The Impact of Head Position on Neurological and Histopathological Outcome Following Controlled Automated Reperfusion of the Whole Body (CARL) in a Pig Model.

Introduction: Based on extracorporeal circulation, targeted reperfusion strategies have been developed to improve survival and neurologic recovery in refractory cardiac arrest: Controlled Automated Reperfusion of the whoLe Body (CARL). Furthermore, animal and human cadaver studies have shown beneficial effects on cerebral pressure due to head elevation during conventional cardiopulmonary resuscitation. Our aim was to evaluate the impact of head elevation on survival, neurologic recovery and histopathologic outcome in addition to CARL in an animal model. Methods: After 20 min of ventricular fibrillation, 46 domestic pigs underwent CARL, including high, pulsatile extracorporeal blood flow, pH-stat acid-base management, priming with a colloid, mannitol and citrate, targeted oxygen, carbon dioxide and blood pressure management, rapid cooling and slow rewarming. N = 25 were head-up (HUP) during CARL, and N = 21 were supine (SUP). After weaning from ECC, the pigs were extubated and followed up in the animal care facility for up to seven days. Neuronal density was evaluated in neurohistopathology. Results: More animals in the HUP group survived and achieved a favorable neurological recovery, 21/25 (84%) versus 6/21 (29%) in the SUP group. Head positioning was an independent factor in neurologically favorable survival (p < 0.00012). Neurohistopathology showed no significant structural differences between HUP and SUP. Distinct, partly transient clinical neurologic deficits were blindness and ataxia. Conclusions: Head elevation during CARL after 20 min of cardiac arrest independently improved survival and neurologic outcome in pigs. Clinical follow-up revealed transient neurologic deficits potentially attributable to functions localized in the posterior perfusion area, whereas histopathologic findings did not show corresponding differences between the groups. A possible explanation of our findings may be venous congestion and edema as modifiable contributing factors of neurologic injury following prolonged cardiac arrest.

Effects of Prolonged Serum Calcium Suppression during Extracorporeal Cardiopulmonary Resuscitation in Pigs.

Controlled reperfusion by monitoring the blood pressure, blood flow, and specific blood parameters during extracorporeal reperfusion after cardiac arrest has the potential to limit ischemia-reperfusion injury. The intracellular calcium overload as part of the ischemia-reperfusion injury provides the possibility for the injury to be counteracted by the early suppression of serum calcium with the aim of improving survival and the neurological outcome. We investigated the effects of prolonged serum calcium suppression via sodium citrate during extracorporeal resuscitation using the CARL protocol (CARL-controlled automated reperfusion of the whole body) compared to a single-dose approach in a porcine model after prolonged cardiac arrest. A control group (N = 10) was resuscitated after a 20 min cardiac arrest, initially lowering the intravascular calcium with the help of a single dose of sodium citrate as part of the priming solution. Animals in the intervention group (N = 13) received additional sodium citrate for the first 15 min of reperfusion. In the control group, 9/10 (90.0%) animals survived until day 7 and 7/13 (53.8%) survived in the intervention group (p = 0.09). A favorable neurological outcome on day 7 after the cardiac arrest was observed in all the surviving animals using a species-specific neurological deficit score. The coronary perfusion pressure was significantly lower with a tendency towards more cardiac arrhythmias in the intervention group. In conclusion, a prolonged reduction in serum calcium levels over the first 15 min of reperfusion after prolonged cardiac arrest tended to be unfavorable regarding survival and hemodynamic variables compared to a single-dose approach in this animal model.

Development of an in-vitro model for extracorporeal blood pumps to study the effects of artificial pulsatility on human blood.

