Hydroxyethyl Starch, but Not Modified Fluid Gelatin, Affects Inflammatory Response in a Rat Model of Polymicrobial Sepsis with Capillary Leakage

Granulozytentransfusion: Update 2020

Die therapeutische Anwendung von Granulozytenkonzentraten erfolgt im klinischen Alltag im Gegensatz zu der anderer Blutprodukte nur selten und unregelmäßig. Der zurückhaltende Einsatz beruht unter anderem auf dem Fehlen einer breiten Evidenz, logistischen und wirtschaftlichen Problemen und dem Vorhandensein anderer potenter Therapieoptionen neutropener Infektionen. Dennoch gab es in den letzten Jahren neue wissenschaftliche Erkenntnisse nicht nur zu Physiologie und Pathophysiologie der Granulozyten, wie neu charakterisierten zellulären Verteidigungsstrategien oder deren Mitwirkung bei thrombotischen oder malignen Ereignissen, sondern auch zu deren therapeutischem Effekt. Dieser wird von einer Vielzahl an Parametern, wie der Art der Infektion, dem Transfusionszeitpunkt und der Dosis, beeinflusst. Das macht die Indikationsstellung zu einer komplexen Einzelfallentscheidung und es gilt, die heterogene Datenlage systematisch zusammenzufassen. Außerdem wurden die etablierten Indikationen neutropener bzw. neutropathischer Infektionen um experimentelle, mögliche neue Anwendungsgebiete wie die Mukositis oder Leukämiebehandlung erweitert. Die erfolgreiche Anwendung setzt eine geeignete, moderne Herstellungsweise voraus. Neben der Apherese, bei der eine relativ hohe Spenderbelastung unter anderem durch Nebenwirkungen von Mobilisationsregime und Sedimentationsbeschleunigern berücksichtigt werden muss, existieren weitere Verfahren wie die Gewinnung von Granulozyten aus Buffy Coats von Vollblutspenden. Diese versprechen eine Reduktion logistischer Probleme und unerwünschter Wirkungen auf den Spender. Unerwünschte Wirkungen bei Empfängern von Granulozytentransfusionen sollten nach wie vor berücksichtigt und gegen einen erhofften therapeutischen Effekt abgewogen werden.

Effects of End-Tidal Carbon Dioxide-Guided Fluid Resuscitation on Outcomes in a Cecal Ligation and Puncture Induced Rat Model of Sepsis

Cecal ligation and puncture (CLP) was used to cause severe sepsis in male Sprague-Dawley rats. There are four groups in this study: sham (n = 5), CLP (n = 10), end-tidal carbon dioxide (ETCO2) (n = 10), and mean arterial pressure (MAP) (n = 10). In ETCO2 group, fluid resuscitation (FR) began when ETCO2 at most 25 mmHg. In MAP group, FR began when MAP at most 100 mmHg. Electrocardiogram, aortic pressure, core temperature, and ETCO2 values were recorded at baseline, 2, 4, 6, 8, 10, and 12 h post-CLP. Lactate level, cardiac output (CO), perfused small vessel density (PSVD), and microvascular flow index (MFI) were assessed at the same time points as above. The results showed that MAP, CO, and ETCO2 gradually decreased after CLP. After FR, MAP, ETCO2, and CO in the ETCO2 group increased compared with the MAP group 12 h after CLP (all P < 0.05). Lactate level remains high in MAP group while decreasing in the ETCO2 group 8 h post-CLP. Both PSVD and MFI deteriorated after CLP in CLP group, though significantly improved in the ETCO2 group 8 h post-CLP. The average survival time in the ETCO2 group was significantly greater than MAP group (14.95 ± 3.90 h vs. 11.15 ± 1.76 h; t = 2.804, P = 0.012). Moreover, ETCO2 showed a negative correlation with lactic acid levels and a positive correlation with CO, PSVD, and MFI. In conclusion, ETCO2 can guide FR implement and improve outcomes of severe sepsis in CLP-inducted rat model. ETCO2 might be a potential index to guiding early FR in severe sepsis.

Impact of hydroxyethyl starch and modified fluid gelatin on granulocyte phenotype and function

BACKGROUND

Patients with neutropenia or granulocyte dysfunction may require granulocyte transfusions for adequate immune restoration. High-molecular-weight hydroxyethyl starch (HES) is the most commonly used sedimentation agent to enhance granulocyte collection efficiency. However, authorities recently restricted the use of HES due to its unfavorable risk-benefit profile. As modified fluid gelatin (MFG) is already used as an alternative sedimentation agent, we tested the hypothesis that MFG is not inferior to HES in terms of the functionality and viability of granulocytes.

STUDY DESIGN AND METHODS

Granulocytes from ten healthy donors were isolated, aliquoted and incubated in parallel for 2 hours with either 0% (control), 7.5%, 15%, or 30% MFG (Gelafundin) or HES (Hespan), respectively, and granulocyte migration, chemotaxis, reactive oxygen species (ROS) production, neutrophil extracellular trap formation (NETosis), antigen expression, and viability were subsequently investigated in vitro.

