Exploring the surge current degradation of natural ester oil-based nanofluids

The surge endurance of natural ester oil-based nanofluids against surge events is investigated experimentally. The focus of this work is the examination, through dielectric spectroscopy measurements, of the alteration of the real and imaginary parts of the complex relative permittivity of iron oxide nanofluids as a result of an accelerated degradation test employing a sequence of repetitive current impulses produced via a 12 kV/6 kA combination wave generator. The target is the exploration of a possible implementation of nanofluids as multipurpose liquids that act, in addition to insulation and coolants, as surge absorption media. Promising experimental results are discussed and compared with those of mineral oil that is widely used as a conventional insulating liquid in power transformers.

Iatrogenic hyperchloremia: An overview in hospitalized patients for pharmacists

DISCLAIMER

In an effort to expedite the publication of articles, AJHP is posting manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time.

PURPOSE

The purpose of this therapeutic update is to provide pharmacists with a general overview of the pathophysiology of hyperchloremia and describe strategies to help prevent development of this electrolyte abnormality in hospitalized patients.

SUMMARY

Hyperchloremia is an electrolyte abnormality associated with an increased incidence of acute kidney injury and metabolic acidosis. Intravenous (IV) fluids utilized for volume resuscitation, medication diluents, and total parental nutrition all may contribute to the development of hyperchloremia. Current evidence suggests that administration of balanced crystalloids for either fluid resuscitation or maintenance fluids may impact serum chloride levels and patient outcomes. In multiple randomized controlled trials, administering balanced crystalloids for fluid resuscitation in critically ill patient populations did not decrease mortality. However, further analyses of subpopulations within these trials have demonstrated that patients with sepsis may benefit from receiving balanced crystalloids for initial fluid resuscitation. Results from several small studies suggest that altering the composition of these IV fluids may help prevent development of hyperchloremia.

CONCLUSION

Management of hyperchloremia is preventative in nature and can be mitigated through management of resuscitation fluids, medication diluents, and total parenteral nutrition. Inpatient pharmacists should be aware of the potential risk of fluid-associated hyperchloremia and assist with optimal fluid management to prevent and manage hyperchloremia.

Pathophysiology of severe burn injuries: new therapeutic opportunities from a systems perspective

Severe burn injury elicits a profound stress response with the potential for high morbidity and mortality. If polytrauma is present, patient outcomes appear to be worse. Sex-based comparisons indicate females have worse outcomes than males. There are few effective drug therapies to treat burn shock and secondary injury progression. The lack of effective drugs appears to arise from the current treat-as-you-go approach rather than a more integrated systems approach. In this review, we present a brief history of burns research and discuss its pathophysiology from a systems' perspective. The severe burn injury phenotype appears to develop from a rapid and relentless barrage of damage-associated molecular patterns (DAMPs), pathogen-associated molecular patterns (PAMPs) and neural afferent signals, which leads to a state of hyperinflammation, immune dysfunction, coagulopathy, hypermetabolism and intense pain. We propose that if the central nervous system (CNS) control of cardiovascular function and endothelial-glycocalyx-mitochondrial coupling can be restored early, these secondary injury processes may be minimized. The therapeutic goal is to switch the injury phenotype to a healing phenotype by reducing fluid leak and maintaining tissue O2 perfusion. Currently, no systems-based therapies exist to treat severe burns. We have been developing a small-volume fluid therapy comprising adenosine, lidocaine and magnesium (ALM) to treat hemorrhagic shock, traumatic brain injury and sepsis. Our early studies indicate that the ALM therapy holds some promise in supporting cardiovascular and pulmonary functions following severe burns. Future research will investigate the ability of ALM therapy to treat severe burns with polytrauma and sex disparities, and potential translation to humans.

Unraveling the role of vaporization momentum in self-jumping dynamics of freezing supercooled droplets at reduced pressures

Supercooling of water complicates phase change dynamics, the understanding of which remains limited yet vital to energy-related and aerospace processes. Here, we investigate the freezing and jumping dynamics of supercooled water droplets on superhydrophobic surfaces, induced by a remarkable vaporization momentum, in a low-pressure environment. The vaporization momentum arises from the vaporization at droplet's free surface, progressed and intensified by recalescence, subsequently inducing droplet compression and finally self-jumping. By incorporating liquid-gas-solid phase changes involving vaporization, freezing recalescence, and liquid-solid interactions, we resolve the vaporization momentum and droplet dynamics, revealing a size-scaled jumping velocity and a nucleation-governed jumping direction. A droplet-size-defined regime map is established, distinguishing the vaporization-momentum-dominated self-jumping from evaporative drying and overpressure-initiated levitation, all induced by depressurization and vaporization. Our findings illuminate the role of supercooling and low-pressure mediated phase change in shaping fluid transport dynamics, with implications for passive anti-icing, advanced cooling, and climate physics.

Multicompartmental coacervate-based protocell by spontaneous droplet evaporation

Hierarchical compartmentalization, a hallmark of both primitive and modern cells, enables the concentration and isolation of biomolecules, and facilitates spatial organization of biochemical reactions. Coacervate-based compartments can sequester and recruit a large variety of molecules, making it an attractive protocell model. In this work, we report the spontaneous formation of core-shell cell-sized coacervate-based compartments driven by spontaneous evaporation of a sessile droplet on a thin-oil-coated substrate. Our analysis reveals that such far-from-equilibrium architectures arise from multiple, coupled segregative and associative liquid-liquid phase separation, and are stabilized by stagnation points within the evaporating droplet. The formation of stagnation points results from convective capillary flows induced by the maximum evaporation rate at the liquid-liquid-air contact line. This work provides valuable insights into the spontaneous formation and maintenance of hierarchical compartments under non-equilibrium conditions, offering a glimpse into the real-life scenario.

Triboelectric Nanogenerators Based on Fluid Medium: From Fundamental Mechanisms toward Multifunctional Applications

Fluid-based triboelectric nanogenerators (FB-TENGs) are at the forefront of promising energy technologies, demonstrating the ability to generate electricity through the dynamic interaction between two dissimilar materials, wherein at least one is a fluidic medium (such as gas or liquid). By capitalizing on the dynamic and continuous properties of fluids and their interface interactions, FB-TENGs exhibit a larger effective contact area and a longer-lasting triboelectric effect in comparison to their solid-based counterparts, thereby affording longer-term energy harvesting and higher-precision self-powered sensors in harsh conditions. In this review, various fluid-based mechanical energy harvesters, including liquid-solid, gas-solid, liquid-liquid, and gas-liquid TENGs, have been systematically summarized. Their working mechanism, optimization strategies, respective advantages and applications, theoretical and simulation analysis, as well as the existing challenges, have also been comprehensively discussed, which provide prospective directions for device design and mechanism understanding of FB-TENGs.

Bacteria Living in Biofilms in Fluids: Could Chemical Antibiofilm Pretreatment of Culture Represent a Paradigm Shift in Diagnostics?

