Perioperative hypotension and use of vasoactive agents in non-cardiac surgery: A scoping review.

BACKGROUND: Perioperative hypotension is common and associated with adverse patient outcomes. Vasoactive agents are often used to manage hypotension, but the ideal drug, dose and duration of treatment has not been established. With this scoping review, we aim to provide an overview of the current body of evidence regarding the vasoactive agents used to treat perioperative hypotension in non-cardiac surgery. METHODS: We included all studies describing the use of vasoactive agents for the treatment of perioperative hypotension in non-cardiac surgery. We excluded literature reviews, case studies, and studies on animals and healthy subjects. We posed the following research questions: (1) in which surgical populations have vasoactive agents been studied? (2) which agents have been studied? (3) what doses have been assessed? (4) what is the duration of treatment? and (5) which desirable and undesirable outcomes have been assessed? RESULTS: We included 124 studies representing 10 surgical specialties. Eighteen different agents were evaluated, predominantly phenylephrine, ephedrine, and noradrenaline. The agents were administered through six different routes, and numerous comparisons between agents, dosages and routes were included. Then, 88 distinct outcome measures were assessed, of which 54 were judged to be non-patient-centred. CONCLUSIONS: We found that studies concerning vasoactive agents for the treatment of perioperative hypotension varied considerably in all aspects. Populations were heterogeneous, interventions and exposures included multiple agents compared against themselves, each other, fluids or placebo, and studies reported primarily non-patient-centred outcomes.

Hypernatremia in hospitalised adult patients: A protocol for a scoping review.

BACKGROUND: Hypernatremia is a common electrolyte disturbance in hospitalised patients associated with adverse outcomes. The aetiology is diverse but often related to fluid therapy and sodium-containing medicaments. We aim to outline the evidence base on hypernatremia in adult hospitalised patients. METHODS: We will conduct a scoping review and adhere to the preferred reporting items for systematic and meta-analysis extension for scoping reviews (PRISMA-ScR). We will systematically search the Cochrane Library, Medline, Pubmed, and Embase from inception with no limitations to language, and include all study designs. We will use the population, exposure, comparator, and outcome-based approach to define eligibility criteria. The population: adult hospitalised patients; exposure: hypernatremia; comparator: no hypernatremia or all types of treatments of hypernatremia; and outcomes: all reported outcomes. Two authors will independently screen and select studies followed by full-text assessment and data extraction in duplicate. All outcome measures will be reported, and descriptive analyses will be performed. The certainty of evidence will be assessed according to an adapted grading of recommendations assessment, development, and evaluation (GRADE) approach. DISCUSSION: This scoping review will provide an overview of the current evidence regarding the incidence of hypernatremia, treatment modalities, and outcomes reported for hospitalised adult patients with hypernatremia.

Selective decontamination of the digestive tract in burn patients: Protocol for a systematic review.

BACKGROUND: Nosocomial infections contribute significantly to mortality and morbidity in burn patients. Selective decontamination of the digestive tract is an infection prevention measure that has been shown to improve survival in mechanically ventilated intensive care unit (ICU) patients. It has been hypothesized that burn patients may benefit from selective decontamination of the digestive tract. METHODS/DESIGN: We will conduct a systematic review with meta-analysis and trial sequential analysis of randomized clinical trials (RCTs) assessing the patient-important effects of selective decontamination of the digestive tract in burn patients, as compared with placebo or no intervention/standard of care. The primary outcome will be 30-day mortality. Secondary outcomes include serious adverse events, anti-microbial resistance, pneumonia, blood stream infections, ICU- and hospital-free days and 90-day mortality. We will search the following databases: CENTRAL, MEDLINE, EMBASE, BIOSIS, Web of Science and CINAHL and follow the recommendations provided by the Cochrane Collaboration and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The certainty of evidence will be assessed according to the GRADE approach: Grading of Recommendations Assessment, Development and Evaluation. DISCUSSION: There is clinical equipoise about the use of selective decontamination of the digestive tract in burn patients. In the outlined systematic review and meta-analysis, we will assess the desirable and undesirable effects of selective decontamination of the digestive tract in burn patients.

