Developing Guidance for Donor Intervention Randomized Controlled Trials: Initial Discussions From the Canada-United Kingdom 2022 Workshop.

BACKGROUND: Donor interventions, including medications, protocols, and medical devices administered to donors, can enhance transplantable organ quality and quantity and maximize transplantation success. However, there is paucity of high-quality evidence about their effectiveness, in part because of ethical, practical, and regulatory challenges, and lack of guidance about conduct of donor intervention randomized controlled trials (RCTs). METHODS: With the vision to develop authoritative guidance for conduct of donor intervention RCTs, we convened a workshop of Canadian-United Kingdom experts in organ donation and transplantation ethics, research, and policy to identify stakeholders, explore unique challenges, and develop research agenda to inform future work in this promising field. RESULTS: Donor intervention trials should consider perspectives of broad group of stakeholders including donors, transplant recipients, and their families; researchers in donation and transplantation; research ethics boards; and healthcare providers and administrators involved in donation and transplantation. Unique challenges include (1) research ethics (living versus deceased status of the donor at the time of intervention, intervention versus outcomes assessment in different individuals, harm-benefit analysis in donors versus recipients, consent, and impact on research bystanders); (2) outcome data standardization and linkage; and (3) regulatory and governance considerations. CONCLUSIONS: Donor intervention RCTs hold potential to benefit organ transplantation outcomes but face unique research ethics, outcome data, and regulatory challenges. By developing research agenda to address these challenges, our workshop was an important first step toward developing Canada-United Kingdom guidance for donor intervention RCTs that are poised to improve the quality and availability of transplantable organs.

A Canadian survey of perceptions and practices related to ordering of blood tests in the intensive care unit.

PURPOSE: The ordering of routine blood test panels in advance is common in intensive care units (ICUs), with limited consideration of the pretest probability of finding abnormalities. This practice contributes to anemia, false positive results, and health care costs. We sought to understand practices and attitudes of Canadian adult intensivists regarding ordering of blood tests in critically ill patients. METHODS: We conducted a nationwide Canadian cross-sectional survey consisting of 15 questions assessing three domains (global perceptions, test ordering, daily practice), plus 11 demographic questions. The target sample was one intensivist per adult ICU in Canada. We summarized responses using descriptive statistics and present data as mean with standard deviation (SD) or count with percentage as appropriate. RESULTS: Over seven months, 80/131 (61%) physicians responded from 77 ICUs, 50% of which were from Ontario. Respondents had a mean (SD) clinical experience of 12 (9) years, and 61% worked in academic centres. When asked about their perceptions of how frequently unnecessary blood tests are ordered, 61% responded "sometimes" and 23% responded "almost always." Fifty-seven percent favoured ordering complete blood counts one day in advance. Only 24% of respondents believed that advanced blood test ordering frequently led to changes in management. The most common factors perceived to influence blood test ordering in the ICU were physician preferences, institutional patterns, and order sets. CONCLUSION: Most respondents to this survey perceived that unnecessary blood testing occurs in the ICU. The survey identified possible strategies to decrease the number of blood tests.

RéSUMé: OBJECTIF: La prescription à l'avance de tests sanguins de routine est courante dans les unités de soins intensifs (USI), avec une prise en compte limitée de la probabilité de découverte d'anomalies avant le test. Cette pratique contribue à l'anémie, aux résultats faussement positifs et aux coûts des soins de santé. Nous avons cherché à comprendre les pratiques et les attitudes des intensivistes pour adultes au Canada en ce qui concerne la prescription d'analyses sanguines chez la patientèle gravement malade. MéTHODE: Nous avons mené un sondage transversal à l'échelle nationale au Canada en posant 15 questions évaluant trois domaines (perceptions globales, commande de tests, pratique quotidienne), ainsi que 11 questions démographiques. L'échantillon cible était composé d'un·e intensiviste par unité de soins intensifs pour adultes au Canada. Nous avons résumé les réponses à l'aide de statistiques descriptives et présenté les données sous forme de moyennes avec écarts type (ET) ou de dénombrements avec pourcentages, selon le cas. RéSULTATS: Sur une période de sept mois, 80 médecins sur 131 (61%) ont répondu dans 77 unités de soins intensifs, dont 50% en Ontario. Les répondant·es avaient une expérience clinique moyenne (ET) de 12 (9) ans, et 61% travaillaient dans des centres universitaires. Lorsqu'on leur a demandé ce qu'ils ou elles pensaient de la fréquence à laquelle des tests sanguins inutiles étaient prescrits, 61% ont répondu « parfois ¼ et 23% ont répondu « presque toujours ¼. Cinquante-sept pour cent étaient en faveur de la réalisation d'une formule sanguine complète un jour à l'avance. Seulement 24% des personnes interrogées estimaient que la prescription de tests sanguins à l'avance entraînait fréquemment des changements dans la prise en charge. Les facteurs les plus souvent perçus comme influençant la prescription d'analyses sanguines à l'unité de soins intensifs étaient les préférences des médecins, les habitudes institutionnelles et les ensembles d'ordonnances. CONCLUSION: La plupart des répondant·es à ce sondage ont l'impression que des tests sanguins inutiles sont prescrits aux soins intensifs. L'enquête a permis d'identifier des stratégies possibles pour réduire le nombre de tests sanguins.