Biofilms are multicellular aggregates of bacteria immersed in an extracellular matrix that forms on various surfaces, including biological tissues and artificial surfaces. However, more and more reports point out the fact that even biological fluids and semifluid, such as synovial liquid, blood, urine, or mucus and feces, harbor "non-attached" biofilm aggregates of bacteria, which represent a significant phenomenon with critical clinical implications that remain to be fully investigated. In particular, biofilm aggregates in biological fluid samples have been shown to play a relevant role in bacterial count and in the overall accuracy of microbiological diagnosis. In line with these observations, the introduction in the clinical setting of fluid sample pretreatment with an antibiofilm chemical compound called dithiothreitol (DTT), which is able to dislodge microorganisms from their intercellular matrix without killing them, would effectively improve the microbiological yield and increase the sensitivity of cultural examination, compared to the current microbiological techniques. While other ongoing research continues to unveil the complexity of biofilm formation in biological fluids and its impact on infection pathogenesis and diagnosis, we here hypothesize that the routine use of a chemical antibiofilm pretreatment of fluid and semi-solid samples may lead to a paradigm shift in the microbiological approach to the diagnosis of biofilm-related infections and should be further investigated and eventually implemented in the clinical setting.

Flow-induced periodic chiral structures in an achiral nematic liquid crystal

Supramolecular chirality typically originates from either chiral molecular building blocks or external chiral stimuli. Generating chirality in achiral systems in the absence of a chiral input, however, is non-trivial and necessitates spontaneous mirror symmetry breaking. Achiral nematic lyotropic chromonic liquid crystals have been reported to break mirror symmetry under strong surface or geometric constraints. Here we describe a previously unrecognised mechanism for creating chiral structures by subjecting the material to a pressure-driven flow in a microfluidic cell. The chirality arises from a periodic double-twist configuration of the liquid crystal and manifests as a striking stripe pattern. We show that the mirror symmetry breaking is triggered at regions of flow-induced biaxial-splay configurations of the director field, which are unstable to small perturbations and evolve into lower energy structures. The simplicity of this unique pathway to mirror symmetry breaking can shed light on the requirements for forming macroscopic chiral structures.

Rethinking Fluid Responsiveness during Septic Shock: Ameliorate Accuracy of Noninvasive Cardiac Output Measurements through Evaluation of Arterial Biomechanical Properties

Beat-to-beat estimates of cardiac output from the direct measure of peripheral arterial blood pressure rely on the assumption that changes in the waveform morphology are related to changes in blood flow and vasomotor tone. However, in septic shock patients, profound changes in vascular tone occur that are not uniform across the entire arterial bed. In such cases, cardiac output estimates might be inaccurate, leading to unreliable evaluation of fluid responsiveness. Pulse wave velocity is the gold-standard method for assessing different arterial biomechanical properties. Such methods might be able to guide, personalize and optimize the management of septic patients.

The effect of a 'Sip til Send' policy on patient satisfaction: a quality improvement project

Patients often are nil by mouth for prolonged periods pre-operatively, which is associated with adverse effects including discomfort, anxiety, thirst and nausea. As a result, several hospitals have introduced a more liberal regimen of pre-operative drinking, with patients encouraged to sip small volumes of water until transfer to the operating theatre ('Sip til Send'). The impact of 'Sip til Send' on patient satisfaction is still to be determined. We hypothesised that the introduction of a 'Sip til Send' policy would increase patient's satisfaction with their pre-operative fluid management regimen. We conducted a staged implementation of a 'Sip til Send' quality improvement initiative in two campuses of a large tertiary teaching hospital. This involved a targeted education and implementation programme that was refined and delivered through 'plan, do, study and act' cycles. Patient satisfaction with their pre-operative fluid management was measured by rating the statement "I am happy with the management of pre-operative drinking", against a five-point Likert scale (0, strongly disagree; 1, disagree; 2, neutral; 3, agree; and 4, strongly agree). Patient satisfaction with pre-operative fluid management was high at baseline, with pooled data for both campuses showing a median (IQR [range]) satisfaction score of 4 (3-4 [1-4]). After the implementation of 'Sip til Send', this improved to a median (IQR [range]) satisfaction score of 4 (4-4 [2-4]) (p < 0.001). The introduction of a 'Sip til Send' policy resulted in an increase in patient satisfaction. Key factors in successful implementation included the provision of a clear explanation of the underlying rationale to patients, nursing and anaesthetic staff, and establishing the policy as the default position for all elective patients.

Early sepsis in Australia and New Zealand: A point-prevalence study of haemodynamic resuscitation practices

OBJECTIVE

Optimal resuscitation of sepsis-induced hypotension is uncertain, particularly the role of restrictive fluid strategies, leading to variability in usual practice. The objective of this study is to understand resuscitation practices in patients presenting to ED with early sepsis.

METHODS

Design, participants and setting: Prospective, observational, multicentre, single-day, point-prevalence study enrolling adult patients present in 51 Australian and New Zealand ICUs at 10.00 hours, 8 June 2021.

MAIN OUTCOME MEASURES

Site-level data on sepsis policies and patient-level demographic data, presence of sepsis and fluid and vasopressor administration in the first 24 h post-ED presentation.

RESULTS

A total of 722 patients were enrolled. ED was the ICU admission source for 222 of 722 patients (31.2%) and 78 of 222 patients (35%) met the criteria for sepsis within 24 h of ED presentation. Median age of the sepsis cohort was 61 (48-72) years, 58% were male and respiratory infection was the commonest cause (53.8%). The sepsis cohort had a higher severity of illness than the non-sepsis cohort (144/222 patients) and chronic immunocompromise was more common. Of 78 sepsis patients, 55 (71%) received ≥1 fluid boluses with 500 and 1000 mL boluses equally common (both 49%). In the first 24 h, 2335 (1409-3125) mL (25.3 [13.2-42.9] mL/kg) was administered. Vasopressors were administered in 53 of 78 patients (68%) and for 25 patients (47%) administration was peripheral.

CONCLUSIONS

ICU patients presenting to the ED with sepsis receive less fluids than current international recommendations and peripheral vasopressor administration is common. This finding supports the conduct of clinical trials evaluating optimal fluid dose and vasopressor timing for early sepsis-induced hypotension.

Optimal free-surface pumping by an undulating carpet

Examples of fluid flows driven by undulating boundaries are found in nature across many different length scales. Even though different driving mechanisms have evolved in distinct environments, they perform essentially the same function: directional transport of liquid. Nature-inspired strategies have been adopted in engineered devices to manipulate and direct flow. Here, we demonstrate how an undulating boundary generates large-scale pumping of a thin liquid near the liquid-air interface. Two dimensional traveling waves on the undulator, a canonical strategy to transport fluid at low Reynolds numbers, surprisingly lead to flow rates that depend non-monotonically on the wave speed. Through an asymptotic analysis of the thin-film equations that account for gravity and surface tension, we predict the observed optimal speed that maximizes pumping. Our findings reveal how proximity to free surfaces, which ensure lower energy dissipation, can be leveraged to achieve directional transport of liquids.