Society of Critical Care Medicine and American Society of Health-System Pharmacists Guideline for the Prevention of Stress-Related Gastrointestinal Bleeding in Critically Ill Adults.

RATIONALE: Critically ill adults can develop stress-related mucosal damage from gastrointestinal hypoperfusion and reperfusion injury, predisposing them to clinically important stress-related upper gastrointestinal bleeding (UGIB). OBJECTIVES: The objective of this guideline was to develop evidence-based recommendations for the prevention of UGIB in adults in the ICU. DESIGN: A multiprofessional panel of 18 international experts from dietetics, critical care medicine, nursing, and pharmacy, and two methodologists developed evidence-based recommendations in alignment with the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology. Conflict-of-interest policies were strictly followed during all phases of guideline development including task force selection and voting. METHODS: The panel members identified and formulated 13 Population, Intervention, Comparison, and Outcome questions. We conducted a systematic review for each question to identify the best available evidence, statistically analyzed the evidence, and then assessed the certainty of the evidence using the GRADE approach. We used the evidence-to-decision framework to formulate the recommendations. Good practice statements were included to provide additional guidance. RESULTS: The panel generated nine conditional recommendations and made four good practice statements. Factors that likely increase the risk for clinically important stress-related UGIB in critically ill adults include coagulopathy, shock, and chronic liver disease. There is no firm evidence for mechanical ventilation alone being a risk factor. Enteral nutrition probably reduces UGIB risk. All critically ill adults with factors that likely increase the risk for stress-related UGIB should receive either proton pump inhibitors or histamine-2 receptor antagonists, at low dosage regimens, to prevent UGIB. Prophylaxis should be discontinued when critical illness is no longer evident or the risk factor(s) is no longer present despite ongoing critical illness. Discontinuation of stress ulcer prophylaxis before transfer out of the ICU is necessary to prevent inappropriate prescribing. CONCLUSIONS: The guideline panel achieved consensus regarding the recommendations for the prevention of stress-related UGIB. These recommendations are intended for consideration along with the patient's existing clinical status.

Glucose evaluation and management in the ICU (GEM-ICU): Protocol for a bi-centre cohort study.

INTRODUCTION: Hyperglycaemia is common in intensive care unit (ICU) patients. Glycaemic monitoring and effective glycaemic control with insulin are crucial in the ICU to improve patient outcomes. However, glycaemic control and insulin use vary between ICU patients and hypo- and hyperglycaemia occurs. Therefore, we aim to provide contemporary data on glycaemic control and management, and associated outcomes, in adult ICU patients. We hypothesise that the occurrence of hypoglycaemia in acutely admitted ICU patients is lower than that of hyperglycaemia. METHODS: We will conduct a bi-centre cohort study of 300 acutely admitted adult ICU patients. Routine data will be collected retrospectively at baseline (ICU admission) and daily during ICU stay up to a maximum of 30 days. The primary outcome will be the number of patients with hypoglycaemia during their ICU stay. Secondary outcomes will be occurrence of severe hypoglycaemia, occurrence of hyperglycaemia, time below blood glucose target range, time above target range, all-cause mortality at Day 30, number of days alive without life support at Day 30 and number of days alive and out of hospital at Day 30. Process outcomes include the number of in-ICU days, glucose measurements (number of measurements and method) and use of insulin (including route of administration and dosage). All statistical analyses will be descriptive. CONCLUSIONS: This cohort study will provide a contemporary overview of glucose evaluation and management practices in adult ICU patients and, thus, highlight potential areas for improvement through future clinical trials in this area.

Associations between enteral nutrition and outcomes in the SUP-ICU trial: Results of exploratory post hoc analyses.