Introduction: The application of extracorporeal circulation (ECC) systems is known to be associated with several implications regarding hemolysis, inflammation, and coagulation. In the last years, systems with pulsatile blood flow are increasingly used with the intention to improve hemodynamics in reperfusion. However, their implications on the aforementioned aspects remain largely unknown. To investigate the effects of pulsatility, this ex-vivo study was initiated. Methods: Test circuits (primed with human whole blood) were set up in accordance with the recommendations of international standards for in-vitro evaluation of new components and systems of ECC. Diagonal pumps were either set up with non-pulsatile (n = 5, NPG) or pulsatile (n = 5, PG) pump settings and evaluated for 6 h. All analyses were conducted with human whole blood. Blood samples were repeatedly drawn from the test circuits and analyzed regarding free hemoglobin, interleukin 8 (IL-8), platelet aggregation and acquired von Willebrand syndrome (AVWS). Results: After 1 h of circulation, a significant coagulation impairment (impaired platelet function and AVWS) was observed in both groups. After 6 h of circulation, increased IL-8 concentrations were measured in both groups (NPG: 0.05 ± 0.03 pg./mL, PG: 0.03 ± 0.01 pg./mL, p = 0.48). Pulsatile pump flow resulted in significantly increased hemolysis after 6 h of circulation (NPG: 37.3 ± 12.4 mg/100 L; PG: 59.6 ± 14.5 mg/100 L; p < 0.05). Conclusion: Our results indicate that the coagulative impairment takes place in the early phase of ECC. Pulsatility did not affect the occurrence of AVWS ex-vivo. Prolonged durations of pulsatile pump flow led to increased hemolysis and therefore, its prolonged use should be employed cautiously in clinical practice with appropriate monitoring.

Hydro-geomorphic perspectives on microplastic distribution in freshwater river systems: A critical review.

Freshwater river systems are commonly defined as the main transport paths of microplastics (MP) from land into the seas. A shift in research interest from oceans to rivers can be observed, as a large number of i) case studies, ii) review papers and iii) experimental studies in this field have been published recently. Still, studies often lack an in-depth consideration of quantification, as units are mostly based on item numbers. Spatiotemporal aspects are often neglected. Transport paths linking MP sources and sinks in the environment are insufficiently understood and only recently the awareness increased that sustainable management of the MP pollution cannot be addressed without a sound knowledge of water- and sediment-driven MP transport. Within this review paper, we therefore i) reviewed 92 MP case-studies, with a special focus on spatiotemporal aspects and ii) gathered and compared global load-estimation data from these studies. We then outlined the key processes determining MP movement in rivers on the basis of existing laboratory experiments and theoretical approaches. A procedure to effectively compare units of MP in the water column and in riverine sediments was developed on the basis of i) an extensive MP-dataset in German waterways and ii) suspended sediment concentrations (SSC) of nearest monitoring stations of the German water and shipping authority. Our analysis indicates that relating MP in water samples to SSC reduces the often stated large difference between MP concentrations in the water column and bed sediments and therefore relativizes the importance of river beds as a major "MP sink". As for a quantification of MP fluxes, the use of MP masses as unit is crucial, we applied an approach to convert MP items to masses with the help of i) a power-law distribution of MP-particle size, triangular distributions of ii) form-ratios and iii) polymer densities. An evaluation with an own, extensive dataset of MP-particles showed reasonable results. Therefore, we translated global load data from item numbers to mass values for further analysis. Values were within a reasonable range, especially when considering the respective catchment size of each river at the sampling site.

Effects of microplastics mixed with natural particles on Daphnia magna populations.

The toxicity of microplastics on Daphnia magna as a key model for freshwater zooplankton is well described. While several studies predict population-level effects based on short-term, individual-level responses, only very few have validated these predictions experimentally. Thus, we exposed D. magna populations to irregular polystyrene microplastics and diatomite as natural particle (both ≤63 µm) over 50 days. We used mixtures of both particle types at fixed particle concentrations (50,000 particles mL-1) and recorded the effects on overall population size and structure, the size of the individual animals, and resting egg production. Particle exposure adversely affected the population size and structure and induced resting egg production. The terminal population size was 28-42 % lower in exposed compared to control populations. Interestingly, mixtures containing diatomite induced stronger effects than microplastics alone, highlighting that natural particles are not per se less toxic than microplastics. Our results demonstrate that an exposure to synthetic and natural particles has negative population-level effects on zooplankton. Understanding the mixture toxicity of microplastics and natural particles is important given that aquatic organisms will experience exposure to both. Just as for chemical pollutants, better knowledge of such joint effects is essential to fully understand the environmental impacts of complex particle mixtures. ENVIRONMENTAL IMPLICATIONS: While microplastics are commonly considered hazardous based on individual-level effects, there is a dearth of information on how they affect populations. Since the latter is key for understanding the environmental impacts of microplastics, we investigated how particle exposures affect the population size and structure of Daphnia magna. In addition, we used mixtures of microplastics and natural particles because neither occurs alone in nature and joint effects can be expected in an environmentally realistic scenario. We show that such mixtures adversely affect daphnid populations and highlight that population-level and mixture-toxicity designs are one important step towards more environmental realism in microplastics research.