Spontaneous shock waves in pulse-stimulated flocks of Quincke rollers

Active matter demonstrates complex spatiotemporal self-organization not accessible at equilibrium and the emergence of collective behavior. Fluids comprised of microscopic Quincke rollers represent a popular realization of synthetic active matter. Temporal activity modulations, realized by modulated external electric fields, represent an effective tool to expand the variety of accessible dynamic states in active ensembles. Here, we report on the emergence of shockwave patterns composed of coherently moving particles energized by a pulsed electric field. The shockwaves emerge spontaneously and move faster than the average particle speed. Combining experiments, theory, and simulations, we demonstrate that the shockwaves originate from intermittent spontaneous vortex cores due to a vortex meandering instability. They occur when the rollers' translational and rotational decoherence times, regulated by the electric pulse durations, become comparable. The phenomenon does not rely on the presence of confinement, and multiple shock waves continuously arise and vanish in the system.

The Effect of Fluid Resuscitation Timing in Early Sepsis Resuscitation

PURPOSE

The dose and timing of early fluid resuscitation in sepsis remains a debated topic. The objective of this study is to evaluate the effect of fluid timing in early sepsis management on mortality and other clinical outcomes.

METHODS

Single-center, retrospective cohort study of emergency-department-treated adults (>18 years, n = 1032) presenting with severe sepsis or septic shock. Logistic regression evaluating the impact of 30 mL/kg crystalloids timing and mortality-versus-time plot controlling for mortality in emergency department sepsis score, lactate, antibiotic timing, obesity, sex, systemic inflammatory response syndrome criteria, hypotension, and heart and renal failures. This study is a subanalysis of a previously published investigation.

RESULTS

Mortality was 17.1% (n = 176) overall and 20.4% (n = 133 of 653) among those in septic shock. 30 mL/kg was given to 16.9%, 32.2%, 16.2%, 14.5%, and 20.3% of patients within ≤1, 1 ≤ 3, 3 ≤ 6, 6 ≤ 24, and not reached within 24 h, respectively. A 24-h plot of adjusted mortality versus time did not reach significance, but within the first 12 h, the linear function showed a per-hour mortality increase (odds ratio [OR] 1.29, 95% confidence interval [CI] 1.02-1.67) which peaks around 5h, although the quadratic function does not reach significance (P = .09). When compared to patients receiving 30 mL/kg within 1 h, increased mortality was observed when not reached within 24 h (OR 2.69, 95% CI 1.37-5.37) but no difference when receiving this volume between 1 and 3 (OR 1.11, 95% CI 0.62-2.01), 3 and 6 (OR 1.83, 95% CI 0.97-3.52), or 6 and 24 h (OR 1.51, 95% CI 0.75-3.06). Receiving 30 mL/kg between 1 and 3 versus <1 h increased the incidence of delayed hypotension (OR 1.83, 95% CI 1.23-2.72) but did not impact need for intubation, intensive care unit admission, or vasopressors.

CONCLUSIONS

We observed weak evidence that supports that earlier is better for survival when reaching fluid goals of 30 mL/kg, but benefits may wane at later time points. These findings should be viewed as hypothesis generating.

The association between hypoalbuminemia and microcirculation, endothelium, and glycocalyx disorders in children with sepsis

OBJECTIVE

The objective of this study was to evaluate the association between serum albumin levels and microcirculation changes, glycocalyx degradation, and the clinical outcomes of interest.

METHODS

Observational, prospective study in children with sepsis. The primary outcome was the association between hypoalbuminemia and microcirculation disorders, endothelial activation and glycocalyx degradation using a perfused boundary region (PBR) (abnormal >2.0 μm on sublingual video microscopy) or plasma biomarkers (syndecan-1, angiopoietin-2).

RESULTS

A total of 125 patients with sepsis were included. The median age was 2.0 years (IQR 0.5-12.5). Children with hypoalbuminemia had more abnormal microcirculation with a higher PBR (2.16 μm [IQR 2.03-2.47] vs. 1.92 [1.76-2.28]; p = .01) and more 4-6 μm capillaries recruited (60% vs. 40%; p = .04). The low albumin group that had the worst PBR had the most 4-6 μm capillaries recruited (rho 0.29; p < .01), 48% higher Ang-2 (p = .04), worse annexin A5 (p = 0.03) and no syndecan-1 abnormalities (p = .21). Children with hypoalbuminemia and a greater percentage of blood volume in their capillaries needed mechanical ventilation more often (56.3% vs. 43.7%; aOR 2.01 95% CI 1.38-3.10: p < .01).

CONCLUSIONS

In children with sepsis, an association was found between hypoalbuminemia and microcirculation changes, vascular permeability, and greater endothelial glycocalyx degradation.

Anisotropy in spinodal-like dynamics of unknown water at ice V-water interface

Experimentally demonstrating the existence of waters with local structures unlike that of common water is critical for understanding both the origin of the mysterious properties of water and liquid polymorphism in single component liquids. At the interfaces between water and ices Ih, III, and VI grown/melted under pressure, we previously discovered low- and high-density unknown waters, that are immiscible with the surrounding water. Here, we show, by in-situ optical microscopy, that an unknown water appears at the ice V-water interface via spinodal-like dynamics. The dewetting dynamics of the unknown water indicate that its characteristic velocity is ~ 90 m/s. The time evolution of the characteristic length of the spinodal-like undulation suggests that the dynamics may be described by a common model for spinodal decomposition of an immiscible liquid mixture. Spinodal-like dewetting dynamics of the unknown water transiently showed anisotropy, implying the property of a liquid crystal.

Liquid-liquid phase separation within fibrillar networks

Complex fibrillar networks mediate liquid-liquid phase separation of biomolecular condensates within the cell. Mechanical interactions between these condensates and the surrounding networks are increasingly implicated in the physiology of the condensates and yet, the physical principles underlying phase separation within intracellular media remain poorly understood. Here, we elucidate the dynamics and mechanics of liquid-liquid phase separation within fibrillar networks by condensing oil droplets within biopolymer gels. We find that condensates constrained within the network pore space grow in abrupt temporal bursts. The subsequent restructuring of condensates and concomitant network deformation is contingent on the fracture of network fibrils, which is determined by a competition between condensate capillarity and network strength. As a synthetic analog to intracellular phase separation, these results further our understanding of the mechanical interactions between biomolecular condensates and fibrillar networks in the cell.

Possible development and resolution of dilated cardiomyopathy phenotype secondary to atypical hypoadrenocorticism in a dog

OBJECTIVE

To report the possible occurrence of dilated cardiomyopathy phenotype associated with atypical hypoadrenocorticism and subsequent marked improvement with treatment in a mixed breed dog.

CASE SUMMARY

A 4.5-year-old, neutered male mixed breed dog was evaluated for a history and clinicopathological changes consistent with atypical hypoadrenocorticism. The dog was being fed a grain-free diet. While hospitalized for supportive care and diagnostics, the patient developed and was diagnosed with biventricular congestive heart failure secondary to dilated cardiomyopathy phenotype and IV fluid administration. The left-sided congestive heart failure resolved with discontinuation of IV fluid therapy and short-term administration of diuretics. After treatment of atypical hypoadrenocorticism with glucocorticoid supplementation, and while continuing to be fed varying grain-free diets, the patient's dilated cardiomyopathy phenotype largely resolved. The patient fully recovered and did not require any long-term cardiac medications.