BACKGROUND: Enteral nutrition may affect risks of gastrointestinal bleeding, pneumonia and mortality in critically ill patients and may also modify the effects of pharmacological stress ulcer prophylaxis. We undertook post hoc analyses of the stress ulcer prophylaxis in the intensive care unit trial to assess for any associations and interactions between enteral nutrition and pantoprazole. METHODS: Extended Cox models with time-varying co-variates and competing events were used to assess potential associations, adjusted for baseline severity of illness. Potential interactions between daily enteral nutrition and allocation to pantoprazole on outcomes were similarly assessed. RESULTS: Enteral nutrition was associated with lower risk of clinically important gastrointestinal bleeding (cause-specific hazard ratio [HR]: 0.29, 95% confidence interval: [CI] 0.19-0.44, p < .001), higher risk of pneumonia (HR: 1.44, 95% CI: 1.14-1.82, p = .003), and lower risk of all-cause mortality (HR: 0.22, 95% CI: 0.18-0.27, p < .001). Enteral nutrition with allocation to pantoprazole was associated with a lower risk of mortality (HR: 0.27, 95% CI: 0.21-0.35, p < .001), similar to enteral nutrition with allocation to placebo (HR: 0.17, 95% CI: 0.13-0.23, p < .001). Allocation to pantoprazole with no enteral nutrition had little effect on mortality (HR: 0.83, 95% CI: 0.63-1.09, p = .179), whilst allocation to pantoprazole and receipt of enteral nutrition was mostly compatible with increased all-cause mortality (HR: 1.27, 95% CI: 0.99-1.64, p = .061). The test of interaction between enteral nutrition and pantoprazole treatment allocation for all-cause mortality was statistically significant (p = .024). CONCLUSIONS: Enteral nutrition was associated with an increased risk of pneumonia and a reduced risk of gastrointestinal bleeding. The interaction between pantoprazole and enteral nutrition suggesting an increased risk of mortality requires further study.

Platelet transfusions in adult ICU patients with thrombocytopenia: A sub-study of the PLOT-ICU inception cohort study.

BACKGROUND: Platelet transfusions are frequently used in the intensive care unit (ICU), but current practices including used product types, volumes, doses and effects are unknown. STUDY DESIGN AND METHODS: Sub-study of the inception cohort study 'Thrombocytopenia and Platelet Transfusions in the ICU (PLOT-ICU)', including acutely admitted, adult ICU patients with thrombocytopenia (platelet count <150 × 109/L). The primary outcome was the number of patients receiving platelet transfusion in ICU by product type. Secondary outcomes included platelet transfusion details, platelet increments, bleeding, other transfusions and mortality. RESULTS: Amongst 504 patients with thrombocytopenia from 43 hospitals in 10 countries in Europe and the United States, 20.8% received 565 platelet transfusions; 61.0% received pooled products, 21.9% received apheresis products and 17.1% received both with a median of 2 (interquartile range 1-4) days from admission to first transfusion. The median volume per transfusion was 253 mL (180-308 mL) and pooled products accounted for 59.1% of transfusions, however, this varied across countries. Most centres (73.8%) used fixed dosing (medians ranging from 2.0 to 3.5 × 1011 platelets/transfusion) whilst some (mainly in France) used weight-based dosing (ranging from 0.5 to 0.7 × 1011 platelets per 10 kg body weight). The median platelet count increment for a single prophylactic platelet transfusion was 2 (-1 to 8) × 109/L. Outcomes of patients with thrombocytopenia who did and did not receive platelet transfusions varied. CONCLUSIONS: Among acutely admitted, adult ICU patients with thrombocytopenia, 20.8% received platelet transfusions in ICU of whom most received pooled products, but considerable variation was observed in product type, volumes and doses across countries. Prophylactic platelet transfusions were associated with limited increases in platelet counts.

ESAIC focused guideline for the use of cardiac biomarkers in perioperative risk evaluation: Endorsement by the Scandinavian Society of Anaesthesiology and Intensive Care Medicine.

BACKGROUND: The Clinical Practice Committee of the Scandinavian Society of Anaesthesiology and Intensive Care Medicine endorses the clinical practice guideline "ESAIC focused guideline for the use of cardiac biomarkers in perioperative risk evaluation." The guideline can provide guidance to Nordic anaesthesiologists on the perioperative use of cardiac biomarkers in patients undergoing non-cardiac surgery.