Limiting calcium overload after cardiac arrest: The role of human albumin in controlled automated reperfusion of the whole body.

BACKGROUND: Regarding the overall inadequate results after cardiopulmonary resuscitation, the development of new treatment concepts is urgently needed. Controlled Automated Reperfusion of the whoLe body (CARL) represents a therapy bundle to control the conditions of reperfusion and the composition of the reperfusate after cardiac arrest (CA). The aim of this study was to investigate the plasma expander's role in the CARL priming solution and examine its mechanism of action. METHODS: Viscosity, osmolality, colloid osmotic pressure (COP), pH and calcium binding of different priming solutions were measured in vitro and compared to in vivo data. N = 16 pigs were allocated to receive CARL following 20 min of untreated CA with either human albumin 20% (HA, N = 8) or gelatin polysuccinate 4% (GP, N = 8). Blood gas analyses were performed during the first hour of reperfusion and catecholamine and fluid requirements were recorded. Neurological outcome was assessed by neurological deficit scoring (NDS) on the seventh day. RESULTS: In vitro, addition of HA to the CARL priming solution resulted in higher COP and higher calcium-binding than GP. In vivo, treatment with HA led to greater reduction of ionized calcium and higher extracorporeal flows within the first 30 min of reperfusion with no difference in catecholamine support and fluid requirement. Seven-day survival of 75% with no difference in NDS was observed in both groups. CONCLUSIONS: Our data show that the plasma expander in the CARL priming solution has a significant effect on the initial reperfusate and can potentially influence the course of resuscitation. However, seven-day survival and NDS did not differ between groups.

Serum proteome alterations during conventional and extracorporeal resuscitation in pigs.

BACKGROUND: Only a small number of patients survive an out-of-hospital cardiac arrest (CA) and can be discharged from hospital alive with a large percentage of these patients retaining neurological impairments. In recent years, extracorporeal cardiopulmonary resuscitation (ECPR) has emerged as a beneficial strategy to optimize cardiac arrest treatment. However, ECPR is still associated with various complications. To reduce these problems, a profound understanding of the underlying mechanisms is required. This study aims to investigate the effects of CA, conventional cardiopulmonary resuscitation (CPR) and ECPR using a whole-body reperfusion protocol (controlled and automated reperfusion of the whole body-CARL) on the serum proteome profiles in a pig model of refractory CA. METHODS: N = 7 pigs underwent 5 min of untreated CA followed by 30 min CPR and 120 min perfusion with CARL. Blood samples for proteomic analysis were drawn at baseline, after CPR and at the end of the CARL period. Following albumin-depletion, proteomic analysis was performed using liquid chromatography-tandem mass spectrometry. RESULTS: N = 21 serum samples were measured resulting in the identification and quantification of 308-360 proteins per sample and 388 unique proteins in total. The three serum proteome profiles at the investigated time points clustered individually and segregated almost completely when considering a 90% confidence interval. Differential expression analysis showed significant abundance changes in 27 proteins between baseline and after CPR and in 9 proteins after CARL compared to CPR. Significant findings were further validated through a co-abundance cluster analysis corroborating the observed abundance changes. CONCLUSIONS: The presented data highlight the impact of systemic ischemia and reperfusion on the entire serum proteome during resuscitation with a special focus on changes regarding haemolysis, coagulation, inflammation, and cell-death processes. Generally, the observed changes contribute to post-ischemic complications. Better understanding of the underlying mechanisms during CA and resuscitation may help to limit these complications and improve therapeutic options.

Beneficial Effects of Adjusted Perfusion and Defibrillation Strategies on Rhythm Control within Controlled Automated Reperfusion of the Whole Body (CARL) for Refractory Out-of-Hospital Cardiac Arrest.