Evidence-Based Checklist to Delay Cardiac Arrest in Brain-Dead Potential Organ Donors: The DONORS Cluster Randomized Clinical Trial.

Importance: The effectiveness of goal-directed care to reduce loss of brain-dead potential donors to cardiac arrest is unclear. Objective: To evaluate the effectiveness of an evidence-based, goal-directed checklist in the clinical management of brain-dead potential donors in the intensive care unit (ICU). Design, Setting, and Participants: The Donation Network to Optimize Organ Recovery Study (DONORS) was an open-label, parallel-group cluster randomized clinical trial in Brazil. Enrollment and follow-up were conducted from June 20, 2017, to November 30, 2019. Hospital ICUs that reported 10 or more brain deaths in the previous 2 years were included. Consecutive brain-dead potential donors in the ICU aged 14 to 90 years with a condition consistent with brain death after the first clinical examination were enrolled. Participants were randomized to either the intervention group or the control group. The intention-to-treat data analysis was conducted from June 15 to August 30, 2020. Interventions: Hospital staff in the intervention group were instructed to administer to brain-dead potential donors in the intervention group an evidence-based checklist with 13 clinical goals and 14 corresponding actions to guide care, every 6 hours, from study enrollment to organ retrieval. The control group provided or received usual care. Main Outcomes and Measures: The primary outcome was loss of brain-dead potential donors to cardiac arrest at the individual level. A prespecified sensitivity analysis assessed the effect of adherence to the checklist in the intervention group. Results: Among the 1771 brain-dead potential donors screened in 63 hospitals, 1535 were included. These patients included 673 males (59.2%) and had a median (IQR) age of 51 (36.3-62.0) years. The main cause of brain injury was stroke (877 [57.1%]), followed by trauma (485 [31.6%]). Of the 63 hospitals, 31 (49.2%) were assigned to the intervention group (743 [48.4%] brain-dead potential donors) and 32 (50.8%) to the control group (792 [51.6%] brain-dead potential donors). Seventy potential donors (9.4%) at intervention hospitals and 117 (14.8%) at control hospitals met the primary outcome (risk ratio [RR], 0.70; 95% CI, 0.46-1.08; P = .11). The primary outcome rate was lower in those with adherence higher than 79.0% than in the control group (5.3% vs 14.8%; RR, 0.41; 95% CI, 0.22-0.78; P = .006). Conclusions and Relevance: This cluster randomized clinical trial was inconclusive in determining whether the overall use of an evidence-based, goal-directed checklist reduced brain-dead potential donor loss to cardiac arrest. The findings suggest that use of such a checklist has limited effectiveness without adherence to the actions recommended in this checklist. Trial Registration: ClinicalTrials.gov Identifier: NCT03179020.

Frequency of screening and SBT Technique Trial-North American Weaning Collaboration (FAST-NAWC): an update to the protocol and statistical analysis plan.

