Organotypic heterogeneity in microvascular endothelial cell responses in sepsis-a molecular treasure trove and pharmacological Gordian knot

In the last decades, it has become evident that endothelial cells (ECs) in the microvasculature play an important role in the pathophysiology of sepsis-associated multiple organ dysfunction syndrome (MODS). Studies on how ECs orchestrate leukocyte recruitment, control microvascular integrity and permeability, and regulate the haemostatic balance have provided a wealth of knowledge and potential molecular targets that could be considered for pharmacological intervention in sepsis. Yet, this information has not been translated into effective treatments. As MODS affects specific vascular beds, (organotypic) endothelial heterogeneity may be an important contributing factor to this lack of success. On the other hand, given the involvement of ECs in sepsis, this heterogeneity could also be leveraged for therapeutic gain to target specific sites of the vasculature given its full accessibility to drugs. In this review, we describe current knowledge that defines heterogeneity of organ-specific microvascular ECs at the molecular level and elaborate on studies that have reported EC responses across organ systems in sepsis patients and animal models of sepsis. We discuss hypothesis-driven, single-molecule studies that have formed the basis of our understanding of endothelial cell engagement in sepsis pathophysiology, and include recent studies employing high-throughput technologies. The latter deliver comprehensive data sets to describe molecular signatures for organotypic ECs that could lead to new hypotheses and form the foundation for rational pharmacological intervention and biomarker panel development. Particularly results from single cell RNA sequencing and spatial transcriptomics studies are eagerly awaited as they are expected to unveil the full spatiotemporal signature of EC responses to sepsis. With increasing awareness of the existence of distinct sepsis subphenotypes, and the need to develop new drug regimen and companion diagnostics, a better understanding of the molecular pathways exploited by ECs in sepsis pathophysiology will be a cornerstone to halt the detrimental processes that lead to MODS.

Effects of Different Types of Early Restrictive Fluid Resuscitation on Immune Function and Multiorgan Damage on Hemorrhagic Shock Rat Model in a Hypothermic Environment

Objective

This study was aimed at investigating the effects of different types of fluid restriction fluid resuscitation on the immune dysfunction and organ injury of hemorrhagic shock rats under a hypothermic environment.

Methods

SD rats were divided into sham operation group (SHAM), hemorrhagic shock model group (HS), crystal liquid limited resuscitation group (CRLLR), colloidal liquid limited resuscitation group (COLLR), and nonlimited resuscitation group (NLR); rats in each group were placed in a low-temperature environment of 0-5°C for 30 min, and then, a hemorrhagic shock rat model was prepared. Sodium lactate Ringer's restricted resuscitation solution, hydroxyethyl starch restricted resuscitation solution, and hydroxyethyl starch were used for resuscitation, and hemodynamic examination was performed. The mortality rate, inflammatory factors, oxidative stress factors, and immune function were detected by ELISA. The dysfunction and injury of the intestinal, lung, liver, and kidney were examined by histological methods.

Results

Hemorrhagic shock resulted in decreased immune function and activation of inflammation. Unrestricted fluid infusion further activated the inflammatory response. The crystalloid-restricted fluid infusion performed effectively to regulate inflammatory response, promote antioxidative activity, and reduce the immunosuppressive reaction. Rehydration could regulate the coagulation. The hydroxyethyl starch reduced the expression of platelet glycoproteins Ib and IIb/IIIa and blocked the binding of fibrinogen to activated platelets, thereby inhibiting intrinsic coagulation and platelet adhesion and aggregation. Rats in the CRLLR group showed to relieve the injury of the lung, liver, kidney, and intestine from hemorrhagic shock in low-temperature environment.

Conclusion

The early application of restrictive crystalloid resuscitation in hemorrhagic shock rats in hypothermic environment showed the best therapy results. Early LR-restrictive fluid replacement promotes the balance of inflammatory response and the recovery of immunosuppressive state, resists oxidative stress, stabilizes the balance of coagulation and fibrinolysis, improves coagulation function, and relieves organ injury.