RESULTS

Relative to the controls, all three concentrations of HES compared to only 15% and 30% MFG lowered migration distances, and the 15% and 30% concentrations of both sedimentation agents reduced track straightness. HES resulted in lower CD11b expression and higher CD62L expression compared to MFG and the controls, whereas the differences for CD66b did not reach statistical significance. No significant differences in the timing of ROS production or NETosis, or in neutrophil viability or respiratory burst were observed.

CONCLUSION

These results indicate that MFG is not inferior to HES in terms of granulocyte function in vitro when used at equal concentrations, and that potential impairment of granulocyte function can occur with HES.

Hydroxyethyl Starch 130/0.4 Binds to Neutrophils Impairing Their Chemotaxis through a Mac-1 Dependent Interaction

Several studies showed that hydroxyethyl starch (HES), a synthetic colloid used in volume replacement therapies, interferes with leukocyte-endothelium interactions. Although still unclear, the mechanism seems to involve the inhibition of neutrophils' integrin. With the aim to provide direct evidence of the binding of HES to neutrophils and to investigate the influence of HES on neutrophil chemotaxis, we isolated and treated the cells with different concentrations of fluorescein-conjugated HES (HES-FITC), with or without different stimuli (N-Formylmethionine-leucyl-phenylalanine, fMLP, or IL-8). HES internalization was evaluated by trypan blue quenching and ammonium chloride treatment. Chemotaxis was evaluated by under-agarose assay after pretreatment of the cells with HES or a balanced saline solution. The integrin interacting with HES was identified by using specific blocking antibodies. Our results showed that HES-FITC binds to the plasma membrane of neutrophils without being internalized. Additionally, the cell-associated fluorescence increased after stimulation of neutrophils with fMLP (p < 0.01) but not IL-8. HES treatment impaired the chemotaxis only towards fMLP, event mainly ascribed to the inhibition of CD-11b (Mac-1 integrin) activity. Therefore, the observed effect mediated by HES should be taken into account during volume replacement therapies. Thus, HES treatment could be advantageous in clinical conditions where a low activation/recruitment of neutrophils may be beneficial, but may be harmful when unimpaired immune functions are mandatory.

Resuscitation with centhaquin and 6% hydroxyethyl starch 130/0.4 improves survival in a swine model of hemorrhagic shock: a randomized experimental study

PURPOSE

To investigate the effects of the combination of centhaquin and 6% hydroxyethyl starch 130/0.4 (HES 130/0.4) in a swine model of hemorrhagic shock.

METHODS

Twenty Landrace-Large White pigs were instrumented and subjected to hemorrhagic shock. The animals were randomly allocated in two experimental groups, the control (group CO, n = 10) and the centhaquin groups (0.015 mg/kg, n = 10, group CH). Acute hemorrhage was induced by stepwise blood withdrawal (18 mL/min) from the internal jugular vein until MAP decreased to 40-45 mmHg, whereas anesthesia remained constant. All animals received HES 130/0.4 solution in the resuscitation phase until their mean arterial pressure (MAP) reached 90% of the baseline. The animals were observed for 60 min, during which no further resuscitation was attempted.

RESULTS

The total amount of blood and the bleeding time did not differ significantly between group CO and group CH (120 ± 13 vs. 120 ± 14 mL, p = 0.6; 20 ± 2 vs. 20 ± 1 min, p = 0.62, respectively). During the hemorrhagic phase, only a difference in heart rate (97.6 ± 4.4 vs. 128.4 ± 3.6 beats/min, p = 0.038) was observed between the two groups. The time required to reach the target MAP was significantly shorter in the centhaquin group compared to controls (13.7 ± 0.4 vs. 19.6 ± 0.84 min, p = 0.012). During the resuscitation phase, a statistical significant difference was observed in MAP (75.2 ± 1.6 vs. 89.8 ± 2.1 mmHg, p = 0.02) between group CO and group CH. During the observation phase, a statistical significant difference was observed in SVR (1109 ± 32.65 vs. 774.6 ± 21.82 dyn s/cm⁵, p = 0.039) and cardiac output (5.82 ± 0.31 vs. 6.9 ± 0.78 L/min, p = 0.027) between the two groups. Two animals of group CO and seven animals of group CH survived for 24 h (p = 0.008). We observed a marked increase in microvascular capillary permeability in group CO compared to group CH, with the wet/dry weight ratio being significantly higher in group CO compared to group CH (4.8 ± 1.6 vs. 3.08 ± 0.6, p < 0.001).

CONCLUSIONS

The combination of centhaquin 0.015 mg/kg and HES 130/0.4 resulted in shorter time to target MAP, lower wet-to-dry ratio, and better survival rates after resuscitation from hemorrhagic shock.

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.

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.

Hydroxyethyl starch: a review of pharmacokinetics, pharmacodynamics, current products, and potential clinical risks, benefits, and use

OBJECTIVE

To review and summarize the pharmacokinetics and pharmacodynamics of hydroxyethyl starch (HES), as well as reported risks and benefits of HES infusion, and to provide administration and monitoring recommendations for HES use in dogs and cats.

DATA SOURCES

Veterinary and human peer-reviewed medical literature, including scientific reviews, clinical and laboratory research articles, and authors' clinical experience.

