A survey of Canadian specialist anesthesiologists and family practice anesthetists: rural operating room use, a mixed model of care, and mentoring.

PURPOSE: The aim of this project was to collect data on the delivery of anesthesia in Canada. Specifically, our goal was to increase knowledge by identifying provider demographics and different models of anesthesia delivery, and to explore relationships among specialist anesthesiologists (SAs) and family practice anesthetists (FPAs) with a focus on mentoring. METHODS: An online questionnaire was circulated to SAs and FPAs holding membership with the Canadian Anesthesiologists' Society or the Society of Rural Physicians of Canada. A total of 274/2,578 individuals completed the survey (170 SAs and 104 FPAs), providing a response rate of 10.6%. The survey included questions about demographics, anesthesia training, anesthesia resources, models of care, and mentoring relationships. RESULTS: Three major themes emerged from the data: 1) FPAs and rural operating rooms are underused resources as 65% (64/98) of FPAs reported having capacity to increase their individual volume of anesthesia services and 41% (40/98) thought capacity existed within their hospital to increase the volume of surgery; 2) 20 hospitals employed a mixed model of anesthesia care whereby SAs and FPAs worked collectively within the same site; providers working within this model reported high levels of satisfaction and independence; 3) most SAs and FPAs perceived a benefit to mentoring and were interested in participating in a mentoring program. CONCLUSION: This survey shows perceived capacity to expand surgical services in rural areas, a precedent for a mixed SA-FPA model of anesthesia delivery at the same site, and desire for anesthesia providers to engage in mentoring. Such options should be considered to strengthen the physician-led anesthesiology profession in Canada.

RéSUMé: OBJECTIF: L'objectif de ce projet était de recueillir des données sur la prestation de l'anesthésie au Canada. Plus précisément, notre objectif était d'accroître les connaissances en identifiant les caractéristiques démographiques des prestataires et les différents modèles de prestation d'anesthésie, et d'explorer les relations entre les anesthésiologistes spécialisé·es (AS) et les anesthésiologistes en médecine familiale (AMF) en mettant l'accent sur le mentorat. MéTHODE: Un questionnaire en ligne a été distribué aux AS et aux AMF membres avec la Société canadienne des anesthésiologistes ou la Société de la médecine rurale du Canada. Au total, 274 personnes sur 2578 ont répondu à l'enquête (170 AS et 104 AMF), soit un taux de réponse de 10,6 %. L'enquête comprenait des questions sur les données démographiques, la formation en anesthésie, les ressources en anesthésie, les modèles de soins et les relations de mentorat. RéSULTATS: Trois grands thèmes se sont dégagés des données : 1) Les AMF et les salles d'opération en milieu rural sont des ressources sous-utilisées, puisque 65 % (64/98) des AMF ont déclaré avoir la capacité d'augmenter le volume individuel de leurs services d'anesthésie et 41 % (40/98) pensaient qu'il existait une capacité au sein de leur hôpital pour augmenter le volume chirurgical; 2) 20 hôpitaux utilisent un modèle mixte de soins d'anesthésie dans lequel les AS et les AMF travaillent collectivement sur le même site; les prestataires qui travaillent dans le cadre de ce modèle ont fait état de niveaux élevés de satisfaction et d'indépendance; 3) la plupart des AS et des AMF perçoivent un avantage au mentorat et sont intéressé·es à participer à un programme de mentorat. CONCLUSION: Cette enquête montre la capacité perçue d'étendre les services chirurgicaux dans les zones rurales, un précédent pour un modèle mixte AS-AMF de prestation d'anesthésie sur le même site, et le désir des prestataires d'anesthésie de s'engager dans le mentorat. De telles options devraient être envisagées pour renforcer la profession médicale de l'anesthésiologie au Canada.

Rare causes of abdominal pain: a primer for the admitting general surgeon.

The broad uptake of the acute surgical unit (ASU) model of surgical care in Australia has resulted in general surgeons becoming increasingly involved in the management of patients with acute abdominal pain (AAP), some of whom will be labelled as having non-specific abdominal pain (NSAP) (Kinnear N, Jolly S, Herath M, et al. The acute surgical unit: An updated systematic review and meta-analysis. review. Int. J. Surg. 2021;94:106109; Lehane CW, Jootun RN, Bennett M, Wong S, Truskett P. Does an acute care surgical model improve the management and outcome of acute cholecystitis? ANZ J. Surg. 2010;80:438-42). NSAP patients lack a clear diagnosis of surgical pathology based on standard clinical, laboratory and imaging work-up, although they may require ASU admission for pain control and assessment. This article provides a review of uncommon conditions, presenting as AAP, that could possibly be mis-labelled as NSAP, with a focus on aspects of the presentation that may aid diagnosis and management including specific demographic features, clinical findings, key investigations and initial treatment priorities for ASU clinicians. Ultimately, most of the conditions discussed will not require surgical intervention, however, they require a diagnosis to be made and initial treatment planning before on-referral to the appropriate specialty. For the on-call general surgeon, some knowledge of these conditions and an index of suspicion are invaluable for the prompt diagnosis and efficient management of these patients.