Renal microvascular endothelial cell responses in sepsis-induced acute kidney injury

Microvascular endothelial cells in the kidney have been a neglected cell type in sepsis-induced acute kidney injury (sepsis-AKI) research; yet, they offer tremendous potential as pharmacological targets. As endothelial cells in distinct cortical microvascular segments are highly heterogeneous, this Review focuses on endothelial cells in their anatomical niche. In animal models of sepsis-AKI, reduced glomerular blood flow has been attributed to inhibition of endothelial nitric oxide synthase activation in arterioles and glomeruli, whereas decreased cortex peritubular capillary perfusion is associated with epithelial redox stress. Elevated systemic levels of vascular endothelial growth factor, reduced levels of circulating sphingosine 1-phosphate and loss of components of the glycocalyx from glomerular endothelial cells lead to increased microvascular permeability. Although coagulation disbalance occurs in all microvascular segments, the molecules involved differ between segments. Induction of the expression of adhesion molecules and leukocyte recruitment also occurs in a heterogeneous manner. Evidence of similar endothelial cell responses has been found in kidney and blood samples from patients with sepsis. Comprehensive studies are needed to investigate the relationships between segment-specific changes in the microvasculature and kidney function loss in sepsis-AKI. The application of omics technologies to kidney tissues from animals and patients will be key in identifying these relationships and in developing novel therapeutics for sepsis.

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.

Immune response in fluid therapy with crystalloids of different ratios or colloid for rats in haemorrhagic shock

This study investigated the association between different ratios of balanced salt based-crystalloid (PLASMA SOLUTION-A [CJ HealthCare, Seoul, Korea]) (the ratios of crystalloid for blood loss, 1:1, 1:2 and 1:3) or balanced salt-based colloid (VOLULYTE 6% [Fresenius Kabi, Germany]) (the ratio of colloid for blood loss, 1:1) to restore blood loss and immune response in rats with haemorrhagic shock. About 50% of total estimated blood volume was removed after anaesthesia. The fluid was administered for resuscitation after exsanguination, according to the type of fluid and the ratios of exsanguinated volume and fluid volume for resuscitation. After sacrifice, expression of immune cells in blood and tissues was evaluated. Histological analyses and syndecan-1 immunohistochemistry assays were performed on tissues. Endothelial damage according to syndecan-1 and cytokine levels in blood was also assessed. Fluid resuscitation with same, two-fold, or three-fold volumes of crystalloid, or same volume of colloid, to treat haemorrhagic shock in rats resulted in a similar increase in blood pressure. The expression of neutrophils in blood decreased significantly after colloid administration, compared to before exsanguination. Syndecan-1 expression increased after exsanguination and fluid resuscitation in all groups, without any significant difference. In conclusion, same volume of balanced salt-based crystalloid for blood loss was enough to restore BP at the choice of fluid for the management of haemorrhagic shock in the rats, compared with different ratios of crystalloid or same volume of colloid, on the aspect of immune response.

The Beneficial Effect of HES on Vascular Permeability and Its Relationship With Endothelial Glycocalyx and Intercellular Junction After Hemorrhagic Shock

Background

Vascular leakage is a common complication of hemorrhagic shock. Endothelial glycocalyx plays a crucial role in the protection of vascular endothelial barrier function. Hydroxyethyl starch (HES) is a commonly used resuscitation fluid for hemorrhagic shock. However, whether the protective effect of HES on vascular permeability after hemorrhagic shock is associated with the endothelial glycocalyx is unclear.

Methods

Using hemorrhagic shock rat model and hypoxia treated vascular endothelial cells (VECs), effects of HES (130/0.4) on pulmonary vascular permeability and the relationship to endothelial glycocalyx were observed.

Results

Pulmonary vascular permeability was significantly increased after hemorrhagic shock, as evidenced by the increased permeability of pulmonary vessels to albumin-fluorescein isothiocyanate conjugate (FITC-BSA) and Evans blue, the decreased transendothelial electrical resistance of VECs and the increased transmittance of FITC-BSA. The structure of the endothelial glycocalyx was destroyed, showing a decrease in thickness. The expression of heparan sulfate, hyaluronic acid, and chondroitin sulfate, the components of the endothelial glycocalyx, was significantly decreased. HES (130/0.4) significantly improved the vascular barrier function, recovered the thickness and the expression of components of the endothelial glycocalyx by down-regulating the expression of heparinase, hyaluronidase, and neuraminidase, and meanwhile increased the expression of intercellular junction proteins ZO-1, occludin, and VE-cadherin. Degradation of endothelial glycocalyx with degrading enzyme (heparinase, hyaluronidase, and neuraminidase) abolished the beneficial effect of HES on vascular permeability, but had no significant effect on the recovery of the expression of endothelial intercellular junction proteins induced by HES (130/0.4). HES (130/0.4) decreased the expression of cleaved-caspase-3 induced by hemorrhagic shock.