NEW OR UNIQUE INFORMATION PROVIDED

Development of dilated cardiomyopathy phenotype has not been described in dogs as a sequela of untreated hypoadrenocorticism but has been reported in human literature. Given the fact that standard management of hypoadrenocorticism typically involves aggressive fluid resuscitation, awareness of this potential sequela is important for patients that fail to respond or develop signs consistent with volume overload.

Pulse Pressure Variance (PPV)-Guided Fluid Management in Adult Patients Undergoing Supratentorial Tumor Surgeries: A Randomized Controlled Trial

Objective  Appropriate fluid management in neurosurgery is critical due to the risk of secondary brain injury. Determination of volume status is challenging with static variables being unreliable. Goal-directed fluid therapy with dynamic variables allows reliable determination of fluid responsiveness and promises better outcomes. We aimed to compare the intraoperative fluid requirement between conventional central venous pressure (CVP)-guided and pulse pressure variance (PPV)-guided fluid management in supratentorial tumor surgeries. Materials and Methods  This prospective, randomized, double-blind, single-center trial was conducted with 72 adults undergoing supratentorial tumor surgery in a supine position. Patients were divided into two groups of 36 patients each receiving CVP- and PPV-guided fluid therapy. The CVP-guided group received boluses to target CVP greater than 8 mm Hg along with hourly replacement of intraoperative losses and maintenance fluids. The PPV-guided group received boluses to target PPV less than 13% in addition to maintenance fluids. Total intraoperative fluids administered and the incidence of hypotension was recorded along with the brain relaxation score. Postoperatively, serum lactate levels, periorbital and conjunctival edema, as well as postoperative nausea and vomiting were assessed. Statistical Analyses  All statistical analyses were performed with Statistical Package for Social Sciences, version-20 (SPSS-20, IBM, Chicago, Illinois, United States). To compare the means between the two groups (CVP vs. PPV), independent samples t -test was used for normal distribution data and Mann-Whitney U test for nonnormal distribution data. The chi-square test or Fischer's exact test was used for categorical variables. Results  The CVP group received significantly more intraoperative fluids than the PPV group (4,340 ± 1,010 vs. 3,540 ± 740 mL, p  < 0.01). Incidence of hypotension was lower in the PPV group (4 [11.1%] vs. 0 [0%], p  = 0.04). Brain relaxation scores, serum lactate levels, periorbital and conjunctival edema, and incidence of postoperative nausea and vomiting were comparable between the groups. Conclusion  The requirement for intraoperative fluids was less in PPV-guided fluid management with better hemodynamic stability, adequate brain conditions, and no compromise of perfusion.

Intraoperative use of balanced crystalloids versus 0.9% saline: a systematic review and meta-analysis of randomised controlled studies

BACKGROUND

The evidence regarding optimal crystalloid use in the perioperative period remains unclear. As the primary aim of this study, we sought to summarise the data from RCTs examining whether use of balanced crystalloids compared with 0.9% saline (saline) leads to differences in patient-important outcomes.

METHODS

We searched Ovid MEDLINE, Embase, the Cochrane library, and Clinicaltrials.gov, from inception until December 15, 2022, and included RCTs that intraoperatively randomised adult participants to receive either balanced fluids or saline. We pooled data using a random-effects model and present risk ratios (RRs) or mean differences (MDs), along with 95% confidence intervals (CIs). We assessed individual study risk of bias using the modified Cochrane tool, and certainty of evidence using GRADE.

RESULTS

Of 5959 citations, we included 38 RCTs (n=3776 patients). Pooled analysis showed that intraoperative use of balanced fluids compared with saline had an uncertain effect on postoperative mortality analysed at the longest point of follow-up (RR 1.51, 95% CI: 0.42-5.36) and postoperative need for renal replacement therapy (RR 0.95, 95% CI: 0.56-1.59), both very low certainty. Furthermore, use of balanced crystalloids probably leads to a higher postoperative serum pH (MD 0.05, 95% CI: 0.04-0.06), moderate certainty.

CONCLUSIONS

Use of balanced crystalloids, compared with saline, in the perioperative setting has an uncertain effect on mortality and need for renal replacement therapy but probably improves postoperative acid-base status. Further research is needed to determine whether balanced crystalloid use affects patient-important outcomes.

CLINICAL TRIAL REGISTRATION

CRD42022367593.

Impact of hierarchical water dipole orderings on the dynamics of aqueous salt solutions

Ions exhibit highly ion-specific complex behaviours when solvated in water, which remains a mystery despite the fundamental importance of ion solvation in nature, science, and technology. Here we explain these ion-specific properties by the ion-induced hierarchical dipolar, translational, and bond-orientational orderings of ion hydration shell under the competition between ion-water electrostatic interactions and inter-water hydrogen bonding. We first characterise this competition by a new length λHB(q), explaining the ion-specific effects on solution dynamics. Then, by continuously tuning ion size and charge, we find that the bond-orientational order of the ion hydration shell highly develops for specific ion size and charge combinations. This ordering drastically stabilises the hydration shell; its degree changes the water residence time around ions by 11 orders of magnitude for main-group ions. These findings are fundamental to ionic processes in aqueous solutions, providing a physical principle for electrolyte design and application.

Hemolytic Anemia-Related Acute Kidney Injury: A Case Report With Complications Including Posterior Reversible Encephalopathy Syndrome

INTRODUCTION

The condition known as posterior reversible encephalopathy syndrome (PRES) is characterized by symptoms such as headaches, seizures, and vision problems due to brain swelling, which often can be seen in brain scans. While there have been some cases of PRES linked to conditions such autoimmune diseases and high blood pressure, we're sharing a unique case here. Our case involves severe kidney damage caused by idiopathic hemolytic anaemia. The patient also experienced loss of consciousness, seizures, and headache. Brain scans confirmed the signs of PRES. We managed to help the patient recover fully through careful treatment, including fluids, managing seizures, and transfusions.

CASE DETAILS

Our patient was dealing with severe kidney damage from idiopathic hemolytic anaemia. They had episodes of loss of consciousness, seizures, and headaches. Brain scans showed that they had PRES.

DIAGNOSIS AND TREATMENT

We found out that the patient had severe kidney damage because of hemolytic anaemia, and she also had PRES. We treated her by giving fluids, managing her seizures, and doing blood transfusions, along with other supportive care.

CONCLUSIONS

With our treatment, the patient got better, her neurological symptoms improved, and her brain scans showed fewer signs of PRES. This case tells us something interesting - sometimes, anaemia can lead to rare neurological problems like PRES. We need to be aware of these possibilities to help patients better. Our successful treatment in this case emphasizes how important quick and comprehensive care can be for good outcomes.

