Dust storms increase the tolerance of phytoplankton to thermal and pH changes.

Aquatic communities are increasingly subjected to multiple stressors through global change, including warming, pH shifts, and elevated nutrient concentrations. These stressors often surpass species tolerance range, leading to unpredictable consequences for aquatic communities and ecosystem functioning. Phytoplankton, as the foundation of the aquatic food web, play a crucial role in controlling water quality and the transfer of nutrients and energy to higher trophic levels. Despite the significance in understanding the effect of multiple stressors, further research is required to explore the combined impact of multiple stressors on phytoplankton. In this study, we used a combination of crossed experiment and mechanistic model to analyze the ecological and biogeochemical effects of global change on aquatic ecosystems and to forecast phytoplankton dynamics. We examined the effect of dust (0-75 mg L-1 ), temperature (19-27°C), and pH (6.3-7.3) on the growth rate of the algal species Scenedesmus obliquus. Furthermore, we carried out a geospatial analysis to identify regions of the planet where aquatic systems could be most affected by atmospheric dust deposition. Our mechanistic model and our empirical data show that dust exerts a positive effect on phytoplankton growth rate, broadening its thermal and pH tolerance range. Finally, our geospatial analysis identifies several high-risk areas including the highlands of the Tibetan Plateau, western United States, South America, central and southern Africa, central Australia as well as the Mediterranean region where dust-induced changes are expected to have the greatest impacts. Overall, our study shows that increasing dust storms associated with a more arid climate and land degradation can reverse the negative effects of high temperatures and low pH on phytoplankton growth, affecting the biogeochemistry of aquatic ecosystems and their role in the cycles of the elements and tolerance to global change.

Comparative analysis of hospitalization risk for incident heart failure in non-Hispanic Black versus non-Hispanic White individuals with type 2 diabetes on empagliflozin (Empa-AA): Insights from real-world data.

AIM: There are limited data to evaluate hospitalization for heart failure (hHF) in non-Hispanic Black (hereafter Black) or non-Hispanic White (hereafter White) individuals without previous hHF. Our goal was to evaluate the risk of hHF among Black versus White patients with type 2 diabetes (T2DM) who were initially prescribed empagliflozin using real-world data. METHODS: This multicentre retrospective cohort study included participants aged ≥18 years who had T2DM, were either Black or White, had no previous hHF, and were prescribed empagliflozin between August 2014 and December 2019. Our primary outcome was time to first hHF after the initial prescription of empagliflozin. A propensity-score (PS)-weighted analysis was performed to balance characteristics by race. The inverse probability treatment weighting method based on PS was used to make treatment comparisons. To compare Black with White, a PS-weighted Cox's cause-specific hazards model was used. RESULTS: In total, 8789 participants were eligible for inclusion (Black = 3216 vs. White = 5573). The Black cohort was significantly younger, had a higher proportion of females, and had a higher prevalence of chronic kidney disease, hypertension and diabetic retinopathy, while the White cohort had a higher prevalence of coronary artery disease. After adjustment for confounding factors such as age, gender, coronary artery disease, hypertension and diabetic retinopathy, the hazard ratio for first-time hHF was not significantly different between the two racial groups [hazard ratio (95% confidence interval) = 1.09 (0.84-1.42), p = .52]. CONCLUSION: This study showed no significant difference in incident hHF among Black versus White individuals with T2DM following a prescription for empagliflozin.

Dermatology mycology diagnostics in Ireland: National deficits identified in 2022 that are relevant internationally.

BACKGROUND: Conventional testing methods for dermatophytes are time-consuming, and resource limitations in our institution have prompted curtailed access to these diagnostics. OBJECTIVES: Evaluation of our hospital's dermatological mycology diagnostic services and similar services nationally. METHODS: This was a retrospective observational study on skin, hair and nail mycology samples in our institution comparing twenty five-year periods (2011-2015 and 2016-2021), including analysis of dermatology clinic data and correspondence related to fungal infection. A survey of national public hospitals' laboratories was conducted to evaluate their mycology testing capabilities. RESULTS: The total 5 year test count prior to curtailment was 4851 specimens comprising 90% (n = 4344) from general practice and 6% (n = 290) from dermatology clinics. For the 5 years post curtailment, 64.5% (582/903) of specimens were from dermatology clinics. Dermatology clinic data demonstrated doubling of attendances (for all conditions) and of correspondence related to fungal infection. During this time also, national dermatological antifungal purchasing increased 11%. Ten of 28 Irish public hospital laboratories reported the provision of in-house dermatological mycology testing, and none had routine availability of susceptibility or molecular testing of dermatophytes. CONCLUSION: This study is the first to report an appraisal of dermatological fungal diagnostic services in Ireland. Insufficient testing capacity implies that patients are either being treated for fungal infection without appropriate diagnostic confirmation, or being left untreated because of the lack of access to diagnostics. The introduction of molecular detection methods and susceptibility systems would enhance testing capabilities and reduce the requirement for the external referral.