Conclusions

HES (130/0.4) has protective effect on vascular barrier function after hemorrgic shock.The mechanism is mainly related to the protective effect of HES on endothelial glycocalyx and intercellular junction proteins. The protective effect of HES on endothelial glycocalyx was associated with the down-regulated expression of heparinase, hyaluronidase, and neuraminidase. HES (130/0.4) had an anti-apoptotic effect in hemorrhagic shock.

The protective effect of hydroxyethyl starch solution on the glycocalyx layer in an acute hemorrhage mouse model

PURPOSE

Fluid therapy focused on glycocalyx (GCX) protection in hemorrhagic shock is a current focus of research. Hydroxyethyl starch (HES) solution is commonly used for fluid resuscitation; however, its effects on the GCX remain unclear. The primary aim of this study was to explore the protective effect of HES130 in maintaining GCX thickness and reducing plasma syndecan-1 expression.

METHODS

An acute hemorrhage murine model with the dorsal skin chambers was used to measure GCX thickness and to evaluate vascular permeability. Groups of mice were treated with normal saline (NS), albumin (NS-A), HES130 (NS-V), or no exsanguination or infusion (C). We measured syndecan-1 plasma concentrations, performed blood gas analysis, and analyzed the 7-day cumulative mortality.

RESULTS

GCX thickness in NS mice was significantly reduced compared to that in group C, but no other groups showed a difference compared to group C. The plasma concentration of syndecan-1 was significantly higher in NS mice than in group C. There were no significant differences in the fluorescence intensity of dextran in the interstitial space. HES70 leakage was suppressed in NS-V mice compared to those in other groups. HES70 was localized to the inner vessel wall in C, NS, and NS-A mice, but not in group NS-V. Blood gas analysis indicated that pH and lactate showed the greatest improvements in NS-V mice. The 7-day cumulative mortality rate was the highest in group NS.

CONCLUSION

Resuscitation with HES130 protected the GCX and suppressed vascular permeability of HES70 during early stages of acute massive hemorrhage.

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.

Comparison between Colloid Preload and Coload in Bone Cement Implantation Syndrome under Spinal Anesthesia: A Randomized Controlled Trial

Background:

Bone cement implantation syndrome (BCIS) is characterized by hypoxia hypotension cardiac arrest. There is not any research that investigated the hemodynamic effects of colloid use during and before cement implantation regarding BCIS development.

Aims:

We aimed to compare the effects of colloid preloading before or coloading simultaneously at cement implantation on BCIS development and hemodynamic parameters in patients who underwent total knee arthroplasty.

Settings and Design:

This is a prospective, randomized, clinical trial with the participation of 109 patients over 60 years of age and patients physical status American Society of Anesthesiologists Classes I and II to undergo knee surgery. The patients were administered spinal anesthesia, divided into three groups.

Subjects and Methods:

The patients in Group I were infused 8 mL/kg hydroxyethyl starch (130/0.4) 20 min before the cement implantation, those in Group II were infused the same simultaneously during cement implantation. Group III was infused 8 mL/kg/h sodium chloride during the anesthesia management. Hemodynamic parameters of the patients were recorded at before and after cement implantation and once the tourniquet was removed.

Statistical Analysis Used:

The descriptive statistics were presented as the mean ± standard deviation for normally distributed variables, as the median for nonnormally distributed variables, and as the number of cases and (%) for nominal variables. Pearson's Chi-square test and Fisher's exact test were used in the analysis of categorical variables.

Results:

Compared to the control group, Groups I and II were hemodynamically more stable. The development of moderate hypoxia during cement implantation was significantly different between the study groups (P < 0.05).

Conclusions:

We suggest that avoiding intravascular volume depletion by using the colloids, particularly in elderly patients, is important for preventing from the BCIS.

The effect of repeated stimulated granulocyte donations on hematopoietic indexes in donors: a 24-year donor center experience

BACKGROUND

Short- and long-term effects of mobilization regimens in hematopoietic stem cell and granulocyte donors have been well characterized. In this study, we examined the longitudinal hematopoietic changes related to repeat stimulated granulocyte donation.

