Iron Phosphide Nanobundles for Efficient Electrochemical Hydrogen Evolution Reaction in Acidic and Basic Media.

Earth-abundant transition metal phosphide (TMP) nanomaterials have gained significant attention as potential replacements for Pt-based electrocatalysts in green energy applications, such as the hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and overall water splitting. In particular, FeP nanostructures exhibit superior electrical conductivity and high stability. Moreover, their diverse composition and unique crystal structures position FeP nanomaterials as emerging candidates for HER electrocatalysts. However, the synthesis or fabrication method employed for FeP nanostructures can significantly affect their overall electrocatalytic properties. For example, the solution synthesis of pure-phase FeP nanostructures remains challenging due to the formation of multiple binary phases and undesirable agglomeration. In this work, we use a simple approach to synthesizing FeP nanobundles by reacting ß-FeOOH (iron oxyhydroxide) with trioctylphosphine (TOP). FeP nanobundles were evaluated as HER electrocatalysts in both acidic and basic conditions, demonstrating good HER activity with overpotential values of 170 and 338 mV at a current density of -10 mA cm-2 in acidic and alkaline solutions, respectively. Additionally, they exhibited low values of Tafel slopes in both acidic and alkaline environments. In acidic media with a pH of 0.45, the nanobundles showed no signs of deterioration for up to 15 h (-50 mA cm-2). In basic media with a pH of 13.69, the nanobundles remain stable for up to 8 h (-50 mA cm-2). These results demonstrate a simple and effective method for producing highly efficient earth-abundant and cost-effective TMP-based electrocatalysts, which could play a vital role in the hydrogen economy of the future.

Intraoperative Oxygen Treatment, Oxidative Stress, and Organ Injury Following Cardiac Surgery: A Randomized Clinical Trial.

Importance: Liberal oxygen (hyperoxia) is commonly administered to patients during surgery, and oxygenation is known to impact mechanisms of perioperative organ injury. Objective: To evaluate the effect of intraoperative hyperoxia compared to maintaining normoxia on oxidative stress, kidney injury, and other organ dysfunctions after cardiac surgery. Design, Setting, and Participants: This was a participant- and assessor-blinded, randomized clinical trial conducted from April 2016 to October 2020 with 1 year of follow-up at a single tertiary care medical center. Adult patients (>18 years) presenting for elective open cardiac surgery without preoperative oxygen requirement, acute coronary syndrome, carotid stenosis, or dialysis were included. Of 3919 patients assessed, 2501 were considered eligible and 213 provided consent. Of these, 12 were excluded prior to randomization and 1 following randomization whose surgery was cancelled, leaving 100 participants in each group. Interventions: Participants were randomly assigned to hyperoxia (1.00 fraction of inspired oxygen [FiO2]) or normoxia (minimum FiO2 to maintain oxygen saturation 95%-97%) throughout surgery. Main Outcomes and Measures: Participants were assessed for oxidative stress by measuring F2-isoprostanes and isofurans, for acute kidney injury (AKI), and for delirium, myocardial injury, atrial fibrillation, and additional secondary outcomes. Participants were monitored for 1 year following surgery. Results: Two hundred participants were studied (median [IQR] age, 66 [59-72] years; 140 male and 60 female; 82 [41.0%] with diabetes). F2-isoprostanes and isofurans (primary mechanistic end point) increased on average throughout surgery, from a median (IQR) of 73.3 (53.1-101.1) pg/mL at baseline to a peak of 85.5 (64.0-109.8) pg/mL at admission to the intensive care unit and were 9.2 pg/mL (95% CI, 1.0-17.4; P = .03) higher during surgery in patients assigned to hyperoxia. Median (IQR) change in serum creatinine (primary clinical end point) from baseline to postoperative day 2 was 0.01 mg/dL (-0.12 to 0.19) in participants assigned hyperoxia and -0.01 mg/dL (-0.16 to 0.19) in those assigned normoxia (median difference, 0.03; 95% CI, -0.04 to 0.10; P = .45). AKI occurred in 21 participants (21%) in each group. Intraoperative oxygen treatment did not affect additional acute organ injuries, safety events, or kidney, neuropsychological, and functional outcomes at 1 year. Conclusions: Among adults receiving cardiac surgery, intraoperative hyperoxia increased intraoperative oxidative stress compared to normoxia but did not affect kidney injury or additional measurements of organ injury including delirium, myocardial injury, and atrial fibrillation. Trial Registration: ClinicalTrials.gov Identifier: NCT02361944.