Warming increased bark beetle-induced tree mortality by 30% during an extreme drought in California.

Quantifying the responses of forest disturbances to climate warming is critical to our understanding of carbon cycles and energy balances of the Earth system. The impact of warming on bark beetle outbreaks is complex as multiple drivers of these events may respond differently to warming. Using a novel model of bark beetle biology and host tree interactions, we assessed how contemporary warming affected western pine beetle (Dendroctonus brevicomis) populations and mortality of its host, ponderosa pine (Pinus ponderosa), during an extreme drought in the Sierra Nevada, California, United States. When compared with the field data, our model captured the western pine beetle flight timing and rates of ponderosa pine mortality observed during the drought. In assessing the influence of temperature on western pine beetles, we found that contemporary warming increased the development rate of the western pine beetle and decreased the overwinter mortality rate of western pine beetle larvae leading to increased population growth during periods of lowered tree defense. We attribute a 29.9% (95% CI: 29.4%-30.2%) increase in ponderosa pine mortality during drought directly to increases in western pine beetle voltinism (i.e., associated with increased development rates of western pine beetle) and, to a much lesser extent, reductions in overwintering mortality. These findings, along with other studies, suggest each degree (°C) increase in temperature may have increased the number of ponderosa pine killed by upwards of 35%-40% °C-1 if the effects of compromised tree defenses (15%-20%) and increased western pine beetle populations (20%) are additive. Due to the warming ability to considerably increase mortality through the mechanism of bark beetle populations, models need to consider climate's influence on both host tree stress and the bark beetle population dynamics when determining future levels of tree mortality.

The first assessment of the genetic diversity and structure of the endangered West Indian manatee in Cuba.

The coastal waters of Cuba are home to a small, endangered population of West Indian manatee, which would benefit from a comprehensive characterization of the population's genetic variation. We conducted the first genetic assessment of Cuban manatees to determine the extent of the population's genetic structure and characterize the neutral genetic diversity among regions within the archipelago. We genotyped 49 manatees at 18 microsatellite loci, a subset of 27 samples on 1703 single nucleotide polymorphisms (SNPs), and sequenced 59 manatees at the mitochondrial control region. The Cuba manatee population had low nuclear (microsatellites HE = 0.44, and SNP HE = 0.29) and mitochondrial genetic diversity (h = 0.068 and π = 0.00025), and displayed moderate departures from random mating (microsatellite FIS = 0.12, SNP FIS = 0.10). Our results suggest that the western portion of the archipelago undergoes periodic exchange of alleles based on the evidence of shared ancestry and low but significant differentiation. The southeast Guantanamo Bay region and the western portion of the archipelago were more differentiated than southwest and northwest manatees. The genetic distinctiveness observed in the southeast supports its recognition as a demographically independent unit for natural resource management regardless of whether it is due to historical isolation or isolation by distance. Estimates of the regional effective population sizes, with the microsatellite and SNP datasets, were small (all Ne < 60). Subsequent analyses using additional samples could better examine how the observed structure is masking simple isolation by distance patterns or whether ecological or biogeographic forces shape genetic patterns.

Outcomes After Liver Transplantation With Incidental Cholangiocarcinoma.

Cholangiocarcinoma (CCA) is currently a contraindication to liver transplantation (LT) in the United Kingdom (UK). Incidental CCA occurs rarely in some patients undergoing LT. We report on retrospective outcomes of patients with incidental CCA from six UK LT centres. Cases were identified from pathology records. Data regarding tumour characteristics and post-transplant survival were collected. CCA was classified by TNM staging and anatomical location. 95 patients who underwent LT between 1988-2020 were identified. Median follow-up after LT was 2.1 years (14 days-18.6 years). Most patients were male (68.4%), median age at LT was 53 (IQR 46-62), and the majority had underlying PSC (61%). Overall median survival after LT was 4.4 years. Survival differed by tumour site: 1-, 3-, and 5-year estimated survival was 82.1%, 68.7%, and 57.1%, respectively, in intrahepatic CCA (n = 40) and 58.5%, 42.6%, and 30.2% in perihilar CCA (n = 42; p = 0.06). 1-, 3-, and 5-year estimated survival was 95.8%, 86.5%, and 80.6%, respectively, in pT1 tumours (28.2% of cohort), and 65.8%, 44.7%, and 31.1%, respectively, in pT2-4 (p = 0.018). Survival after LT for recipients with incidental CCA is inferior compared to usual outcomes for LT in the United Kingdom. LT for earlier stage CCA has similar survival to LT for hepatocellular cancer, and intrahepatic CCAs have better survival compared to perihilar CCAs. These observations may support LT for CCA in selected cases.

Oviposition Model for a Southern Population of Mountain Pine Beetle.

We develop a predictive oviposition model for a southern population of mountain pine beetle (MPB) using a previously developed rate curve, incorporating variation in both oviposition rate and fecundity. We also introduce a method for determining the time delay before oviposition. The model describes the probability of oviposition for a season of MPB attacks using hourly phloem temperature and adult MPB attack data. We also develop an asymptotic approximation of MPB oviposition that is much less computationally taxing. The detailed oviposition model and its asymptotic approximation are compared with other ovipositional models for MPB; the predictive capacity of each model is evaluated using previously published observations.