BACKGROUND: This update summarizes key changes made to the protocol for the Frequency of Screening and Spontaneous Breathing Trial (SBT) Technique Trial-North American Weaning Collaborative (FAST-NAWC) trial since the publication of the original protocol. This multicenter, factorial design randomized controlled trial with concealed allocation, will compare the effect of both screening frequency (once vs. at least twice daily) to identify candidates to undergo a SBT and SBT technique [pressure support + positive end-expiratory pressure vs. T-piece] on the time to successful extubation (primary outcome) in 760 critically ill adults who are invasively ventilated for at least 24 h in 20 North American intensive care units. METHODS/DESIGN: Protocols for the pilot, factorial design trial and the full trial were previously published in J Clin Trials ( https://doi.org/10.4172/2167-0870.1000284 ) and Trials (https://doi: 10.1186/s13063-019-3641-8). As planned, participants enrolled in the FAST pilot trial will be included in the report of the full FAST-NAWC trial. In response to the onset of the coronavirus disease of 2019 (COVID-19) pandemic when approximately two thirds of enrollment was complete, we revised the protocol and consent form to include critically ill invasively ventilated patients with COVID-19. We also refined the statistical analysis plan (SAP) to reflect inclusion and reporting of participants with and without COVID-19. This update summarizes the changes made and their rationale and provides a refined SAP for the FAST-NAWC trial. These changes have been finalized before completion of trial follow-up and the commencement of data analysis. TRIAL REGISTRATION: Clinical Trials.gov NCT02399267.

Differences in directives to limit treatment and discontinue mechanical ventilation between elderly and very elderly patients: a substudy of a multinational observational study.

PURPOSE: The aim of this study was to characterize differences in directives to limit treatments and discontinue invasive mechanical ventilation (IMV) in elderly (65-80 years) and very elderly (> 80 years) intensive care unit (ICU) patients. METHODS: We prospectively described new written orders to limit treatments, IMV discontinuation strategies [direct extubation, direct tracheostomy, spontaneous breathing trial (SBT), noninvasive ventilation (NIV) use], and associations between initial failed SBT and outcomes in 142 ICUs from 6 regions (Canada, India, United Kingdom, Europe, Australia/New Zealand, United States). RESULTS: We evaluated 788 (586 elderly; 202 very elderly) patients. Very elderly (vs. elderly) patients had similar withdrawal orders but significantly more withholding orders, especially cardiopulmonary resuscitation and dialysis, after ICU admission [67 (33.2%) vs. 128 (21.9%); p = 0.002]. Orders to withhold reintubation were written sooner in very elderly (vs. elderly) patients [4 (2-8) vs. 7 (4-13) days, p = 0.02]. Very elderly and elderly patients had similar rates of direct extubation [39 (19.3%) vs. 113 (19.3%)], direct tracheostomy [10 (5%) vs. 40 (6.8%)], initial SBT [105 (52%) vs. 302 (51.5%)] and initial successful SBT [84 (80%) vs. 245 (81.1%)]. Very elderly patients experienced similar ICU outcomes (mortality, length of stay, duration of ventilation) but higher hospital mortality [26 (12.9%) vs. 38 (6.5%)]. Direct tracheostomy and initial failed SBT were associated with worse outcomes. Regional differences existed in withholding orders at ICU admission and in withholding and withdrawal orders after ICU admission. CONCLUSIONS: Very elderly (vs. elderly) patients had more orders to withhold treatments after ICU admission and higher hospital mortality, but similar ICU outcomes and IMV discontinuation. Significant regional differences existed in withholding and withdrawal practices.

Calcineurin Inhibition in Deceased Organ Donors: A Systematic Review and Meta-analysis of Preclinical Studies.

Background: Preconditioning deceased organ donors with calcineurin inhibitors (CNIs) may reduce ischemia-reperfusion injury to improve transplant outcomes. Methods: We searched MEDLINE, EMBASE, Cochrane Library, and conference proceedings for animal models of organ donation and transplantation, comparing donor treatment with CNIs with either placebo or no intervention, and evaluating outcomes for organ transplantation. Reviewers independently screened and selected studies, abstracted data, and assessed the risk of bias and clinical relevance of included studies. Where possible, we pooled results using meta-analysis; otherwise, we summarized findings descriptively. Results: Eighteen studies used various animals and a range of CNI agents and doses and evaluated their effects on a variety of transplant outcomes. The risk of bias and clinical applicability were poorly reported. Pooled analyses suggested benefit of CNI treatment on early graft function in renal transplants (3 studies; serum creatinine: ratio of means [RoM] 0.54; 95% confidence interval [CI], 0.34-0.86) but not for liver transplants (2 studies; serum alanine transaminase: RoM 0.61; 95% CI, 0.30-1.26; and serum aspartate aminotransferase: RoM 0.58; 95% CI, 0.26-1.31). We found no reduction in graft loss at 7 d (2 studies; risk ratio 0.54; 95% CI, 0.08-3.42). CNI treatment was associated with reduced transplant recipient levels of interleukin-6 (4 studies; RoM 0.36; 95% CI, 0.19-0.70), tumor necrosis factor-alpha (5 studies; RoM 0.36; 95% CI, 0.12-1.03), and cellular apoptosis (4 studies; RoM 0.30; 95% CI, 0.19-0.47). Conclusions: Although this compendium of animal experiments suggests that donor preconditioning with CNIs may improve early kidney graft function, the limited ability to reproduce a true clinical environment in animal experiments and to assess for risk of bias in these experiments is a serious weakness that precludes current clinical application.