Predictive modelling for postoperative acute kidney injury: big data enhancing quality or the Emperor's new clothes?

The increased availability of large clinical datasets together with increasingly sophisticated computing power has facilitated development of numerous risk prediction models for various adverse perioperative outcomes, including acute kidney injury (AKI). The rationale for developing such models is straightforward. However, despite numerous purported benefits, the uptake of preoperative prediction models into clinical practice has been limited. Barriers to implementation of predictive models, including limitations in their discrimination and accuracy, as well as their ability to meaningfully impact clinical practice and patient outcomes, are increasingly recognised. Some of the purported benefits of predictive modelling, particularly when applied to postoperative AKI, might not fare well under detailed scrutiny. Future research should address existing limitations and seek to demonstrate both benefit to patients and value to healthcare systems from implementation of these models in clinical practice.

Determinants and Practice Variability of Oxygen Administration during Surgery in the United States: A Retrospective Cohort Study.

BACKGROUND: The best approaches to supplemental oxygen administration during surgery remain unclear, which may contribute to variation in practice. This study aimed to assess determinants of oxygen administration and its variability during surgery. METHODS: Using multivariable linear mixed-effects regression, the study measured the associations between intraoperative fraction of inspired oxygen and patient, procedure, medical center, anesthesiologist, and in-room anesthesia provider factors in surgical cases of 120 min or longer in adult patients who received general anesthesia with tracheal intubation and were admitted to the hospital after surgery between January 2016 and January 2019 at 42 medical centers across the United States participating in the Multicenter Perioperative Outcomes Group data registry. RESULTS: The sample included 367,841 cases (median [25th, 75th] age, 59 [47, 69] yr; 51.1% women; 26.1% treated with nitrous oxide) managed by 3,836 anesthesiologists and 15,381 in-room anesthesia providers. Median (25th, 75th) fraction of inspired oxygen was 0.55 (0.48, 0.61), with 6.9% of cases less than 0.40 and 8.7% greater than 0.90. Numerous patient and procedure factors were statistically associated with increased inspired oxygen, notably advanced American Society of Anesthesiologists classification, heart disease, emergency surgery, and cardiac surgery, but most factors had little clinical significance (less than 1% inspired oxygen change). Overall, patient factors only explained 3.5% (95% CI, 3.5 to 3.5%) of the variability in oxygen administration, and procedure factors 4.4% (95% CI, 4.2 to 4.6%). Anesthesiologist explained 7.7% (95% CI, 7.2 to 8.2%) of the variability in oxygen administration, in-room anesthesia provider 8.1% (95% CI, 7.8 to 8.4%), medical center 23.3% (95% CI, 22.4 to 24.2%), and 53.0% (95% CI, 52.4 to 53.6%) was unexplained. CONCLUSIONS: Among adults undergoing surgery with anesthesia and tracheal intubation, supplemental oxygen administration was variable and appeared arbitrary. Most patient and procedure factors had statistical but minor clinical associations with oxygen administration. Medical center and anesthesia provider explained significantly more variability in oxygen administration than patient or procedure factors.

Effectiveness of Oral Iron Therapy in Anemic Inpatient Pregnant Women: A Single Center Retrospective Cohort Study.

