Evaluating a unique enhanced recovery protocol in laparoscopic donor nephrectomy: A single center experience.

INTRODUCTION: Enhanced recovery after surgery (ERAS) protocols have been associated with a reduction in opioid consumption and a hastening in recovery in abdominal surgery. However, their impact on laparoscopic donor nephrectomy (LDN) has not been fully elucidated. The aim of this study is to evaluate opioid consumption and other relevant outcome measures before and after implementation of a unique LDN ERAS protocol. METHODS: 244 LDN patients were included in this retrospective cohort study. Forty-six underwent LDN prior to implementation of ERAS, whereas 198 patients received ERAS perioperative care. The primary outcome was daily oral morphine equivalent (OME) consumption averaged over the entire postoperative stay. Due to removal of preoperative oral morphine from the protocol partway through the study period, the ERAS group was further subdivided into morphine recipients and non-recipients for subgroup analysis. Secondary outcomes included the incidence of postoperative nausea and vomiting (PONV), length of stay, pain scores, and other relevant measures. RESULTS: ERAS donors consumed significantly fewer average daily OMEs than Pre-ERAS donors (21.5 vs. 37.6, respectively; p < .0001). There were no statistically significant differences in OME consumption between morphine recipients and non-recipients. The ERAS group experienced less PONV (44.4% requiring one or more rescue antiemetic postoperatively, vs. 60.9% of Pre-ERAS donors; p = .008). CONCLUSIONS: A protocol pairing lidocaine and ketamine with a comprehensive approach to preoperative PO intake, premedication, intraoperative fluid management and postoperative pain control is associated with reduced opioid consumption in LDN.

The Bitter and the Sweet: Relationship of Lactate, Glucose, and Mortality After Severe Blunt Trauma.

BACKGROUND: Hyperglycemia is associated with mortality after trauma; however, few studies have simultaneously investigated the association of depth of shock and acute hyperglycemia. We evaluated lactate, as a surrogate measure for depth of shock, and glucose levels on mortality following severe blunt trauma. We hypothesize that measurements of both lactate and glucose are associated with mortality when considered simultaneously. METHODS: This is a retrospective cohort study at a single academic trauma center. Inclusion criteria are age 18-89 years, blunt trauma, injury severity score (ISS) ≥15, and transferred from the scene of injury. All serum blood glucose and lactate values were analyzed within the first 24 hours of admission. Multiple metrics of glucose and lactate were calculated: first glucose (Glucadm) and lactate (Lacadm) at hospital admission, mean 24-hour after hospital admission glucose (Gluc24-hMean) and lactate (Lac24-hMean), maximum 24-hour after hospital admission glucose (Gluc24-hMax) and lactate (Lac24-hMax), and time-weighted 24-hour after hospital admission glucose (Gluc24-hTW) and lactate (Lac24-hTW). Primary outcome was in-hospital mortality. Multivariable logistic regression modeling assessed the odds ratio (OR) of mortality, after adjusting for confounding variables. RESULTS: A total of 1439 trauma patients were included. When metrics of both glucose and lactate were analyzed, after adjusting for age, ISS, and admission shock index, only lactate remained significantly associated with mortality: Lacadm (OR, 1.28; 95% confidence interval [CI], 1.13-1.44); Lac24-hMean (OR, 1.86; 95% CI, 1.52-2.28); Lac24-hMax (OR, 1.39; 95% CI, 1.23-1.56); and Lac24-hTW (OR, 1.86; 95% CI, 1.53-2.26). CONCLUSIONS: Lactate is associated with mortality in severely injured blunt trauma patients, after adjusting for injury severity, age, and shock index. However, we did not find evidence for an association of glucose with mortality after adjusting for lactate.

Assessing modified aluminum-based water treatment residuals as a plant-available phosphorus source.