Epidemiology of dermatomycoses and onychomycoses in Ireland (2001-2020): A single-institution review.

BACKGROUND: Fungal skin infections are recognised as one of the most common health disorders globally, and dermatophyte infections of the skin, hair and nails are the most common fungal infections. Dermatophytes can be classified as anthropophilic, zoophilic or geophilic species based on their primary habitat association, and this classification makes epidemiological analysis useful for the prevention and control of these infections. The Irish contribution to the epidemiology of these infections has been scant, with just two papers (both reporting paediatric tinea capitis only) published in the last 20 years, and none in the last seven. OBJECTIVES: To perform a comprehensive retrospective epidemiological analysis of all dermatological mycology tests performed in University Hospital Limerick over a 20-year period. METHODS: All mycology laboratory test results were extracted from the Laboratory Information Management System (LIMS, iLab, DXC Technologies) from 2001 to 2020 inclusive for analysis. Specimen types were categorised according to the site of sampling. The data were analysed using Microsoft Excel. RESULTS: About 12,951 specimens of skin, hair and nails were studied. Median patient age was 42 years (IQR 26-57) with a slight female preponderance (57.2%). Two thirds of samples (67%, n = 8633) were nail, 32% were skin scrapings (n = 4118) and 200 hair samples (1.5%) were received. Zoophilic dermatophytes were more commonly present in females (38% F, 23% M, proportion of dermatophytes) and in those under 10 years of age or from 45 to 70 years (36% and 34% zoophiles, respectively, proportion of dermatophytes), although anthropophiles predominated every age and gender category. Anthropophiles had their highest prevalence in the 10-20 years age category (80% anthropophiles, proportion of dermatophytes), and yeast infections were more prevalent in older patients (29% of >60 year olds vs. 17% of <60 year olds, proportion of all fungal positives). Trichophyton rubrum was the most prevalent pathogen detected, accounting for 53% of all dermatophytes detected, 61% of those detected from nail samples and 34% from skin and hair samples. Trichophyton tonsurans was the most prevalent dermatophyte in tinea capitis, accounting for 37% of dermatophytes detected. Both of these organisms are anthropophilic, and this group showed consistently increased prevalence in proportion to all fungal isolates. The proportion of this dermatophyte class (anthropophiles) increased among both nail samples and skin/hair samples during the study period, from 55% of samples in the first 5 years of the study (2001-2005) to 88% (proportion of dermatophytes) in the final 5 years. Conversely, yeast detection decreased. CONCLUSIONS: This study provides a detailed overview of the epidemiology of the fungal cultures of skin, nail and hair samples in the Mid-West of Ireland over a 20-year period. Monitoring this changing landscape is important in identifying likely sources of infections, to identifying potential outbreaks, and may help guide empiric treatment. To the best of our knowledge, this study provides the first detailed analysis from Ireland of fungal detections from skin, hair and nail samples, and is the first epidemiological fungal report of any kind in over 7 years.

Effects of Perioperative Selective Serotonin Reuptake Inhibitor Use in Primary Total Hip and Knee Arthroplasty.

BACKGROUND: The aim of this study is to compare functional outcomes and perioperative complications between patients on a selective serotonin reuptake inhibitor (SSRI) and those who are not on an SSRI preoperatively at the time of total joint arthroplasty. METHODS: A retrospective study was performed on 28,386 patients who received a primary total hip (THA) or knee (TKA) arthroplasty. Patients were compared based on SSRI utilization. We measured patient-reported function and health-related quality of life using the Western Ontario and McMaster Universities Arthritis Index (WOMAC) and the EuroQol-5 Dimensions (EQ-5D-5L) instruments. Chi-squared test was used to compare categorical variables and t-test was used to compare the continuous variables of 2 study groups. RESULTS: Patients on SSRIs have lower preoperative baseline WOMAC and EQ-5D-5L scores than those not using SSRI (P < .001). Patient-reported outcomes improved significantly following surgery, but functional outcome scores remained inferior in patients using SSRI. After adjusting for baseline variables, SSRI use in TKA predicted lower EQ-5D-5L scores than non-SSRI users (P = .036) while the WOMAC scores were not different (P = .118). For the THA cohort, SSRI use predicted lower EQ-5D-5L (P = .001) and WOMAC scores than non-SSRI users (P = .008). SSRI use was associated with increased transfusion rate, length of stay, readmission rate, and medical events. About 11.3% of TKA and 13.3% of THA patients stopped using SSRI at 12 months after arthroplasty. CONCLUSION: Patients using an SSRI show improvement comparable to patients not on an SSRI, but their 12-month functional scores continue to be inferior. SSRI utilization was associated with increased adverse events including needing a blood transfusion.

Meta-analysis and Meta-regression of Survival After Liver Transplantation for Unresectable Perihilar Cholangiocarcinoma.