Survival and neurological outcomes after out-of-hospital cardiac arrest (OHCA) remain low. The further development of prehospital extracorporeal resuscitation (ECPR) towards Controlled Automated Reperfusion of the Whole Body (CARL) has the potential to improve survival and outcome in these patients. In CARL therapy, pulsatile, high blood-flow reperfusion is performed combined with several modified reperfusion parameters and adjusted defibrillation strategies. We aimed to investigate whether pulsatile, high-flow reperfusion is feasible in refractory OHCA and whether the CARL approach improves heart-rhythm control during ECPR. In a reality-based porcine model of refractory OHCA, 20 pigs underwent prehospital CARL or conventional ECPR. Significantly higher pulsatile blood-flow proved to be feasible, and critical hypotension was consistently prevented via CARL. In the CARL group, spontaneous rhythm conversions were observed using a modified priming solution. Applying potassium-induced secondary cardioplegia proved to be a safe and effective method for sustained rhythm conversion. Moreover, significantly fewer defibrillation attempts were needed, and cardiac arrhythmias were reduced during reperfusion via CARL. Prehospital CARL therapy thus not only proved to be feasible after prolonged OHCA, but it turned out to be superior to conventional ECPR regarding rhythm control.

A Systematic Review with Meta-Analysis Investigating the Impact of Targeted Perfusion Parameters during Extracorporeal Cardiopulmonary Resuscitation in Out-of-Hospital and Inhospital Cardiac Arrest.

Evidence regarding perfusion conditions during extracorporeal cardiopulmonary resuscitation (ECPR) is rare. Therefore, we investigated the impact of perfusion parameters on neurologic outcome and survival in patients with in- or out-of-hospital cardiac arrest (IHCA; OHCA) treated with ECPR. We performed a systematic review with meta-analysis. The focus was set on perfusion parameters and their impact on survival and a goal neurological outcome using the cerebral performance category score of 1-2. We conducted random- and mixed-effects meta-analyses and computed pooled estimates and 95% confidence intervals (CI). We included a total of n = 1,282 ECPR (100%) patients from 20 ECPR studies. The target values of flow and mean arterial pressure (MAP) were frequently available. We transferred flow and MAP target values to high, medium, and low categories. The meta-analysis could not demonstrate a single effect of flow or MAP on outcome variables. In a second mixed-effects model, the combined occurrence of targeted flow and MAP as medium and high showed a significant effect on survival (OHCA: 52%, 95% CI: 29%, 74%; IHCA: 60%, 95% CI: 35%, 85%) and on neurological outcomes (OHCA: 53%, 95% CI: 27%, 78%; IHCA: 62%, 95% CI: 38%, 86%). Random-effects analysis showed also that IHCA led to a significant 11% (p = 0.006; 95% CI: 3%, 18%) improvement in survival and 12% (p = .005; 95% CI: 4%, 21%) improvement in neurological outcomes compared to OHCA. A combination of medium flow and high MAP showed advantages in survival and for neurological outcomes. We also identified improved outcomes for IHCA.

Leaching prediction for vertical test panels coated with plaster and mortars exposed under real conditions by a PHREEQC leaching model.

A requirement of the Construction Products Regulation (CPR) in the European Union states that construction works must be designed in such a way that throughout their entire life cycle, they have no exceedingly high environmental impact. The objective of the current work was to simulate the leaching of selected metals and sulfate in vertical test panels (VTPs) covered by plaster and mortar. The investigation is based on 18-month leaching outdoor tests (LOT) under real weather conditions. A leaching model was developed using the geochemical model PHREEQC with the Lawrence Livermore National Laboratory (LLNL) thermodynamic data base and coupled with MATLAB in order to optimize the run-off and weather parameters. The model was calibrated by comparing the data from laboratory Dynamic Surface Leaching Tests (DSLT) with simulation results up to an acceptable fit. The parameters obtained were then used in the LOT simulations and validated. The model allows predictions on the substance discharge from various plasters and mortars under real weather conditions. Physical characteristics of the material (e.g., thickness and absorption capacity) play an important role in the leaching of substances in façades covered with plaster and mortar. The lower the thickness and absorption capacity of the material applied, the greater the run-off and discharge of leached substances.

Influence of oscillating main flow on separation efficiency in asymmetrical flow field-flow fractionation.

The steadily rising interest in the investigation of interactions between nanomaterials and biological media has also led to an increasing interest in asymmetrical flow field-flow fractionation (AF-FFF). The biggest strength of AF-FFF is the possibility to alter the flow profiles to suit a specific separation problem. In this paper, the influence of an oscillating main flow on the separation efficiency of AF-FFF is investigated. Such oscillations can e.g. be caused by the main pump To investigate the influence of such flow conditions on the separation efficiency in AF-FFF systematically, different oscillation profiles were applied and their influence on the elution profile and the retention times was observed. It could be shown, that the separation mechanism is extremely robust and a fractionation is still possible even under unfavorable conditions.