Inorganic phosphorus (P) fertilizers are a finite resource; alternative means of creating P fertilizers from current municipal and agricultural waste sources may reduce our reliance on phosphate rock mining, and improve waste disposal and nutrient cycling. Previous research demonstrated that organic aluminum water treatment residual composites (Al/O-WTR), created by mixing aluminum water treatment residuals (Al-WTR) with swine wastewater, have the potential to be a source of plant-available P. A greenhouse study was conducted to compare spring wheat (Triticum aestivum L.) growth with increasing application rates of swine wastewater-derived Al/O-WTR and commercial P fertilizer (both applied at 34, 67, and 135 kg P2O5 ha-1) in either sandy loam or sandy clay loam soil. Spring wheat straw and grain P uptake were comparable across all treatments in the sandy loam, while straw and grain P uptake were lower with Al/O-WTR in the sandy clay loam. The Al/O-WTR did not affect soil organic P concentrations, but did increase phosphatase activity in both soils. Increased phosphatase activity suggests that Al/O-WTR application stimulated microorganisms and enhanced the extent to which microbial communities mineralized Al/O-WTR-bound organic P. Overall, these results suggest that Al-WTR can be used to make P fertilizer, combining two "waste" products to create a useful product. Phosphorus harvesting via Al/O-WTR may be a feasible future alternative to mining phosphate rock, while avoiding unnecessary waste disposal and improving agricultural nutrient cycling.

Mechanisms Responsible for Soil Phosphorus Availability Differences between Sprinkler and Furrow Irrigation.

From a historical perspective, human-induced soil erosion and resulting soil phosphorus (P) losses have likely occurred for thousands of years. In modern times, erosion risk and off-site P transport can be decreased if producers convert from furrow to sprinkler irrigation, but conversion may alter nutrient dynamics. Our study goal was to determine soil P dynamics in furrow- (in place since the early 1900s) versus sprinkler-irrigated (installed within the last decade) soils from four paired producer fields in Idaho. Furrow- and sprinkler-irrigated soils (0-5 cm; Aridisols) contained on average 38 and 20 mg kg of Olsen-extractable P (i.e., plant-available P), respectively; extractable P values over 40 mg kg limit Idaho producers to P application based on crop uptake only. Soil samples were also analyzed using a modified Hedley extraction. Furrow-irrigated soils contained greater inorganic P concentrations in the soluble+aluminum (Al)-bound+iron (Fe)-bound, occluded, and amorphous Fe-bound pools. Phosphorus -edge X-ray absorption near-edge structure (XANES) spectroscopy was unable to detect Fe-associated P but indicated greater amounts of apatite-like or octacalcium phosphate-like P in furrow-irrigated producer soils, while sprinkler-irrigated fields had lower amounts of apatite-like P and greater proportions of P bound to calcite. Findings from a controlled USDA-ARS sprinkler- versus furrow-irrigation study suggested that changes in P dynamics occur slowly over time, as few differences were observed. Overall findings suggest that Fe redox chemistry or changes in calcium (Ca)-associated P in flooded conditions altered P availability under furrow irrigation, even in aridic, calcareous soils, contributing to greater Olsen-extractable P concentrations in long-term furrow-irrigated fields.

X-Ray Spectroscopic Quantification of Struvite and Dittmarite Recovered from Wastewater.

Phosphorus recovery from wastewater as struvite (MgNHPO⋅6HO) or dittmarite (MgNHPO⋅HO) can decrease water pollution risk, as well as produce a P-rich material suitable as fertilizer. However, most studies to date have focused on the removal of P from wastewater, rather than on characterization of the recovered P materials. The objective of this work was to apply microfocused X-ray fluorescence (XRF) spectroscopy, and both bulk and microfused X-ray absorption near edge structure (XANES) spectroscopy, to provide insight into the speciation of recovered P in various struvite-containing and struvite-like materials. Three materials were investigated: homogeneous crystalline struvite on apatite seed, homogeneous dittmarite, and heterogeneous struvite with sand contamination (referred to as the "sandy" material). The struvite materials were recovered from dairy wastewater, whereas the dittmarite was from a cheese processing plant. Phosphorus speciation in the crystalline struvite on apatite seed material was ∼17% apatite and 83% struvite; in the "sandy" material, P was ∼24% apatite and ∼76% struvite, with an uncertainty of approximately ±15%. The P -edge XANES spectra of recovered dittmarite appeared pure. These findings highlight the heterogeneity of recovered P materials and underscore the importance of P speciation to understand P release behavior and bioavailability from recovered phosphates.

Combining spectroscopic and isotopic techniques gives a dynamic view of phosphorus cycling in soil.