Transplant Recipient Preferences Regarding Organ Donor Research: Their Role in Consent and use of Their Data.

Research on deceased organ donors has been hindered by concerns related to seeking research consent from transplant recipients. We undertook this qualitative study to elucidate solid organ transplant recipients views on organ donor research, their role in the consent for such research, and their preferences related to providing their data. We conducted interviews with 18 participants and three themes emerged from the data. The first centered around participant research literacy. The second described practical preferences of participating in research, and the third related to the connection between donor and recipient. We concluded that previously held views about the requirement for transplant recipients to have a consenting role in donor research is not always suitable.

The Intersection of Death Investigation and Organ Donation Systems: A Scoping Review.

Introduction: Death investigators (DIs) such as coroners, medical examiners, and forensic pathologists play important and evolving roles in deceased organ donation. DIs communicate with organ donation organizations (ODOs) to gather case-specific information and release or restrict organs depending on the medicolegal requirements. This scoping review aims to identify the breadth of roles and decision-making processes that may facilitate or hinder deceased donation in DI cases. Methods: This study was conducted using a scoping literature review and subsequent thematic analysis. Results: Thirty-one eligible papers described 8 common themes with region-specific nuances. These include: 1) shared (ODO and DI) protocols for early communication around each case; 2) shared standards and education for death investigation practices related to organ donation; 3) DI support staff or teams to facilitate organ donation; 4) DI authority to order additional testing and imaging before organ recovery; 5) donation-specific legislation to enhance DI and/or ODO operations; 6) legally trained DI authority to veto medical decisions to proceed with organ donation; 7) DI attendance at organ recovery; and 8) surgeons recording specific DI evidence during organ recovery. Conclusion: These findings have cultural and resource-allocation implications and expose gaps in the international literature describing practices at the intersection of deceased organ donation and death investigation. A better understanding of the rationale and execution of various systems for DI and ODO cooperation may serve to advance both organ donation and death investigation.

Intravenous Vitamin C in Adults with Sepsis in the Intensive Care Unit.

BACKGROUND: Studies that have evaluated the use of intravenous vitamin C in adults with sepsis who were receiving vasopressor therapy in the intensive care unit (ICU) have shown mixed results with respect to the risk of death and organ dysfunction. METHODS: In this randomized, placebo-controlled trial, we assigned adults who had been in the ICU for no longer than 24 hours, who had proven or suspected infection as the main diagnosis, and who were receiving a vasopressor to receive an infusion of either vitamin C (at a dose of 50 mg per kilogram of body weight) or matched placebo administered every 6 hours for up to 96 hours. The primary outcome was a composite of death or persistent organ dysfunction (defined by the use of vasopressors, invasive mechanical ventilation, or new renal-replacement therapy) on day 28. RESULTS: A total of 872 patients underwent randomization (435 to the vitamin C group and 437 to the control group). The primary outcome occurred in 191 of 429 patients (44.5%) in the vitamin C group and in 167 of 434 patients (38.5%) in the control group (risk ratio, 1.21; 95% confidence interval [CI], 1.04 to 1.40; P = 0.01). At 28 days, death had occurred in 152 of 429 patients (35.4%) in the vitamin C group and in 137 of 434 patients (31.6%) in the placebo group (risk ratio, 1.17; 95% CI, 0.98 to 1.40) and persistent organ dysfunction in 39 of 429 patients (9.1%) and 30 of 434 patients (6.9%), respectively (risk ratio, 1.30; 95% CI, 0.83 to 2.05). Findings were similar in the two groups regarding organ-dysfunction scores, biomarkers, 6-month survival, health-related quality of life, stage 3 acute kidney injury, and hypoglycemic episodes. In the vitamin C group, one patient had a severe hypoglycemic episode and another had a serious anaphylaxis event. CONCLUSIONS: In adults with sepsis receiving vasopressor therapy in the ICU, those who received intravenous vitamin C had a higher risk of death or persistent organ dysfunction at 28 days than those who received placebo. (Funded by the Lotte and John Hecht Memorial Foundation; LOVIT ClinicalTrials.gov number, NCT03680274.).