SUMMARY

HES solutions are the most frequently used synthetic colloid plasma volume expanders in human and veterinary medicine. The majority of research in human medicine has focused on the adverse effects of HES infusion, with emphasis on acute kidney injury and coagulation derangements. The studies often differ in or fail to report factors, such as the type, amount, interval, and concentration of HES administered; the patient population studied; or concurrent fluids administered. Currently, there is no definitive clinical evidence that the reported adverse effects of HES use in human medicine occur in veterinary species. There is little information available on HES administration techniques or simultaneous administration of additional fluids in human and veterinary medicine. The rationale for HES use in small animals has been largely extrapolated from human medical studies and guidelines. A controlled approach to intravenous fluid resuscitation using crystalloid and HES volumes titrated to reach desired resuscitation end point parameters is outlined for small animal practitioners.

CONCLUSION

The extrapolation of data from human studies directly to small animals should be done with the knowledge that there may be species variations and different pharmacokinetics with different HES solutions. Veterinary reports indicate that bolus and continuous rate infusions of 6% hetastarch solutions at moderate doses are well tolerated in feline and canine subjects. Further research in domesticated species is necessary to better define and expand the knowledge regarding use of HES solutions in small animal medicine.

Guiding principles of fluid and volume therapy

Fluid therapy is a core concept in the management of perioperative and critically ill patients for maintenance of intravascular volume and organ perfusion. Recent evidence regarding the vascular barrier and its role in terms of vascular leakage has led to a new concept for fluid administration. The choice of fluid used should be based on the fluid composition and the underlying pathophysiology of the patient. Avoidance of both hypo- and hypervolaemia is essential when treating circulatory failure. In daily practice, the assessment of individual thresholds in order to optimize cardiac preload and avoid hypovolaemia or deleterious fluid overload remains a challenge. Liberal versus restrictive fluid management has been challenged by recent evidence, and the ideal approach appears to be goal-directed fluid therapy.

Hypometabolism and hypothermia in the rat model of endotoxic shock: independence of circulatory hypoxia

We tested the hypothesis that development of hypothermia instead of fever in endotoxic shock is consequential to hypoxia. Endotoxic shock was induced by bacterial lipopolysaccharide (LPS, 500 μg kg(-1) i.v.) in rats at an ambient temperature of 22 °C. A β3-adrenergic agonist known to activate metabolic heat production, CL316,243, was employed to evaluate whether thermogenic capacity could be impaired by the fall in oxygen delivery (ḊO2) during endotoxic shock. This possibility was rejected as CL316,243 (0.15 mg kg(-1) i.v.) evoked similar rises in oxygen consumption (V̇O2) in the presence and absence of endotoxic shock. Next, to investigate whether a less severe form of circulatory hypoxia could be triggering hypothermia, the circulating volume of LPS-injected rats was expanded using 6% hetastarch with the intention of improving tissue perfusion and alleviating hypoxia. This intervention attenuated not only the fall in arterial pressure induced by LPS, but also the associated falls in V̇O2 and body temperature. These effects, however, occurred independently of hypoxia, as they were not accompanied by any detectable changes in NAD(+)/NADH ratios. Further experimentation revealed that even the earliest drops in cardiac output and ḊO2 during endotoxic shock did not precede the reduction in V̇O2 that brings about hypothermia. In fact, ḊO2 and V̇O2 fell in such a synchrony that the ḊO2/V̇O2 ratio remained unaffected. Only when hypothermia was prevented by exposure to a warm environment (30 °C) did an imbalance in the ḊO2/V̇O2 ratio become evident, and such an imbalance was associated with reductions in the renal and hypothalamic NAD(+)/NADH ratios. In conclusion, hypometabolism and hypothermia in endotoxic shock are not consequential to hypoxia but serve as a pre-emptive strategy to avoid hypoxia in this model.

Pros and cons of tetrastarch solution for critically ill patients

Proper fluid management is crucial for the management of critically ill patients. However, there is a continuing debate about the choice of the fluid, i.e., crystalloid vs. colloid. Colloid solution is theoretically advantageous to the crystalloid because of larger volume effect and less interstitial fluid accumulation, and hydroxyethyl starch (HES) is most frequently used for perioperative setting. Nevertheless, application of HES solution is relatively limited due to its side effects including renal toxicity and coagulopathy. Since prolonged presence of large HES molecule is responsible for these side effects, rapidly degradable HES solution with low degree of substitution (tetrastarch) supposedly has less potential for negative effects. Thus, tetrastarch may be more frequently used in the ICU setting. However, several large-scale randomized trials reported that administration of tetrastarch solution to the patients with severe sepsis has negative effects on mortality and renal function. These results triggered further debate and regulatory responses around the world. This narrative review intended to describe the currently available evidence about the advantages and disadvantages of tetrastarch in the ICU setting.