Hospital in the home-based management of acute diverticulitis: a safe and effective alternative to inpatient care.

BACKGROUND: The traditional approach to management of acute uncomplicated diverticulitis involves admission to hospital, antibiotic therapy, gut rest and monitoring for the development of complications. Despite evidence to suggest this can safely be performed in an outpatient setting, inpatient care remains standard practice in Australia potentially due to a variety of factors (van Dijk et al. 2018; Cirocchi et al. 2019). Hospital in the home (HIH) allows patients requiring complex care including intravenous antibiotics, intravenous fluids and complex pain relief to be managed at home. This study examined the safety and efficacy of HIH-based care for acute diverticulitis over a 16-year period. METHODOLOGY: A retrospective review of cases of acute diverticulitis managed under our HIH service from the period of 1st of January 2004 to 20th of October 2020 was completed. Baseline descriptive data relating to age, co-morbidities and severity of diverticulitis was collected. Details of medical treatment provided and subsequent complications were also collected. RESULTS: During the study period, 23 patients with acute diverticulitis were treated under the HIH unit. Among the study population, the median age was 60 (interquartile range 15) with a slight female predominance (n = 13, 56.5%). This represented the first presentation in 60.9% of patients. Average length of stay was 3.6 days (SD = 1.0) with no acute complications recorded in the study period. Two patients (8.7%) had further episodes of acute diverticulitis within 60 days. CONCLUSION: In this study, the lack of complications demonstrated indicates that HIH-based management of acute diverticulitis may be a viable and safe alternative to inpatient care.

Effects of chemical speciation on the bioaccessibility of zinc in spiked and smelter-affected soils.

Previous studies have suggested that understanding soil metal speciation, rather than relying solely on total metal content, can improve the accuracy and utility of contaminated site risk assessments. Because soil properties and reaction time can alter metal speciation, speciation should influence metal bioaccessibility. For example, under gastrointestinal conditions, it is expected that metal species will differ in bioaccessibility depending on their stability in acidic pH environments. We studied the links between metal speciation and bioaccessibility. A combination of synchrotron-based X-ray diffraction and X-ray absorption near edge structure (XANES) was used to identify the zinc (Zn) speciation in spiked and smelter-affected soils. After conducting in vitro digestion tests on the soil samples, XANES and linear combination fitting were carried out on the residual pellets to identify the species of Zn that remained after digesting the soils in the simulated gastric and duodenal fluids. The metal species that were not present in the residual pellets were inferred to have been dissolved and, thus, more bioaccessible. Sphalerite (ZnS), ZnO, and outer-sphere Zn contributed more to Zn bioaccessibility than franklinite (ZnFe2 O4 ) and Zn incorporated into a hydroxy interlayer mineral (Zn-HIM). The bioaccessibility of Zn-aluminum layered double hydroxides (Zn-Al-LDH) was found to be inversely proportional to its residence time in soil. It was also observed that the relatively high pH of the duodenum favors metal reprecipitation and readsorption, leading to a reduction in bioaccessible metal concentration. These results imply that metal speciation mainly controls metal bioaccessibility. Environ Toxicol Chem 2019;38:448-459. © 2018 SETAC.

Chemical speciation and fate of tripolyphosphate after application to a calcareous soil.

Adsorption and precipitation reactions often dictate the availability of phosphorus in soil environments. Tripolyphosphate (TPP) is considered a form of slow release P fertilizer in P limited soils, however, investigations of the chemical fate of TPP in soils are limited. It has been proposed that TPP rapidly hydrolyzes in the soil solution before adsorbing or precipitating with soil surfaces, but in model systems, TPP also adsorbs rapidly onto mineral surfaces. To study the adsorption behavior of TPP in calcareous soils, a short-term (48 h) TPP spike was performed under laboratory conditions. To determine the fate of TPP under field conditions, two different liquid TPP amendments were applied to a P limited subsurface field site via an in-ground injection system. Phosphorus speciation was assessed using X-ray absorption spectroscopy, total and labile extractable P, and X-ray diffraction. Adsorption of TPP to soil mineral surfaces was rapid (< 48 h) and persisted without fully hydrolyzing to ortho-P. Linear combination fitting of XAS data indicated that the distribution of adsorbed P was highest (~ 30-40%) throughout the site after the first TPP amendment application (high water volume and low TPP concentrations). In contrast, lower water volumes with more concentrated TPP resulted in lower relative fractions of adsorbed P (15-25%), but a significant increase in total P concentrations (~ 3000 mg P kg soil) and adsorbed P (60%) directly adjacent to the injection system. This demonstrates that TPP application increases the adsorbed P fraction of calcareous soils through rapid adsorption reactions with soil mineral surfaces.

