fluid ratios 1.4:1 [crystalloids to hydroxyethyl starch] and 1.1:1 [crystalloids to gelatin]). After day 5, fluid balance was more negative in the crystalloid group. Hydroxyethyl starch and gelatin were independent risk factors for acute kidney injury (odds ratio, 95% confidence interval 2.55, 1.76-3.69 and 1.85, 1.31-2.62, respectively). Patients receiving synthetic colloids received significantly more allogeneic blood products. Shock reversal was achieved equally fast with synthetic colloids or crystalloids. Use of colloids resulted in only marginally lower required volumes of resuscitation fluid. Both low molecular weight hydroxyethyl starch and gelatin may impair renal function.

Preoperative autologous blood donation and acute normovolemic hemodilution affect intraoperative blood loss during sagittal split ramus osteotomy

IntroductionThis study aimed to determine the effects of acute normovolemic hemodilution (ANH) using low-molecular-weight hydroxyethyl starch (LMW-HES) on intraoperative blood loss in patients who had received preoperative autologous blood donation (PABD) and had undergone sagittal split ramus osteotomy (SSRO). MethodsPatients who had undergone SSRO were analyzed. All 250 patients received PABD of 400–800mL until 2weeks before surgery. ANH was performed by withdrawing whole blood, which was replaced by the same volume of LMW-HES. ANH was performed in 197 cases for 200mL replacement (ANH-200) and in 5 cases for 400mL replacement (ANH-400); it was not performed in 48 cases (ANH-0). ResultsBlood loss in ANH-200 was greater than that in ANH-0, despite no differences in hemoglobin concentrations at pre- and post-PABD, prothrombin time, activated partial thromboplastin time, fibrinogen and platelet counts between the groups before surgery. Blood loss increased as the total withdrawn blood (sum of PABD and ANH) increased. ConclusionIncreased intraoperative blood loss was associated with total withdrawn blood before the operation as well as ANH.

Is perioperative low molecular weight hydroxyethyl starch infusion a risk factor for delayed graft function in renal transplant recipients?

Crystalloid or colloid fluids may be utilized during kidney transplantation. Histopathological and clinical data indicate that hydroxyethyl starch (HES) may have nephrotoxic potential. This retrospective single-centre cohort study screened 192 and included 113 patients who underwent renal transplantation between 2003 and 2007 at University of Leipzig Medical Faculty, Germany. The primary outcome parameter was delayed graft function (DGF). Patients were divided into two groups. Patients in group CRYS (N = 73) received crystalloid solution (acetated Ringer's or normal saline) only. Patients in the group HES (N = 40) received a minimum of 500 mL 6% HES 130/0.4 and additional crystalloid solution by discretion of the transplant team. Patients in both groups did not differ with respect to demographic data and American Society of Anesthesiologists Physical Status Classification System scores, except for the donor age, which was significantly lower in the group HES. The rate of DGF was not found to be different in group CRYS (31.5%) when compared to group HES (32.5%) (P = 1.00, n.s.). In this single-centre retrospective cohort study, infusion of low molecular weight 6% HES 130/0.4 during and after renal transplantation was found to have no significant negative effect upon the rate of DGF.

Preparation of granulocyte concentrates by apheresis: collection modalities in the USA

Preparation of granulocyte concentrates by apheresis: collection modalities in the USA

Carbon monoxide releasing molecule-2 enhances coagulation and attenuates fibrinolysis by two mechanisms: insights gained with colloid dilution