Colloids in sepsis: evenly distributed molecules surrounded by uneven questions

Colloids are frequently used for fluid expansion in the intensive care unit, although its use on several clinical scenarios remains unproven of any relevant clinical benefit. The purpose of this article was to carry out a narrative review regarding the safety and efficacy of colloids in patients with sepsis and septic shock, with emphasis on the most commonly used colloids, albumin and starches. Colloids are effective fluid expanders and are able to restore the hemodynamic profile with less total volume than crystalloids. These properties appear to be preserved even in patients with sepsis with increased capillary permeability. However, some colloids are associated with renal impairment and coagulation abnormalities. Starch use was associated with increased mortality in two large clinical trials. Also, starches probably have significant renal adverse effects and may be related to more need for renal replacement therapy in severe sepsis. Albumin is the only colloid that has been shown safe in patients with sepsis and that may be associated with improved outcomes on specific subpopulations. No trial so far found any robust clinical end point favoring colloid use in patients with sepsis. Because there is no proven benefit of the use of most colloids in patients with sepsis, its use should not be encouraged outside clinical trials. Albumin is the only colloid solution that has proven to be safe, and its use may be considered on hypoalbuminemic patients with sepsis. Nevertheless, there are no robust data to recommend routine albumin administration in sepsis. Starch use should be avoided in patients with sepsis because of the recent findings of a multicenter randomized study until further evidence is available.

Effects of synthetic colloids on oxidative stress and inflammatory response in hemorrhagic shock: comparison of hydroxyethyl starch 130/0.4, hydroxyethyl starch 200/0.5, and succinylated gelatin

INTRODUCTION

This study compared the effects of hydroxyethyl starch 130/0.4, hydroxyethyl starch 200/0.5, and succinylated gelatin on oxidative stress and the inflammatory response in a rodent hemorrhagic shock model.

METHODS

Sodium pentobarbital-anesthetized adult male Wistar rats (200 g to 220 g) were subjected to a severe volume-controlled hemorrhage using arterial blood withdrawal (30 mL/kg to 33 mL/kg) and resuscitated with a colloid solution at the same volume as blood withdrawal (hydroxyethyl starch 130/0.4, hydroxyethyl starch 200/0.5, or succinylated gelatin). Arterial blood gas parameters were monitored. Malondialdehyde (MDA) content and myeloperoxidase (MPO) activity in the liver, lungs, intestine, and brain were measured two hours after resuscitation. The levels of tumor necrosis factor-alpha (TNF-α) and interleukin-6 in the intestine were also measured.

RESULTS

Infusions of hydroxyethyl starch 130/0.4, but not hydroxyethyl starch 200/0.5 or succinylated gelatin, significantly reduced MDA levels and MPO activity in the liver, intestine, lungs and brain, and it also inhibited the production of TNF-α in the intestine two hours after resuscitation. However, no significant difference between hydroxyethyl starch 200/0.5 and succinylated gelatin was observed.

CONCLUSIONS

Hydroxyethyl starch 130/0.4, but not hydroxyethyl starch 200/0.5 or succinylated gelatin, treatment after hemorrhagic shock ameliorated oxidative stress and the inflammatory response in this rat model. No significant differences were observed after hydroxyethyl starch 200/0.5 or succinylated gelatin administration at doses of approximately 33 mL/kg.

Comparison of the effects of gelatin, Ringer's solution and a modern hydroxyl ethyl starch solution after coronary artery bypass graft surgery

OBJECTIVE

The aim of this study was to compare the effect of 6% hydroxyl ethyl starch solution with 4% gelatin and Ringer's solutions on the haemodynamic stability of patients after coronary artery bypass graft (CABG) surgery and immediately after discontinuation of cardiopulmonary bypass (CPB).

METHODS

This was a randomised, double-blind clinical trial of 92 patients who were candidates for on-pump CABG. After discontinuation of CPB, all patients were transferred to the intensive care unit (ICU) and divided randomly into three groups. The first group received Ringer's solution, the second group 4% gelatin, and the third 6% hydroxyl ethyl starch (HES) solution (Voluven). Haemodynamic parameters such as heart rate, mean arterial pressure, systolic blood pressure, diastolic blood pressure, central venous pressure, cardiac output and the presence of arrhythmias were documented.

RESULTS

The volume needed for maintaining normal blood pressure and central venous pressure in the range of 10-14 mmHg was less in the HES group than in the other groups. The volume was similar however in the gelatin and Ringer's groups in the first 24 hours after surgery. Urinary output in the first four and 24 hours after surgery were significantly higher in the HES group than in the other two groups. Mean creatinine levels were significantly lower in the HES group.

CONCLUSION

HES (6%) had a better volume-expanding effect than gelatin (4%) and Ringer's solutions, and its short-term effects on renal function were also better than gelatin and Ringer's solutions.

Clinical utility of intra-operative 6% hydroxyethyl starch (130 / 0.4) supplementation in hypoxemic femur injury patients: a preliminary report of twenty cases