OBJECTIVE: To systematically review studies reporting survival data following neoadjuvant chemoradiation and orthotopic liver transplantation (NCR-OLT) for unresectable perihilar cholangiocarcinoma (pCC). BACKGROUND: Despite survival improvements for other cancers, the prognosis of pCC remains dismal. Since publication of the Mayo protocol in 2000, increasing numbers of series globally are reporting outcomes after NCR-OLT. METHODS: MEDLINE, EMBASE, Scopus, and Web of Science databases were searched from January 2000 to February 2019. A meta-analysis of proportions was conducted, pooling 1, 3-, and 5-year overall survival and recurrence rates following NCR-OLT across centers. Per protocol and intention to treat data were interrogated. Meta-regression was used to evaluate PSC as a confounder affecting survival. RESULTS: Twenty studies comprising 428 patients were eligible for analysis. No RCTs were retrieved; the majority of studies were noncomparative cohort studies. The pooled 1, 3-, and 5-year overall survival rates following OLT without neoadjuvant therapy were 71.2% (95% CI 62.2%-79.4%), 48.0% (95% CI 35.0%-60.9%), and 31.6% (95% CI 23.1%-40.7%). These improved to 82.8% (95% CI 73.0%-90.8%), 65.5% (95% CI 48.7%-80.5%), and 65.1% (95% CI 55.1%-74.5%) if neoadjuvant chemoradiation was completed. Pooled recurrence after 3 years was 24.1% (95% CI 17.9%-30.9%) with neoadjuvant chemoradiation, 51.7% (95% CI 33.8%-69.4%) without. CONCLUSIONS: In unresectable pCC, NCR-OLT confers long-term survival in highly selected patients able to complete neoadjuvant chemoradiation followed by transplantation. PSC patients appear to have the most favorable outcomes. A high recurrence rate is of concern when considering extending national graft selection policy to pCC.

Sodium-glucose co-transporter-2 inhibitors and atrial fibrillation in the cardiovascular and renal outcome trials.

Dapagliflozin is a sodium-glucose co-transporter-2 (SGLT2) inhibitor that has recently been shown to reduce the incidence of reported episodes of atrial fibrillation (AF)/atrial flutter in the DECLARE-TIMI 58 trial. This raises the question regarding whether SGLT2 inhibitors can reduce the incidence of AF in a high-risk population. We searched for trials comparing SGLT2 inhibitors to placebo in high-risk individuals with or without diabetes (ie, cardiovascular and renal outcome trials) and that reported the incidence of AF as a serious adverse event. The EMPA-REG OUTCOME trial, CANVAS, CANVAS-R, the DECLARE-TIMI 58 trial, CREDENCE, DAPA-HF, VERTIS-CV and DAPA-CKD were included. The incidence of AF, reported as a serious adverse event, was 0.9% in individuals who received an SGLT2 inhibitor compared to 1.1% in those who received placebo. Pooled results showed a significantly lower incidence of AF in individuals with and without diabetes (relative risk 0.79, 95% confidence interval 0.67,0.93). This review suggests that there is a significantly lower risk of incident AF for individuals on SGLT2 inhibitors versus placebo. While there was a statistically significant lower incidence of AF, reported as a serious adverse event, more research is needed to evaluate its clinical significance.

28 Models Later: Model Competition and the Zombie Apocalypse.

Between Fall 2011 and Fall 2012 students at Utah State University played several rounds of Humans versus Zombies (HvZ), a role-playing variant of tag popular on college campuses. The goal of the game is for the zombies to tag humans, converting them into more zombies. Based on portrayals of 'zombieism' in popular culture, one might treat HvZ as a disease system. However, a traditional SIR model with mass-action dynamics does a poor job of modeling HvZ, leading to the natural question: What mechanisms drive the dynamics of the HvZ system? We use model competition, with Bayesian Information Criterion as arbiter, to answer this question. First, we develop a suite of models with a variety of transmission mechanisms and fit to data from fall 2011. We use model competition to determine which model(s) have the most support from the data, thereby offering insight into driving mechanisms for HvZ. Bootstrapping is used to both assess the significance of individual mechanisms and to determine confidence in the performance of our models. Finally, we test predictions of the best models with data from fall 2012. Results indicate that through both years of the game humans tend to cluster defensively, zombies tend to hunt in groups, some zombies are more proficient hunters, and some humans leave the game.

Modeling the impact of temperature on the population abundance of the ambrosia beetle Xyleborus affinis (Curculionidae: Scolytinae) under laboratory-reared conditions.