Observation of interaction forces by investigation of the influence of eluent additives on the retention behavior of aqueous nanoparticle dispersions in asymmetrical flow field-flow fractionation.

The investigation and subsequent understanding of the interactions of nanomaterials with components of their surrounding media is important to be able to evaluate both potential use cases as well as potential risks for human health and for the environment. To investigate such interactions, asymmetrical flow field-flow fractionation (AF4) is an interesting analytical tool. This statement grounds on the fact that interactions of the analyte with the membrane and with components of the eluent are crucial for the retention behavior of the analyte within the field-flow fractionation (FFF) channel. Therefore, the investigation of the retention behavior provides an insight in the nature of the interactions between analyte, membrane and eluent. Within this publication, the influence of the composition of the eluent on the retention behavior of aqueous dispersions of two model analytes is investigated. Eluents with different types of salts and surfactants and eluents with different salt concentrations were prepared and the influence of the composition of these eluents on the retention behavior of polystyrene and polyorganosiloxane particles was compared. Three main trends were observed: Elution times increase with increasing electrolyte concentration; when comparing different electrolyte anions, the retention time increases the more kosmotropic the anion is; when comparing different electrolyte cations, the retention order depends on the surfactant. Additional dynamic light scattering (DLS) measurements were conducted to verify that the differences in retention times are not caused by actual differences in particle size. Instead, the differences in elution time can be correlated with the concentration and with the chao-/kosmotropicity of the added electrolyte ions. Therefore, AF4 proves to be sensitive to subtile changes of interaction forces on the level of Coulomb and van der Waals forces. The experimentally gathered elution times were used to develop a model describing the retention behavior, based on an enhanced version of the standard AF4 model: By introducing particle-medium-membrane interactions in the standard AF4 model via the respective Hamaker constants, the calculation of retention times was possible. The congruence of the calculated with the experimental retention times confirmed the validity of the simulation.

Complications and Effects of Dorsal Root Ganglion Stimulation in the Treatment of Chronic Neuropathic Pain: A Nationwide Cohort Study in Denmark.

OBJECTIVES: Dorsal root ganglion (DRG) stimulation is a novel treatment of chronic neuropathic pain and has been shown to be efficacious across several case reports and randomized trials. However, long-term follow-up is limited, as are reports of complication rates. This study presents efficacy and complications for patients treated with DRG stimulation. MATERIALS AND METHODS: We performed an observational, multicenter cohort study of all patients in Denmark implanted with FDA-approved DRG stimulation systems to treat chronic, neuropathic pain between 2014 and 2018. Follow-up period was one to three years. RESULTS: Forty-three patients underwent trial DRG stimulation; 33 were subsequently fully implanted. Pain location: 58% lower extremity; 21% upper extremity; 21% thoracic/abdominal. At the end of the observation period, 58% of fully implanted patients were still implanted; 42% had fully functional systems. In these patients, average Numerical Rating Scale (NRS)-score of pain was reduced from 6.8 to 3.5 (p = 0.00049) and worst NRS-score was reduced from 8.6 to 6.0 (p = 0.0039) at 12 months follow-up. Pain Catastrophizing Score was reduced from 32 to 15 (p = 0.0039). Thirteen patients experienced complications related to defect leads (39% of implanted systems). In four patients (12%), lead removal left fragments in the root canal due to lead fracture, and three patients suffered permanent nerve damage during attempts to replace broken leads. CONCLUSIONS: This study suggests a significant, clinically relevant effect of DRG stimulation on neuropathic pain, but also demonstrates substantial problems with maintenance and revision of currently available systems. Consequently, treatment with equipment marketed specifically for DRG stimulation is currently paused in Denmark.

Comparative assessment of microplastics in water and sediment of a large European river.