Assessment of Fiber Bragg Grating Sensors for Monitoring Shaft Vibrations of Hydraulic Turbines

The structural dynamic response of hydraulic turbines needs to be continuously monitored to predict incipient failures and avoid catastrophic breakdowns. Current methods based on traditional off-board vibration sensors mounted on fixed components do not permit inferring loads induced on rotating parts with enough accuracy. Therefore, the present paper assesses the performance of fiber Bragg grating sensors to measure the vibrations induced on a rotating shaft-disc assembly partially submerged in water resembling a hydraulic turbine rotor. An innovative mounting procedure for installing the sensors is developed and tested, which consists of machining a thin groove along a shaft line to embed a fiber-optic array that can pass through the bearings. At the top of the shaft, a rotary joint is used to extract, in real time, the signals to the interrogator. The shaft strain distribution is measured with high spatial resolution at different rotating speeds in air and water. From this, the natural frequencies, damping ratios, and their associated mode shapes are quantified at different operating conditions. Additionally, the change induced in the modes of vibration by the rotation effects is well captured. All in all, these results validate the suitability of this new fiber-optic technology for such applications and its overall better performance in terms of sensitivity and spatial resolution relative to traditional equipment. The next steps will consist of testing this new sensing technology in actual full-scale hydraulic turbines.

New Insights into the Fluid Management in Patients with Septic Shock

The importance of fluid resuscitation therapy during the early stages of sepsis management is a well-established principle. Current Surviving Sepsis Campaign (SSC) guidelines recommend the early administration of intravenous crystalloid fluids for sepsis-related hypotension or hyperlactatemia due to tissue hypoperfusion, within the first 3 h of resuscitation and suggest using balanced solutions (BSs) instead of normal saline (NS) for the management of patients with sepsis or septic shock. Studies comparing BS versus NS administration in septic patients have demonstrated that BSs are associated with better outcomes including decreased mortality. After initial resuscitation, fluid administration has to be judicious in order to avoid fluid overload, which has been associated with increased mortality, prolonged mechanical ventilation, and worsening of acute kidney injury. The "one size fits all" approach may be "convenient" but it should be avoided. Personalized fluid management, based on patient-specific hemodynamic indices, provides the foundations for better patient outcomes in the future. Although there is a consensus on the need for adequate fluid therapy in sepsis, the type, the amount of administered fluids, and the ideal fluid resuscitation strategy remain elusive. Well-designed large randomized controlled trials are certainly needed to compare fluid choices specifically in the septic patient, as there is currently limited evidence of low quality. This review aims to summarize the physiologic principles and current scientific evidence regarding fluid management in patients with sepsis, as well as to provide a comprehensive overview of the latest data on the optimal fluid administration strategy in sepsis.

Navigating nutrition and hydration care in the adult patient with short bowel syndrome

Attending diligently to the nutrition and hydration needs of patients with short bowel syndrome (SBS) is a key tenet of their care, both postoperatively and in the years that follow. For, without each, patients are left to themselves to navigate the nutrition consequences of SBS, including malnutrition, nutrient deficiencies, renal compromise, osteoporosis, fatigue, depression, and impaired quality of life. The intent of this review is to discuss the initial nutrition assessment, oral diet, hydration, and home nutrition support for the patient with SBS.

United Kingdom artificial nutrition database: the changing landscape of adult home parenteral support 2005 to 2016

BACKGROUND & AIMS

The United Kingdom (UK) nutrition database monitors the changing landscape of adult home parenteral nutrition support (HPS) to inform clinicians and policy makers of the need for this life saving treatment.

METHODS

The UK database is administered by the British Association for Parenteral and Enteral Nutrition (BAPEN). Data for home parenteral nutrition (HPN) has been collected since 2005 and home intravenous fluids (HIVF) since 2011. During this study the reporting of data to the database by healthcare workers has been voluntary. Data were analysed using linear regression.

RESULTS

A 3-fold increase of new registrations for HPS patients was noted on this 10-year period, with notable increase in the numbers of patients with advanced malignancy supported with HPS. Crohn's disease and short bowel syndrome were the leading causes for both HPN and HIVF in the UK. A statistically significant increase in older (p<0.001) and less independent patients using HPS was noted.

CONCLUSIONS

The prevalence of HPS is steadily increasing in size with broadening of acceptable performance status. The launch of the Intestinal Failure Registry and mandatory registration will increase accuracy in data reporting. This article is protected by copyright. All rights reserved.

The collective burst mechanism of angular jumps in liquid water

Understanding the microscopic origins of collective reorientational motions in aqueous systems requires techniques that allow us to reach beyond our chemical imagination. Herein, we elucidate a mechanism using a protocol that automatically detects abrupt motions in reorientational dynamics, showing that large angular jumps in liquid water involve highly cooperative orchestrated motions. Our automatized detection of angular fluctuations, unravels a heterogeneity in the type of angular jumps occurring concertedly in the system. We show that large orientational motions require a highly collective dynamical process involving correlated motion of many water molecules in the hydrogen-bond network that form spatially connected clusters going beyond the local angular jump mechanism. This phenomenon is rooted in the collective fluctuations of the network topology which results in the creation of defects in waves on the THz timescale. The mechanism we propose involves a cascade of hydrogen-bond fluctuations underlying angular jumps and provides new insights into the current localized picture of angular jumps, and its wide use in the interpretations of numerous spectroscopies as well in reorientational dynamics of water near biological and inorganic systems. The role of finite size effects, as well as of the chosen water model, on the collective reorientation is also elucidated.

A micro-vibration-driven direct ink write printing method of gallium-indium alloys

Combining liquid fluidity and metallic conductivity, gallium-indium (Ga-In) alloys are making a splash in areas such as stretchable electronic circuits and wearable medical devices. Due to high flexibility, direct ink write printing is already widely employed for printing Ga-In alloys. Currently, pneumatic extrusion is the main method of direct ink write printing, but the oxide skin and low viscosity of the Ga-In alloys make it challenging to control after extrusion. This work proposed a method for direct ink write printing of Ga-In alloys utilizing micro-vibration-driven extrusion. Micro-vibration reduces the surface tension of Ga-In alloy droplets and avoids the appearance of random droplets during printing. Under micro-vibration, the nozzle tip pierces the oxide skin to form small droplets which have a high moldability. The droplet growth process is significantly slowed down by optimizing suitable micro-vibration parameters. Therefore, the Ga-In alloy droplets with high moldability can be maintained at the nozzle for a long period, which improves printability. Furthermore, better printing outcomes were obtained with micro-vibrations by choosing the proper nozzle height and printing speed. Experiment results demonstrated the superiority of the method in terms of Ga-In alloys extrusion control. With this method, the printability of the liquid metals is enhanced.

