Association between arterial oxygen and mortality across critically ill patients with hematologic malignancies: results from an international collaborative network

PURPOSE

Patients with hematological malignancies are at high risk for life-threatening complications. To date, little attention has been paid to the impact of hyperoxemia and excess oxygen use on mortality. The aim of this study was to investigate the association between partial pressure of arterial oxygen (PaO2) and 28-day mortality in critically ill patients with hematologic malignancies.

METHODS

Data from three international cohorts (Europe, Canada, Oceania) of patients who received respiratory support (noninvasive ventilation, high-flow nasal cannula, invasive mechanical ventilation) were obtained. We used mixed-effect Cox models to investigate the association between day one PaO2 or excess oxygen use (inspired fraction of oxygen ≥ 0.6 with PaO2 > 100 mmHg) on day-28 mortality.

RESULTS

11,249 patients were included. On day one, 5716 patients (50.8%) had normoxemia (60 ≤ PaO2 ≤ 100 mmHg), 1454 (12.9%) hypoxemia (PaO2 < 60 mmHg), and 4079 patients (36.3%) hyperoxemia (PaO2 > 100 mmHg). Excess oxygen was used in 2201 patients (20%). Crude day-28 mortality rate was 40.6%. There was a significant association between PaO2 and day-28 mortality with a U-shaped relationship (p < 0.001). Higher PaO2 levels (> 100 mmHg) were associated with day-28 mortality with a dose-effect relationship. Subgroup analyses showed an association between hyperoxemia and mortality in patients admitted with neurological disorders; however, the opposite relationship was seen across those admitted with sepsis and neutropenia. Excess oxygen use was also associated with subsequent day-28 mortality (adjusted hazard ratio (aHR) [95% confidence interval (CI)]: 1.11[1.04-1.19]). This result persisted after propensity score analysis (matched HR associated with excess oxygen:1.31 [1.20-1.1.44]).

CONCLUSION

In critically-ill patients with hematological malignancies, exposure to hyperoxemia and excess oxygen use were associated with increased mortality, with variable magnitude across subgroups. This might be a modifiable factor to improve mortality.

CCL14 testing to guide clinical practice in patients with AKI: Results from an international expert panel

PURPOSE

Urinary C-C motif chemokine ligand 14 (CCL14) is a strong predictor of persistent stage 3 acute kidney injury (AKI). Multiple clinical actions are recommended for AKI but how these are applied in individual patients and how the CCL14 test results may impact their application is unknown.

METHODS

We assembled an international panel of 12 experts and conducted a modified Delphi process to evaluate patients at risk for persistent stage 3 AKI (lasting 72 hours or longer). Using a Likert scale, we rated 11 clinical actions based on international guidelines applied to each case before and after CCL14 testing and analyzed the association between the strength and direction of recommendations and CCL14 results.

RESULTS

The strength and direction of clinical recommendations were strongly influenced by CCL14 results (P < 0.001 for the interaction). Nine (82%) recommendations for clinical actions were significantly impacted by CCL14 results (P < 0.001 comparing low to highest CCL14 risk category).

CONCLUSIONS

Most recommendations for care of patients with stage 2-3 by an international panel of experts were strongly modified by CCL14 test results. This work should set the stage for clinical practice protocols and studies to determine the effects of recommended actions informed by CCL14.

Hemoadsorption: Consensus report of the 30th Acute Disease Quality Initiative workgroup

Adsorption-based extracorporeal therapies have been subject to technical developments and clinical application for close to five decades. More recently, new technological developments in membrane and sorbent manipulation have made it possible to deliver more biocompatible extracorporeal adsorption therapies to patients with a variety of conditions. There are several key rationales based on physicochemical principles and clinical considerations that justify the application and investigation of such therapies as evidenced by multiple ex-vivo, experimental, and clinical observations. Accordingly, unspecific adsorptive extracorporeal therapies have now been applied to the treatment of a wide array of conditions from poisoning to drug overdoses, to inflammatory states and sepsis, and acute or chronic liver and kidney failure. In response to the rapidly expanding knowledge base and increased clinical evidence, we convened an Acute Disease Quality Initiative (ADQI) consensus conference dedicated to such treatment. The data show that hemoadsorption has clinically acceptable short-term biocompatibility and safety, technical feasibility, and experimental demonstration of specified target molecule removal. Pilot studies demonstrate potentially beneficial effects on physiology and larger studies of endotoxin-based hemoadsorption have identified possible target phenotypes for larger randomized controlled trials (RCTs). Moreover, in a variety of endogenous and exogenous intoxications, removal of target molecules has been confirmed in vivo. However, some studies have raised concerns about harm or failed to deliver benefits. Thus, despite many achievements, modern hemoadsorption remains a novel and experimental intervention with limited data, and a large research agenda.

Quantifying the Impact of Alternative Definitions of Sepsis-Associated Acute Kidney Injury on its Incidence and Outcomes: A Systematic Review and Meta-Analysis

OBJECTIVES

To derive a pooled estimate of the incidence and outcomes of sepsis-associated acute kidney injury (SA-AKI) in ICU patients and to explore the impact of differing definitions of SA-AKI on these estimates.

DATA SOURCES

Medline, Medline Epub, EMBASE, and Cochrane CENTRAL between 1990 and 2023.

STUDY SELECTION

Randomized clinical trials and prospective cohort studies of adults admitted to the ICU with either sepsis and/or SA-AKI.

DATA EXTRACTION

Data were extracted in duplicate. Risk of bias was assessed using adapted standard tools. Data were pooled using a random-effects model. Heterogeneity was assessed by using a single covariate logistic regression model. The primary outcome was the proportion of participants in ICU with sepsis who developed AKI.

DATA SYNTHESIS

A total of 189 studies met inclusion criteria. One hundred fifty-four reported an incidence of SA-AKI, including 150,978 participants. The pooled proportion of patients who developed SA-AKI across all definitions was 0.40 (95% CI, 0.37-0.42) and 0.52 (95% CI, 0.48-0.56) when only the Risk Injury Failure Loss End-Stage, Acute Kidney Injury Network, and Improving Global Outcomes definitions were used to define SA-AKI. There was significant variation in the incidence of SA-AKI depending on the definition of AKI used and whether AKI defined by urine output criteria was included; the incidence was lowest when receipt of renal replacement therapy was used to define AKI (0.26; 95% CI, 0.24-0.28), and highest when the Acute Kidney Injury Network score was used (0.57; 95% CI, 0.45-0.69; p < 0.01). Sixty-seven studies including 29,455 participants reported at least one SA-AKI outcome. At final follow-up, the proportion of patients with SA-AKI who had died was 0.48 (95% CI, 0.43-0.53), and the proportion of surviving patients who remained on dialysis was 0.10 (95% CI, 0.04-0.17).