Carbon monoxide releasing molecule-2 (CORM-2, tricarbonyldichlororuthenium (II) dimer) enhances coagulation and attenuates vulnerability to fibrinolysis. Our goal was to further define the CORM-2-mediated mechanisms using colloids with known effects on coagulation/fibrinolytic proteins. Plasma diluted 0 or 30% with 0.9% NaCl, 5% human albumin, low molecular weight hydroxyethyl starch (130 kDa) or high molecular weight hydroxyethyl starch (450 kDa) was exposed to 0 or 100 μmol/l CORM-2 before activation with tissue factor (n = 8 per condition). A second identically diluted series of experiments were performed with the addition of tissue-type plasminogen activator. Thrombelastographic data were collected until clot strength stabilized or clot lysis occurred. Dilution resulted in fluid-specific decreases in velocity of clot growth, strength and clot growth time with progressive increases in macromolecule size. CORM-2 exposure significantly increased the velocity of clot formation and strength (thin fibrin fiber promoting), but not clot growth time, under all conditions. Fibrinolysis was enhanced to the greatest extent by hydroxyethyl starch (antiα2-antiplasmin effect), and CORM-2 addition attenuated fibrinolysis in all conditions (α2-antiplasmin enhancement). CORM-2 exposure attenuated the decrease in coagulation kinetics mediated by hemodilution by two different mechanisms based on kinetic profile differences between the diluents tested. Further laboratory-based investigation is warranted to further define the molecular mechanisms responsible for CORM-2-mediated effects on coagulation and fibrinolysis.

Influence of colloid infusion on coagulation during off-pump coronary artery bypass grafting

This study was conducted to determine the influence of colloid infusion on coagulation in patients undergoing off-pump coronary artery bypass grafting (OP-CABG). Thirty patients undergoing elective OP-CABG received medium molecular weight hydroxyethyl starch group I (MMW-HES 200/0.5), low molecular weight hydroxyethyl starch group II (LMW-HES 130/0.4) or gelatin group III (GEL) in a prospective randomized trial. Blood samples were assessed for hemoglobin (Hb), activated coagulation time (ACT), prothrombin time (PT), activated partial thromboplastin time (aPPT), platelet count, fibrinogen and von Willebrand factor (vWF) at specified intervals. Total volume of the colloid infused and postoperative chest-time drainage was also measured. There was a significant decrease in Hb, platelet count, fibrinogen levels in all these groups, which did not warrant blood transfusion. After the colloid infusion, vWF decreased significantly to 67% from baseline in group I as compared to 85 and 79% in group II and group III, respectively. vWF levels remained lower than the baseline value in the first 24 hours in group I, whereas this factor level increased above the baseline values in groups II and III, 6 hours postoperatively. Postoperative chest tube drainage in 24 hours was significantly higher in group I (856 ± 131 ml) as compared to group II (550 ± 124 ml) and group III (582 ± 159 ml). LMW-HES 130/0.4 was superior to MMW-HES 200/0.5 and gelatin in patients undergoing OP-CABG, in terms of better preservation of coagulation associated with enhanced volume effect.

Coagulation and biochemical effects of balanced salt‐based high molecular weight vs saline‐based low molecular weight hydroxyethyl starch solutions during the anhepatic period of liver transplantation

The anhepatic period of liver transplantation is generally marked by a decrease in preload, and the infusion of hydroxyethyl starch (HES) solution is often an effective way to restore volume deficits in non-anaemic patients. However, the infusion of even limited amounts of HES solution during the anhepatic period may result in a worsening coagulopathy. Moreover, lactate-containing HES solution may cause some degree of biochemical derangements in compromised recipients. Therefore, we compared two different types of HES solutions: a balanced salt-based high molecular weight HES solution (670/0.75; high MW group) and a saline-based low molecular weight HES solution (130/0.4; low MW group) with respect to coagulation and biochemical profiles. First, in an in vitro study (n = 48), thromboelastography was performed to determine the effects of two HES solutions on coagulation after diluting (11%) the recipient's blood sample with each HES solution. Second, in an in vivo study, 500 ml of one of the two 6% HES solution was administered to 74 recipients (n = 37, each group) for 30 min after starting the anhepatic period. The coagulation profiles, including thromboelastography, and biochemical profiles were measured before and 30 min after the end of infusion. Less impairment in the thromboelastography profiles and aPTT was observed in the high MW group. A higher calcium concentration and less reduction in platelet count were noted in the high MW group, but lactate accumulation was greater. In conclusion, a balanced salt-based high molecular weight HES solution is a more effective volume replacement during the anhepatic period of liver transplantation with respect to coagulation than a saline-based low molecular weight HES solution, although lactate accumulation is a possible concern.