Aquatic ecosystems are globally contaminated with microplastics (MP). However, comparative data on MP levels in freshwater systems is still scarce. Therefore, the aim of this study is to quantify MP abundance in water and sediment of the German river Elbe using visual, spectroscopic (Fourier-transform infrared spectroscopy) and thermo analytical (pyrolysis gas chromatography mass spectrometry) methods. Samples from eleven German sites along the German part of the Elbe were collected, both in the water and sediment phase, in order to better understand MP sinks and transport mechanisms. MP concentrations differed between the water and sediment phase. Sediment concentrations (mean: 3,350,000 particles m-3, 125-5000 µm MP) were in average 600,000-fold higher than water concentrations (mean: 5.57 particles m-3, 150-5000 µm MP). The abundance varied between the sampling sites: In sediments, the abundance decreased in the course of the river while in water samples no such clear trend was observed. This may be explained by a barrage retaining sediments and limiting tidal influence in the upstream parts of the river. Particle shape differed site-specifically with one site having exceptionally high quantities of spheres, most probably due to industrial emissions of PS-DVB resin beads. Suspended MP consisted predominantly of polyethylene and polypropylene whereas sediments contained a higher diversity of polymer types. Determined MP concentrations correspond well to previous results from other European rivers. In a global context, MP levels in the Elbe relate to the lower (water) to middle section (sediment) of the global range of MP concentrations determined for rivers worldwide. This highlights that elevated MP levels are not only found in single countries or continents, but that MP pollution is an issue of global concern.

Influence of façade orientation on the leaching of biocides from building façades covered with mortars and plasters.

Biocides used in building façades to prevent potential growth of algae, fungi and bacteria are of major concern regarding the quality of stormwater runoff. The aim of the study was to analyze the influence of the façade orientation on the biocide release under real weather conditions to gain information for the development of on-site treatment systems. Field tests with model houses containing two different plaster compositions were carried out over a period of 18 months. The results of the analyzed rain events demonstrate that façade orientation plays an important role in the leaching loads of biocides. Biocide loads in the runoff decreased corresponding to the wind direction. High cumulated active substance discharges of diuron (149 mg/m2), carbendazim (43.5 mg/m2), terbutryn (9.3 mg/m2) and octylisothiazolinone (OIT) (31.9 mg/m2) were found in the runoff of the façades facing the predominant weather orientation. Meanwhile, the highest concentrations of diuron (2.8 mg/L) and OIT (0.7 mg/L) were observed in the runoff from façades with smaller runoff volumes. The obtained results demonstrate that treatment facilities have to be installed at all building sides. The hydraulic and the substance load is highest at the weather side, which has a strong influence on the dimension and the lifetime of the treatment system.

Does winter cold really limit the dengue vector Aedes aegypti in Europe?

BACKGROUND: Aedes aegypti is a potential vector for several arboviruses including dengue and Zika viruses. The species seems to be restricted to subtropical/tropical habitats and has difficulties in establishing permanent populations in southern Europe, probably due to constraints during the winter season. The aim of this study was to systematically analyze the cold tolerance (CT) of Ae. aegypti in its most cold-resistant life stage, the eggs. METHODS: The CT of Ae. aegypti eggs was compared with that of Ae. albopictus which is well established in large parts of Europe. By systematically studying the literature (meta-analysis), we recognized that CT has been rarely tested in Ae. aegypti eggs, but eggs can survive at zero and sub-zero temperatures for certain exposure periods. To overcome potential bias from experimental differences between studies, we then conducted species comparisons using a harmonized high-resolution CT measuring method. From subtropical populations of the same origin, the survival (hatching in %) and emergence of adults of both species were measured after zero and sub-zero temperature exposures for up to 9 days (3 °C, 0 °C and - 2 °C: ≤ 9 days; - 6 °C: ≤ 2 days). RESULTS: Our data show that Ae. aegypti eggs can survive low and sub-zero temperatures for a short time period similar to or even better than those of Ae. albopictus. Moreover, after short sub-zero exposures of eggs of both species, individuals still developed into viable adults (Ae. aegypti: 3 adults emerged after 6 days at - 2 °C, Ae. albopictus: 1 adult emerged after 1 day at - 6 °C). CONCLUSIONS: Thus, both the literature and the present experimental data indicate that a cold winter may not be the preventing factor for the re-establishment of the dengue vector Ae. aegypti in southern Europe.

Toxicity of microplastics and natural particles in the freshwater dipteran Chironomus riparius: Same same but different?