CONCLUSIONS

SA-AKI is common in ICU patients with sepsis and carries a high risk of death and persisting kidney impairment. The incidence and outcomes of SA-AKI vary significantly depending on the definition of AKI used.

Sepsis-associated acute kidney injury: recent advances in enrichment strategies, sub-phenotyping and clinical trials

Acute kidney injury (AKI) often complicates sepsis and is associated with high morbidity and mortality. In recent years, several important clinical trials have improved our understanding of sepsis-associated AKI (SA-AKI) and impacted clinical care. Advances in sub-phenotyping of sepsis and AKI and clinical trial design offer unprecedented opportunities to fill gaps in knowledge and generate better evidence for improving the outcome of critically ill patients with SA-AKI. In this manuscript, we review the recent literature of clinical trials in sepsis with focus on studies that explore SA-AKI as a primary or secondary outcome. We discuss lessons learned and potential opportunities to improve the design of clinical trials and generate actionable evidence in future research. We specifically discuss the role of enrichment strategies to target populations that are most likely to derive benefit and the importance of patient-centered clinical trial endpoints and appropriate trial designs with the aim to provide guidance in designing future trials.

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.

Hierarchical endpoints in critical care: A post-hoc exploratory analysis of the standard versus accelerated initiation of renal-replacement therapy in acute kidney injury and the intensity of continuous renal-replacement therapy in critically ill patients trials

PURPOSE

To perform a post-hoc reanalysis of the Standard versus Accelerated Initiation of Renal-Replacement Therapy in Acute Kidney Injury (STARRT-AKI) and the Intensity of Continuous Renal-Replacement Therapy in Critically Ill Patients (RENAL) trials through hierarchical composite endpoint analysis using win ratio (WR).

MATERIAL AND METHODS

All patients with complete information from the STARRT-AKI (which compared accelerated versus standard approaches for renal replacement therapy - RRT initiation) and RENAL (which compared two different RRT doses in critically ill patients) trials were selected. WR was defined as a hierarchical composite endpoint using 90-day mortality, RRT dependency at 90-days, intensive care unit (ICU) length-of-stay (LOS), and hospital LOS (primary analysis); values above the unit represent a benefit of the intervention for the hierarchical composite endpoint. A secondary analysis replacing LOS by days alive and free of RRT was performed. Stratified analyses were performed according to illness severity score, surgical status, and the presence of sepsis.

RESULTS

The WR analysis produced 2,141,830 pairs for the STARRT-AKI trial and 536,446 pairs for the RENAL trial, respectively. The WR results for STARRT-AKI and RENAL were 1.04 (95% confidence interval [CI] 0.96-1.13; p = 0.33) and 1.02 (95% CI; 0.90-1.15; p = 0.75) for the primary analysis, and 0.88 (95% CI; 0.79-0.99; p = 0.03) and 1.02 (95% CI; 0.87-1.21; p = 0.77) for the secondary analysis, respectively. The stratified analysis of the primary suggested possible benefit of the accelerated-strategy in the STARRT-AKI trial for non-surgical patients with sepsis, while the secondary analysis suggested possible harm of the accelerated-strategy for surgical patients without sepsis. There was no evidence of heterogeneity in treatment effects in stratified analyses in the RENAL trial.

CONCLUSION

WR approach using a hierarchical composite endpoint is feasible for trials in critical care nephrology. The primary re-analyses of the STARRT-AKI and RENAL trials both yielded neutral results; however, there was suggestion of heterogeneity in treatment effect in stratified analyses of the STARRT-AKI trial by surgical status and sepsis. Selection of the endpoints and hierarchical ordering before trial design using the WR approach can have important implications for trial interpretation.

TRIAL REGISTRY

ClinicalTrials.gov number NCT02568722 (STARRT-AKI) and NCT00076219 (RENAL).

Public perception of participation in low-risk clinical trials in critical care using waived consent: a Canadian national survey

PURPOSE

The acceptability of waiver of consent for participation in clinical research in intensive care unit (ICU) settings is uncertain. We sought to survey the Canadian public to assess levels of support, comfort, and acceptability for waived consent for low-risk clinical trials.

METHODS

We performed a prospective cross-sectional survey of the Canadian public aged 18 yr or older. The survey was conducted by Ipsos between 19 and 23 November 2020. The survey content was derived from a literature review and in consultation with a patient and family partnership committee. The survey focused on attitudes and beliefs on waived consent for participation in low-risk clinical trials in ICU settings. The survey contained 35 items focused on sociodemographics, general health status, participation in medical research, and levels of support and comfort with research and with waived consent. The survey used a case study of a low-risk clinical trial intervention in ICU patients. Analysis was descriptive.

RESULTS

We included 2,000 participants, 38% of whom reported experience with ICU and 16% with medical research. Participation in medical research was more common among those with postsecondary education, those with chronic disease, and those who were employed in health care. Most (80%) would support a model of waived consent for low-risk clinical trials, citing medical benefits (36%) and low perceived risk (34%). Most (77%) were comfortable with personally participating in a low-risk clinical trial. Most (80%) believed waived consent approaches were acceptable. Half (52%) believed the waived consent process should provide information about the research and include the option of opting out. When asked whether participants should always give full informed consent, regardless of the practicality or level of risk, 74% and 72% agreed, respectively.

CONCLUSIONS

There is public support for models of waived consent for participation in low-risk pragmatic clinical trials in ICU settings in Canada; however, this is not universal. This information can inform and guide education, ethics, policy, and legal discussion on consent models.

Modelling the potential increase in eligible participants in clinical trials with inclusion of community intensive care unit patients in Alberta, Canada: a decision tree analysis

PURPOSE

Critical care research in Canada is conducted primarily in academically affiliated intensive care units (ICUs) with established research infrastructure. Efforts are made to engage community hospital ICUs in research, although the impacts of their inclusion in clinical research have never been explicitly quantified. We therefore sought to determine the number of additional eligible patients that could be recruited into critical care trials and the change in time to study completion if community ICUs were included in clinical research.