Effect of Awake Prone Positioning on Endotracheal Intubation in Patients With COVID-19 and Acute Respiratory Failure: A Randomized Clinical Trial.

Importance: The efficacy and safety of prone positioning is unclear in nonintubated patients with acute hypoxemia and COVID-19. Objective: To evaluate the efficacy and adverse events of prone positioning in nonintubated adult patients with acute hypoxemia and COVID-19. Design, Setting, and Participants: Pragmatic, unblinded randomized clinical trial conducted at 21 hospitals in Canada, Kuwait, Saudi Arabia, and the US. Eligible adult patients with COVID-19 were not intubated and required oxygen (≥40%) or noninvasive ventilation. A total of 400 patients were enrolled between May 19, 2020, and May 18, 2021, and final follow-up was completed in July 2021. Intervention: Patients were randomized to awake prone positioning (n = 205) or usual care without prone positioning (control; n = 195). Main Outcomes and Measures: The primary outcome was endotracheal intubation within 30 days of randomization. The secondary outcomes included mortality at 60 days, days free from invasive mechanical ventilation or noninvasive ventilation at 30 days, days free from the intensive care unit or hospital at 60 days, adverse events, and serious adverse events. Results: Among the 400 patients who were randomized (mean age, 57.6 years [SD, 12.83 years]; 117 [29.3%] were women), all (100%) completed the trial. In the first 4 days after randomization, the median duration of prone positioning was 4.8 h/d (IQR, 1.8 to 8.0 h/d) in the awake prone positioning group vs 0 h/d (IQR, 0 to 0 h/d) in the control group. By day 30, 70 of 205 patients (34.1%) in the prone positioning group were intubated vs 79 of 195 patients (40.5%) in the control group (hazard ratio, 0.81 [95% CI, 0.59 to 1.12], P = .20; absolute difference, -6.37% [95% CI, -15.83% to 3.10%]). Prone positioning did not significantly reduce mortality at 60 days (hazard ratio, 0.93 [95% CI, 0.62 to 1.40], P = .54; absolute difference, -1.15% [95% CI, -9.40% to 7.10%]) and had no significant effect on days free from invasive mechanical ventilation or noninvasive ventilation at 30 days or on days free from the intensive care unit or hospital at 60 days. There were no serious adverse events in either group. In the awake prone positioning group, 21 patients (10%) experienced adverse events and the most frequently reported were musculoskeletal pain or discomfort from prone positioning (13 of 205 patients [6.34%]) and desaturation (2 of 205 patients [0.98%]). There were no reported adverse events in the control group. Conclusions and Relevance: In patients with acute hypoxemic respiratory failure from COVID-19, prone positioning, compared with usual care without prone positioning, did not significantly reduce endotracheal intubation at 30 days. However, the effect size for the primary study outcome was imprecise and does not exclude a clinically important benefit. Trial Registration: ClinicalTrials.gov Identifier: NCT04350723.

Predictors of 1-year mortality after adult lung transplantation: Systematic review and meta-analyses.