Modeling the impact of temperature on each life stage of a beetle population represents a continuing challenge. This study evaluates the effects of five temperature treatments (20, 23, 26, 29 and 32 °C) on population abundance and timing of a colony of ambrosia beetles Xyleborus affinis reared under laboratory conditions and use this data to develop demographic and phenological models. Abundances at each life stage (eggs, larvae, pupae and adult) were examined through periodic destructive sampling; given that it was not possible to track individuals. To assess the effects of temperature on oviposition, development and survival rates we developed a novel estimation strategy based on cohorts, which does not require individual developmental data. Since oviposition was entirely unwitnessed, we assessed competing empirical ovipositional models. Rates of development were computed using a modal rate curve for each life stage, and rates were projected to cohorts in life stages assuming log-normal developmental variance. Temperature-driven survival rates were assumed to be logistic with a quadratic exponent to capture modal temperature dependence. Parameters were estimated simultaneously using minimum negative log posterior likelihood, assuming Poisson distribution of observations and using priors to inform unobserved developmental rates and enforce mechanistic constraints on oviposition models. A parabolic function best described oviposition rate. Optimal developmental temperatures were 30.5 °C, 29 °C and 27.5 °C, with maximum developmental rates of 0.26/day, 0.12/day and 0.23/day for eggs, larvae and pupae, respectively. The survival rates in the range 20-29 °C were equal to 1 in the eggs-to-larvae transition, from 0.72 to 0.35 in larvae-to-pupae transition, and from 0.2 to 0.89 in pupae-to-adults transition. This procedure effectively characterized the direct thermal effects on development and survival of each life stage in the X. affinis under laboratory conditions and would be suitable for estimating temperature dependence for other species in which individual observations are not possible.

Effect of Intensive Blood-Pressure Treatment on Patient-Reported Outcomes.

BACKGROUND: The previously published results of the Systolic Blood Pressure Intervention Trial showed that among participants with hypertension and an increased cardiovascular risk, but without diabetes, the rates of cardiovascular events were lower among those who were assigned to a target systolic blood pressure of less than 120 mm Hg (intensive treatment) than among those who were assigned to a target of less than 140 mm Hg (standard treatment). Whether such intensive treatment affected patient-reported outcomes was uncertain; those results from the trial are reported here. METHODS: We randomly assigned 9361 participants with hypertension to a systolic blood-pressure target of less than 120 mm Hg or a target of less than 140 mm Hg. Patient-reported outcome measures included the scores on the Physical Component Summary (PCS) and Mental Component Summary (MCS) of the Veterans RAND 12-Item Health Survey, the Patient Health Questionnaire 9-item depression scale (PHQ-9), patient-reported satisfaction with their blood-pressure care and blood-pressure medications, and adherence to blood-pressure medications. We compared the scores in the intensive-treatment group with those in the standard-treatment group among all participants and among participants stratified according to physical and cognitive function. RESULTS: Participants who received intensive treatment received an average of one additional antihypertensive medication, and the systolic blood pressure was 14.8 mm Hg (95% confidence interval, 14.3 to 15.4) lower in the group that received intensive treatment than in the group that received standard treatment. Mean PCS, MCS, and PHQ-9 scores were relatively stable over a median of 3 years of follow-up, with no significant differences between the two treatment groups. No significant differences between the treatment groups were noted when participants were stratified according to baseline measures of physical or cognitive function. Satisfaction with blood-pressure care was high in both treatment groups, and we found no significant difference in adherence to blood-pressure medications. CONCLUSIONS: Patient-reported outcomes among participants who received intensive treatment, which targeted a systolic blood pressure of less than 120 mm Hg, were similar to those among participants who received standard treatment, including among participants with decreased physical or cognitive function. (Funded by the National Institutes of Health; SPRINT ClinicalTrials.gov number, NCT01206062 .).

Real-time RT-qPCR assay to detect sequences in the Piscine orthoreovirus-1 genome segment S1 associated with heart and skeletal muscle inflammation in Atlantic salmon.

During the last decade, Piscine orthoreovirus was identified as the main causative agent of heart and skeletal muscle inflammation (HSMI) in Atlantic Salmon, Norway. A recent study showed that PRV-1 sequences from salmonid collected in North Atlantic Pacific Coast (NAPC) grouped separately from the Norwegian sequences found in Atlantic Salmon diagnosed with HSMI. Currently, the routine assay used to screen for PRV-1 in NAPC water and worldwide cannot differentiate between the two groups of PRV-1. Therefore, this study aimed at developing a real-time polymerase chain reaction (RT-qPCR) assay to target the PRV-1 genome segments specific for variants associated with HSMI. The assay was optimized and tested against 71 tissue samples collected from different regions including Norway, Chile and both coast of Canada and different hosts farmed Atlantic Salmon, wild Coho Salmon and escaped Atlantic Salmon collected in British Columbia, West Coast of Canada. This assay has the potential to be used for screening salmonids and non-salmonids that may carry PRV-1 potentially causing HSMI.

The effect of tranexamic acid on wound complications in primary total Hip Arthroplasty: A meta-analysis.