Population-based heteropolymer design to mimic protein mixtures

Biological fluids, the most complex blends, have compositions that constantly vary and cannot be molecularly defined1. Despite these uncertainties, proteins fluctuate, fold, function and evolve as programmed2-4. We propose that in addition to the known monomeric sequence requirements, protein sequences encode multi-pair interactions at the segmental level to navigate random encounters5,6; synthetic heteropolymers capable of emulating such interactions can replicate how proteins behave in biological fluids individually and collectively. Here, we extracted the chemical characteristics and sequential arrangement along a protein chain at the segmental level from natural protein libraries and used the information to design heteropolymer ensembles as mixtures of disordered, partially folded and folded proteins. For each heteropolymer ensemble, the level of segmental similarity to that of natural proteins determines its ability to replicate many functions of biological fluids including assisting protein folding during translation, preserving the viability of fetal bovine serum without refrigeration, enhancing the thermal stability of proteins and behaving like synthetic cytosol under biologically relevant conditions. Molecular studies further translated protein sequence information at the segmental level into intermolecular interactions with a defined range, degree of diversity and temporal and spatial availability. This framework provides valuable guiding principles to synthetically realize protein properties, engineer bio/abiotic hybrid materials and, ultimately, realize matter-to-life transformations.

Retrospective evaluation of intravenous catheterization in client-owned lizards at a veterinary teaching hospital: 21 cases (2018-2021)

OBJECTIVE

To assess the prevalence of lizards presenting to a university teaching hospital that had an IV catheter placed, the catheterization sites used, and complications arising with the placement of the catheter both in the short and long term.

DESIGN

Retrospective study.

SETTING

University teaching hospital.

ANIMALS

Twenty-one lizards, including inland bearded dragons (Pogona vitticeps; 15/21), green iguanas (Iguana iguana; 4/21), and veiled chameleons (Chamaeleo calyptratus; 2/21).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of 129 lizard consultations performed between September 27, 2018 and September 27, 2021, 21 catheters were placed, resulting in an overall prevalence of 16.3%. Reasons for catheter placement included hospitalization for fluid therapy (10/21 [47.6%]), anesthesia or surgery ± hospitalization (7/21 [33.3%]), computed tomography scan with contrast (2/21 [9.5%]), euthanasia only (1/21 [4.8%]), and CPR only (1/21 [4.8%]). All catheters were placed in the ventral coccygeal vein via a ventral approach. Sedation was used in 6 of 21 (28.6%) of the catheters placed. Seven of the catheters (35%) were used for administration of fluids only, 4 (20%) were used for administering drugs/medications only, and 9 (45%) catheters administered both fluids and drugs/medications. No complications were noticed in any of the lizards that had catheters placed, both in the short and long term.

CONCLUSIONS

Based on the retrospective evaluation of medical records at a veterinary teaching hospital, IV catheter placement in lizards is feasible, including in conscious animals, with roughly 1 consultation out of 6 resulting in a catheter placed. The most frequent reason for catheter placement was for administration of fluids.

Softness of hydrated salt crystals under deliquescence

Deliquescence is a first-order phase transition, happening when a salt absorbs water vapor. This has a major impact on the stability of crystalline powders that are important for example in pharmacology, food science and for our environment and climate. Here we show that during deliquescence, the abundant salt sodium sulfate decahydrate, mirabilite (Na₂SO₄·10H₂O), behaves differently than anhydrous salts. Using various microscopy techniques combined with Raman spectroscopy, we show that mirabilite crystals not only lose their facets but also become soft and deformable. As a result, microcrystals of mirabilite simultaneously behave crystalline-like in the core bulk and liquid-like at the surface. Defects at the surface can heal at a speed much faster than the deliquescence rate by the mechanism of visco-capillary flow over the surface. While magnesium sulfate hexahydrate (MgSO₄⋅6H₂O) behaves similarly during deliquescence, a soft and deformable state is completely absent for the anhydrous salts sodium chloride (NaCl) and sodium sulfate thenardite (Na₂SO₄). The results highlight the effect of crystalline water, and its mobility in the crystalline structure on the observed softness during deliquescence. Controlled hydrated salts have potential applications such as thermal energy storage, where the key parameter is relative humidity rather than temperature.

Spatially non-uniform condensates emerge from dynamically arrested phase separation

The formation of biomolecular condensates through phase separation from proteins and nucleic acids is emerging as a spatial organisational principle used broadly by living cells. Many such biomolecular condensates are not, however, homogeneous fluids, but possess an internal structure consisting of distinct sub-compartments with different compositions. Notably, condensates can contain compartments that are depleted in the biopolymers that make up the condensate. Here, we show that such double-emulsion condensates emerge via dynamically arrested phase transitions. The combination of a change in composition coupled with a slow response to this change can lead to the nucleation of biopolymer-poor droplets within the polymer-rich condensate phase. Our findings demonstrate that condensates with a complex internal architecture can arise from kinetic, rather than purely thermodynamic driving forces, and provide more generally an avenue to understand and control the internal structure of condensates in vitro and in vivo.

A Review of Subsurface Electrical Conductivity Anomalies in Magnetotelluric Imaging

After 70 years of development, magnetotelluric (MT), a remote sensing technique for subsurface electrical resistivity imaging, has been widely applied in resource exploration and the deep tectonic evolution of the Earth. The electrical resistivity anomalies and their quantitative interpretation are closely related to or even controlled by the interconnected high-conductivity phases, which are frequently associated with tectonic activity. Based on representative electrical resistivity studies mainly of the deep crust and mantle, we reviewed principal electrical conduction mechanisms, generally used conductivity mixing models, and potential causes of high-conductivity including the saline fluid, partial melting, graphite, sulfide, and hydrogen in nominally anhydrous minerals, and the general methods to infer the water content of the upper mantle through electrical anomaly revealed by MT.

Trajectory of plasma syndecan-1 and heparan sulphate during major surgery: A retrospective observational study

BACKGROUND

Surgical trauma-induced inflammation during major surgery may disrupt endothelial integrity and affect plasma concentrations of glycocalyx constituents, such as syndecan-1 and heparan sulphate. To date, no studies have focused on their perioperative temporal changes.

METHODS

As part of a trial, we obtained plasma and urine specimens sampled during the perioperative period in 72 patients undergoing major abdominal surgery. The plasma concentration of syndecan-1 and heparan sulphate was measured on five occasions, from baseline to the second postoperative day. Plasma and urinary creatinine and urinary syndecan-1 concentrations were measured before surgery and on the first postoperative morning.

RESULTS

We observed three different temporal patterns of plasma syndecan-1 concentration. Group 1 'low' (64% of patients) showed only minor changes from baseline despite a median heparan sulphate increase of 67% (p < .005). Group 2 'increase' (21% of patients) showed a marked increase in median plasma syndecan-1 from 27 μg/L to 118 μg/L during the first postoperative day (p < .001) with a substantial (+670%; p < .005) increase in median plasma heparan sulphate from 279 to 2196 μg/L. Group 3 'high' (14% of patients) showed a constant elevation of plasma syndecan-1 to >100 μg/L, but low heparan sulphate levels. The plasma C-reactive protein concentration did not differ across the three groups and 90% of colon surgeries occurred in Group 1. Treatment with dexamethasone was similar across the three groups. Surgical blood loss, duration of surgery and liver resection were greatest in Group 2.