European Society of Intensive Care Medicine clinical practice guideline on fluid therapy in adult critically ill patients. Part 1: the choice of resuscitation fluids.

PURPOSE: This is the first of three parts of the clinical practice guideline from the European Society of Intensive Care Medicine (ESICM) on resuscitation fluids in adult critically ill patients. This part addresses fluid choice and the other two will separately address fluid amount and fluid removal. METHODS: This guideline was formulated by an international panel of clinical experts and methodologists. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology was applied to evaluate the certainty of evidence and to move from evidence to decision. RESULTS: For volume expansion, the guideline provides conditional recommendations for using crystalloids rather than albumin in critically ill patients in general (moderate certainty of evidence), in patients with sepsis (moderate certainty of evidence), in patients with acute respiratory failure (very low certainty of evidence) and in patients in the perioperative period and patients at risk for bleeding (very low certainty of evidence). There is a conditional recommendation for using isotonic saline rather than albumin in patients with traumatic brain injury (very low certainty of evidence). There is a conditional recommendation for using albumin rather than crystalloids in patients with cirrhosis (very low certainty of evidence). The guideline provides conditional recommendations for using balanced crystalloids rather than isotonic saline in critically ill patients in general (low certainty of evidence), in patients with sepsis (low certainty of evidence) and in patients with kidney injury (very low certainty of evidence). There is a conditional recommendation for using isotonic saline rather than balanced crystalloids in patients with traumatic brain injury (very low certainty of evidence). There is a conditional recommendation for using isotonic crystalloids rather than small-volume hypertonic crystalloids in critically ill patients in general (very low certainty of evidence). CONCLUSIONS: This guideline provides eleven recommendations to inform clinicians on resuscitation fluid choice in critically ill patients.

Empirical meropenem versus piperacillin/tazobactam for adult patients with sepsis (EMPRESS) trial: Protocol.

BACKGROUND: Piperacillin/tazobactam may be associated with less favourable outcomes than carbapenems in patients with severe bacterial infections, but the certainty of evidence is low. METHODS: The Empirical Meropenem versus Piperacillin/Tazobactam for Adult Patients with Sepsis (EMPRESS) trial is an investigator-initiated, international, parallel-group, randomised, open-label, adaptive clinical trial with an integrated feasibility phase. We will randomise adult, critically ill patients with sepsis to empirical treatment with meropenem or piperacillin/tazobactam for up to 30 days. The primary outcome is 30-day all-cause mortality. The secondary outcomes are serious adverse reactions within 30 days; isolation precautions due to resistant bacteria within 30 days; days alive without life support and days alive and out of hospital within 30 and 90 days; 90- and 180-day all-cause mortality and 180-day health-related quality of life. EMPRESS will use Bayesian statistical models with weak to somewhat sceptical neutral priors. Adaptive analyses will be conducted after follow-up of the primary outcome for the first 400 participants concludes and after every 300 subsequent participants, with adaptive stopping for superiority/inferiority and practical equivalence (absolute risk difference <2.5%-points) and response-adaptive randomisation. The expected sample sizes in scenarios with no, small or large differences are 5189, 5859 and 2570 participants, with maximum 14,000 participants and ≥99% probability of conclusiveness across all scenarios. CONCLUSIONS: EMPRESS will compare the effects of empirical meropenem against piperacillin/tazobactam in adult, critically ill patients with sepsis. Due to the pragmatic, adaptive design with high probability of conclusiveness, the trial results are expected to directly inform clinical practice.

Effects of IV fluid restriction according to site-specific intensity of standard fluid treatment-protocol.