BACKGROUND: Prognostic factors in lung transplantation are those variables that are associated with transplant outcomes. Knowledge of donor and recipient prognostic variables can aid in the optimal allocation of donor lungs to transplant recipients and can also inform post-operative discussions with patients about prognosis. Current research findings related to prognostic factors in lung transplantation are inconsistent and the relative importance of various factors is unclear. This review aims to provide the best possible estimates of the association between putative prognostic variables and 1-year all-cause mortality in adult lung transplant recipients. METHODS: We searched 5 bibliographic databases for studies assessing the associations between putative predictors (related to lung donors, recipients, or the transplant procedure) and 1-year recipient mortality. We pooled data across studies when justified and utilized GRADE methodology to assess the certainty in the evidence. RESULTS: From 72 eligible studies (2002-2020), there were 34 recipient variables, 4 donor variables, 10 procedural variables, and 7 post-transplant complication variables that were amenable to a meta-analysis. With a high degree of certainty in the evidence only post-transplant need for extra-corporeal membrane oxygenation (ECMO) (HR 1.91, 95% CI 1.79-2.04) predicted 1-year mortality. No donor variables appeared to predict transplant outcome with high or even moderate certainty. CONCLUSION: Across the range of contemporary donors and recipients that clinicians accept for lung transplantation, this review, with high certainty, found 1 prognostic factor that predicted 1-year mortality, and 37 additional factors with a moderate degree of certainty. The lack of prognostic significance for some widely accepted factors (e.g., donor smoking, age) likely relates to existing limits in the range of these variables at the time of donor and recipient selection.

Adherence of Clinical Practice Guidelines for Pharmacologic Treatments of Hospitalized Patients With COVID-19 to Trustworthy Standards: A Systematic Review.

Importance: The COVID-19 pandemic created the need for rapid and urgent guidance for clinicians to manage COVID-19 among patients and prevent transmission. Objective: To appraise the quality of clinical practice guidelines (CPGs) using the National Academy of Medicine (NAM) criteria. Evidence Review: A search of MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials to December 14, 2020, and a search of related articles to February 28, 2021, that included CPGs developed by societies or by government or nongovernment organizations that reported pharmacologic treatments of hospitalized patients with COVID-19. Teams of 2 reviewers independently abstracted data and assessed CPG quality using the 15-item National Guideline Clearinghouse Extent of Adherence to Trustworthy Standards (NEATS) instrument. Findings: Thirty-two CPGs were included in the review. Of these, 25 (78.1%) were developed by professional societies and emanated from a single World Health Organization (WHO) region. Overall, the CPGs were of low quality. Only 7 CPGs (21.9%) reported funding sources, and 12 (37.5%) reported conflicts of interest. Only 5 CPGs (15.6%) included a methodologist, described a search strategy or study selection process, or synthesized the evidence. Although 14 CPGs (43.8%) made recommendations or suggestions for or against treatments, they infrequently rated confidence in the quality of the evidence (6 of 32 [18.8%]), described potential benefits and harms (6 of 32 [18.8%]), or graded the strength of the recommendations (5 of 32 [15.6%]). External review, patient or public perspectives, or a process for updating were rare. High-quality CPGs included a methodologist and multidisciplinary collaborations involving investigators from 2 or more WHO regions. Conclusions and Relevance: In this review, few COVID-19 CPGs met NAM standards for trustworthy guidelines. Approaches that prioritize engagement of a methodologist and multidisciplinary collaborators from at least 2 WHO regions may lead to the production of fewer, high-quality CPGs that are poised for updates as new evidence emerges. Trial Registration: PROSPERO Identifier: CRD42021245239.

Utilization and effect of neuromuscular blockade in a randomized trial of high-frequency oscillation.

PURPOSE: We evaluated characteristics associated with neuromuscular blockade (NMB) use, center-level variation, and whether NMB mediated excess mortality among patients assigned to high-frequency oscillatory ventilation (HFOV) in the OSCILLATE trial. MATERIALS AND METHODS: NMB exposure was defined as receipt after randomization; the primary outcome was hospital mortality. Descriptive analyses compared NMB-exposed vs unexposed patients. Multivariable analyses included patients not on baseline NMB. Cox regression evaluated associations of patient- and center-level variables with NMB use. A log-normal frailty model evaluated center effects. Mediation analysis examined the effect of NMB in HFOV-assigned patients. RESULTS: 376/548 patients (39 centers) received post-randomization NMB, of whom 165 received baseline NMB. Patients receiving post-randomization NMB (vs. not) had worse lung mechanics and gas exchange, received more sedation and vasopressors (p < 0.05), and had higher hospital mortality (44% vs. 34%, p = 0.03). Mean airway pressure ≥ 24 cmH2O, randomization to HFOV, and intensive care unit size ≥ 31 beds were associated with post-randomization NMB. After adjustment, center had a negligible effect on post-randomization NMB (median hazard ratio 1.01, p = 0.047). NMB use did not mediate excess mortality among HFOV-allocated patients (p = 0.80). CONCLUSIONS: In OSCILLATE, receipt of post-randomization NMB was associated with worse outcomes, but NMB use did not mediate HFOV-associated higher mortality.