METHODS

We conducted a decision tree analysis using 2018 Alberta Health Services data. Patient demographics and clinical characteristics for all ICU patients were compared against eligibility criteria from ten landmark, randomized, multicentre critical care trials. Individual patients from academic and community ICUs were assessed for eligibility in each of the ten studies, and decision tree analysis models were built based on prior inclusion and exclusion criteria from those trials.

RESULTS

The number of potentially eligible patients for the ten trials ranged from 2,082 to 10,157. Potentially eligible participants from community ICUs accounted for 40.0% of total potentially eligible participants. The recruitment of community ICU patients in trials would have increased potential enrolment by an average of 64.0%. The inclusion of community ICU patients was predicted to decrease time to trial completion by a mean of 14 months (43% reduction).

CONCLUSION

Inclusion of community ICU patients in critical care research trials has the potential to substantially increase enrolment and decrease time to trial completion.

Pediatric AKI in the real world: changing outcomes through education and advocacy-a report from the 26th Acute Disease Quality Initiative (ADQI) consensus conference

BACKGROUND

Acute kidney injury (AKI) is independently associated with increased morbidity and mortality across the life course, yet care for AKI remains mostly supportive. Raising awareness of this life-threatening clinical syndrome through education and advocacy efforts is the key to improving patient outcomes. Here, we describe the unique roles education and advocacy play in the care of children with AKI, discuss the importance of customizing educational outreach efforts to individual groups and contexts, and highlight the opportunities created through innovations and partnerships to optimize lifelong health outcomes.

METHODS

During the 26th Acute Disease Quality Initiative (ADQI) consensus conference, a multidisciplinary group of experts discussed the evidence and used a modified Delphi process to achieve consensus on recommendations on AKI research, education, practice, and advocacy in children.

RESULTS

The consensus statements developed in response to three critical questions about the role of education and advocacy in pediatric AKI care are presented here along with a summary of available evidence and recommendations for both clinical care and research.

CONCLUSIONS

These consensus statements emphasize that high-quality care for patients with AKI begins in the community with education and awareness campaigns to identify those at risk for AKI. Education is the key across all healthcare and non-healthcare settings to enhance early diagnosis and develop mitigation strategies, thereby improving outcomes for children with AKI. Strong advocacy efforts are essential for implementing these programs and building critical collaborations across all stakeholders and settings.

Fluid assessment, fluid balance, and fluid overload in sick children: a report from the Pediatric Acute Disease Quality Initiative (ADQI) conference

BACKGROUND

The impact of disorders of fluid balance, including the pathologic state of fluid overload in sick children has become increasingly apparent. With this understanding, there has been a shift from application of absolute thresholds of fluid accumulation to an appreciation of the intricacies of fluid balance, including the impact of timing, trajectory, and disease pathophysiology.

METHODS

The 26th Acute Disease Quality Initiative was the first to be exclusively dedicated to pediatric and neonatal acute kidney injury (pADQI). As part of the consensus panel, a multidisciplinary working group dedicated to fluid balance, fluid accumulation, and fluid overload was created. Through a search, review, and appraisal of the literature, summative consensus statements, along with identification of knowledge gaps and recommendations for clinical practice and research were developed.

CONCLUSIONS

The 26th pADQI conference proposed harmonized terminology for fluid balance and for describing a pathologic state of fluid overload for clinical practice and research. Recommendations include that the terms daily fluid balance, cumulative fluid balance, and percent cumulative fluid balance be utilized to describe the fluid status of sick children. The term fluid overload is to be preserved for describing a pathologic state of positive fluid balance associated with adverse events. Several recommendations for research were proposed including focused validation of the definition of fluid balance, fluid overload, and proposed methodologic approaches and endpoints for clinical trials.

Achieving Goals of Care Decisions in Chronic Critical Illness: A Multi-institutional Qualitative Study

BACKGROUND

Physicians, patients, and families alike perceive a need to improve how goals of care (GOC) decisions occur in chronic critical illness (CCI), but little is currently known about this decision-making process.

RESEARCH QUESTION

How do intensivists from various health systems facilitate decision-making about GOC for patients with CCI? What are barriers to, and facilitators of, this decision-making process?

STUDY DESIGN AND METHODS

We conducted semistructured interviews with a purposeful sample of intensivists from the United States and Canada using a mental models approach adapted from decision science. We analyzed transcripts inductively using qualitative description.

RESULTS

We interviewed 29 intensivists from six institutions. Participants across all sites described GOC decision-making in CCI as a complex, longitudinal, and iterative process that involved substantial preparatory work, numerous stakeholders, and multiple family meetings. Intensivists required considerable time to collect information on prior events and conversations, and to arrive at a prognostic consensus with other involved physicians prior to meeting with families. Many intensivists stressed the importance of scheduling multiple family meetings to build trust and relationships prior to explicitly discussing GOC. Physician-identified barriers to GOC decision-making included 1-week staffing models, limited time and cognitive bandwidth, difficulty eliciting patient values, and interpersonal challenges with care team members or families. Potential facilitators included scheduled family meetings at regular intervals, greater interprofessional involvement in decisions, and consistent messaging from care team members.

INTERPRETATION

Intensivists described a complex time and labor-intensive group process to achieve GOC decision-making in CCI. System-level interventions that improve how information is shared between physicians and decrease logistical and relational barriers to timely and consistent communication are key to improving GOC decision-making in CCI.

Outcomes of Prophylactic Peritoneal Dialysis Catheter Insertion in Children Undergoing Cardiac Surgery: A Systematic Review and Meta-Analysis

OBJECTIVES

The objective of this Prospective Register of Systematic Reviews (CRD42022384192) registered systematic review and meta-analysis was to determine whether prophylactic peritoneal dialysis (PD) catheter insertion at the time of pediatric cardiac surgery is associated with improved short-term outcomes.

DATA SOURCES

Databases search of the MEDLINE, EMBASE, CINAHL, and Cochrane Library completed in April 2021 and updated October 2023.

STUDY SELECTION

Two reviewers independently completed study selection, data extraction, and bias assessment. Inclusion criteria were randomized controlled trials (RCTs) and observational studies of children (≤ 18 yr) undergoing cardiac surgery with cardiopulmonary bypass. We evaluated use of prophylactic PD catheter versus not.

DATA EXTRACTION

The primary outcome was in-hospital mortality, as well as secondary short-term outcomes. Pooled random-effect meta-analysis odds ratio with 95% CI are reported.