BACKGROUND: Variation in usual practice in fluid trials assessing lower versus higher volumes may affect overall comparisons. To address this, we will evaluate the effects of heterogeneity in treatment intensity in the Conservative versus Liberal Approach to Fluid Therapy of Septic Shock in Intensive Care trial. This will reflect the effects of differences in site-specific intensities of standard fluid treatment due to local practice preferences while considering participant characteristics. METHODS: We will assess the effects of heterogeneity in treatment intensity across one primary (all-cause mortality) and three secondary outcomes (serious adverse events or reactions, days alive without life support and days alive out of hospital) after 90 days. We will classify sites based on the site-specific intensity of standard fluid treatment, defined as the mean differences in observed versus predicted intravenous fluid volumes in the first 24 h in the standard-fluid group while accounting for differences in participant characteristics. Predictions will be made using a machine learning model including 22 baseline predictors using the extreme gradient boosting algorithm. Subsequently, sites will be grouped into fluid treatment intensity subgroups containing at least 100 participants each. Subgroups differences will be assessed using hierarchical Bayesian regression models with weakly informative priors. We will present the full posterior distributions of relative (risk ratios and ratios of means) and absolute differences (risk differences and mean differences) in each subgroup. DISCUSSION: This study will provide data on the effects of heterogeneity in treatment intensity while accounting for patient characteristics in critically ill adult patients with septic shock. REGISTRATIONS: The European Clinical Trials Database (EudraCT): 2018-000404-42, ClinicalTrials. gov: NCT03668236.

Empirical carbapenems or piperacillin/tazobactam for infections in intensive care: An international retrospective cohort study.

BACKGROUND: Critically ill patients in intensive care units (ICU) are frequently administered broad-spectrum antibiotics (e.g., carbapenems or piperacillin/tazobactam) for suspected or confirmed infections. This retrospective cohort study aimed to describe the use of carbapenems and piperacillin/tazobactam in two international, prospectively collected datasets. METHODS: We conducted a post hoc analysis of data from the "Adjunctive Glucocorticoid Therapy in Patients with Septic Shock" (ADRENAL) trial (n = 3713) and the "Antimicrobial de-escalation in the critically ill patient and assessment of clinical cure" (DIANA) study (n = 1488). The primary outcome was the proportion of patients receiving initial antibiotic treatment with carbapenems and piperacillin/tazobactam. Secondary outcomes included mortality, days alive and out of ICU and ICU length of stay at 28 days. RESULTS: In the ADRENAL trial, carbapenems were used in 648 out of 3713 (17%), whereas piperacillin/tazobactam was used in 1804 out of 3713 (49%) participants. In the DIANA study, carbapenems were used in 380 out of 1480 (26%), while piperacillin/tazobactam was used in 433 out of 1488 (29%) participants. Mortality at 28 days was 23% for patients receiving carbapenems and 24% for those receiving piperacillin/tazobactam in ADRENAL and 23% and 19%, respectively, in DIANA. We noted variations in secondary outcomes; in DIANA, patients receiving carbapenems had a median of 13 days alive and out of ICU compared with 18 days among those receiving piperacillin/tazobactam. In ADRENAL, the median hospital length of stay was 27 days for patients receiving carbapenems and 21 days for those receiving piperacillin/tazobactam. CONCLUSIONS: In this post hoc analysis of ICU patients with infections, we found widespread initial use of carbapenems and piperacillin/tazobactam in international ICUs, with the latter being more frequently used. Randomized clinical trials are needed to assess if the observed variations in outcomes may be drug-related effects or due to confounders.

Effects of sceptical priors on the performance of adaptive clinical trials with binary outcomes.

It is unclear how sceptical priors impact adaptive trials. We assessed the influence of priors expressing a spectrum of scepticism on the performance of several Bayesian, multi-stage, adaptive clinical trial designs using binary outcomes under different clinical scenarios. Simulations were conducted using fixed stopping rules and stopping rules calibrated to keep type 1 error rates at approximately 5%. We assessed total sample sizes, event rates, event counts, probabilities of conclusiveness and selecting the best arm, root mean squared errors (RMSEs) of the estimated treatment effect in the selected arms, and ideal design percentages (IDPs; which combines arm selection probabilities, power, and consequences of selecting inferior arms), with RMSEs and IDPs estimated in conclusive trials only and after selecting the control arm in inconclusive trials. Using fixed stopping rules, increasingly sceptical priors led to larger sample sizes, more events, higher IDPs in simulations ending in superiority, and lower RMSEs, lower probabilities of conclusiveness/selecting the best arm, and lower IDPs when selecting controls in inconclusive simulations. With calibrated stopping rules, the effects of increased scepticism on sample sizes and event counts were attenuated, and increased scepticism increased the probabilities of conclusiveness/selecting the best arm and IDPs when selecting controls in inconclusive simulations without substantially increasing sample sizes. Results from trial designs with gentle adaptation and non-informative priors resembled those from designs with more aggressive adaptation using weakly-to-moderately sceptical priors. In conclusion, the use of somewhat sceptical priors in adaptive trial designs with binary outcomes seems reasonable when considering multiple performance metrics simultaneously.