Current understanding of phosphorus (P) cycling in soils can be enhanced by integrating previously discrete findings concerning P speciation, exchange kinetics, and the underlying biological and geochemical processes. Here, we combine sequential extraction with P K-edge X-ray absorption spectroscopy and isotopic methods (33P and 18O in phosphate) to characterize P cycling on a climatic gradient in Hawaii. We link P pools to P species and estimate the turnover times for commonly considered P pools. Dissolved P turned over in seconds, resin-extractable P in minutes, NaOH-extractable inorganic P in weeks to months, and HCl-extractable P in years to millennia. Furthermore, we show that in arid-zone soils, some primary mineral P remains even after 150 ky of soil development, whereas in humid-zone soils of the same age, all P in all pools has been biologically cycled. The integrative information we provide makes possible a more dynamic, process-oriented conceptual model of P cycling in soils.

Phosphorus Sorption Characteristics in Aluminum-based Water Treatment Residuals Reacted with Dairy Wastewater: 1. Isotherms, XRD, and SEM-EDS Analysis.

We examined P sorption characteristics in Al-based water treatment residuals (Al-WTR) generated from slightly alkaline surface water and in an organic residual composite (WW-Al/O-WTR), produced by using the Al-WTR to treat organic-rich and high P concentration dairy wastewater. Solids from both residuals were examined using scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) and X-ray diffraction (XRD), and exposed to P additions of 0 to 4000 mg L in a sorption experiment. The Al-WTR removed ∼97% of the added P, whereas WW-Al/O-WTR removed only 78% of the added P in the addition range of 0 to 100 mg P L. With P additions of ≥100 mg L, the removal rate declined to <38% by Al-WTR and to 16% by WW-Al/O-WTR, possibly implying a change in sorption mechanisms. Analysis by XRD indicated that the major mineral was calcite, with some silica and poorly crystalline Al hydroxides. Analysis by SEM-EDS, which used three-element overlay maps of the residual surfaces, indicated that P was sparsely sorbed on both calcic and Al (hydr)oxide surfaces, along with a few clusters, even at low P concentrations of the treated waters. Ternary clusters of P, Al, and Ca were more abundant on the WW-Al/O-WTR. Carbon distribution suggested that organic substances covered Al surfaces. Sorption of P onto WW-Al/O-WTR may be reversible due to relatively weak Ca-P and Al-P bonds induced by the slight alkaline nature and in the presence of organic moieties, enhancing the WW-Al/O-WTR potential to act as a P source, rather than a P sink, in agricultural applications.

Phosphorus Sorption to Aluminum-based Water Treatment Residuals Reacted with Dairy Wastewater: 2. X-Ray Absorption Spectroscopy.

Phosphorus capture from wastewater can decrease water pollution and provide a P-rich fertilizer alternative for use in agricultural production. This study was conducted to elucidate P retention mechanisms in Al-based water treatment residuals (Al-WTR) to gain insight regarding P sorption and the potential for P release from Al-WTR after reaction with dairy wastewater. Synchrotron-based microfocused X-ray fluorescence (micro-XRF) spectrometry, bulk P -edge X-ray absorption near edge structure spectroscopy (XANES), and P -edge micro-XANES spectroscopy were used to determine P distribution and speciation within the Al-WTR materials. Bulk XANES analyses indicated a shift from ∼56 P atom % Ca-associated P in the initial Al-WTR to ∼32% P atom % Ca-associated P after reaction with wastewater; Al-associated P made up the remainder of the P species. According to XANES analyses, adsorption appeared to be the primary P retention mechanism in the Al-WTR materials. However, micro-XANES analyses depicted a more complicated picture of P retention mechanisms, with regions of primarily Al-associated P, regions of primarily Ca-associated P, regions of mixed Al- and Ca-associated P, and distinct apatite- or octocalcium phosphate-like P grains. Synchrotron micro-XRF mapping further suggested that exposure of the aggregate exteriors to wastewater caused P to diffuse into the porous Al-WTR aggregates. Organic P species were not explicitly identified via P -edge XANES despite high organic matter content, suggesting that organic P may have been predominantly associated with mineral surfaces. Although diffusion and sorption to Al may decrease P bioavailability, Ca-associated P may increase P bioavailability from Al-WTR that is reused as a soil amendment.