Background and aim Oral iron therapy is effective in treating iron deficiency anemia in outpatient pregnant women but has not been studied in inpatient pregnant women. We aimed to evaluate the effect of oral iron therapy versus no therapy during hospitalization on maternal and neonatal outcomes in women with anemia who are hospitalized for pregnancy-related morbidities (i.e., preterm premature rupture of membranes, preterm labor, pre-eclampsia, abnormal placentation, or fetal monitoring). Methods A retrospective, single-center study was conducted in hospitalized pregnant women (2018 to 2020) with inpatient stays of more than three days. The primary outcome was a change in hemoglobin level from admission to delivery in women treated with oral iron compared with those left untreated. Secondary outcomes included the total amount of iron administered before delivery, the time interval from admission to delivery, and neonatal effects. Results Two hundred sixty-three women were admitted, 79 women had anemia, and 29 (36.7%) received at least one dose of oral iron. Baseline patient characteristics were similar between groups. The median (interquartile range) dose of iron in the oral iron group was 1185.0 (477.0, 1874.0) mg. Neither absolute hemoglobin before delivery (control group: 10.0±1.2 g/dL; iron group: 10.1±1.1 g/dL; p=0.774) nor change in hemoglobin from admission to delivery (control group: -0.1±1.1 g/dL vs. iron group: 0.4±1.1 g/dL; p=0.232) differed between groups. Women in the control group had shorter length of stay (LOS) median (IQR) than women in the iron group (control group: 7.1 (5.0, 13.7) days; iron group: 11.4 (7.4, 25.9) days; p=0.03). There were no differences in maternal mode of delivery, though each group had high rates of cesarean delivery (control group: 53.7%; iron group: 72.4%; p=0.181). There were no differences in estimated blood loss at delivery (control group: 559±401; iron group: 662.1±337.4;p=0.264) in either group. Neonatal birthweight (control group: 1.9±0.7 kg; iron group: 1.9±0.7 kg; p=0.901), birth hemoglobin (control group: 16.3±2.2 g/dL; iron group: 16±2.2 g/dL; p=0.569), neonatal intensive care unit (NICU) admission (control group: 93.3%; iron group: 84.8%;p=0.272 ), or neonatal death (control group: 8.9%; iron group: 3%; p=0.394) were not different between groups. Conclusions Oral iron administered to anemic inpatient pregnant women was not associated with higher hemoglobin concentrations before delivery. Lack of standardized iron regimens and short hospital stays may contribute to the inefficacy of oral iron for this inpatient pregnant population. The small sample size and retrospective nature of this study are limiting factors in drawing conclusive evidence from this study.

Candidate Kidney Protective Strategies for Patients Undergoing Major Abdominal Surgery: A Secondary Analysis of the RELIEF Trial Cohort.

BACKGROUND: Acute kidney injury (AKI) is common after major abdominal surgery. Selection of candidate kidney protective strategies for testing in large trials should be based on robust preliminary evidence. METHODS: A secondary analysis of the Restrictive versus Liberal Fluid Therapy in Major Abdominal Surgery (RELIEF) trial was conducted in adult patients undergoing major abdominal surgery and randomly assigned to a restrictive or liberal perioperative fluid regimen. The primary outcome was maximum AKI stage before hospital discharge. Two multivariable ordinal regression models were developed to test the primary hypothesis that modifiable risk factors associated with increased maximum stage of postoperative AKI could be identified. Each model used a separate approach to variable selection to assess the sensitivity of the findings to modeling approach. For model 1, variable selection was informed by investigator opinion; for model 2, the Least Absolute Shrinkage and Selection Operator (LASSO) technique was used to develop a data-driven model from available variables. RESULTS: Of 2,444 patients analyzed, stage 1, 2, and 3 AKI occurred in 223 (9.1%), 59 (2.4%), and 36 (1.5%) patients, respectively. In multivariable modeling by model 1, administration of a nonsteroidal anti-inflammatory drug or cyclooxygenase-2 inhibitor, intraoperatively only (odds ratio, 1.77 [99% CI, 1.11 to 2.82]), and preoperative day-of-surgery administration of an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker compared to no regular use (odds ratio, 1.84 [99% CI, 1.15 to 2.94]) were associated with increased odds for greater maximum stage AKI. These results were unchanged in model 2, with the additional finding of an inverse association between nadir hemoglobin concentration on postoperative day 1 and greater maximum stage AKI. CONCLUSIONS: Avoiding intraoperative nonsteroidal anti-inflammatory drugs or cyclooxygenase-2 inhibitors is a potential strategy to mitigate the risk for postoperative AKI. The findings strengthen the rationale for a clinical trial comprehensively testing the risk-benefit ratio of these drugs in the perioperative period.

Psychological risk factors predictive of suicidal distress in men receiving a community-based brief psychological intervention.