Critical appraisal of clinical practice guidelines.

Ten questions to assess to what degree a clinical practice guideline is likely to be trustworthy: 1) Do the authors have conflicts of interests? 2) Is the clinical question relevant? 3) Have relevant stakeholders been involved? 4) Have methods for study selection been described? 5) Is there a link between evidence and recommendations (transparent methods)? 6) Has the certainty of evidence been assessed? 7) Have the methods for reaching recommendations been described? 8) Are the recommendations unambiguous? 9) Are the recommendations relevant in your situation? 10) Is there an implementation strategy?

GRADE pearls and pitfalls-Part 1: Systematic reviews and meta-analyses.

BACKGROUND: The Grading of Recommendation, Assessment, Development and Evaluation (GRADE) approach is used to assess the certainty of evidence in systematic reviews and meta-analyses. METHODS: We describe how the GRADE approach is used in systematic reviews and meta-analyses, including key points and examples. This overview is aimed at clinicians and researchers who are, or plan to be, involved in the development or assessment of systematic reviews with meta-analyses using GRADE. RESULTS: We outline how the certainty of evidence is assessed, how the evidence is summarized using GRADE evidence profiles or summary of findings tables, how the results are communicated, and we discuss challenges, advantages, and disadvantages with using GRADE. CONCLUSIONS: This overview aims to provide an overview of how GRADE is used in systematic reviews and meta-analyses, and may be used by systematic review developers, methodologists, and evidence end-users.

GRADE pearls and pitfalls-Part 2: Clinical practice guidelines.

BACKGROUND: The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach is the de facto standard framework for summarising evidence in systematic reviews and developing recommendations in clinical practice guidelines. METHODS: We describe how the GRADE approach is used in clinical practice guidelines, including key points and examples. The intended audience of this overview of GRADE is clinicians and researchers who are, or plan to be, involved in the development or assessment of clinical practice guidelines. RESULTS: We cover guideline endorsement and adaptation; guideline panels and sponsors; conflicts of interest; guideline questions and outcome prioritisation; systematic review creation, updating and re-use; rating the overall certainty of evidence; development of recommendations and implications; and peer review, publication, implementation and updating of guidelines. CONCLUSIONS: This overview aims to help developers, assessors and users of clinical practice guidelines understand how trustworthy, high-quality guidelines are developed using the GRADE approach.

Heterogeneity of treatment effect of higher dose dexamethasone by geographic region (Europe vs. India) in patients with COVID-19 and severe hypoxemia - a post hoc evaluation of the COVID STEROID 2 trial.

Background: In the COVID-STEROID 2 trial there was suggestion of heterogeneity of treatment effects (HTE) between patients enrolled from Europe vs. India on the primary outcome. Whether there was HTE for the remaining patient-centred outcomes is unclear. Methods: In this post hoc analysis of the COVID-STEROID 2 trial, which compared 12 mg vs. 6 mg dexamethasone in adults with COVID-19 and severe hypoxemia, we evaluated HTE by geographical region (Europe vs. India) for secondary outcomes with analyses adjusted for stratification variables. Results are presented as risk differences (RDs) or mean differences (MDs) with 99% confidence intervals (CIs) and P-values from interaction tests. Findings: There were differences in mortality at day 28 (RD for Europe -8.3% (99% CI: -17.7 to 1.0) vs. India 0.1% (99% CI: -10.0 to 10.0)), mortality at day 90 (RD for Europe -7.4% (99% CI: -17.1 to 2.0) vs. India -1.4% (99% CI: -12.8 to 9.8)), mortality at day 180 (RD for Europe -6.7% (99% CI: -16.4 to 2.9) vs. India -1.0% (99% CI: -12.3 to 10.3)), and number of days alive without life support at day 90 (MD for Europe 6.1 days (99% CI: -1.3 to 13.4) vs. India 1.7 days (99% CI: -8.4 to 11.8)). For serious adverse reactions, the direction was reversed (RD for Europe -1.0% (99% CI: -7.1 to 5.2) vs. India -5.3% (99% CI: -16.2 to 5.0). Interpretation: Our analysis suggests higher dose dexamethasone may have less beneficial effects for patients in India as compared with those in Europe; however, the evidence is weak, and this could represent a chance finding. Funding: None for this analysis. The COVID STEROID 2 trial was funded by The Novo Nordisk Foundation and supported by Rigshospitalet's Research Council.