Citrate Addition Increased Phosphorus Bioavailability and Enhanced Gasoline Bioremediation.

Phosphorus (P) bioavailability often limits gasoline biodegradation in calcareous cold-region soils. One possible method to increase P bioavailability in such soils is the addition of citrate. Citrate addition at the field scale may increase hydrocarbon degradation by: (i) enhancing inorganic and organic P dissolution and desorption, (ii) increasing hydrocarbon bioavailability, and/or (iii) stimulating microbial activity. Alternatively, citrate addition may inhibit activity due to competitive effects on carbon metabolism. Using a field-scale in situ biostimulation study, we evaluated if citrate could stimulate gasoline degradation and what the dominant mechanism of this stimulation will be. Two large bore injectors were constructed at a site contaminated with gasoline, and a biostimulation solution of 11 mM MgSO, 1 mM HPO, and 0.08 mM HNO at pH 6.5 in municipal potable water was injected at ∼5000 L d for about 4 mo. Following this, 10 mM citric acid was incorporated into the existing biostimulation solution and the site continued to be stimulated for 8 mo. After citrate addition, the bioavailable P fraction in groundwater and soil increased. Iron(II) groundwater concentrations increased and corresponded to decreases in benzene, toluene, ethylbenzene, xylenes (BTEX) in groundwater, as well as a decrease in F1 in the soil saturated zone. Overall, citrate addition increased P bioavailability and may stimulate anaerobic microbial activity, resulting in accelerated anaerobic gasoline bioremediation in cold-region calcareous soils.

Mechanisms of tripolyphosphate adsorption and hydrolysis on goethite.

Linear tripolyphosphates (TPP) are used extensively in liquid fertilizers though little is known about their chemical fate after sorption on mineral surfaces. The initial rapid adsorption of TPP to metal oxide surfaces has been observed, but it is not known whether this adsorption will catalyze or inhibit TPP hydrolysis. To determine the effects of adsorption upon TPP hydrolysis, batch reactors were set up with two surface loadings of TPP adsorbed on goethite (α-FeOOH) for up to 3months at pH 4.5, 6.5 and 8.5. Samples were analyzed for; adsorbed phosphorus (P), P speciation via both P K-edge XANES and FTIR vibrational spectroscopies. Additionally, it was learned through in-situ ATR-FTIR that drying of adsorbed TPP in the presence of Ca results in the formation of a Ca-trimetaphosphate type of surface complex. The rates of adsorbed TPP hydrolysis as measured with ex-situ FTIR were most rapid at pH 4.5 with 100% of the TPP fully hydrolyzed by 3months. Slower rates were observed at pH 6.5 and 8.5 through 3months. Compared to published rates of aqueous TPP hydrolysis, adsorption to mineral surfaces catalyzes TPP hydrolysis.

Effects of Dolomitic Limestone Application on Zinc Speciation in Boreal Forest Smelter-Contaminated Soils.

Anthropogenic activities at the HudBay Minerals, Inc., Flin Flon (Manitoba, Canada) mining and processing facility have severely affected the surrounding boreal forest ecosystem. Soil contamination occurred via a combination of metal and sulfuric acid deposition and has resulted in forest dieback and ineffective natural recovery. A community-led effort to revegetate areas of the landscape through the application of a dolomitic limestone has been met with varied success. Zinc (Zn) speciation has shown to be closely linked to the presence or absence of an invasive metal-tolerant grass species, with soils being broadly classed into two revegetation response groups. Group I, characterized by the absence of metal-tolerant grasses, and group II, characterized by the presence of metal-tolerant grasses. The systematic approach used to lime areas of the landscape produced a liming chronosequence for each group. This study used a combination of X-ray absorption spectroscopy, X-ray fluorescence mapping, and X-ray diffraction techniques to determine the effect of liming on Zn speciation in these chronosequences. Liming group I soils resulted in the formation of a neo-phase Zn-Al-hydroxy interlayer coprecipitate and subsequent rapid boreal forest revegetation. The effect of liming on Zn speciation on the group II soils resulted in a gradual transition of increasingly stable adsorption species, culminating with a stable Zn-Al-layered double hydroxide precipitate. Boreal forest vegetation has failed to recolonize group II soils during the study. However, the formation of the layered double hydroxide species resulted in a significant reduction in CaCl-extractable Zn. Further research is required to determine how to promote the revegetation of these soils.