STUDY DESIGN AND METHODS

Complete blood counts for consecutive granulocyte donors between October 1994 and May 2017 were compared to unstimulated granulocyte donors. Plateletpheresis donors served as controls. The longitudinal change in precollection white blood cell (WBC) counts for these donor groups were modeled using a linear mixed-effects model. The investigated variables were granulocyte, lymphocyte, and monocyte counts and the granulocyte collection yield. Contrasts were performed to explore the effect of donation number on precollection counts.

RESULTS

For the granulocyte-colony-stimulating factor plus dexamethasone (G-CSF/Dex)-stimulated group, both the granulocyte and the lymphocyte counts decreased 6.51 × 10⁹ /L (-23.1%, p < 0.001) and 0.21 × 10⁹ /L (-20.4%, p < 0.001), respectively, between Donation 1 and Donation 20. This effect was still present at the 3- to 4-year interval (b = -0.0008313, SE = 0.00029, p = 0.004). For the unstimulated donor group between Donation 1 and Donation 20, the lymphocyte count decreased by 0.62 × 10⁹ /L (-51.5%, p < 0.001). This effect was only significant up to Year 2 (b = -0.0026, SE = 0.0010, p = 0.013).

CONCLUSIONS

Past granulocyte donations were found to have a statistically strong negative effect on precollection granulocyte counts and lymphocyte counts and decreased granulocyte yield both in the G-CSF/Dex-stimulated donors and the unstimulated donors. In this statistical model, for both these groups, the effect of past donations on granulocyte and WBC counts were still detectable 2 years later.

6% Hydroxyethyl starch (HES 130/0.4) diminishes glycocalyx degradation and decreases vascular permeability during systemic and pulmonary inflammation in mice

Background

Increased vascular permeability is a pathophysiological hallmark of sepsis and results in increased transcapillary leakage of plasma fluid, hypovolemia, and interstitial edema formation. 6% hydroxyethyl starch (HES 130/0.4) is commonly used to treat hypovolemia to maintain adequate organ perfusion and oxygen delivery. The present study was designed to investigate the effects of 6% HES 130/0.4 on glycocalyx integrity and vascular permeability in lipopolysaccharide (LPS)-induced pulmonary inflammation and systemic inflammation in mice.

Methods

6% HES 130/0.4 or a balanced electrolyte solution (20 ml/kg) was administered intravenously 1 h after cecal ligation and puncture (CLP) or LPS inhalation. Sham-treated animals receiving 6% HES 130/0.4 or the electrolyte solution served as controls. The thickness of the endovascular glycocalyx was visualized by intravital microscopy in lung (LPS inhalation model) or cremaster muscle (CLP model). Syndecan-1, hyaluronic acid, and heparanase levels were measured in blood samples. Vascular permeability in the lungs, liver, kidney, and brain was measured by Evans blue extravasation.

Results

Both CLP induction and LPS inhalation resulted in increased vascular permeability in the lung, liver, kidney, and brain. 6% HES 130/0.4 infusion led to significantly reduced plasma levels of syndecan-1, heparanase, and hyaluronic acid, which was accompanied by a preservation of the glycocalyx thickness in postcapillary venules of the cremaster (0.78 ± 0.09 μm vs. 1.39 ± 0.10 μm) and lung capillaries (0.81 ± 0.09 μm vs. 1.49 ± 0.12 μm).

Conclusions

These data suggest that 6% HES 130/0.4 exerts protective effects on glycocalyx integrity and attenuates the increase of vascular permeability during systemic inflammation.

Electronic supplementary material

The online version of this article (doi: 10.1186/s13054-017-1846-3) contains supplementary material, which is available to authorized users.

The effects of crystalloid versus synthetic colloid in vitro on immune cells, co-cultured with mouse splenocytes