Real-world causal evidence for planned predictive enrichment in critical care trials: A scoping review.

BACKGROUND: Randomised clinical trials in critical care are prone to inconclusiveness due, in part, to undue optimism about effect sizes and suboptimal accounting for heterogeneous treatment effects. Although causal evidence from rich real-world critical care can help overcome these challenges by informing predictive enrichment, no overview exists. METHODS: We conducted a scoping review, systematically searching 10 general and speciality journals for reports published on or after 1 January 2018, of randomised clinical trials enrolling adult critically ill patients. We collected trial metadata on 22 variables including recruitment period, intervention type and early stopping (including reasons) as well as data on the use of causal evidence from secondary data for planned predictive enrichment. RESULTS: We screened 9020 records and included 316 unique RCTs with a total of 268,563 randomised participants. One hundred seventy-three (55%) trials tested drug interventions, 101 (32%) management strategies and 42 (13%) devices. The median duration of enrolment was 2.2 (IQR: 1.3-3.4) years, and 83% of trials randomised less than 1000 participants. Thirty-six trials (11%) were restricted to COVID-19 patients. Of the 55 (17%) trials that stopped early, 23 (42%) used predefined rules; futility, slow enrolment and safety concerns were the commonest stopping reasons. None of the included RCTs had used causal evidence from secondary data for planned predictive enrichment. CONCLUSION: Work is needed to harness the rich multiverse of critical care data and establish its utility in critical care RCTs. Such work will likely need to leverage methodology from interventional and analytical epidemiology as well as data science.

Albumin use in patients with septic shock-Post-hoc analyses of an international randomised fluid trial.

BACKGROUND: Albumin administration is suggested in patients with sepsis and septic shock who have received large volumes of crystalloids. Given lack of firm evidence, clinical practice variation may exist. To address this, we investigated if patient characteristics or trial site were associated with albumin use in septic shock. METHODS: We conducted a post-hoc study of the CLASSIC international, randomised clinical trial of fluid volumes in septic shock. Associations between selected baseline variables and trial site with albumin use during ICU stay were assessed in Cox models considering death, ICU discharge, and loss-to-follow-up as competing events. Baseline variables were first assessed individually, adjusted for treatment allocation (restrictive vs. standard IV fluid), and then adjusted for allocation and the other baseline variables. Site was assessed in a model adjusted for allocation and baseline variables. RESULTS: We analysed 1541 of 1554 patients randomised in CLASSIC (99.2%). During ICU stay, 36.3% of patients in the restrictive-fluid group and 52.6% in the standard-fluid group received albumin. Gastrointestinal focus of infection and higher doses of norepinephrine were most strongly associated with albumin use (subgroup with highest quartile of norepinephrine doses, hazard ratio (HR) 2.58, 95% CI 1.89 to 3.53). HRs for associations between site and albumin use ranged from 0.11 (95% CI 0.05 to 0.26) to 1.70 (95% CI 1.06 to 2.74); test for overall effect of site: p < .001. CONCLUSIONS: In adults with septic shock, gastrointestinal focus of infection and higher doses of norepinephrine at baseline were associated with albumin use, which also varied substantially between sites.