DATA SYNTHESIS

Seventeen studies met inclusion criteria, including four RCTs. The non-PD catheter group received supportive care that included diuretics and late placement of PD catheters in the ICU. Most study populations included children younger than 1 year and weight less than 10 kg. Cardiac surgery was most commonly used for arterial switch operation. In-hospital mortality was reported in 13 studies; pooled analysis showed no association between prophylactic PD catheter placement and in-hospital mortality. There were mixed results for ICU length of stay and time to negative fluid balance, with some studies showing shortened duration associated with use of prophylactic PD catheter insertion and others showing no difference. Overall, the studies had high risk for bias, mainly due to small sample size and lack of generalizability.

CONCLUSIONS

In this meta-analysis, we have failed to demonstrate an association between prophylactic PD catheter insertion in children and infants undergoing cardiac surgery and reduced in-hospital mortality. Other relevant short-term outcomes, including markers of fluid overload, require further study.

Regional Practice Variation and Outcomes in the Standard Versus Accelerated Initiation of Renal Replacement Therapy in Acute Kidney Injury (STARRT-AKI) Trial: A Post Hoc Secondary Analysis

OBJECTIVES

Among patients with severe acute kidney injury (AKI) admitted to the ICU in high-income countries, regional practice variations for fluid balance (FB) management, timing, and choice of renal replacement therapy (RRT) modality may be significant.

DESIGN

Secondary post hoc analysis of the STandard vs. Accelerated initiation of Renal Replacement Therapy in Acute Kidney Injury (STARRT-AKI) trial (ClinicalTrials.gov number NCT02568722).

SETTING

One hundred-fifty-three ICUs in 13 countries.

PATIENTS

Altogether 2693 critically ill patients with AKI, of whom 994 were North American, 1143 European, and 556 from Australia and New Zealand (ANZ).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Total mean FB to a maximum of 14 days was +7199 mL in North America, +5641 mL in Europe, and +2211 mL in ANZ (p < 0.001). The median time to RRT initiation among patients allocated to the standard strategy was longest in Europe compared with North America and ANZ (p < 0.001; p < 0.001). Continuous RRT was the initial RRT modality in 60.8% of patients in North America and 56.8% of patients in Europe, compared with 96.4% of patients in ANZ (p < 0.001). After adjustment for predefined baseline characteristics, compared with North American and European patients, those in ANZ were more likely to survive to ICU (p < 0.001) and hospital discharge (p < 0.001) and to 90 days (for ANZ vs. Europe: risk difference [RD], -11.3%; 95% CI, -17.7% to -4.8%; p < 0.001 and for ANZ vs. North America: RD, -10.3%; 95% CI, -17.5% to -3.1%; p = 0.007).

CONCLUSIONS

Among STARRT-AKI trial centers, significant regional practice variation exists regarding FB, timing of initiation of RRT, and initial use of continuous RRT. After adjustment, such practice variation was associated with lower ICU and hospital stay and 90-day mortality among ANZ patients compared with other regions.

Designing acute kidney injury clinical trials

Acute kidney injury (AKI) is a common clinical condition with various causes and is associated with increased mortality. Despite advances in supportive care, AKI increases not only the risk of premature death compared with the general population but also the risk of developing chronic kidney disease and progressing towards kidney failure. Currently, no specific therapy exists for preventing or treating AKI other than mitigating further injury and supportive care. To address this unmet need, novel therapeutic interventions targeting the underlying pathophysiology must be developed. New and well-designed clinical trials with appropriate end points must be subsequently designed and implemented to test the efficacy of such new interventions. Herein, we discuss predictive and prognostic enrichment strategies for patient selection, as well as primary and secondary end points that can be used in different clinical trial designs (specifically, prevention and treatment trials) to evaluate novel interventions and improve the outcomes of patients at a high risk of AKI or with established AKI.

The trajectory of very old critically ill patients

The demographic shift, together with financial constraint, justify a re-evaluation of the trajectory of care of very old critically ill patients (VIP), defined as older than 80 years. We must avoid over- as well as under-utilisation of critical care interventions in this patient group and ensure the inclusion of health care professionals, the patient and their caregivers in the decision process. This new integrative approach mobilises expertise at each step of the process beginning prior to intensive care unit (ICU) admission and extending to long-term follow-up. In this review, several international experts have contributed to provide recommendations that can be universally applied. Our aim is to define a minimum core dataset of information to be shared and discussed prior to ICU admission and to facilitate the shared-decision-making process with the patient and their caregivers, throughout the patient journey. Documentation of uncertainty may contribute to a tailored level of care and ultimately to discussions around possible limitations of life sustaining treatments. The goal of ICU care is not only to avoid death, but more importantly to maintain an acceptable quality of life and functional autonomy after hospital discharge. Societal consideration is important to highlight, together with alternatives to ICU admission. We discuss challenges for the future and potential areas of research. In summary, this review provides a state-of-the-art current overview and aims to outline future directions to address the challenges in the treatment of VIP.

Determinants of fluid use and the association between volume of fluid used and effect of balanced solutions on mortality in critically ill patients: a secondary analysis of the BaSICS trial

PURPOSE

Fluid use could modulate the effect of balanced solutions (BS) on outcome of intensive care unit (ICU) patients. It is uncertain whether fluid use practices are driven more by patient features or local practices. It is also unclear whether a "dose-response" for the potential benefits of balanced solutions exists.

METHODS

The secondary analysis of the Balanced Solution in Intensive Care Study (BaSICS) compared 0.9% saline versus Plasma-Lyte 148® (BS) for fluid therapy in the ICU. The relative contribution of patient features and enrolling site (the random effect) on the volume of fluid used up to day 3 after admission was assessed using different methods, including a Bayesian regression, a frequentist mixed model, and a random forest, all adjusted for relevant patient confounders. Subsequently, a variety of methods were used to assess whether volume of fluid used modulated the effect of BS on 90-day mortality, including a traditional subgroup analysis for patients that remained alive and in the ICU up to 3 days, a Bayesian network accounting for competing risks, and an analysis based on site practices.