CONCLUSION

Changes in syndecan-1 and heparan sulphate after surgery appear to show three different patterns, with the greatest increases in those patients with greater blood loss, more liver surgery and longer operations. These observations suggest that increases in syndecan-1 and heparan sulphate reflect the degree of surgical injury.

Heterogeneous Strain Distribution Based Programmable Gated Microchannel for Ultrasensitive and Stable Strain Sensing

Developing highly sensitive strain sensors requires conduction pathways capable of rapidly switching between disconnection and reconnection in response to strain. Ion channels in living organisms exactly control the channel switch through protein-composed gates, achieving changeable ion currents. Herein, inspired by the gating characteristics of the ion channels, a programmable fluidic strain sensor enhanced by gating ion pathways through heterogeneous strain distribution of discrete micropillars is proposed. During stretching, the contraction and closure of the widthwise gaps between discrete micropillars greatly weaken or even nearly cut off the conduction pathway, resulting in orders of magnitude increase in resistance and thus ultrahigh sensitivity. By adjusting the combination form and structural parameters of the discrete micropillars in the fluidic channel, the sensitivity and strain range can be customized. Thus, a gauge factor of up to 45 300 and a stretch range of 590% are obtained. Benefiting from the fluidic gating mechanism, no mechanical mismatch can be observed at the interface, breaking through the sensing stability issue of flexible sensors. The proposed sensor can be used to detect the full range of human motion, and integrated into a data glove to achieve human-machine interaction.

Exploiting ferrofluidic wetting for miniature soft machines

Miniature magnetic soft machines could significantly impact minimally invasive robotics and biomedical applications. However, most soft machines are limited to solid magnetic materials, whereas further progress also relies on fluidic constructs obtained by reconfiguring liquid magnetic materials, such as ferrofluid. Here we show how harnessing the wettability of ferrofluids allows for controlled reconfigurability and the ability to create versatile soft machines. The ferrofluid droplet exhibits multimodal motions, and a single droplet can be controlled to split into multiple sub-droplets and then re-fuse back on demand. The soft droplet machine can negotiate changing terrains in unstructured environments. In addition, the ferrofluid droplets can be configured as a liquid capsule, enabling cargo delivery; a wireless omnidirectional liquid cilia matrix capable of pumping biofluids; and a wireless liquid skin, allowing multiple types of miniature soft machine construction. This work improves small magnetic soft machines' achievable complexity and boosts their future biomedical applications capabilities.

Rail induced lateral migration of particles across intact co-flowing liquids

This paper presents a rail guided method to apply a Layer-by-Layer (LbL) coating on particles in a microfluidic device. The passive microfluidic approach allows handling suspensions of particles to be coated in the system. The trajectory of the particles is controlled using engraved rails, inducing lateral movement of particles while keeping the axially oriented liquid flow (and the interface of different liquids) undisturbed. The depth and angle of the rails together with the liquid velocity were studied to determine a workable geometry of the device. A discontinuous LbL coating procedure was converted into one continuous process, demonstrating that the chip can perform seven consecutive steps normally conducted in batch operation, further easily extendable to larger cycle numbers. Coating of the particles with two bilayers was confirmed by fluorescence microscopy.

Quantitative Determination of Endogenous Tetrahydroisoquinolines, Potential Parkinson's Disease Biomarkers, in Mammals

Current diagnostic options for Parkinson's disease are very limited and primarily based on characteristic clinical symptoms. Thus, there are urgent needs for reliable biomarkers that enable us to diagnose the disease in the early stages, differentiate it from other atypical Parkinsonian syndromes, monitor its progression, increase knowledge of its pathogenesis, and improve the development of potent therapies. A promising group of potential biomarkers are endogenous tetrahydroisoquinoline metabolites, which are thought to contribute to the multifactorial etiology of Parkinson's disease. The aim of this critical review is to highlight trends and limitations of available traditional and modern analytical techniques for sample pretreatment (extraction and derivatization procedures) and quantitative determination of tetrahydroisoquinoline derivatives in various types of mammalian fluids and tissues (urine, plasma, cerebrospinal fluid, brain tissue, liver tissue). Particular attention is paid to the most sensitive and specific analytical techniques, involving immunochemistry and gas or liquid chromatography coupled with mass spectrometric, fluorescence, or electrochemical detection. The review also includes a discussion of other relevant agents proposed and tested in Parkinson's disease.

Kinetic arrest during the drying of cellulose nanocrystal films from aqueous suspensions analogous to the freezing of thermal motions

A comprehensive understanding of controlling the iridescence of cellulose films by manipulating the alignment and helical pitch of cellulose nanocrystals (CNCs) is required to advance cellulose photonics and its optoelectronic applications. Aqueous suspensions of CNCs exhibit a cholesteric liquid crystal (LC) phase with structural color; however, attaining a uniformly colored film is extremely difficult. Presumably, because multiple interrelated factors influence the CNC molecular alignment and helical pitch, existing models are not necessarily conclusive and remain a subject of debate. To eventually achieve homogeneously colored films, we compare aqueous CNC suspensions as a lyotropic liquid LC with thermotropic ones, and we spectroscopically confirm that the coloration of CNC droplets originates from the periodic CNC structure. The suspension drying process significantly influences the quality of iridescence of CNC films. Rapidly drying a droplet of a CNC suspension forms a concentric rainbow film, with red edges and a blue center, typical of the coffee-ring effect observed in air-dried films. By contrast, slow drying under controlled humidity, which reduces capillary flow, provides higher uniformity and a large blue area. Orbitally shaking films while drying under high humidity further improves the uniformity. Therefore, the evaporation rate significantly influences the thermodynamically stabilized helical pitch of CNCs, which determines the structural color. We qualitatively model the kinetic arrest induced by the rapid evaporation of lyotropic LCs in a manner equivalent to that induced by the rate of temperature change in thermotropic LCs and other materials.

Fluids or vasopressors for the initial resuscitation of septic shock

Intravenous fluid resuscitation is recommended first-line treatment for sepsis-associated hypotension and/or hypoperfusion. The rationale is to restore circulating volume and optimize cardiac output in the setting of shock. Nonetheless, there is limited high-level evidence to support this practice. Over the past decade emerging evidence of harm associated with large volume fluid resuscitation among patients with septic shock has led to calls for a more conservative approach. Specifically, clinical trials undertaken in Africa have found harm associated with initial fluid resuscitation in the setting of infection and hypoperfusion. While translating these findings to practice in other settings is problematic, there has been a re-appraisal of current practice with some recommending earlier use of vasopressors rather than repeated fluid boluses as an alternative to restore perfusion in septic shock. There is consequently uncertainty and variation in practice. The question of fluids or vasopressors for initial resuscitation in septic shock is the subject of international multicentre clinical trials.