INTRODUCTION: Adaptable community-based approaches for assessment and delivery of suicide prevention interventions for men experiencing suicidal crisis are needed. The lay your cards on the table (LYCT) component of the James' Place Model is a novel therapeutic approach comprised of four sets of card variables that correspond with suicidal risk factors. This study investigated the LYCT in predicting suicidal distress among men. METHODS: Cross-sectional data of 511 men aged 18-69 years (M = 34.59 years; SD = 12.30) collected between 1st August 2018 and 29th July 2021 were assessed to predict suicidal distress measured using the CORE Clinical Outcome Measures (CORE-OM). RESULTS: From four categories comprising the LYCT, correlational analyses demonstrated that 20 associations emerged as statistically significant (r's = 0.12-0.19). When these were included in regression analyses, effect sizes explained 2%-5% variance in CORE-OM outcomes (R2). CONCLUSION: Use of LYCT is supported for engaging men in the assessment of suicide risk factors and to inform tailoring of intervention delivery to suit the individual needs of men experiencing suicidal crisis.

Poor Agreement Between Preoperative Transthoracic Echocardiography and Intraoperative Transesophageal Echocardiography for Grading Diastolic Dysfunction.

BACKGROUND: Guidelines for the evaluation and grading of diastolic dysfunction are available for transthoracic echocardiography (TTE). Transesophageal echocardiography (TEE) is used for this purpose intraoperatively but the level of agreement between these 2 imaging modalities for grading diastolic dysfunction is unknown. We assessed agreement between awake preoperative TTE and intraoperative TEE for grading diastolic dysfunction. METHODS: In 98 patients undergoing cardiac surgery, key Doppler measurements were obtained using TTE and TEE at the following time points: TTE before anesthesia induction (TTEawake), TTE following anesthesia induction (TTEanesth), and TEE following anesthesia induction (TEEanesth). The primary endpoint was grade of diastolic dysfunction categorized by a simplified algorithm, and measured by TTEawake and TEEanesth, for which the weighted κ statistic assessed observed agreement beyond chance. Secondary endpoints were peak early diastolic lateral mitral annular tissue velocity (e'lat) and the ratio of peak early diastolic mitral inflow velocity (E) to e'lat (E/e'lat), measured by TTEawake and TEEanesth, were compared using Bland-Altman limits of agreement. RESULTS: Disagreement in grading diastolic dysfunction by ≥1 grade occurred in 43 (54%) of 79 patients and by ≥2 grades in 8 (10%) patients with paired measurements for analysis, yielding a weighted κ of 0.35 (95% confidence interval [CI], 0.19-0.51) for the observed level of agreement beyond chance. Bland-Altman analysis of paired data for e'lat and E/e'lat demonstrated a mean difference (95% CI) of 0.51 (-0.06 to 1.09) and 0.70 (0.07-1.34), respectively, for measurements made by TTEawake compared to TEEanesth. The percentage (95% CI) of paired measurements for e'lat and E/e'lat that lay outside the [-2, +2] study-specified boundary of acceptable agreement was 36% (27%-48%) and 39% (29%-51%), respectively. Results were generally robust to sensitivity analyses, including comparing measurements between TTEawake and TTEanesth, between TTEanesth and TEEanesth, and after regrading diastolic dysfunction by the American Society of Echocardiography (ASE)/European Association of CardioVascular Imaging (EACVI) algorithm. CONCLUSIONS: There was poor agreement between TTEawake and TEEanesth for grading diastolic dysfunction by a simplified algorithm, with disagreement by ≥1 grade in 54% and by ≥2 grades in 10% of the evaluable cohort. Future studies, including comparing the prognostic utility of TTEawake and TEEanesth for clinically important adverse outcomes that may be a consequence of diastolic dysfunction, are needed to understand whether this disagreement reflects random variability in Doppler variables, misclassification by the changed technique and physiological conditions of intraoperative TEE, or the accurate detection of a clinically relevant change in diastolic dysfunction.

Formation of Iron Phosphide Nanobundles from an Iron Oxyhydroxide Precursor.