This study assessed the effects of crystalloid versus synthetic colloid in vitro on immune cells co-cultured with mouse splenocytes. Mouse splenocytes were co-cultured with three different types of fluid: Plasma solution-A^® (CJ HealthCare, Seoul, Korea; the crystalloid group); Tetraspan 6%^® (B. Braun Medical, Melsungen, Germany; the Colloid-T group); and Volulyte 6%^® (Fresenius Kabi, Bad Homburg vor dér-Höhe, Germany; Colloid-V group). To evaluate the acquired immune response, cluster of differentiation (CD) 4⁺ T cells and CD8⁺ T cells were measured. To evaluate the innate immune response, neutrophils were measured. The frequencies of CD4⁺ and CD8⁺ T cells did not differ significantly among the three groups on day 1 or 3. However, the frequencies of CD4⁺ and CD8⁺ T cells in the two synthetic colloid groups were significantly higher than those in the crystalloid group on day 7. On day 1, the frequency of neutrophils was significantly lower in the two synthetic colloid groups, compared with the crystalloid group. However, the values on the other days were similar among all three groups. In conclusion, crystalloid had a limited effect on the immune response; on the other hand, synthetic colloid increased the acquired immune response, although it temporarily inhibited the innate immune response.

Pyruvate as a novel carrier of hydroxyethyl starch 130/0.4 may protect kidney in rats subjected to severe burns

BACKGROUND

The carrier of hydroxyethyl starch (HES) may play a critical role in kidney injury in fluid resuscitation. This study aimed mainly to compare effects of pyruvate-enriched saline with normal saline (NS) and acetate Ringer's (AR) solution as a carrier in HES130/0.4 on kidney function in rats subjected to severe burns.

METHODS

Using a lethal burn model, 140 rats were randomly allocated in seven groups (n = 20): sham group (group S); no fluid after burn (group N); burn resuscitated with NS (group NS); burn resuscitated with pyruvate saline (group PS); burn resuscitated with AR plus pyruvate-HES (group SP); burn resuscitated with AR plus acetate-HES (group SA), and burn resuscitated with AR plus NS-HES (group SN). A low volume (18.75 mL·kg^-1 during 12 h) of HES130/0.4 was infused with the ratio of 1:1 to crystalloids. Renal surface blood flow, blood creatinine and blood urea nitrogen, early sensitive indicators of kidney function: alpha-1 microglobulin, cystatin-C, and neutrophil gelatinase-associated lipocalin in blood and urine, and kidney tissue water contents were determined. Renal histopathological alterations with Paller scores were also measured at 8 h and 24 h after burn (n = 10), respectively.

RESULTS

The results showed in a comparable manner that group SP was the best in three HES groups and group PS was superior to group NS in renal preservation; group SP appeared significantly beneficial compared with group PS in renal surface blood flow, cystatin-C, neutrophil gelatinase-associated lipocalin, water contents, and Paller scores at 8-h or both time points after burn, respectively (all P < 0.05).

CONCLUSIONS

The carrier of HES130/0.4 played a crucial role in kidney injury in fluid resuscitation of rats subjected to severe burns. Pyruvate-enriched HES130/0.4 was superior and HES130/0.4, per se, might be not renocytotoxic, but renoprotective. Further studies are warranted.

Efficacy of hyaluronic acid and hydroxyethyl starch in preventing adhesion following endoscopic sinus surgery

Adhesion is a major complication of endoscopic sinus surgery that may lead to recurrence of chronic rhinosinusitis, necessitating revision surgery. The purpose of this study was to evaluate the effect of hyaluronic acid and hydroxyethyl starch (HA-HES) relative to hyaluronic acid and carboxymethylcellulose (HA-CMC) with regard to anti-adhesion effect. In this multi-center, prospective, single-blind, randomized controlled study, 77 consecutive patients who underwent bilateral endoscopic sinus surgery were enrolled between March 2014 and March 2015. HA-HES and HA-CMC were applied to randomly assigned ethmoidectomized cavities after the removal of middle meatal packing. At the 1st, 2nd and 4th weeks after surgery, the presence and grades of adhesion, edema, and infection were, respectively, examined via endoscopy by a blinded assessor. The incidence and grades of adhesion at the 2-week follow-up were significantly less in the HA-CMC group than in the HA-HES group (p < 0.05). However, with the exception of week 2, there were no significant differences in the incidence or grades of adhesion, edema, and infection between the two groups. When the primary endpoint-the presence of adhesion at the 4-week follow-up-was compared between two groups, the incidence of adhesion in HA-HES group at the 4-week follow-up was 32% and in HA-CMC was 41.3%, indicating that HA-HES was not inferior to HA-CMC in terms of anti-adhesive effect. No severe adverse reactions were noted during the study period. In conclusion, HA-HES is a safe substitutional anti-adhesion agent that has equivalent effect as HA-CMC after endoscopic sinus surgery.