Abstract

Posttraumatic intravasation of fat and debris can lead to a cascade of events. Hydroxyethyl starches (HES) markedly suppress neutrophil influx by decreasing pulmonary capillary permeability and facilitating tissue oxygenation by improving microcirculation. It was hypothesized that in hypoxemic femur injury patients undergoing operative stabilization, HES administration will prevent the deterioration of respiratory variables and facilitates recovery. This prospective, double-blind, randomized preliminary study, enrolled twenty posttraumatic hypoxemic patients (room air PaO2 < 70 mmHg, Schonfeld fat embolism index score (SS) > 5) scheduled for femur fracture stabilization under general anesthesia. Patients were allocated to receive either; 6% HES 130/0.42, 15 mL/kg or 0.9% normal saline (NS) to maintain their central venous pressure (CVP) 12 + 2 mm Hg. Blood was transfused according to the maximum allowable blood loss and by serial hematocrit estimations. Perioperative Glasgow Coma Scale (GCS), physiological variables, arterial oxygen saturation (SpO2), arterial blood gas (ABG), SS and P/F ratios were recorded until recovery. The partial pressure of oxygen in arterial blood / fraction of inspired oxygen ratio (PaO2/FiO2) improved from a preoperative value of 273.33 ± 13.05 to 435.70 in the 6% Hydroxyethyl starch group (HES) and from 275.24 ± 15.34 to 302.25 ± 70.35 in the NS group over a period of six days (P values =0.970, 0.791, 0.345, 0.226, 0.855, 0.083, 0.221). Time taken to achieve a P/F ratio > 300 and for persistent reduction of Murray’s lung injury score (LIS) were comparable (P = 0.755 and 0.348, respectively). The number of ventilator, intensive care unit (ICU) and hospital stay days, did not differ (P value = 0.234, 1.00, 0. 301, respectively). There were no adverse sequelae or mortalities. A trend showing relatively fast improvement in the P/F ratio and an early reduction in LIS values was observed in hypoxemic, femur injury patients receiving intraoperative colloid supplementation.

In a porcine model of mixed acidemia HES 130/0.4 may support more stable hemodynamics during CVVH when compared to gelatine

PURPOSE

Continuous veno-venous hemofiltration (CVVH) and mixed acidemia often occur simultaneously in critically ill patients. In a previous study in non-acidemic pigs we found that colloids and CVVH interact specifically with respect to hemodynamic stability, with favorable effects for 6% HES 130/0.4 versus 4% gelatine (GEL) infusion. In a porcine model, we investigated whether these colloid-type associated differences are still dominant under acidemic conditions.

METHODS

We utilized 5 groups, a non-acidemic reference group receiving HES130 and CVVH; two acidemic groups receiving HES130 infusion (one with and one without CVVH); and two acidemic groups receiving GEL infusion (one with and one without CVVH). Mixed acidemia (pH ~7.20) was established by low tidal volume ventilation and acid infusion. Stable acidemia/CVVH application was maintained for 3 hours. Hemodynamics and blood gases were recorded.

RESULTS

Mixed acidemia led to a significant decrease in MAP and increase in MPAP in all groups. CVVH led to a further decrease in MAP but improved MPAP. During CVVH, HES130 ensured significantly higher MAP, Hb, and DO2 values than GEL infusion. In the groups without CVVH these differences between HES 130/0.4 and GEL were not observed.

CONCLUSIONS

As in a previous study in non-acidemic pigs, we found a colloid-specific influence of HES130 versus GEL on hemodynamics during CVVH under acidemia. Again, HES130 infusion may lead to favorable effects. In contrast, acidemia without CVVH application was dominant over the impact of a respective colloid. The application of a CVVH seems to be an important trigger for the overall circulatory response to a particular colloid.

Hydroxyethyl starch resuscitation reduces the risk of intra-abdominal hypertension in severe acute pancreatitis

OBJECTIVES

This study aimed to address whether hydroxyethyl starch (HES) is beneficial for intra-abdominal pressure (IAP) in severe acute pancreatitis (SAP) in early stages.

METHODS

Forty-one patients with SAP were randomized to HES group (n = 20) and the Ringer's lactate (RL) group (n = 21). The groups received 6% HES 130/0.4 for 8 days and RL solution without colloid, respectively. The primary end point was the IAP. The secondary end points were fluid balance, major organ complications, the Acute Physiology and Chronic Heath Evaluation II score, and the serum levels of C-reactive protein, interleukin-6, and interleukin-8.

RESULTS

The characteristics of baseline data were similar in the 2 groups. In the HES group, the IAP was significantly lower in 2 to 7 days, and fewer patients received mechanical ventilation (15.0% vs 47.6%). A negative fluid balance was observed earlier in the HES group than in the RL group (2.5 ± 2.2 vs 4.0 ± 2.5 days).

CONCLUSIONS

Fluid resuscitation with HES in the early stages of SAP can decrease the risk of intra-abdominal hypertension and reduce the use of mechanical ventilation.

Does 6% hydroxyethyl starch 130/0.4 impact differently on blood glucose than 4% gelatin in patients receiving open heart surgery?

Objectives: To investigate whether starch-based colloid may impact differently on blood glucose than a gelatin-based colloid in adult patients receiving open heart surgery.

Methods: 70 adult patients scheduled for elective first-time cardiac surgery were enrolled and randomized into two groups. The circuits were primed with either 6% HES 130/0.4 or 4% gelatin. The peak glucose level, incidence of hyperglycemia, glucose variation and glucose level at different time points during operation were compared between the two groups. A p-value ≤ 0.05 was accepted as significant.

Results: The peak glucose (150±30mg/dl vs 142±27, p=0.236) and glucose variation demonstrated by standard deviation (26±12mg/dl vs 23±11mg/dl, p=0.202) were comparable between the two groups. Repeated measurement ANOVA revealed that the main effect for artificial colloid was not significant (p=0.349).