Total Phosphate Influences the Rate of Hydrocarbon Degradation but Phosphate Mineralogy Shapes Microbial Community Composition in Cold-Region Calcareous Soils.

Managing phosphorus bioaccessibility is critical for the bioremediation of hydrocarbons in calcareous soils. This paper explores how soil mineralogy interacts with a novel biostimulatory solution to both control phosphorus bioavailability and influence bioremediation. Two large bore infiltrators (1 m diameter) were installed at a PHC contaminated site and continuously supplied with a solution containing nutrients and an electron acceptor. Soils from eight contaminated sites were prepared and pretreated, analyzed pretrial, spiked with diesel, placed into nylon bags into the infiltrators, and removed after 3 months. From XAS, we learned that three principal phosphate phases had formed: adsorbed phosphate, brushite, and newberyite. All measures of biodegradation in the samples (in situ degradation estimates, mineralization assays, culturable bacteria, catabolic genes) varied depending upon the soil's phosphate speciation. Notably, adsorbed phosphate increased anaerobic phenanthrene degradation and bzdN catabolic gene prevalence. The dominant mineralogical constraints on community composition were the relative amounts of adsorbed phosphate, brushite, and newberyite. Overall, this study finds that total phosphate influences microbial community phenotypes whereas relative percentages of phosphate minerals influences microbial community genotype composition.

Characterizing Zinc Speciation in Soils from a Smelter-Affected Boreal Forest Ecosystem.

HudBay Minerals, Inc., has mined and/or processed Zn and Cu ore in Flin Flon, MB, Canada, since the 1930s. The boreal forest ecosystem and soil surrounding these facilities have been severely impacted by mixed metal contamination and HSO deposition. Zinc is one of the most prevalent smelter-derived contaminants and has been identified as a key factor that may be limiting revegetation. Metal toxicity is related to both total concentrations and speciation; therefore, X-ray absorption spectroscopy and X-ray fluorescence mapping were used to characterize Zn speciation in soils throughout the most heavily contaminated areas of the landscape. Zinc speciation was linked to two distinct soil types. Group I soils consist of exposed soils in weathered positions of bedrock outcrops with Zn present primarily as franklinite, a (ZnFeO) spinel mineral. Group II soils are stabilized by an invasive metal-tolerant grass species, with Zn found as a mixture of octahedral (Fe oxides) and tetrahedral Mn oxides) adsorption complexes with a franklinite component. Soil erosion influences Zn speciation through the redistribution of Zn and soil particulates from Group I landscape positions to Group II soils. Despite Group II soils having the highest concentrations of CaCl-extractable Zn, they support metal-tolerant plant growth. The metal-tolerant plants are probably preferentially colonizing these areas due to better soil and nutrient conditions as a result of soil deposition from upslope Group I areas. Zinc concentration and speciation appears to not influence the colonization by metal-tolerant grasses, but the overall soil properties and erosion effects prevent the revegetation by native boreal forest species.

Rates and mechanisms of Zn2+ adsorption on a meat and bonemeal biochar.

Biochars produced from meat and bonemeal (MBM) waste materials contain large amounts of calcium phosphate and are potentially useful sorbents for the remediation of metals. Because the reactivity of biochars depends strongly upon the conditions used in their production, the objective of this study was to evaluate the rates and mechanisms of Zn sorption onto a commercially supplied MBM biochar prior to its application in a field-scale revegetation project. Sorption experiments varying pH, time, and Zn concentration found that, above pH 6.1, Zn adsorbed to MBM biochar quickly (within 5 h) with a maximum adsorption capacity of 0.65 mmol Zn g(-1). Synchrotron-based Zn K-edge extended X-ray absorption fine structure spectroscopy was consistent with a tetrahedral Zn bound to phosphate groups in a monodentate inner-sphere surface complex for all conditions tested. With an acidification pretreatment and at more acidic pH, MBM biochar causes precipitation of a ZnPO4 phase. On the basis of these results, this MBM biochar has a high capacity to rapidly adsorb Zn in adsorption experiments and can be considered a promising sorbent for Zn remediation of contaminated soils.