Evolution of practice patterns in the management of acute respiratory distress syndrome: A secondary analysis of two successive randomized controlled trials.

PURPOSE: We sought to examine changes in acute respiratory distress syndrome (ARDS) management over a 12-year period of two successive randomized trials. METHODS: Analyses included baseline data, from eligible patients, prior to influence of trial protocols, and daily study data, from randomized patients, of variables not determined by trial protocols. Mixed linear regressions examined changes in practice year-on-year. RESULTS: A total of 2376 patients met the inclusion criteria. Over the 12-year period, baseline tidal volume index decreased (9.0 to 7.0 ml/kg, p < 0.001), plateau pressures decreased (30.8 to 29.0 cmH2O, p < 0.05), and baseline positive end-expiratory pressures increased (10.8 to 13.2 cmH2O, p < 0.001). Volume-controlled ventilation declined from 29.4 to 14.0% (p < 0.01). Use of corticosteroids increased (baseline: 7.7 to 30.3%; on study: 32.6 to 61.2%; both p < 0.001), as did neuromuscular blockade (baseline: 12.3 to 24.5%; on study: 55.5 to 70.0%; both p < 0.01). Inhaled nitric oxide use increased (24.9 to 65.8%, p < 0.05). We observed no significant change in prone positioning (16.2 to 18.9%, p = 0.70). CONCLUSIONS: Clear trends were apparent in tidal volume, airway pressures, ventilator modes, adjuncts and rescue therapies. With the exception of prone positioning, and outside the context of rescue therapy, these trends appear consistent with the evolving literature on ARDS management.

Antemortem Heparin in Organ Donation After Circulatory Death Determination: A Systematic Review of the Literature.

Donation after circulatory death determination frequently involves antemortem heparin administration to mitigate peri-arrest microvascular thrombosis. We systematically reviewed the literature to: (1) describe heparin administration practices and (2) explore the effects on transplant outcomes. We searched MEDLINE and EMBASE for studies reporting donation after circulatory death determination heparin practices including use, dosage, and timing (objective 1). To explore associations between antemortem heparin and transplant outcomes (objective 2), we (1) summarized within-study comparisons and (2) used meta-regression analyses to examine associations between proportions of donors that received heparin and transplant outcomes. We assessed risk of bias using the Newcastle Ottawa Scale and applied the GRADE methodology to determine certainty in the evidence. For objective 1, among 55 eligible studies, 48 reported heparin administration to at least some donors (range: 15.8%-100%) at variable doses (up to 1000 units/kg) and times relative to withdrawal of life-sustaining therapy. For objective 2, 7 studies that directly compared liver transplants with and without antemortem heparin reported lower rates of primary nonfunction, hepatic artery thrombosis, graft failure at 5 y, or recipient mortality (low certainty of evidence). In contrast, meta-regression analysis of 32 liver transplant studies detected no associations between the proportion of donors that received heparin and rates of early allograft dysfunction, primary nonfunction, hepatic artery thrombosis, biliary ischemia, graft failure, retransplantation, or patient survival (very low certainty of evidence). In conclusion, antemortem heparin practices vary substantially with an uncertain effect on transplant outcomes. Given the controversies surrounding antemortem heparin, clinical trials may be warranted.

Ventilator Weaning and Discontinuation Practices for Critically Ill Patients.