BACKGROUND: Allogeneic blood transfusion has been linked with an increase in the risk of surgical site infections (SSIs) through the mechanism of immunomodulation. However, no studies to date have investigated the direct relationship between blood conserving strategies including antifibrinolytics and wound complications after total hip arthroplasties (THA). METHODS: A systematic review and meta-analysis of published randomised controlled trials (RCTs) to investigate the effect of tranexamic acid (TXA) on wound complications after THAs has been conducted. RESULTS: We identified 25 clinical trials which were suitable for detailed data extraction. There were no trials which utilised TXA in revision THA. All studies reported on wound complications including a total of 1608 patients. Using TXA led to a 2% reduction in the risk of developing wound complications compared to the control group with no significant statistical heterogeneity among the study groups (Risk Difference -0.02, 95%, confidence interval CI -0.04 to -0.00, P = 0.01, Heterogeneity I2 = 0%). However, there was no significant difference in clinical outcomes in terms of antibiotic treatment or surgical intervention among the study groups. TXA also reduced intraoperative, postoperative and total blood loss and led to a significant reduction in the proportion of patients requiring allogeneic blood transfusion with no significant differences in deep venous thrombosis, pulmonary embolisms, or other complications between the study groups. CONCLUSION: TXA reduced blood loss and transfusion rates after primary THA surgery. It also reduced wound complication rates but the clinical significance of this needs further investigation through well designed and adequately powered RCTs.

One-stage versus 2-stage bilateral total joint arthroplasty: a matched cohort study.

Background: Patients with bilateral end-stage hip or knee arthritis want to know if it is safe to have bilateral surgery under a single anesthetic, to restore their quality of life as quickly as possible. The purpose of this study was to assess if there is an increase in the rate of postoperative medical adverse events, length of stay (LOS), blood transfusion rate and 30-day readmission rate among patients who undergo 1-stage bilateral total hip arthroplasty (BTHA) and 1-stage bilateral total knee arthroplasty (BTKA) compared with patients who undergo 2-stage BTHA and BTKA. Methods: Our study cohorts included patients who underwent BTHA and BTKA between Apr. 1, 2009, and Jan. 31, 2016, in Alberta, Canada. To minimize selection bias associated with our retrospective study design, we matched patients who underwent 1-stage BTHA and BTKA with patients with patients who underwent 2-stage BTHA and BTKA, respectively, for age, sex and number of presurgical risk factors using propensity score in a matching ratio of 1:1. Results: Our study included 1645 patients who underwent BTHA and 4125 patients who underwent BTKA. We matched 195 patients who underwent 1-stage BTHA and 302 patients who underwent 1-stage BTKA with patients who underwent 2-stage BTHA and BTKA, respectively. There was no significant difference in postoperative medical adverse events between the 1-stage and 2-stage matched cohort groups for both BTHA (adjusted odds ratio [OR] 1.3, 95% confidence interval [CI] 0.3-4.9) and BTKA (adjusted OR 0.9, 95% CI 0.3-2.6). There was no difference in inpatient, 30- or 90-day mortality between the 2 groups for BTHA or BTKA. Patients who underwent 1-stage BTHA and BTKA had a shorter acute length of stay but increased total length of stay (acute care and rehabilitation unit) and were less likely to be discharged home postoperatively. One-stage BTHA and BTKA were associated with higher odds of blood transfusion than 2-stage BTHA and BTKA. The 30-day readmission rate was significantly lower for 1-stage BTHA than for the 2-stage BTHA matched cohort (adjusted OR 0.3, 95% CI 0.1-0.8), whereas there was no difference in the 30-day readmission rate (adjusted OR 0.6, 95% CI 0.2-1.7) between the 1-stage and 2-stage BTKA matched cohorts. Finally, operating room time was significantly lower for 1-stage BTHA (49.6 min less) and 1-stage BTKA (66.7 min less) than for the 2-stage arthroplasty procedures. Conclusion: Healthy patients who undergo 1-stage BTHA and BTKA have postoperative medical complication rates comparable to those of patients who undergo 2-stage procedures with the additional benefits of a shorter acute length of stay, but they do have a higher risk of blood transfusion and are less likely to be discharged directly home from the acute care hospital. A multicentre randomized controlled trial on this topic is currently being condcuted by the Canadian Arthroplasty Society.