Conclusions: With the data available, we could not prove that starch-based colloid (HES130) had a different impact on intra-operative blood glucose than a gelatin-based colloid in adult patients receiving open heart surgery.

[Volume replacement in intensive care medicine]

Volume substitution represents an essential component of intensive care medicine. The amount of fluid administered, the composition and the timing of volume replacement seem to affect the morbidity and mortality of critically ill patients. Although restrictive volume strategies bear the risk of tissue hypoperfusion and tissue hypoxia in hemodynamically unstable patients liberal strategies favour the development of avoidable hypervolemia with edema and resultant organ dysfunction. However, neither strategy has shown a consistent benefit. In order to account for the heavily varying oxygen demand of critically ill patients, a goal-directed, demand-adapted volume strategy is proposed. Using this strategy, volume replacement should be aligned to the need to restore tissue perfusion and the evidence of volume responsiveness. As the efficiency of volume resuscitation for correction of tissue hypoxia is time-dependent, preload optimization should be completed in the very first hours. Whether colloids or crystalloids are more suitable for this purpose is still controversially discussed. Nevertheless, a temporally limited use of colloids during the initial stage of tissue hypoperfusion appears to represent a strategy which uses the greater volume effect during hypovolemia while minimizing the risks for adverse reactions.

Perioperative fluid and volume management: physiological basis, tools and strategies

Fluid and volume therapy is an important cornerstone of treating critically ill patients in the intensive care unit and in the operating room. New findings concerning the vascular barrier, its physiological functions, and its role regarding vascular leakage have lead to a new view of fluid and volume administration. Avoiding hypervolemia, as well as hypovolemia, plays a pivotal role when treating patients both perioperatively and in the intensive care unit. The various studies comparing restrictive vs. liberal fluid and volume management are not directly comparable, do not differ (in most instances) between colloid and crystalloid administration, and mostly do not refer to the vascular barrier's physiologic basis. In addition, very few studies have analyzed the use of advanced hemodynamic monitoring for volume management.

This article summarizes the current literature on the relevant physiology of the endothelial surface layer, discusses fluid shifting, reviews available research on fluid management strategies and the commonly used fluids, and identifies suitable variables for hemodynamic monitoring and their goal-directed use.

Hydroxyethyl starch 130/0.4 inhibits production of plasma proinflammatory cytokines and attenuates nuclear factor-kappaB activation and Toll-like receptors expression in monocytes during sepsis

BACKGROUND

Hydroxyethyl starch (HES) is one of the most frequently used plasma substitutes, and could modulate inflammatory response in sepsis. Our aim of this study was to investigate the mechanism of the effect of HES 130/0.4 by studying plasma levels of inflammatory cytokines, nuclear factor-kappaB (NF-kappaB) activation, and Toll-like receptors (TLRs) expression in peripheral monocytes during polymicrobial sepsis.

MATERIALS AND METHODS

Rats with sepsis induced by cecal ligation and puncture (CLP) were treated with HES130/0.4 (7.5, 15, or 30 mL/kg, intravenously); then, rat plasma and monocytes were isolated from blood 5 h later. The plasma level of cytokines (tumor necrosis factor [TNF]-alpha and interleukin [IL]-6), NF-kappaB activity, and mRNA and protein levels of TLRs (TLR2 and TLR4) in peripheral blood monocytes were determined by enzyme-linked immunosorbent assay, electrophoretic mobility shift assay, reverse transcription-polymerase chain reaction, and Western blotting, respectively.

RESULTS

HES130/0.4 dose-dependently reduced the plasma level of TNF-alpha and IL-6 in rats with sepsis. HES130/0.4 also significantly inhibited NF-kappaB activation, and TLRs mRNA and protein levels in peripheral monocytes.

CONCLUSION

During sepsis, HES130/0.4 can down-regulate the inflammatory response, possibly through inhibition of the TLRs/NF-kappaB signaling pathway, and could be one more appropriate plasma substitute in sepsis.

Effects of hydroxyethyl starch resuscitation on extravascular lung water and pulmonary permeability in sepsis-related acute respiratory distress syndrome

OBJECTIVE

Hydroxyethyl starch (HES) has greater volume expansion effect and longer intravascular persistence than crystalloids. HES also decreases microvascular permeability and capillary leakage by biophysically plugging endothelial leaks, exerting an anti-inflammatory effect, and decreasing activation of endothelial cells. The aim of our study was to determine whether medium molecular weight HES (pentastarch) resuscitation in the early stage of acute respiratory distress syndrome (ARDS) simultaneously increases cardiac output without worsening pulmonary edema and whether it attenuates pulmonary vascular permeability.

DESIGN

Prospective observational study.

SETTING

Twenty-bed medical intensive care unit of a tertiary medical center.

PATIENTS

Twenty patients with early-stage ARDS.

INTERVENTION

Volume expansion with a 500-mL infusion of 10% pentastarch (HES 200/0.5) at a rate of 10 mL/kg/hr.