RESULTS

10,505 patients were analyzed. Median fluid use in the BS arm and in the 0.9% saline arm were 2500 mL and 2488 mL, respectively. The random effect in the Bayesian regression explained 0.32 (95% credible intervals (CrI) 0.24-0.41) of all model variance (0.33, 95% credible intervals from 0.32-0.35). Frequentist and random forest models produced similar results. In the analysis including only patients alive and in the ICU at 3 days, there was a strong suggestion of interaction between fluid use and the effect of BS, driven mostly by a lower mortality with BS compared to 0.9% saline as fluid use increased for patients with sepsis. These results were consistent in the Bayesian network analysis and in an analysis based on site practices, where septic patients enrolled to BS at high fluid use sites had a lower mortality (absolute risk reduction of - 0.13 [95% credible interval - 0.27 to - 0.01]; 0.98 probability of benefit).

CONCLUSION

Baseline patient characteristics collected in the BaSICS trial explain less of the variance of fluid use during the first 3 days than the enrolling site. Volume of fluid used and the effects of BS appear to interact, mostly in the sepsis subgroup where there was a strong association between fluid use after enrollment and the effect of BS on 90-day mortality.

Designing a Behaviour Change Wheel guided implementation strategy for a hypoxaemic respiratory failure and ARDS care pathway that targets barriers

BACKGROUND

A significant gap exists between ideal evidence-based practice and real-world application of evidence-informed therapies for patients with hypoxaemic respiratory failure (HRF) and acute respiratory distress syndrome (ARDS). Pathways can improve the quality of care provided by helping integrate and organise the use of evidence informed practices, but barriers exist that can influence their adoption and successful implementation. We sought to identify barriers to the implementation of a best practice care pathway for HRF and ARDS and design an implementation science-based strategy targeting these barriers that is tailored to the critical care setting.

METHODS

The intervention assessed was a previously described multidisciplinary, evidence-based, stakeholder-informed, integrated care pathway for HRF and ARDS. A survey questionnaire (12 open text questions) was administered to intensive care unit (ICU) clinicians (physicians, nurses, respiratory therapists) in 17 adult ICUs across Alberta. The Behaviour Change Wheel, capability, opportunity, motivation - behaviour components, and Theoretical Domains Framework (TDF) were used to perform qualitative analysis on open text responses to identify barriers to the use of the pathway. Behaviour change technique (BCT) taxonomy, and Affordability, Practicality, Effectiveness and cost-effectiveness, Acceptability, Side effects and safety and Equity (APEASE) criteria were used to design an implementation science-based strategy specific to the critical care context.

RESULTS

Survey responses (692) resulted in 16 belief statements and 9 themes with 9 relevant TDF domains. Differences in responses between clinician professional group and hospital setting were common. Based on intervention functions linked to each belief statement and its relevant TDF domain, 26 candidate BCTs were identified and evaluated using APEASE criteria. 23 BCTs were selected and grouped to form 8 key components of a final strategy: Audit and feedback, education, training, clinical decision support, site champions, reminders, implementation support and empowerment. The final strategy was described using the template for intervention description and replication framework.

CONCLUSIONS

Barriers to a best practice care pathway were identified and were amenable to the design of an implementation science-based mitigation strategy. Future work will evaluate the ability of this strategy to improve quality of care by assessing clinician behaviour change via better adherence to evidence-based care.

Key performance indicators in extracorporeal membrane oxygenation (ECMO): protocol for a systematic review

INTRODUCTION

Extracorporeal membrane oxygenation (ECMO) is an intervention used in critically ill patients with severe cardiopulmonary failure that is expensive and resource intensive and requires specialised care. There remains a significant practice variation in its application. This systematic review will assess the evidence for key performance indicators (KPIs) in ECMO.

METHODS AND ANALYSIS

We will search Ovid MEDLINE, Ovid EMBASE, Cumulative Index to Nursing and Allied Health Literature and the Cochrane Library including the Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials and databases from the National Information Center of Health Services Research and Health Care Technology, for studies involving KPIs in ECMO. We will rate methodological quality using the Newcastle-Ottawa Quality Assessment Scale. Randomized controlled trials (RCTs) will be evaluated with the Cochrane Risk of Bias tool, and qualitative studies will be evaluated using the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN checklist). Grey literature sources will be searched for technical reports, practice guidelines and conference proceedings. We will identify relevant organisations, industry leaders and non-profit organisations that represent key opinion leads in the use of ECMO. We will search the Agency of Healthcare Research and Quality National Quality Measures Clearinghouse for ECMO-related KPIs. Studies will be included if they contain quality measures that occur in critically ill patients and are associated with ECMO. The analysis will be primarily descriptive. Each KPI will be evaluated for importance, scientific acceptability, utility and feasibility using the four criteria proposed by the US Strategic Framework Board for a National Quality Measurement and Reporting System. Finally, KPIs will be evaluated for their potential operational characteristics, their potential to be integrated into electronic medical records and their affordability, if applicable.

ETHICS AND DISSEMINATION

Ethical approval is not required as no primary data will be collected. Findings will be published in a peer-reviewed journal and presented at academic.

PROSPERO REGISTRATION NUMBER

9 August 2022. CRD42022349910.

Critical illness among patients experiencing homelessness: a retrospective cohort study

PURPOSE

To understand the epidemiology and healthcare use of critically ill patients experiencing homelessness compared to critically ill patients with stable housing.

METHODS

This retrospective population-based cohort study included adults admitted to any ICU in Alberta, Canada, for a 3-year period. Administrative and clinical data from the hospital, ICU and emergency department were used to examine healthcare resource use (processes of care, ICU and hospital length of stay, hospital readmission and emergency room visits). Regression was used to quantify differences in healthcare use by housing status.

RESULTS

2.3% (n = 1086) of patients admitted to the ICU were experiencing homelessness; these patients were younger, more commonly admitted for medical reasons and had fewer comorbidities compared to those with stable housing. Processes of care in the ICU were mostly similar, but healthcare use after ICU was different; patients experiencing homelessness who survived their index hospitalization were more than twice as likely to have a visit to the emergency department (OR = 2.3 times, 95% CI 2.0-2.6, < 0.001) or be readmitted to hospital (OR = 2.1, 95% CI 1.8-2.4, p < 0.001) within 30 days, and stayed 10.1 days longer in hospital (95% CI 8.6-11.6, p < 0.001), compared with those who have stable housing.

CONCLUSIONS

Patients experiencing homelessness have different characteristics at ICU admission and have similar processes of care in ICU, but their subsequent use of healthcare resources was higher than patients with stable housing. These findings can inform strategies to prepare patients experiencing homelessness for discharge from the ICU to reduce healthcare resource use after critical illness.