Iron phosphide (FeP) nanoparticles have excellent properties such as fast charge transfer kinetics, high electrical conductivity, and high stability, making them a promising catalyst for hydrogen evolution reaction (HER). A challenge to the wide use of iron phosphide nanomaterials for this application is the available synthesis protocols that limit control over the resulting crystalline phase of the product. In this study, we report a method for synthesizing FeP through a solution-based process. Here, we use iron oxyhydroxide (ß-FeOOH) as a cost-effective, environmentally friendly, and air-stable source of iron, along with tri-n-octylphosphine (TOP) as the phosphorus source and solvent. FeP is formed in a nanobundle morphology in the solution phase reaction at a temperature of 320 °C. The materials were characterized by pXRD and transmission electron microscopy (TEM). The optimization parameters evaluated to produce the phosphorus-rich FeP phase included the reaction rate, time, amount of TOP, and reaction temperature. Mixtures of Fe2P and FeP phases were obtained at shorter reaction times and slow heating rates (4.5 °C /min), while longer reaction times and faster heating rates (18.8 °C/min) favored the formation of phosphorus-rich FeP. Overall, the reaction lever that consistently yielded FeP as the predominant crystalline phase was a fast heat rate.

Anti-Factor-Xa and Activated Partial Thromboplastin Time Concordance and Outcomes in Adults Undergoing Extracorporeal Membrane Oxygenation: A Secondary Analysis of the Pilot Low-Dose Heparin in Critically Ill Patients Undergoing Extracorporeal Membrane Oxygenation Randomized Trial.

OBJECTIVES: To determine the concordance between activated partial thromboplastin time (aPTT) and anti-factor-Xa (anti-Xa) in adults undergoing extracorporeal membrane oxygenation (ECMO) and to identify the factors associated with discordant paired aPTT/anti-Xa. DESIGN: Pre-planned secondary analysis of the Low-Dose Heparin in Critically Ill Patients Undergoing Extracorporeal Membrane Oxygenation pilot randomized unblinded, parallel-group controlled trial. SETTING: Two ICUs in two university hospitals. PATIENTS: Thirty-two critically ill patients who underwent ECMO and who had at least one paired aPTT and anti-Xa assay performed at the same time. INTERVENTIONS: We analyzed the concordance between aPTT and anti-Xa and identified factors associated with discordant paired aPTT/anti-Xa based on their respective therapeutic ranges. We also compared biological parameters between heparin resistance episode and no heparin resistance. MEASUREMENTS AND MAIN RESULTS: Of the 32 patients who were included in this study, 24 (75%) had at least one discordant paired aPTT/anti-Xa. Of the 581 paired aPTT/anti-Xa that were analyzed, 202 were discordant. The aPTT was relatively lower than anti-Xa in 66 cases (32.7%) or relatively higher than anti-Xa in 136 cases (67.3%). Thirty-three heparin resistance episodes were identified in six patients (19%). CONCLUSIONS: In these critically ill patients undergoing ECMO, one third of paired aPTT/anti-Xa measures was discordant. Coagulopathy and heparin resistance might be the reasons for discordance. Our results support the potential importance of routinely monitoring both tests in this setting.

A mixed-methods evaluation of the acceptability and fidelity of the James' Place model for men experiencing suicidal crisis.

Background: Research supports development of informal, community-based suicide prevention interventions that can be tailored to suit men's unmet needs. The James' Place model (JPM) is a community-based, clinical suicide prevention intervention for men experiencing suicidal crisis. Evidence supports the efficacy of the JPM and there are plans to expand to additional sites across the UK. This study evaluates therapists perceived acceptability of the JPM, and if fidelity to the planned delivery of the model is maintained within therapeutic practice. Method: A mixed-methods design was used. Descriptive analyses of 30 completed intervention cases were examined to review fidelity of the model against the intervention delivery plan. Eight therapists took part in semi-structured interviews between November 2021 and March 2022 exploring the perceived acceptability, and barriers and facilitators to delivering the JPM. Results: Descriptive analyses of James' Place audit notes revealed high levels of adherence to the JPM amongst therapists, but highlighted components of the model needed to be tailored according to individual men's needs. Thematic analysis led to the development of five themes. The first theme, therapeutic environment highlighted importance of the therapy setting. The second theme identified was specialised suicide prevention training in the JPM that facilitated therapists understanding and expertise. The third theme identified was therapy engagement which discusses men's engagement in therapy. The fourth theme, person-centred care related to adaptation of delivery of JPM components. The final theme, adapting the JPM to individual needs describes tailoring of the JPM by therapists to be responsive to individual men's needs. Conclusion: The findings evidence therapist's acceptability and their moderate adherence to the JPM. Flexibility in delivery of the JPM enables adaptation of the model and co-production of therapy to meet men's needs. Implications for clinical practice are discussed.