MEASUREMENTS AND MAIN RESULTS

Baseline hemodynamics including systemic and pulmonary artery blood pressures, central venous pressure, pulmonary artery occlusion pressure, and cardiac output were obtained from an online HP Component Monitoring System and a pulmonary artery catheter. Intrathoracic blood volume (ITBV), global end-diastolic volume, extravascular lung water (EVLW), and pulmonary vascular permeability (EVLW/ITBV) were measured with a PiCCOplus monitor. Hemodynamic measurements were repeated immediately and 2, 4, and 6 hours after volume expansion. Pentastarch loading significantly increased central venous pressure, pulmonary artery occlusion pressure, pulmonary arterial pressures, and cardiac output. Pulmonary mechanics, venous admixtures, and EVLW values remained unchanged throughout the study. EVLW/ITBV significantly decreased immediately after the pentastarch infusion.

CONCLUSIONS

In patients with early ARDS, pentastarch resuscitation significantly improved their hemodynamics and cardiac output without worsening pulmonary edema and pulmonary mechanics. It even attenuated pulmonary vascular permeability.

Effects of recombinant human erythropoietin on neuropathic pain and cerebral expressions of cytokines and nuclear factor-kappa B

PURPOSE

The effect of recombinant human erythropoietin (rhEPO) on neuropathic pain remains unclear. This study aimed to determine the effects of preemptive administration of rhEPO on the behavioural changes and neuroinflammatory responses in a rat model of neuropathic pain.

METHODS

Fifty rats were randomly allocated into five groups, sham-operation treated with saline and L5 spinal nerve transection treated with different doses of rhEPO (0 [saline], 1000, 3000, or 5000 U x kg(-1), respectively). The rats were intraperitoneally treated from 1 day before surgery to post-surgery day 7. The mechanical (paw pressure thresholds, PPT) and thermal thresholds (paw withdrawal latencies, PWL) were measured on post-surgery days 1, 3, and 7. The contralateral brain was obtained on post-surgery day 7 to determine the expressions of tumour necrosis factor (TNF-alpha), interleukin (IL)-1beta, IL-6, L-10, and nuclear factor-kappa B (NF-kappaB) activity.

RESULTS

There were significant decreases in PPT and PWL after L5 spinal nerve transection (P < 0.001). Compared with the saline group, the rhEPO 3000 and 5000 U x kg(-1) groups resulted in significant increases in PPT and PWL (P < 0.001) and reduced the cerebral expressions of TNF-alpha, IL-1beta, IL-6, and NF-kappaB activity associated with the increase in IL-10 (rhEPO3000 group, P < 0.05, and rhEPO5000 group, P < 0.001, respectively). Administration of rhEPO 1000 U x kg(-1) had no significant effects on these variables.

CONCLUSIONS

Preemptive rhEPO dose-dependently attenuated the mechanical and thermal hyperalgesia in L5 spinal nerve transection rats, which correlated with the decreased cerebral expressions of TNF-alpha, IL-1beta, and IL-6 via downregulating NF-kappaB activity and the increased expression of IL-10.

Effects of propofol on pro-inflammatory cytokines and nuclear factor kappaB during polymicrobial sepsis in rats

Nuclear factor kappa B (NF-kappaB) plays a central role in regulating the transcription of several genes associated with sepsis/septic shock. Therefore, the author investigated the effects of propofol on the plasma tumor necrosis factor alpha and interleukin 6 (TNF-alpha and IL-6) levels and NF-kappaB activation during polymicrobial sepsis in rats. Male Sprague-Dawlay rats were subjected to cecal ligation and puncture (CLP, a model of polymicrobial sepsis) or sham operation. The animals were randomly assigned into four equal groups (n = 10): sham CLP group, CLP group, PPF (propofol) I group and PPF II group. Thirty minutes before CLP, propofol (5 and 10 mg kg(-1) h(-1), respectively) was infused continuously through the left femoral vein cannula in PPF I group or PPF II group, CLP group and sham CLP group receiving 0.9% saline only at the rates of 5 ml kg(-1) h(-1). The right femoral artery was cannulated to monitor mean arterial pressure (MAP) and heart rates (HR). CLP produced progressive hypotension and a first increase followed by a decrease in HR. The plasma TNF-alpha and IL-6 levels and the hepatic NF-kappaB activation significantly increased after CLP alone. Compared with CLP group, propofol treatment reversed hypotension, slightly steadied heartbeats, and decreased the plasma TNF-alpha and IL-6 levels, and significantly suppressed NF-kappaB activation. Propofol has inhibited the hepatic NF-kappaB activation and the pro-inflammatory cytokine response during polymicrobial sepsis in rats.

Is albumin administration in hypoalbuminemic elderly cardiac surgery patients of benefit with regard to inflammation, endothelial activation, and long-term kidney function?

BACKGROUND

Because patients with low albumin levels may benefit from human albumin (HA) administration, we studied correction of hypovolemia with HA in hypoalbuminic elderly cardiac surgery patients.

METHODS

In a prospective, randomized study, 50 patients aged >80 yr undergoing cardiac surgery using cardiopulmonary bypass with a preoperative serum albumin concentration of <3.5 mg/dL, received either 5% HA (n = 25) or hydroxyethyl starch (6% HES 130/0.4) (n = 25). Volume was added to the priming (500 mL) and given until the morning of the second postoperative day to keep pulmonary capillary wedge pressure or central venous pressure between 12 and 14 mm Hg.