A Systematic Bibliometric Analysis of High-Impact Articles in Critical Care Nephrology

INTRODUCTION

Critical care nephrology is a subspecialty that merges critical care and nephrology in response to shared pathobiology, clinical care, and technological innovations. To date, there has been no description of the highest impact articles. Accordingly, we systematically identified high impact articles in critical care nephrology.

METHODS

This was a bibliometric analysis. The search was developed by a research librarian. Web of Science was searched for articles published between January 1, 2000 and December 31, 2020. Articles required a minimum of 30 citations, publication in English language, and reporting of primary (or secondary) original data. Articles were screened by two reviewers for eligibility and further adjudicated by three experts. The "Top 100" articles were hierarchically ranked by adjudication, citations in the 2 years following publication and journal impact factor (IF). For each article, we extracted detailed bibliometric data. Risk of bias was assessed for randomized trials by the Cochrane Risk of Bias tool. Analyses were descriptive.

RESULTS

The search yielded 2,805 articles. Following initial screening, 307 articles were selected for full review and adjudication. The Top 100 articles were published across 20 journals (median [IQR] IF 10.6 [8.9-56.3]), 38% were published in the 5 years ending in 2020 and 62% were open access. The agreement between adjudicators was excellent (intraclass correlation, 0.96; 95% CI, 0.84-0.99). Of the Top 100, 44% were randomized trials, 35% were observational, 14% were systematic reviews, 6% were nonrandomized interventional studies and one article was a consensus document. The risk of bias among randomized trials was low. Common subgroup themes were RRT (42%), AKI (30%), fluids/resuscitation (14%), pediatrics (10%), interventions (8%), and perioperative care (6%). The citations for the Top 100 articles were 175 (95-393) and 9 were cited >1,000 times.

CONCLUSION

Critical care nephrology has matured as an important subspecialty of critical care and nephrology. These high impact papers have focused largely on original studies, mostly clinical trials, within a few core themes. This list can be leveraged for curricula development, to stimulate research, and for quality assurance.

Myocardial Injury After Noncardiac Surgery in Major General Surgical Patients a Prospective Observational Cohort Study

OBJECTIVE

The objective of this study was to determine the prognostic relevance, clinical characteristics, and 30-day outcomes associated with myocardial injury after noncardiac surgery (MINS) in major general surgery patients.

BACKGROUND

MINS has been independently associated with 30-day mortality after noncardiac surgery. The characteristics and prognostic importance of MINS in major general surgical patients have not been described.

METHODS

This was an international prospective cohort study of a representative sample of 22,552 noncardiac surgery patients 45 years or older, of whom 4490 underwent major general surgery in 24 centers in 13 countries. All patients had fifth-generation plasma high-sensitivity troponin T (hsTnT) concentrations measured during the first 3 postoperative days. MINS was defined as a hsTnT of 20-65 ng/L and absolute change >5 ng/L or hsTnT ≥65 ng/L secondary to ischemia. The objectives of the present study were to determine (1) whether MINS is prognostically important in major general surgical patients, (2) the clinical characteristics of major general surgical patients with and without MINS, (3) the 30-day outcomes for major general surgical patients with and without MINS, and (4) the proportion of MINS that would have gone undetected without routine postoperative monitoring.

RESULTS

The incidence of MINS in the major general surgical patients was 16.3% (95% CI, 15.3-17.4%). Thirty-day all-cause mortality in the major general surgical cohort was 6.8% (95% CI, 5.1%-8.9%) in patients with MINS compared with 1.2% (95% CI, 0.9%-1.6%) in patients without MINS ( P <0.01). MINS was independently associated with 30-day mortality in major general surgical patients (adjusted odds ratio 4.7, 95% CI, 3.0-7.4). The 30-day mortality was higher both among MINS patients with no ischemic features (ie, no ischemic symptoms or electrocardiogram findings) (5.4%, 95% CI, 3.7%-7.7%) and among patients with 1 or more clinical ischemic features (10.6%, 95% CI, 6.7%-15.8%). The proportion of major general surgical patients who had MINS without ischemic symptoms was 89.9% (95% CI, 87.5-92.0).

CONCLUSIONS

Approximately 1 in 6 patients experienced MINS after major general surgery. MINS was independently associated with a nearly 5-fold increase in 30-day mortality. The vast majority of patients with MINS were asymptomatic and would have gone undetected without routine postoperative troponin measurement.

Digital health and acute kidney injury: consensus report of the 27th Acute Disease Quality Initiative workgroup

Acute kidney injury (AKI), which is a common complication of acute illnesses, affects the health of individuals in community, acute care and post-acute care settings. Although the recognition, prevention and management of AKI has advanced over the past decades, its incidence and related morbidity, mortality and health care burden remain overwhelming. The rapid growth of digital technologies has provided a new platform to improve patient care, and reports show demonstrable benefits in care processes and, in some instances, in patient outcomes. However, despite great progress, the potential benefits of using digital technology to manage AKI has not yet been fully explored or implemented in clinical practice. Digital health studies in AKI have shown variable evidence of benefits, and the digital divide means that access to digital technologies is not equitable. Upstream research and development costs, limited stakeholder participation and acceptance, and poor scalability of digital health solutions have hindered their widespread implementation and use. Here, we provide recommendations from the Acute Disease Quality Initiative consensus meeting, which involved experts in adult and paediatric nephrology, critical care, pharmacy and data science, at which the use of digital health for risk prediction, prevention, identification and management of AKI and its consequences was discussed.

Letter: Exploring the clinical utility of ammonia in critically ill patients with cirrhosis: More to do? Authors' reply

This article is linked to Cardoso et al papers. To view these articles, visit https://doi.org/10.1111/apt.17650 and https://doi.org/10.1111/apt.17698

Initiation of continuous renal replacement therapy versus intermittent hemodialysis in critically ill patients with severe acute kidney injury: a secondary analysis of STARRT-AKI trial

BACKGROUND

There is controversy regarding the optimal renal-replacement therapy (RRT) modality for critically ill patients with acute kidney injury (AKI).

METHODS

We conducted a secondary analysis of the STandard versus Accelerated Renal Replacement Therapy in Acute Kidney Injury (STARRT-AKI) trial to compare outcomes among patients who initiated RRT with either continuous renal replacement therapy (CRRT) or intermittent hemodialysis (IHD). We generated a propensity score for the likelihood of receiving CRRT and used inverse probability of treatment with overlap-weighting to address baseline inter-group differences. The primary outcome was a composite of death or RRT dependence at 90-days after randomization.