Correction: Voltammetric pH sensor based on electrochemically modified pseudo-graphite.

Correction for 'Voltammetric pH sensor based on electrochemically modified pseudo-graphite' by Haoyu Zhu et al., Analyst, 2020, 145, 7252-7259, https://doi.org/10.1039/D0AN01405B.

Effects of Postoperative Blood Pressure Management on Delirium Among Patients in the Intensive Care Unit After Cardiac Surgery: An Observational Cohort Study.

OBJECTIVES: This study aimed to determine whether blood pressure control in the early postoperative period was associated with postoperative delirium in the cardiovascular intensive care unit (ICU). DESIGN: Observational cohort study. SETTING: Single large academic institution with a high volume of cardiac surgery. PARTICIPANTS: Cardiac surgery patients admitted to the cardiovascular ICU after surgery. INTERVENTIONS: Observational study. MEASUREMENTS AND MAIN RESULTS: A total of 517 cardiac surgery patients had mean arterial pressure (MAP) data recorded minute-by-minute for 12 postoperative hours. The time spent in each of the 7 prespecified blood pressure bands was calculated, and the development of delirium was recorded in the ICU. A multivariate Cox regression model was developed using the least absolute shrinkage and selection operator approach to identify associations between time spent in each MAP range band and delirium. Compared with the reference band of 60-to-69 mmHg, longer durations spent in 3 bands were independently associated with a lower risk of delirium: 50-to-59 mmHg band (adjusted hazard ratio [HR] 0.907 [per 10 minutes]; 95% CI 0.861-0.955); 70-to-79 mmHg band (adjusted HR 0.923 [per 10 minutes]; 95% CI 0.902-0.944); 90-to-99 mmHg band (adjusted HR 0.898 [per 10 minutes]; 95% CI 0.853-0.945). CONCLUSIONS: The MAP range bands above and below the authors' reference band of 60-to- 69 mmHg were associated with decreased risk of ICU delirium development; however, this was difficult to reconcile with a plausible biologic mechanism. Therefore, the authors did not find a correlation between early postoperative MAP control and increased risk of the development of ICU delirium after cardiac surgery.

Evaluating the role and effectiveness of co-produced community-based mental health interventions that aim to reduce suicide among adults: A systematic review.

BACKGROUND: Suicide is a major public health risk requiring targeted suicide prevention interventions. The principles of co-production are compatible with tailoring suicide prevention interventions to meet an individual's needs. AIMS: This review aimed to evaluate the role and effectiveness of co-produced community-based suicide prevention interventions among adults. METHODS: Four electronic databases (PsycInfo, CINAHL, MEDLINE and web of science) were systematically searched. A narrative synthesis was conducted. RESULTS: From 590 papers identified through searches, 14 fulfilled the inclusion criteria. Most included studies elicited the views and perspectives of stakeholders in a process of co-design/co-creation of community-based suicide prevention interventions. CONCLUSION: Stakeholder involvement in the creation of community-based suicide prevention interventions may improve engagement and give voice to those experiencing suicidal crisis. However, there is limited evaluation extending beyond the design of these interventions. Further research is needed to evaluate the long-term outcomes of co-produced community-based suicide prevention interventions. PATIENT AND PUBLIC INVOLVEMENT: This paper is a systematic review and did not directly involve patients and/or the public. However, the findings incorporate the views and perspectives of stakeholders as reported within the studies included in this review, and the findings may inform the future involvement of stakeholders in the design, development and delivery of community-based suicide prevention interventions for adults.

Oxygen administration during surgery and postoperative organ injury: observational cohort study.