RESULTS

Inflammatory response (interleukins-6, -10), endothelial activation (intercellular adhesion molecule-1), and kidney function (including glutathione transferase-alpha and neutrophil gelatinase-associated lipocalin) were measured after induction of anesthesia, 5 h after surgery, and the first and second postoperative day. A follow-up, approximately 60 days after discharge from the hospital, was done. Two thousand nine hundred eighty +/- 430 mL of HA and 3060 +/- 680 mL of HES 130/0.4 were given. Serum albumin concentration was significantly increased by HA (to 4.5 +/- 0.3 mg/dL). Serum creatinine, glomerular filtration rate, and urinary levels of alpha-glutathione transferase and neutrophil gelatinase-associated lipocalin were not different in the HA-compared to the HES-treated patients. The inflammatory response was similar in both groups, whereas endothelial activation was less in the HES group. None of the patients developed renal failure requiring renal replacement therapy.

CONCLUSION

Use of HA in hypoalbuminemic cardiac surgery patients aged >80 yr was without benefit with regard to inflammatory response, endothelial activation, and renal function compared to 6% HES 130/0.4.

Influence of dextran-70 on systemic inflammatory response and myocardial ischaemia-reperfusion following cardiac operations

Introduction

Experimental studies have demonstrated that dextran-70 reduces the leukocyte–endothelium interaction, but clinical evidence is still lacking. Our objective was to justify the anti-inflammatory effect of dextran-70 following cardiac operations.

Methods

Forty patients undergoing coronary bypass surgery (n = 32) or aortic valve replacement (n = 8) were enrolled in this prospective, randomized, double-blind study. Two groups were formed. In group A (n = 20), dextran-70 infusion was administered at a dose of 7.5 ml/kg before the initiation of cardiopulmonary bypass and at a dose of 12.5 ml/kg after the cessation of cardiopulmonary bypass. Group B served as a control with identical amounts of gelatin infusion (n = 20). The plasma concentration of procalcitonin, C-reactive protein, IL 6, IL 6r, IL 8, IL 10, soluble endothelial leukocyte adhesion molecule-1, soluble intercellular adhesion molecule-1, cardiac troponin-I and various haemodynamic parameters were measured in the perioperative period. Multivariate methods were used for statistical analysis.

Results

In group A, lower peak (median) plasma levels of procalcitonin (0.2 versus 1.4, p < 0.001), IL 8 (5.6 versus 94.8, p < 0.001), IL 10 (47.2 versus 209.7, p = 0.001), endothelial leukocyte adhesion molecule-1 (88.5 versus 130.6, p = 0.033), intercellular adhesion molecule-1 (806.7 versus 1,375.7, P = 0.001) and troponin-I (0.22 versus 0.66, p = 0.018) were found. There was no significant difference in IL 6, IL-6r and C-reactive protein values between groups. Higher figures of the cardiac index (p = 0.010) along with reduced systemic vascular resistance (p = 0.005) were noted in group A.

Conclusion

Our investigation demonstrated that the use of dextran-70 reduces the systemic inflammatory response and cardiac troponin-I release following cardiac operation.

Trial registration number

ISRCTN38289094.

Comparison of the effects of gelatin and a modern hydroxyethyl starch solution on renal function and inflammatory response in elderly cardiac surgery patients

BACKGROUND

The effects of hydroxyethylstarch (HES) 130/0.4 6% and gelatin 4% on inflammation, endothelial integrity, and renal function after cardiac surgery were compared.

METHODS

Sixty patients aged >80 yr undergoing cardiac surgery were randomized to receive gelatin (n=30) or HES 130/0.4 (n=30). The colloid was used in the priming of the cardiopulmonary bypass circuit (500 ml) and for volume replacement until the second postoperative day (POD). Serum creatinine, creatinine clearance, IL-6, IL-10, intercellular adhesion molecule-1 (sICAM-1), urinary glutathione transferase-alpha, and neutrophil gelatinase-associated lipocalin (NGAL) were measured perioperatively. Serum creatinine was also reported approximately 60 days after discharge.

RESULTS

The mean(sd) volume of gelatin infused was 4180(440) ml, which was greater than the volume of HES infused 2910(330) ml (P=0.002). The mean(sd) volume of serum creatinine on the first POD was 151(24) micromol litre(-1) in the gelatin group and 126(13) micromol litre(-1) in the HES group (P=0.004). Values for the second POD were 161(0.26) and 133(16) micromol litre(-1), respectively (P=0.004). Creatinine clearance was lower in the gelatin group on the first POD [37(7) vs 46(8) ml min(-1) 1.73 m2 (P=0.004)] and the second POD [32(8) vs 45(10) ml min(-1) 1.73 m2 (P=0.002)]. Kidney function approximately 60 days after discharge did not differ between the groups. IL-6, IL-10, and sICAM-1 were significantly lower in the HES group than in the gelatin group on the first and second PODs. Urinary alpha-GST increased in both groups to a comparable extent. Urinary NGAL concentrations were higher in the gelatin than in the HES patients 5 h after surgery and on the first and second PODs.

CONCLUSIONS

In cardiac surgery patients aged >80 years, volume therapy with HES 130/0.4 6% was associated with less marked changes in kidney function and a less marked endothelial inflammatory response than gelatin 4%.