RESULTS

We identified 1590 trial participants who initially received CRRT and 606 who initially received IHD. The composite outcome of death or RRT dependence at 90-days occurred in 823 (51.8%) patients who commenced CRRT and 329 (54.3%) patients who commenced IHD (unadjusted odds ratio (OR) 0.90; 95% confidence interval (CI) 0.75-1.09). After balancing baseline characteristics with overlap weighting, initial receipt of CRRT was associated with a lower risk of death or RRT dependence at 90-days compared with initial receipt of IHD (OR 0.81; 95% CI 0.66-0.99). This association was predominantly driven by a lower risk of RRT dependence at 90-days (OR 0.61; 95% CI 0.39-0.94).

CONCLUSIONS

In critically ill patients with severe AKI, initiation of CRRT, as compared to IHD, was associated with a significant reduction in the composite outcome of death or RRT dependence at 90-days.

Overnight staffing in Canadian neonatal and pediatric intensive care units

Aim

Infants and children who require specialized medical attention are admitted to neonatal and pediatric intensive care units (ICUs) for continuous and closely supervised care. Overnight in-house physician coverage is frequently considered the ideal staffing model. It remains unclear how often this is achieved in both pediatric and neonatal ICUs in Canada. The aim of this study is to describe overnight in-house physician staffing in Canadian pediatric and level-3 neonatal ICUs (NICUs) in the pre-COVID-19 era.

Methods

A national cross-sectional survey was conducted in 34 NICUs and 19 pediatric ICUs (PICUs). ICU directors or their delegates completed a 29-question survey describing overnight staffing by resident physicians, fellow physicians, nurse practitioners, and attending physicians. A comparative analysis was conducted between ICUs with and without in-house physicians.

Results

We obtained responses from all 34 NICUs and 19 PICUs included in this study. A total of 44 ICUs (83%) with in-house overnight physician coverage provided advanced technologies, such as extracorporeal life support, and included all ICUs that catered to patients with cardiac, transplant, or trauma conditions. Residents provided the majority of overnight coverage, followed by the Critical Care Medicine fellows. An attending physician was in-house overnight in eight (15%) out of the 53 ICUs, seven of which were NICUs. Residents participating in rotations in the ICU would often have rotation durations of less than 6 weeks and were often responsible for providing care during shifts lasting 20-24 h.

Conclusion

Most PICUs and level-3 NICUs in Canada have a dedicated in-house physician overnight. These physicians are mainly residents or fellows, but a notable variation exists in this arrangement. The potential effects on patient outcomes, resident learning, and physician satisfaction remain unclear and warrant further investigation.

Early serum ammonia variation in critically ill patients with cirrhosis: A multicentre cohort study

BACKGROUND

Serum ammonia variation in critically ill patients with cirrhosis has been poorly studied.

AIM

To describe and assess the impact of serum ammonia variation in these patients' outcomes.

METHODS

We studied patients ≥18 years old admitted to the intensive care units (ICUs) at University of Alberta Hospital (Edmonton, Canada) and Curry Cabral Hospital (Lisbon, Portugal; derivation cohort, n = 492) and Northwestern University Hospital (Chicago, USA; validation cohort, n = 600) between January 2010 and December 2021. Primary exposure was ICU days 1-3 serum ammonia. Primary endpoint was all-cause hospital mortality.

RESULTS

In the derivation cohort, 330 (67.1%) patients were male and median (IQR) age was 57 (50-63) years. On ICU day 1, median ammonia was higher in patients with grade 3/4 hepatic encephalopathy (HE) than those with grade 2 HE or grade 0/1 HE (112 vs. 88 vs. 77 μmoL/L, respectively; p < 0.001). Furthermore, medium ammonia was higher in hospital non-survivors than survivors (99 vs. 86 μmol/L; p < 0.030). Following adjustment for significant confounders (age, HE, vasopressor use and renal replacement therapy delivery), higher ICU day 2 ammonia was independently associated with higher hospital mortality (adjusted OR per each 10 μmoL/L increment [95% CI] = 1.11 [1.01-1.21]; p = 0.024). In the validation cohort, this model with serial ammonia (ICU days 1 and 3) predicted hospital mortality with reasonably good discrimination (c-statistic = 0.73) and calibration (R2  = 0.19 and Brier score = 0.17).

CONCLUSIONS

Among patients with cirrhosis in the ICU, early serum ammonia variation was independently associated with hospital mortality. In this context, serial serum ammonia may have prognostic value.

Precision management of acute kidney injury in the intensive care unit: current state of the art

Acute kidney injury (AKI) is a prototypical example of a common syndrome in critical illness defined by consensus. The consensus definition for AKI, traditionally defined using only serum creatinine and urine output, was needed to standardize the description for epidemiology and to harmonize eligibility for clinical trials. However, AKI is not a simple disease, but rather a complex and multi-factorial syndrome characterized by a wide spectrum of pathobiology. AKI is now recognized to be comprised of numerous sub-phenotypes that can be discriminated through shared features such as etiology, prognosis, or common pathobiological mechanisms of injury and damage. The characterization of sub-phenotypes can serve to enable prognostic enrichment (i.e., identify subsets of patients more likely to share an outcome of interest) and predictive enrichment (identify subsets of patients more likely to respond favorably to a given therapy). Existing and emerging biomarkers will aid in discriminating sub-phenotypes of AKI, facilitate expansion of diagnostic criteria, and be leveraged to realize personalized approaches to management, particularly for recognizing treatment-responsive mechanisms (i.e., endotypes) and targets for intervention (i.e., treatable traits). Specific biomarkers (e.g., serum renin; olfactomedin 4 (OLFM4); interleukin (IL)-9) may further enable identification of pathobiological mechanisms to serve as treatment targets. However, even non-specific biomarkers of kidney injury (e.g., neutrophil gelatinase-associated lipocalin, NGAL; [tissue inhibitor of metalloproteinases 2, TIMP2]·[insulin like growth factor binding protein 7, IGFBP7]; kidney injury molecule 1, KIM-1) can direct greater precision management for specific sub-phenotypes of AKI. This review will summarize these evolving concepts and recent innovations in precision medicine approaches to the syndrome of AKI in critical illness, along with providing examples of how they can be leveraged to guide patient care.