OBJECTIVE: To examine whether supraphysiological oxygen administration during surgery is associated with lower or higher postoperative kidney, heart, and lung injury. DESIGN: Observational cohort study. SETTING: 42 medical centers across the United States participating in the Multicenter Perioperative Outcomes Group data registry. PARTICIPANTS: Adult patients undergoing surgical procedures ≥120 minutes' duration with general anesthesia and endotracheal intubation who were admitted to hospital after surgery between January 2016 and November 2018. INTERVENTION: Supraphysiological oxygen administration, defined as the area under the curve of the fraction of inspired oxygen above air (21%) during minutes when the hemoglobin oxygen saturation was greater than 92%. MAIN OUTCOMES: Primary endpoints were acute kidney injury defined using Kidney Disease Improving Global Outcomes criteria, myocardial injury defined as serum troponin >0.04 ng/mL within 72 hours of surgery, and lung injury defined using international classification of diseases hospital discharge diagnosis codes. RESULTS: The cohort comprised 350 647 patients with median age 59 years (interquartile range 46-69 years), 180 546 women (51.5%), and median duration of surgery 205 minutes (interquartile range 158-279 minutes). Acute kidney injury was diagnosed in 19 207 of 297 554 patients (6.5%), myocardial injury in 8972 of 320 527 (2.8%), and lung injury in 13 789 of 312 161 (4.4%). The median fraction of inspired oxygen was 54.0% (interquartile range 47.5%-60.0%), and the area under the curve of supraphysiological inspired oxygen was 7951% min (5870-11 107% min), equivalent to an 80% fraction of inspired oxygen throughout a 135 minute procedure, for example. After accounting for baseline covariates and other potential confounding variables, increased oxygen exposure was associated with a higher risk of acute kidney injury, myocardial injury, and lung injury. Patients at the 75th centile for the area under the curve of the fraction of inspired oxygen had 26% greater odds of acute kidney injury (95% confidence interval 22% to 30%), 12% greater odds of myocardial injury (7% to 17%), and 14% greater odds of lung injury (12% to 16%) compared with patients at the 25th centile. Sensitivity analyses evaluating alternative definitions of the exposure, restricting the cohort, and conducting an instrumental variable analysis confirmed these observations. CONCLUSIONS: Increased supraphysiological oxygen administration during surgery was associated with a higher incidence of kidney, myocardial, and lung injury. Residual confounding of these associations cannot be excluded. TRIAL REGISTRATION: Open Science Framework osf.io/cfd2m.

Translating evidence into practice: still a way to go.

Chiu and colleagues report a retrospective analysis describing the 5-yr trend in both intraoperative fluid and vasopressor administration in 32 250 patients undergoing elective abdominal surgery within the Multicenter Perioperative Outcomes Group (MPOG) database from 2015 to 2019, and exploring the association between these two factors and acute kidney injury. Modelling predicted the lowest risk for acute kidney injury when the administered crystalloid volume was 15-20 ml kg-1 h-1, and an 80% increase in risk for acute kidney injury as intraoperative vasopressor use increased from 0 to 0.04 µg kg-1 min-1 of norepinephrine equivalents. Although these results are consistent with those of a large, randomised trial (REstrictive Versus LIbEral Fluid Therapy in Major Abdominal Surgery [RELIEF]) published in 2018, the mean intraoperative volume of crystalloid administered in the current study declined monotonically through every year included, from 6.4 ml kg-1 h-1 in 2015 to 5.5 ml kg-1 h-1 in 2019. These new findings support the broad generalisability of the RELIEF trial; highlight the complexity of the relationship between intravenous crystalloid volume infused, arterial pressure, and acute kidney injury; and demonstrate the ongoing challenge of translating high-quality evidence into clinical practice.

Is an Acute Perioperative Increase in Creatinine Production Rate a Potential Mechanism for an Early Creatinine-Based Signal of Renal Injury After Cardiac Surgery?