Innovative approach for recycling phosphorous from agro-wastewaters using water treatment residuals (WTR).

Phosphorus capture from polluting streams and its re-use using industrial byproducts has the potential to also reduce environmental threats. An innovative approach was developed for P removal from soil leachate and dairy wastewater using Al-based water treatment residuals (Al-WTR) to create an organic-Al-WTR composite (Al/O-WTR), potentially capable of serving as a P fertilizer source. Al-WTR was mixed with either soil leachate, or with dairy wastewater, both of which contained elevated P concentrations (e.g., 7.6-43.5 mg SRP L-1). The Al-WTR removed ∼95% inorganic P, above 80% organic P, and over 60% dissolved organic carbon (DOC) from the waste streams. P removal was correlated with P concentration in the waste streams and was consistent with an increase in Al/O-WTR P content as determined by X-ray fluorescence (XRF) and surface analysis using scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS). Organic C was a major constituent in the original Al-WTR (31.4%) and increased by 1% in the Al/O-WTRs. Organic C accumulation on particles surfaces possibly enhanced weak P bonding. Desorption experiments indicated an initial and substantial P release (30 mg SRP kg-1 Al/O-WTR), followed by relatively constant low P solubility (ca. 10 mg kg-1). Organic C was continuously released to the solution (over 8000 mg kg-1), concomitantly with Ca and other electrolytes, possibly indicating dissolution from inner pores, accounting for the highly porous nature of the Al-WTR, evident by SEM images. The potential of P-loading on Al/O-WTR to promote P recycling should be further studied.

Ab Initio Molecular Dynamics of Uranium Incorporated in Goethite (α-FeOOH): Interpretation of X-ray Absorption Spectroscopy of Trace Polyvalent Metals.

Incorporation of economically or environmentally consequential polyvalent metals into iron (oxyhydr)oxides has applications in environmental chemistry, remediation, and materials science. A primary tool for characterizing the local coordination environment of such metals, and therefore building models to predict their behavior, is extended X-ray absorption fine structure spectroscopy (EXAFS). Accurate structural information can be lacking yet is required to constrain and inform data interpretation. In this regard, ab initio molecular dynamics (AIMD) was used to calculate the local coordination environment of minor amounts of U incorporated in the structure of goethite (α-FeOOH). U oxidation states (VI, V, and IV) and charge compensation schemes were varied. Simulated trajectories were used to calculate the U LIII-edge EXAFS function and fit experimental EXAFS data for U incorporated into goethite under reducing conditions. Calculations that closely matched the U EXAFS of the well-characterized mineral uraninite (UO2), and constrained the S02 parameter to be 0.909, validated the approach. The results for the U-goethite system indicated that U(V) substituted for structural Fe(III) in octahedral uranate coordination. Charge balance was achieved by the loss of one structural proton coupled to addition of one electron into the solid (-1 H+, +1 e-). The ability of AIMD to model higher energy states thermally accessible at room temperature is particularly relevant for protonated systems such as goethite, where proton transfers between adjacent octahedra had a dramatic effect on the calculated EXAFS. Vibrational effects as a function of temperature were also estimated using AIMD, allowing separate quantification of thermal and configurational disorder. In summary, coupling AIMD structural modeling and EXAFS experiments enables modeling of the redox behavior of polyvalent metals that are incorporated in conductive materials such as iron (oxyhydr)oxides, with applications over a broad swath of chemistry and materials science.

Uranium incorporation into aluminum-substituted ferrihydrite during iron(ii)-induced transformation.