Bone Cement Implantation Syndrome in the Perioperative Period of Large Joint Endoprosthesis

Objective: to enhance the efficiency of diagnosis of and intensive therapy for bone cement implantation syndrome in the perioperative period of endoprosthesis of large joints of the lower extremity. Subjects and methods: A study group comprised 18 patients who received standard perioperative intensive therapy for the bone cement implantation syndrome. A control group included 22 patients in whom perioperative correction of hemostatic disorders was made, by including 6% solution into the infusion program of second-generation hydroxyethyl starches (200/0.5) and by postoperatively administering low molecular-weight heparins. To evaluate the state of the basic hemostatic links, the classical laboratory parameters were determined, as described by Z. S. Barkagan, et al. Concurrent with the determination of the classical parameters, an integral estimate was made by rapid blood viscosimetry. Results. Impairments of basic hemostatic links in the bone cement implantation syndrome are characterized by the development of prethrombosis. Rapid blood viscometric parameters, such as the rate of spontaneous platelet aggregation, the onset of clotting, the constants of thrombin, blood clotting, total blood clotting, a fibrin-platelet constant, and the cumulative rate of clot retraction and lysis, correlate with classical biochemical parameters. Conclusion. The pathogenetically warranted use of a combination of low molecular-weight heparin and second-generation hydrox-yethyl starch enhances the efficiency of correction of perioperative impairments of the basic hemostatic links in the cement endoprosthetic replacement of large joints of the lower extremity.

Effects of intravascular volume therapy using hydroxyethyl starch (130/0.4) on post‐operative bleeding and transfusion requirements in children undergoing cardiac surgery: a randomized clinical trial

Hydroxyethyl starch (HES) used for intravascular volume expansion may cause coagulation abnormalities, especially in cardiac patients. Although low molecular weight HES (130/0.4) has been developed to minimize its influence on coagulation, experience with HES (130/0.4) in children is limited. Therefore, we evaluated the effects of a HES (130/0.4) infusion on post-operative blood loss in children undergoing cardiac surgery. Forty-two children undergoing cardiac surgery were assigned at random to receive either 10 ml/kg fresh frozen plasma (FFP group; n=21) or HES (130/0.4) (HES group; n=21) shortly after cardiopulmonary bypass termination. Activated partial thromboplastin time (aPTT) and international normalization ratio (INR) were measured. In addition, post-operative transfusion requirements and blood loss until the end of the first post-operative day were compared. INR was significantly prolonged after HES infusion in comparison to the FFP group (P<0.05). During the first 24 h after surgery, post-operative blood loss, the use of allogenic blood/blood products and aPTT were similar in all children. Our study shows that the administration of a moderate dose of HES (130/0.4) in children undergoing cardiac surgery does not cause more bleeding or a higher transfusion requirement than a FFP infusion, and suggests that the administration of 10 ml/kg HES (130/0.4) is a safe alternative to plasma for intravascular volume replacement in this patient population.

Artificial colloids impair haemostasis. An in vitro study using thromboelastometry coagulation analysis