OBJECTIVES: Previous studies report a creatinine-based signal of injury within hours after cardiac surgery, which is sooner than expected based on creatinine kinetic modelling. A plausible mechanism for such an early signal has not been established, but might be explained by an acute perioperative increase in creatinine production rate (Crprod-rate). The authors sought to test the hypothesis that perioperative Crprod-rate increases from baseline in patients undergoing cardiac surgery. DESIGN: Prospective cohort study. SETTING: Academic medical center. PARTICIPANTS: Fifty adult male patients undergoing cardiac surgery. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Based on the principle of conservation of mass, precisely timed serial measurements of patient weight, plasma and urine creatinine concentration, and urine volume were used to calculate Crprod-rate over 3 consecutive periods: a baseline period immediately before surgery (period 0), the 24-hour period starting from induction of anesthesia (period 1), and again from 24 to 48 hours after induction of anesthesia (period 2). The primary outcome was change in Crprod-rate from period 0 to period 1 (∆Crprod-rate0-1). Median Crprod-rate0 was 5.4 (interquartile range [IQR], 4.7-5.7) µmol/kg/h at baseline and increased to 6.1 (IQR, 5.6-6.5) µmol/kg/h during period 1, a median increase of 14% (95% CI, 8%-27%; p = 0.002). ∆Crprod-rate0-1 ranged from -58% to +129%, with an increase above baseline in 25 patients (76%) and an increase by ≥30% above baseline in 10 patients (30%). CONCLUSIONS: Perioperative Crprod-rate increased from baseline in patients undergoing cardiac surgery. This may represent a mechanism for an earlier creatinine-based signal of renal injury than previously thought possible.

Society of Cardiovascular Anesthesiologists Clinical Practice Update for Management of Acute Kidney Injury Associated With Cardiac Surgery.

Cardiac surgery-associated acute kidney injury (CS-AKI) is common and is associated with increased risk for postoperative morbidity and mortality. Our recent survey of the Society of Cardiovascular Anesthesiologists (SCA) membership showed 6 potentially renoprotective strategies for which clinicians would most value an evidence-based review (ie, intraoperative target blood pressure, choice of specific vasopressor agent, erythrocyte transfusion threshold, use of alpha-2 agonists, goal-directed oxygen delivery on cardiopulmonary bypass [CPB], and the "Kidney Disease Improving Global Outcomes [KDIGO] bundle of care"). Thus, the SCA's Continuing Practice Improvement Acute Kidney Injury Working Group aimed to provide a practice update for each of these strategies in cardiac surgical patients based on the evidence from randomized controlled trials (RCTs). PubMed, EMBASE, and Cochrane library databases were comprehensively searched for eligible studies from inception through February 2021, with search results updated in August 2021. A total of 15 RCTs investigating the effects of the above-mentioned strategies on CS-AKI were included for meta-analysis. For each strategy, the level of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology. Across the 6 potentially renoprotective strategies evaluated, current evidence for their use was rated as "moderate," "low," or "very low." Based on eligible RCTs, our analysis suggested using goal-directed oxygen delivery on CPB and the "KDIGO bundle of care" in high-risk patients to prevent CS-AKI (moderate level of GRADE evidence). Our results suggested considering the use of vasopressin in vasoplegic shock patients to reduce CS-AKI (low level of GRADE evidence). The decision to use a restrictive versus liberal strategy for perioperative red cell transfusion should not be based on concerns for renal protection (a moderate level of GRADE evidence). In addition, targeting a higher mean arterial pressure during CPB, perioperative use of dopamine, and use of dexmedetomidine did not reduce CS-AKI (a low or very low level of GRADE evidence). This review will help clinicians provide evidence-based care, targeting improved renal outcomes in adult patients undergoing cardiac surgery.

The associations of use of social network sites with perceived social support and loneliness.

Research shows that use of social network sites is associated with loneliness and this may be amplified in tertiary students by their transition from home life, especially if they struggle to integrate with peers. The buffering effects of social support may offer a solution and the online dimension may offer a suitable outlet for lonely and isolated students. In this study, N = 111 university students, aged 18-40, completed a frequency assessment of Instagram and WhatsApp, the Spanish version of the UCLA loneliness scale and the Multidimensional Scale of Social Support in an online survey. The statistical analysis was completed by Structural Equation Modeling using AMOS 25.0. The construct validity of social network sites was established by good factor loadings for WhatsApp and Instagram, but Facebook was excluded as it did not load adequately on to the latent measurement model, in keeping with the diminishing trend for Facebook use in young students. Loneliness emerged as pivotal in a mediation model, and online social support from friends/significant others, emerged as salient in the predictive model in contrast to family. However, these associations may not have the same advantageous weight for mature students given the observed negative associations with age. Results may have implications for policy and planning through highlighting the psychological variables that are operative in the dynamics of integration, retention, and adjustment to tertiary level experience.