Uranium retention processes (adsorption, precipitation, and incorporation into host minerals) exert strong controls on U mobility in the environment, and understanding U retention is therefore crucial for predicting the migration of U within surface and groundwater. Uranium can be incorporated into Fe (hydr)oxides during Fe(ii)-induced transformation of ferrihydrite to goethite. However, ferrihydrite seldom exists as a pure phase within soils or sediments, and structural impurities such as Al alter its reactivity. The presence of Al in ferrihydrite, for example, decreases the rate of transformation to goethite, and thus may impact the retention pathway, or extent of retention, of U. Here, we investigate the extent and pathways of U(vi) retention on Al-ferrihydrite during Fe(ii)-induced transformation. Ferrihydrite containing 0%, 1%, 5%, 10%, and 20% Al was reacted with 10 µM U and 300 µM Fe(ii) in the presence of 0 mM and 4 mM Ca(2+) and 3.8 mM carbonate at pH 7.0. Solid reaction products were characterized using U L3-edge EXAFS spectroscopy to differentiate between adsorbed U and U incorporated into the goethite lattice. Uranium incorporation into Al-ferrihydrite declined from ∼70% of solid-phase U at 0% and 1% Al to ∼30% of solid phase U at 20% Al content. The decrease in U incorporation with increasing Al concentration was due to two main factors: (1) decreased transformation of ferrihydrite to goethite; and, (2) a decrease of the goethite lattice with increasing Al, making the lattice less compatible with large U atoms. However, uranium incorporation can occur even with an Al-substituted ferrihydrite precursor in the presence or absence of Ca(2+). The process of U incorporation into Al-goethite may therefore be a potential long-term sink of U in subsurface environments where Al-substituted iron oxides are common, albeit at lower levels of incorporation with increasing Al content.

Uranium incorporation into amorphous silica.

High concentrations of uranium are commonly observed in naturally occurring amorphous silica (including opal) deposits, suggesting that incorporation of U into amorphous silica may represent a natural attenuation mechanism and promising strategy for U remediation. However, the stability of uranium in opaline silicates, determined in part by the binding mechanism for U, is an important factor in its long-term fate. U may bind directly to the opaline silicate matrix, or to materials such as iron (hydr)oxides that are subsequently occluded within the opal. Here, we examine the coordination environment of U within opaline silica to elucidate incorporation mechanisms. Precipitates (with and without ferrihydrite inclusions) were synthesized from U-bearing sodium metasilicate solutions, buffered at pH ∼ 5.6. Natural and synthetic solids were analyzed with X-ray absorption spectroscopy and a suite of other techniques. In synthetic amorphous silica, U was coordinated by silicate in a double corner-sharing coordination geometry (Si at ∼ 3.8-3.9 Å) and a small amount of uranyl and silicate in a bidentate, mononuclear (edge-sharing) coordination (Si at ∼ 3.1-3.2 Å, U at ∼ 3.8-3.9 Å). In iron-bearing synthetic solids, U was adsorbed to iron (hydr)oxide, but the coordination environment also contained silicate in both edge-sharing and corner-sharing coordination. Uranium local coordination in synthetic solids is similar to that of natural U-bearing opals that retain U for millions of years. The stability and extent of U incorporation into opaline and amorphous silica represents a long-term repository for U that may provide an alternative strategy for remediation of U contamination.

Macroscopic and microscopic variation in recovered magnesium phosphate materials: implications for phosphorus removal processes and product re-use.

Phosphorus (P) recovery and re-use will become increasingly important for water quality protection and sustainable nutrient cycling as environmental regulations become stricter and global P reserves decline. The objective of this study was to examine and characterize several magnesium phosphates recovered from actual wastewater under field conditions. Three types of particles were examined including crystalline magnesium ammonium phosphate hexahydrate (struvite) recovered from dairy wastewater, crystalline magnesium ammonium phosphate hydrate (dittmarite) recovered from a food processing facility, and a heterogeneous product also recovered from dairy wastewater. The particles were analyzed using "wet" chemical techniques, powder X-ray diffraction (XRD), and scanning electron microscopy in conjunction with energy dispersive X-ray spectroscopy (SEM-EDS). The struvite crystals had regular and consistent shape, size, and structure, and SEM-EDS analysis clearly showed the struvite crystals as a surface precipitate on calcium phosphate seed material. In contrast, the dittmarite crystals showed no evidence of seed material, and were not regular in size or shape. The XRD analysis identified no crystalline magnesium phosphates in the heterogeneous product and indicated the presence of sand particles. However, magnesium phosphate precipitates on calcium phosphate seed material were observed in this product under SEM-EDS examination. These substantial variations in the macroscopic and microscopic characteristics of magnesium phosphates recovered under field conditions could affect their potential for beneficial re-use and underscore the need to develop recovery processes that result in a uniform, consistent product.