Microplastics (MP) are contaminants of emerging concern in aquatic ecosystems. While the number of studies is rapidly increasing, a comparison of the toxicity of MP and natural particulate matter is largely missing. In addition, research focusses on the impacts of hydrophobic chemicals sorbed to plastics. However, the interactive effects of MP and hydrophilic, dissolved chemicals remain largely unknown. Therefore, we conducted chronic toxicity studies with larvae of the freshwater dipteran Chironomus riparius exposed to unplasticised polyvinyl chloride MP (PVC-MP) as well as kaolin and diatomite as reference materials for 28 days. In addition, we investigated the effects of particles in combination with the neonicotinoid imidacloprid in a multiple-stressor experiment. High concentrations of kaolin positively affected the chironomids. In contrast, exposure to diatomite and PVC-MP reduced the emergence and mass of C. riparius. Likewise, the toxicity of imidacloprid was enhanced in the presence of PVC-MP and slightly decreased in the co-exposure with kaolin. Overall, parallel experiments and chemical analysis indicate that the toxicity of PVC-MP was not caused by leached or sorbed chemicals. Our study demonstrates that PVC-MP induce more severe effects than both natural particulate materials. However, the latter are not benign per se, as the case of diatomite highlights. Considering the high, environmentally irrelevant concentrations needed to induce adverse effects, C. riparius is insensitive to exposures to PVC-MP.

Local and Lower Limb Complications during and after Femoral Cannulation for Extracorporeal Life Support.

OBJECTIVE: The extracorporeal life support system (ECLS) system is a lifesaving option for patients in pulmonary and/or cardiac failure. We reviewed our data on local complications in the leg and groin during and after ECLS explantation. METHODS: Patients were included when an ECLS was cannulated in the groin and the ECLS was successfully weaned and explanted. Data were collected retrospectively in patients from January 2013 to January 2016. RESULTS: In this study, 90 patients were included; 39 (43%) ECLS were implanted with surgical cut down and 51 (57%) ECLS were implanted percutaneously. Most patients needed ECLS support following cardiac surgery: cut down: 25 (64%) versus percutaneous: 28 (55%) (p = 0.40). A distal leg perfusion cannula was implanted simultaneously in 61 (68%) patients (cut down: 25 [64%] vs. percutaneous: 36 [71%], p = 0.36). Distal leg ischemia was diagnosed in a total of 10 (11%) patients (cut down: 2 [5%] vs. percutaneous: 8 [16%], p = 0.18). Of those 10 patients, 5 patients had leg ischemia despite a distal leg perfusion cannula in place (cut down: 1 [3%] vs. percutaneous: 4 [8%], p = 0.38). Revascularization was successfully achieved in all patients and no amputations had to be performed. Similar rates of wound healing disorders were observed in both groups: cut down: 11 (28%) versus percutaneous: 10 (20%) patients (p = 0.45). CONCLUSION: Surgical and percutaneous implantation and explantation of ECLS are safe and feasible with comparable complication rates, including wound healing disorders. We recommend that a lower limb perfusion cannula should be placed to prevent leg ischemia. Surgical cut-down placement of the distal leg perfusion cannula may reduce the incidence of distal leg ischemia compared with percutaneous distal leg cannula implantation. Correct placement of the cannula should be controlled.

Improved Outcome in an Animal Model of Prolonged Cardiac Arrest Through Pulsatile High Pressure Controlled Automated Reperfusion of the Whole Body.

The reperfusion period after extracorporeal cardiopulmonary resuscitation has been recognized as a key player in improving the outcome after cardiac arrest (CA). Our aim was to evaluate the effects of high mean arterial pressure (MAP) and pulsatile flow during controlled automated reperfusion of the whole body. Following 20 min of normothermic CA, high MAP, and pulsatile blood flow (pulsatile group, n = 10) or low MAP and nonpulsatile flow (nonpulsatile group, n = 6) controlled automated reperfusion of the whole body was commenced through the femoral vessels of German landrace pigs for 60 min. Afterwards, animals were observed for eight days. Blood samples were analyzed throughout the experiment and a species-specific neurologic disability score (NDS) was used for neurologic evaluation. In the pulsatile group, nine animals finished the study protocol, while no animal survived postoperative day four in the nonpulsatile group. NDS were significantly better at any given time in the pulsatile group and reached overall satisfactory outcome values. In addition, blood analyses revealed lower levels of lactate in the pulsatile group compared to the nonpulsatile group. This study demonstrates superior survival and neurologic outcome when using pulsatile high pressure automated reperfusion following 20 min of normothermic CA compared to nonpulsatile flow and low MAP. This study strongly supports regulating the reperfusion period after prolonged periods of CA.