The influence of Ringer's lactate or HES 130/0.4 administration on the integrity of the small intestinal mucosa in a pig hemorrhagic shock model under general anesthesia

OBJECTIVE

To determine the effect of fluid resuscitation with 2 different physiological solutions, Ringer's lactate (RL) and hydroxyethyl starch (HES) 130/0.4, on histological lesions of the small intestinal mucosa in anesthetized pigs subjected to severe acute bleeding.

DESIGN

Prospective experimental study.

SETTING

University teaching hospital.

ANIMALS

Twenty-eight healthy Large White pigs, 3 months of age.

INTERVENTIONS

Pigs were subjected to severe acute bleeding (30 mL/kg) under total intravenous anesthesia with propofol and remifentanil. Pigs were randomly allocated to 3 groups: Group 1 (n = 11) received RL solution (25 mL/kg) after bleeding; Group 2 (n = 11) received HES 130/0.4 solution (20 mL/kg) after bleeding; and Group 3 (n = 6) volume replacement nor induced bleeding. Pigs were euthanized and the small intestine was harvested for histopathological analysis.

MEASUREMENTS AND MAIN RESULTS

The small intestine was histologically evaluated and the presence of the following lesions were characterized: edema, congestion, hyperemia, hemorrhage, inflammatory infiltration, cellular degeneration, necrosis, and epithelial detachment. Mucosal loss percentage (%ML) and crypt:interstitium ratio (C:I) were also assessed. In the duodenum, jejunum, and ileum, and the entire small intestine, the %ML was significantly higher in Group 1, than in Groups 2 and 3. Hyperemia in the small intestine was significantly higher in pigs resuscitated with HES 130/0.4 compared to pigs resuscitated with RL.

CONCLUSIONS AND CLINICAL RELEVANCE

In a setting of controlled hemorrhage, resuscitation with HES 130/0.4 was associated with a lower percentage of mucosal loss on the small intestine, compared with resuscitation with RL solution. Our study also suggests that the duodenum may be more sensitive to hypovolemia induced by severe hemorrhage.

Haemodynamic coherence - The relevance of fluid therapy

The ultimate goal of fluid therapy is to improve the oxygenation of cells by improving the cardiac output, thus improving microcirculation by optimizing macrocirculation. This haemodynamic coherence is often altered in patients with haemorrhagic shock and sepsis. The loss of haemodynamic coherence is associated with adverse outcomes. It may be influenced by the mechanisms of the underlying disease and properties of different fluids used for resuscitation in these critically ill patients. Monitoring microcirculation and haemodynamic coherence may be an additional tool to predict the response to fluid administration. In addition, microcirculatory analysis may support the clinician in his decision to not administer fluids when microcirculatory blood flow is preserved. In future, the indication, guidance and termination of fluid therapy may be assessed by bedside microvascular analysis in combination with standard haemodynamic monitoring.

Impact of high doses of 6% hydroxyethyl starch 130/0.42 and 4% gelatin on renal function in a pediatric animal model

OBJECTIVES

Despite serious renal side effects in critically ill adult patients, artificial colloids are still fundamental components of perioperative fluid therapy in infants and children, although the impact of 6% hydroxyethyl starch (HES) and 4% gelatin (GEL) on renal function during pediatric surgery has not been identified yet.

AIM

To determine the impact of high doses of artificial colloids on renal function, we conducted an experimental animal study and hypothesized that neither the infusion of HES nor of GEL would have a serious impact on renal function.

METHODS

Fifteen sedated piglets were randomly assigned to receive an infusion of either 50 ml · kg(-1) HES or GEL, or a balanced electrolyte solution (crystalloid group). Before and 1 week after infusion, serum and urine renal function tests were recorded and renal biopsies were taken.

RESULTS

Serum and urine renal function tests revealed no increase after administration of HES and GEL, and only a discrete increase in serum creatinine (median 9.8 μmol · l(-1), 95% CI 4.0-19.1) in the crystalloid group. Histopathological examination indicated a sparsely, multifocal infiltration of mononuclear cells in all groups and an unspecific pyelectasia of one animal in the GEL group.

CONCLUSIONS

After high doses of HES or GEL in piglets, no relevant impact on renal function could be found. These results confirm that AKI after HES or GEL is very unlikely in hemodynamically stable perioperative patients with normal renal function.