Active boundary layers in confined active nematics

The role of boundary layers in conventional liquid crystals is commonly related to the mesogen anchoring on confining walls. In the classical view, anchoring enslaves the orientational field of the passive material under equilibrium conditions. In this work, we show that an active nematic can develop active boundary layers that topologically polarize the confining walls. We find that negatively-charged defects accumulate in the boundary layer, regardless of the wall curvature, and they influence the overall dynamics of the system to the point of fully controlling the behavior of the active nematic in situations of strong confinement. Further, we show that wall defects exhibit behaviors that are essentially different from those of their bulk counterparts, such as high motility or the ability to recombine with another defect of like-sign topological charge. These exotic behaviors result from a change of symmetry induced by the wall in the director field around the defect. Finally, we suggest that the collective dynamics of wall defects might be described in terms of a model equation for one-dimensional spatio-temporal chaos.

Five material tissue decomposition by dual energy computed tomography

The separation of mixtures of substances into their individual components plays an important role in many areas of science. In medical imaging, one method is the established analysis using dual-energy computed tomography. However, when analyzing mixtures consisting of more than three individual basis materials, a physical limit is reached that no longer allows this standard analysis. In addition, the X-ray attenuation coefficients of chemically complicated basis materials may not be known and also cannot be determined by other or previous analyses. To address these issues, we developed a novel theoretical approach and algorithm and tested it on samples prepared in the laboratory as well as on ex-vivo medical samples. This method allowed both five-material decomposition and determination or optimization of the X-ray attenuation coefficients of the sample base materials via optimizations of objective functions. After implementation, this new multimodal method was successfully tested on self-mixed samples consisting of the aqueous base solutions iomeprol, eosin Y disodiumsalt, sodium chloride, and pure water. As a first proof of concept of this technique for detailed material decomposition in medicine we analyzed exact percentage composition of ex vivo clots from patients with acute ischemic stroke, using histological analysis as a reference standard.

The Effect of Fluid Initiation Timing on Sepsis Mortality: A Meta-Analysis

OBJECTIVE

Current guidelines suggest the immediate initiation of crystalloid for sepsis-induced hypoperfusion but note that supporting evidence is low quality. The aim of this study is to examine the effect of timing of fluid initiation on mortality for adults with sepsis.

DATA SOURCES

Two authors independently reviewed relevant articles and extracted study details from PubMed, Scopus, Cochrane, Google Scholar, and previous relevant systematic reviews from 1-1-2000 to 1-6-2022. Registered with PROSPERO (CRD42021245431) and bias assessed using CLARITY.

STUDY SELECTION

A minimum of severe sepsis (Sepsis-2) or sepsis (Sepsis-3) for patients ≥18 years old. Fluid initiation timing ranging from prehospital to 120 min within sepsis onset defined as "early" initiation.

DATA EXTRACTION

Included studies providing mortality-based odds ratios (or comparable) adjusting for confounders or prospective trials.

DATA SYNTHESIS

From 1643 citations, five retrospective cohort studies were included (n = 20,209) with in-hospital mortality of 21.8%. A pooled analysis (odds ratio = OR [95% CI]) did not observe an impact on mortality for the early initiation of fluids among all patients, OR = 0.79 [0.62-1.02]; heterogeneity: I² = 86% [70-94%], but when studies analyzed cases of hypotension where available, a survival benefit was observed, OR = 0.74 [0.61-0.90]. Initiation of fluids in two prehospital studies did not impact mortality, OR = 0.82 [0.27-2.43]. However, both prehospital cohorts observed benefit among hypotensive patients individually, although heterogenous results precluded significance when pooled, OR = 0.50 [0.21-1.18]. Three hospital-based studies with initiation stratified at 30, 100, and 120 min, observed survival benefit both individually and when pooled, OR = 0.78 [0.63-0.97]. No differences were observed between prehospital versus hospital subgroups.

CONCLUSION

This meta-analysis supports the guideline recommendations for early fluid initiation once sepsis is recognized, especially in cases of hypotension. Findings are limited by the small number, heterogeneity, and retrospective nature of available studies. Further retrospective investigations may be worthwhile as randomized studies on fluid initiation are unlikely.

Modified fluid gelatin 4% for perioperative volume replacement in pediatric patients (GPS): Results of a European prospective noninterventional multicenter study

INTRODUCTION

Modified fluid gelatin 4% is approved for use in children, but there is still a surprising lack of clinical studies including large numbers of pediatric patients. Therefore, we performed a European prospective noninterventional multicenter study to evaluate the use of a modified fluid gelatin 4% in saline (sal-GEL) or an acetate-containing balanced electrolyte solution (bal-GEL) in children undergoing major pediatric surgery.

AIMS

The primary aim was to assess the indications and dosing of modified fluid gelatin, and the secondary aim was to assess the safety and efficacy, focusing, in particular, on routinely collected clinical parameters.

METHODS

Children aged up to 12 years with ASA risk scores of I-III receiving sal-GEL or bal-GEL were followed perioperatively. Demographic data, surgical procedures performed, anesthesia, hemodynamic and laboratory data, adverse events, and adverse drug reactions were documented using a standardized case report form.

RESULTS

601 children that were investigated at 13 European pediatric centers from May 2015 to March 2020 (sal-GEL 20.1%, bal-GEL 79.9%; mean age 29.1 ± 38.6 (range 0-144) months; body weight 12.1 ± 10.5 (1.4-70) kg) were included in the analysis. The most frequent indications for GEL infusion were hemodynamic instability without bleeding (76.0%), crystalloids alone not being sufficient for hemodynamic stabilization (55.7%), replacement of preoperative deficit (26.0%), and significant bleeding (13.0%). Mean infused GEL volume was 13.0 ± 5.3 (2.4-37.5) ml kg^-1 . The total dose was affected by age, with higher doses in younger patients. After gelatin infusion, mean arterial pressure increased (mean change 8.5 ± 7.3 [95% CI: 8 to 9.1] mmHg), and the hemoglobin concentrations decreased significantly (mean change -1.1 ± 1.8 [95% CI: -1.2 to -0.9] g·dL^-1 ). Acid-base parameters were more stable with bal-GEL. No serious adverse drug reactions directly related to gelatin (i.e., anaphylactoid reaction, clotting disorders, and renal failure) were observed.

CONCLUSION

Moderate doses up to 20 ml kg^-1 of modified fluid gelatin were infused most frequently to improve hemodynamic stability in children undergoing major pediatric surgery. The acid-base balance was more stable when gelatin in a balanced electrolyte solution was used instead of saline. No serious adverse drug reactions associated with gelatin were observed.

Fluid management in hospitalized pediatric patients

The proper use of intravenous fluids has likely been responsible for saving more lives than any other group of substances. Proper use includes prescribing an appropriate electrolyte and carbohydrate solution, at a calculated rate or volume, for the right child, at the right time. Forming intravenous fluid plans for hospitalized children requires an understanding of water and electrolyte physiology in healthy children and how different pathology deviates from the norm. This review highlights fluid management in several disease types, including liver disease, diabetic ketoacidosis, syndrome of inappropriate antidiuretic hormone, diabetes insipidus, kidney disease, and intestinal failure as well as in those with nonphysiologic fluid losses. For each disease, the review discusses specific considerations, evaluations, and management strategies to consider when customizing intravenous fluid plans. Ultimately, all hospitalized children should receive an individualized fluid plan with recurrent evaluations and fluid modifications to provide optimal care.