Contexte: Les patients atteints d'arthrite bilatérale de la hanche ou du genou au stade terminal veulent savoir s'il est sécuritaire de subir une chirurgie bilatérale avec une seule anesthésie pour retrouver leur qualité de vie le plus rapidement possible. Le but de cette étude était de comparer le taux de complications postopératoires de nature médicale, la durée du séjour hospitalier, le taux de transfusions sanguines et le taux de réadmissions à 30 jours chez les patients selon que les arthroplasties totales de la hanche bilatérales (ATHB) et les arthroplasties totales du genou bilatérales (ATGB) se font en 1 étape ou en 2 étapes. Méthodes: Les cohortes de notre étude incluaient des patients qui ont subi des ATHB et des ATGB entre le 1er avril 2009 et le 31 janvier 2016 en Alberta, au Canada. Pour réduire le biais de sélection associé à notre protocole d'étude rétrospective, nous avons assorti les patients soumis aux ATHB et aux ATGB en 1 étape à ceux qui les ont subies en 2 étapes, respectivement, selon l'âge, le sexe et le nombre de facteurs de risque préopératoires, avec score de propension et rapport 1:1. Résultats: Notre étude a regroupé 1645 patients soumis à des ATHB et 4125 patients soumis à des ATGB. Nous avons assortis 195 patients soumis aux ATHB en 1 étape et 302 patients soumis aux ATGB en 1 étape avec des patients soumis à des ATHB et des ATGB en 2 étapes, respectivement. On n'a noté aucune différence significative quant aux complications postopératoires de nature médicale entre les groupes des cohortes assorties pour les interventions en 1 et en 2 étapes, tant avec les ATHB (rapport des cotes [RC] ajusté 1,3, intervalle de confiance [IC] de 95% 0,3­4,9), qu'avec les ATGB (RC ajusté 0,9, IC de 95% 0,3­2,6). Il n'y a pas eu de différences au plan de la mortalité à 30 jours ou à 90 jours chez les patients hospitalisés des 2 groupes avec les ATHB ou les ATGB. Les patients soumis aux ATHB et aux ATGB en 1 étape ont séjourné moins longtemps en soins actifs, mais la durée totale de leur séjour a été plus longue (soins actifs et réadaptation) et ils étaient moins susceptibles de retourner à la maison au moment de leur congé hospitalier après l'intervention. Les ATHB et les ATGB en 1 étape ont été associées à un risque plus grand de transfusions sanguines que les ATHB et les ATGB en 2 étapes. Le taux de réadmission à 30 jours a été significativement plus faible avec les ATHB en 1 étape que dans la cohorte assortie soumise aux ATHB en 2 étapes (RC ajusté 0,3, IC de 95% 0,1­0,8), tandis qu'il n'y a eu aucune différence au plan des taux de réadmission à 30 jours (RC ajusté 0,6, IC de 95% 0,2­1,7) entre les cohortes assorties soumises aux ATGB en 1 et 2 étapes. En terminant, le temps opératoire a été significativement plus bref avec les ATHB et les ATGB en 1 étape (respectivement 49,6 minutes et 66,7 minutes de moins) comparativement aux arthroplasties en 2 étapes. Conclusion: Les patients en bonne santé qui subissent des ATHB et des ATGB en 1 étape ont des taux de complications postopératoires de nature médicale comparables à ceux qui les subissent en 2 étapes, avec l'avantage additionnel d'un séjour hospitalier plus bref en soins actifs; mais ils sont exposés à un risque plus grand de transfusions sanguines et sont moins susceptibles de retourner directement à la maison en quittant l'hôpital de soins actifs. La Société canadienne d'arthroplastie procède actuellement à un essai randomisé et contrôlé multicentrique à ce sujet.

Postoperative fever in the time of COVID-19.

Summary: Postoperative fever is common following orthopedic trauma surgery. As the prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection increases in the community, migration into the acute care hospital setting intensifies, creating confusion when fever develops postoperatively. The transmission dynamics of SARS-CoV-2 make it difficult to adequately gauge and pinpoint risk groups with questionnaires at the time of hospital admission. This is particularly problematic when asymptomatic or presymptomatic patients infected with SARS-CoV-2 require urgent surgery and cannot be screened effectively. One approach is to treat every patient as though they were SARS-CoV-2-positive in preparation for surgery, but doing so could exacerbate shortages of personal protective equipment and staffing limitations. Uncertainty regarding the etiology of postoperative fever could be significantly reduced by universal SARS-CoV-2 testing of all surgical patients at the time of hospital admission in addition to routine screening, but testing capacity and a rapid turnaround time would be required.

Does body mass index affect the rate of adverse outcomes in total hip and knee arthroplasty? A retrospective review of a total joint replacement database

Background: Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are reliable surgical options to treat pain and disability resulting from degenerative conditions around the hip and knee. Obesity is a modifiable risk factor that contributes to significant morbidity. The purpose of this study was to retrospectively compare outcomes in primary hip and knee arthroplasty for patients with increased body mass index (BMI) and those with normal BMI, using data from the registry of the Alberta Bone and Joint Health Institute (ABJHI). Methods: We retrospectively reviewed the data compiled in the ABJHI registry between March 2010 and July 2016. We reviewed outcomes with respect to length of stay, discharge destination, 30-day readmission, postoperative infection, postoperative transfusion requirements, postoperative adverse events and in-hospital postoperative mechanical complications. Results: A total of 10 902 patients (6076 women, 4826 men) who underwent THA and 16 485 patients (10 057 women, 6428 men) who underwent TKA were included in the study. For both THA and TKA, patients with increased BMI had an increased number of in-hospital medical events, had an increased rate of deep infection, were less likely to be discharged home (p < 0.001) and had decreased transfusion requirements (p < 0.001) than patients whose weight was in the normal range. Increased BMI increased the rate of 30-day readmission and length of stay in the THA cohort but not in the TKA cohort. Increased BMI had no effect on acute postoperative dislocation or periprosthetic fractures. Patients with a BMI of 30 kg/m2 or greater required a THA 1.7 years earlier than patients of normal weight, patients whose BMI was 35 kg/m2 or greater required a THA 3.4 years earlier, and patients whose BMI was 40 kg/m2 or greater required a THA 5.8 years earlier. In the TKA cohort, patients with a BMI of 30 kg/m2 or greater required a TKA 2.7 years earlier than patients whose weight was in the normal range, patients with a BMI of 35 kg/m2 or greater required a TKA 4.6 years earlier, and patients whose BMI was 40 kg/m2 or greater required a TKA 7.6 years earlier. Conclusion: Our study quantifies the effects of obesity in primary hip and knee arthroplasty. It provides a greater understanding of the risks in the obese population when contemplating joint arthroplasty.