Importance: Although most critically ill patients receive invasive mechanical ventilation (IMV), few studies have characterized how IMV is discontinued in practice. Objective: To describe practice variation in IMV discontinuation internationally, associations between initial discontinuation events and outcomes, and factors associated with the use of select discontinuation strategies and failed initial spontaneous breathing trials (SBTs). Design, Setting, and Participants: Prospective, multinational, observational study of critically ill adults who received IMV for at least 24 hours from 142 intensive care units (ICUs) in 19 countries within 6 regions (27 in Canada, 23 in India, 22 in the UK, 26 in Europe, 21 in Australia/New Zealand, and 23 in the US). Exposures: Receiving IMV. Main Outcomes and Measures: Primary analyses characterized types of initial IMV discontinuation events (extubation, SBT, or tracheostomy) and associations with clinical outcomes (including duration of ventilation, ICU and hospital mortality, and ICU and hospital length of stay). Secondary analyses examined the associations between SBT outcome and SBT timing and clinical outcomes. Results: Among 1868 patients (median [interquartile range] age, 61.8 [48.9-73.1] years; 1173 [62.8%] men) 424 (22.7%) underwent direct extubation, 930 (49.8%) had an initial SBT (761 [81.8%] successful), 150 (8.0%) underwent direct tracheostomy, and 364 (19.5%) died before a weaning attempt. Across regions, there was variation in the use of written directives to guide care, daily screening, SBT techniques, ventilator modes, and the roles played by clinicians involved in weaning. Compared with initial direct extubation, patients who had an initial SBT had higher ICU mortality (20 [4.7%] vs 96 [10.3%]; absolute difference, 5.6% [95% CI, 2.6%-8.6%]), longer duration of ventilation (median of 2.9 vs 4.1 days; absolute difference, 1.2 days [95% CI, 0.7-1.6]), and longer ICU stay (median of 6.7 vs 8.1 days; absolute difference, 1.4 days [95% CI, 0.8-2.4]). Patients whose initial SBT failed (vs passed) had higher ICU mortality (29 [17.2%] vs 67 [8.8%]; absolute difference, 8.4% [95% CI, 2.0%-14.7%]), longer duration of ventilation (median of 6.1 vs 3.5 days; absolute difference, 2.6 days [95% CI, 1.6-3.6]), and longer ICU stay (median of 10.6 vs 7.7 days; absolute difference, 2.8 days [95% CI, 1.1-5.2]). Compared with patients who underwent early initial SBTs, patients who underwent late initial SBTs (>2.3 days after intubation) had longer duration of ventilation (median of 2.1 vs 6.1 days; absolute difference, 4.0 days [95% CI, 3.7-4.5]), longer ICU stay (median of 5.9 vs 10.8 days; absolute difference, 4.9 days [95% CI, 4.0-6.3]), and longer hospital stay (median of 14.3 vs 22.8 days; absolute difference, 8.5 days [95% CI, 6.0-11.0]). Conclusions and Relevance: In this observational study of invasive mechanical ventilation discontinuation in 142 ICUs in Canada, India, the UK, Europe, Australia/New Zealand, and the US from 2013 to 2016, weaning practices varied internationally. Trial Registration: ClinicalTrials.gov Identifier: NCT03955874.

Comparative Effectiveness of Protective Ventilation Strategies for Moderate and Severe Acute Respiratory Distress Syndrome. A Network Meta-Analysis.

Rationale: Choosing the best ventilation strategy for acute respiratory distress syndrome (ARDS) is complex, yet it is highly relevant to clinicians during a respiratory pandemic. Objectives: To compare the effects of low Vt, high Vt, high positive end-expiratory pressure (PEEP), prone ventilation, high-frequency oscillation, and venovenous extracorporeal membrane oxygenation (VV ECMO) on mortality in ARDS. Methods: We performed a network meta-analysis of randomized trials. We applied the Grading of Recommendations Assessment, Development and Evaluation methodology to discern the relative effect of interventions on mortality. Measurements and Main Results: We analyzed 34 trials including 9,085 adults with primarily moderate-to-severe ARDS (median baseline PaO2/FiO2, 118; interquartile range, 110-143). Prone positioning combined with low Vt was the best strategy (risk ratio [RR], 0.74 [95% confidence interval (CI), 0.60-0.92] vs. low Vt; high certainty). VV ECMO was also rated among the best (RR, 0.78 [95% CI, 0.58-1.05] vs. low Vt; RR, 0.66; [95% CI, 0.49-0.88] vs. high Vt) but was rated with lower certainty because VV ECMO was restricted to very severe ARDS (mean baseline PaO2/FiO2<75). High PEEP combined with low Vt was rated intermediately (RR, 0.91 [95% CI, 0.81-1.03] vs. low Vt; low certainty; RR, 0.77 [95% CI, 0.65-0.91] vs. high Vt; moderate certainty). High Vt was rated worst (RR, 1.19 [95% CI, 1.02-1.37] vs. low Vt; moderate certainty), and we found no support for high-frequency oscillation or high Vt with prone ventilation. Conclusions: These findings suggest that combining low Vt with prone ventilation is associated with the greatest reduction in mortality for critically ill adults with moderate-to-severe ARDS.