Hydroxyethyl starch (HES) solutions impair haemostatic mechanisms. The impact of the degree of substitution (DS) of a HES solution on thromboelastometry tracings is unclear. Therefore we tested the hypothesis of whether the DS has an effect on the haemostatic defect caused by HES, and assessed whole blood coagulation by thromboelastometry coagulation analysis (ROTEM, Pentapharm Co., Munich, Germany) in serial in vitro haemodilutions of colloids. Whole blood was withdrawn from 12 volunteers in a crossover study. Six per cent low-molecular weight HES with a high (HES MW 120 kDa/degree of substitution 0.7) and low (HES MW 130 kDa/0.4) degree of substitution, 4% succinylated gelatin (GEL) or 4% albumin (ALB) was added to citrated venous whole blood samples to make 20, 40, 60 vol.% end-concentrations of each of the solutions. Samples were analyzed by ROTEM. There was a comparable decrease in maximum clot firmness (MCF) and shear elastic modulus [G = 5000 x MCF/(100-MCF)] by HES 120/0.7 and HES 130/0.4 at 20 and 40 vol.% dilutions. At 60 vol.% dilution HES 120/0.7 decreased less alpha-angle and MCF than HES 130/0.4 (P < 0.05). With moderate dilutions all colloids shortened coagulation time (CT). At 20, 40 and 60 vol.% dilutions MCF and G were more decreased in both HES groups than in the ALB and GEL groups (P < 0.05). Furthermore, at 40 and 60 vol.% dilutions G deteriorated more in the GEL than in the ALB group (P < 0.05). In vitro the impact of the degree of substitution of HES solution on thromboelastometry coagulation analysis was modest. Haemodilution with gelatin and albumin induced fewer coagulation abnormalities than HES. In addition, the haemodilution with gelatin impaired coagulation more than albumin solution.

The Effects of Low Molecular Weight Hydroxyethyl Starch Replacement Solution in Acute Normovolemic Hemodilution

Background: Unlikely crystalloid, hydroxyethyl starch (HES) solution as a replacement fluid during acute normovolemic hemodilution (ANH) compromises hemodilution-mediated hypercoagulability. However a new HES [130/0.4] preparation may influence hemostasis minimally due to an improved molecular distribution in plasma. This study was designed to estimate the effect of low molecular weight HES solutions (HES [70/0.55] and HES [130/0.4]) during ANH. Methods: Twenty healthy patients scheduled for spine surgery were randomly enrolled in HES 70 and HES 130 groups. All patients underwent moderate ANH before the induction of anesthesia. While whole blood ( ) was being procured, blood deficits were replaced with the same volume of the respective HES solutions. Hematocrit, platelet count, plasma fibrinogen concentration, ionized calcium level, and factor VIII activity were assayed and thrombelastography (TEG) was performed before and after ANH. Statistical tests were conducted to determine the effect of each HES solution. Results: Hematocrit, platelet count, plasma fibrinogen concentration and factor VIII activity were lower than baseline in each group after ANH. According to TEG findings, MA was lower in both groups but R shortened and enhanced in the HES 130 group alone. Comparisons between the HES 70 and HES 130 groups showed that hematocrit, R, and MA changes during ANH differed significantly between the two (repectively, P = 0.019, 0.043, 0.023 and 0.019). Conclusions: HES [130/0.4] solution administered for ANH impairs the hemostatic system to a lesser extent than HES [70/0.55] solution. However, because the volume effect of HES [130/0.4] solution persists for a few hours, a chance of hypovolemia remains during ANH.

Hyperaggregating effect of hydroxyethyl starch components and University of Wisconsin solution on human red blood cells: a risk of impaired graft perfusion in organ procurement?

The standard preservation solution used during organ procurement and preservation of most organs is the University of Wisconsin (UW) solution. Despite its superiority over other cold storage solutions, the inclusion of hydroxyethyl starch (HES) as one of the components of the UW solution has been both advocated and denied. This study determined whether HES had any effect on red blood cell (RBC) aggregability and correlated aggregation parameters with HES molecular weight. Human RBC aggregability and deformability were investigated in vitro, at 4 degrees C, with a laser-assisted optical rotation cell analyzer. The study of RBC aggregation in a binary HES-HES system gave an indication about the nature of HES-RBCs interactions. Bright field microscopy and atomic force microscopy were used to morphologically characterize the aggregates size and form. High molecular weight HES and UW solution had a potent hyperaggregating effect; low molecular weight HES had a hypoaggregating effect on RBC. RBC aggregates were of large size and their resistance to dissociation by flow-induced shear stress was high. The authors' in vitro experiments conclusively showed that the physiologic function of RBCs to form aggregates is significantly affected in the presence of HES. The use of high molecular weight HES in UW solution accounts for extended and accelerated aggregation of erythrocytes that may result in stasis of blood and incomplete washout of donor organs before transplantation.