Contexte: La prothèse totale de la hanche (PTH) et la prothèse totale du genou (PTG) sont des options chirurgicales fiables pour traiter la douleur et l'invalidité résultant de maladies dégénératives de la hanche et du genou. L'obésité est un facteur de risque modifiable qui contribue significativement à la morbidité. Le but de cette étude était de comparer de manière rétrospective le résultat des interventions primaires pour prothèses de la hanche et du genou selon que les patients avaient un indice de masse corporelle (IMC) normal ou élevé à partir des données du registre de l'Alberta Bone and Joint Health Institute (ABJHI). Méthodes: Nous avons analysé de manière rétrospective les données compilées par le registre de l'ABJHI entre mars 2010 et juillet 2016. Nous avons passé en revue les paramètres suivants : durée du séjour hospitalier, destination post-congé, réadmissions dans les 30 jours, infections postopératoires, besoins transfusionnels postopératoires, complications postopératoires et complications mécaniques postopératoires perhospitalières. Résultats: En tout, 10 902 patients (6076 femmes, 4826 hommes) ayant subi une PTH et 16 485 patients (10 057 femmes, 6428 hommes) ayant subi une PTG ont été inclus dans l'étude. Tant pour la PTH que pour la PTG, les patients ayant un IMC élevé ont présenté un plus grand nombre de complications médicales en cours d'hospitalisation; ils ont aussi présenté un nombre plus élevé d'infections profondes, étaient moins susceptibles de pouvoir retourner chez eux au moment de leur congé (p < 0,001) et ont eu moins besoin de transfusions (p < 0,001) comparativement aux patients dont le poids se situait dans l'éventail des valeurs normales. L'IMC élevé a été en corrélation avec une augmentation du taux de réadmission à 30 jours et de la durée du séjour dans la cohorte soumise à une PTH, mais non dans la cohorte soumise à une PTG. L'IMC élevé n'a exercé aucun effet sur la dislocation postopératoire aiguë ou les fractures périprothétiques. Les patients ayant un IMC de 30 kg/m2 ou plus ont eu besoin d'une PTH 1,7 an plus tôt que les patients de poids normal, les patients ayant un IMC de 35 kg/m2 ou plus ont eu besoin d'une PTH 3,4 ans plus tôt, et les patients ayant un IMC de 40 kg/m2 ou plus ont eu besoin d'une PTH 5,8 ans plus tôt. Dans la cohorte soumise à la PTG, les patients ayant un IMC de 30 kg/m2 ou plus ont eu besoin d'une PTG 2,7 ans plus tôt que les patients de poids normal, les patients ayant un IMC de 35 kg/m2 ou plus ont eu besoin d'une PTG 4,6 ans plus tôt, et les patients ayant un IMC de 40 kg/m2 ou plus ont eu besoin d'une PTG 7,6 ans plus tôt. Conclusion: Notre étude quantifie les effets de l'obésité sur le recours aux interventions primaires pour prothèse de la hanche et du genou. Elle permet de mieux comprendre les risques auxquels est exposée la population obèse lorsqu'une intervention pour prothèse articulaire est envisagée.

Bekenstein's Entropy Bound-Particle Horizon Approach to Avoid the Cosmological Singularity.

The cosmological singularity of infinite density, temperature, and spacetime curvature is the classical limit of Friedmann's general relativity solutions extrapolated to the origin of the standard model of cosmology. Jacob Bekenstein suggests that thermodynamics excludes the possibility of such a singularity in a 1989 paper. We propose a re-examination of his particle horizon approach in the early radiation-dominated universe and verify it as a feasible alternative to the classical inevitability of the singularity. We argue that this minimum-radius particle horizon determined from Bekenstein's entropy bound, necessarily quantum in nature as a quantum particle horizon (QPH), precludes the singularity, just as quantum mechanics provided the solution for singularities in atomic transitions as radius r → 0 . An initial radius of zero can never be attained quantum mechanically. This avoids the spacetime singularity, supporting Bekenstein's assertion that Friedmann models cannot be extrapolated to the very beginning of the universe but only to a boundary that is 'something like a particle horizon'. The universe may have begun in a bright flash and quantum flux of radiation and particles at a minimum, irreducible quantum particle horizon rather than at the classical mathematical limit and unrealizable state of an infinite singularity.