A population-based assessment of avoidable hospitalizations and resource use of non-vaccinated patients with COVID-19

OBJECTIVE

The coronavirus disease 2019 (COVID-19) pandemic has precipitated a prolonged public health crisis. Numerous public health protections were widely implemented. The availability of effective and safe vaccines for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) presented an opportunity to resolve this crisis; however, vaccine uptake was slow and inconsistent. This study evaluated the potential for preventable hospitalizations and avoidable resource use among eligible non-vaccinated persons hospitalized for COVID-19 had these persons been vaccinated.

METHODS

This was a retrospective, population-based cohort study. The population-at-risk were persons aged ≥ 12 years in Alberta (mid-year 2021 population ~ 4.4 million). The primary exposure was vaccination status. The primary outcome was hospitalization with confirmed SARS-CoV-2, and secondary outcomes included avoidable hospitalizations, avoidable hospital bed-days, and the potential cost avoidance related to COVID-19. The study inception period was 27 September 2021 to 25 January 2022. Data on COVID-19 hospitalizations, vaccination status, health services, and costs were obtained from the Government of Alberta and from the Discharge Abstract Database.

RESULTS

Hospitalizations occurred in 3835, 1907, and 481 persons who were non-vaccinated, fully vaccinated, and boosted (risk of hospitalization/100,000 population: 886, 92, and 43), respectively. For non-vaccinated persons compared with fully vaccinated and boosted persons, the risk ratios (95%CI) of hospitalization were 9.7 (7.9-11.8) and 20.6 (17.9-23.6), respectively. For non-vaccinated persons, estimates of avoidable hospitalizations and bed-days used were 3439 and 36,331 if fully vaccinated and 3764 and 40,185 if boosted. Estimates of cost avoidance for non-vaccinated persons were $101.46 million if fully vaccinated and $110.24 million if boosted.

CONCLUSION

Eligible non-vaccinated persons with COVID-19 had tenfold and 21-fold higher risks of hospitalization relative to whether they had been fully vaccinated or boosted, resulting in considerable avoidable hospital bed-days and costs.

Intrapulmonary and Intracardiac Shunts in Adult COVID-19 Versus Non-COVID Acute Respiratory Distress Syndrome ICU Patients Using Echocardiography and Contrast Bubble Studies (COVID-Shunt Study): A Prospective, Observational Cohort Study

OBJECTIVES

Studies have suggested intrapulmonary shunts may contribute to hypoxemia in COVID-19 acute respiratory distress syndrome (ARDS) with worse associated outcomes. We evaluated the presence of right-to-left (R-L) shunts in COVID-19 and non-COVID ARDS patients using a comprehensive hypoxemia workup for shunt etiology and associations with mortality.

DESIGN

Prospective, observational cohort study.

SETTING

Four tertiary hospitals in Edmonton, Alberta, Canada.

PATIENTS

Adult critically ill, mechanically ventilated, ICU patients admitted with COVID-19 or non-COVID (November 16, 2020, to September 1, 2021).

INTERVENTIONS

Agitated-saline bubble studies with transthoracic echocardiography/transcranial Doppler ± transesophageal echocardiography assessed for R-L shunts presence.

MEASUREMENTS AND MAIN RESULTS

Primary outcomes were shunt frequency and association with hospital mortality. Logistic regression analysis was used for adjustment. The study enrolled 226 patients (182 COVID-19 vs 42 non-COVID). Median age was 58 years (interquartile range [IQR], 47-67 yr) and Acute Physiology and Chronic Health Evaluation II scores of 30 (IQR, 21-36). In COVID-19 patients, the frequency of R-L shunt was 31 of 182 COVID patients (17.0%) versus 10 of 44 non-COVID patients (22.7%), with no difference detected in shunt rates (risk difference [RD], -5.7%; 95% CI, -18.4 to 7.0; p = 0.38). In the COVID-19 group, hospital mortality was higher for those with R-L shunt compared with those without (54.8% vs 35.8%; RD, 19.0%; 95% CI, 0.1-37.9; p = 0.05). This did not persist at 90-day mortality nor after adjustment with regression.

CONCLUSIONS

There was no evidence of increased R-L shunt rates in COVID-19 compared with non-COVID controls. R-L shunt was associated with increased in-hospital mortality for COVID-19 patients, but this did not persist at 90-day mortality or after adjusting using logistic regression.

Follow-up Care of Critically Ill Patients With Acute Kidney Injury: A Cohort Study

Rationale & Objective

To evaluate follow-up care of critically ill patients with acute kidney injury (AKI).

Study Design

Retrospective cohort study.

Setting & Participants

Patients admitted to the intensive care unit (ICU) with AKI in Alberta, Canada from 2005 to 2018, who survived to discharge without kidney replacement therapy or estimated glomerular filtration rate <15 mL/min/1.73 m2.

Exposure

AKI (defined as ≥50% or ≥0.3 mg/dL serum creatinine increase).

Outcomes

The primary outcome was the cumulative incidence of an outpatient serum creatinine and urine protein measurement at 3 months postdischarge. Secondary outcomes included an outpatient serum creatinine or urine protein measurement or a nephrologist visit at 3 months postdischarge.

Analytical Approach

Patients were followed from hospital discharge until the first of each outcome of interest, death, emigration from the province, kidney replacement therapy (maintenance dialysis or kidney transplantation), or end of study period (March 2019). We used non-parametric methods (Aalen-Johansen) to estimate the cumulative incidence functions of outcomes accounting for competing events (death and kidney replacement therapy).

Results

There were 29,732 critically ill adult patients with AKI. The median age was 68 years (IQR, 57-77), 39% were female, and the median baseline estimated glomerular filtration rate was 72 mL/min/1.73 m2 (IQR, 53-90). The cumulative incidence of having an outpatient creatinine and urine protein measurement at 3 months postdischarge was 25% (95% CI, 25-26). At 3 months postdischarge, 64% (95% CI, 64-65) had an outpatient creatinine measurement, 28% (95% CI, 27-28) had a urine protein measurement, and 5% (95% CI, 4-5) had a nephrologist visit.

Limitations

We lacked granular data, such as urine output.

Conclusions

Many critically ill patients with AKI do not receive the recommended follow-up care. Our findings highlight a gap in the transition of care for survivors of critical illness and AKI.

Methods for determination of optimal positive end-expiratory pressure: a protocol for a scoping review

INTRODUCTION

Titrated application of positive end-expiratory pressure (PEEP) is an important part of any mechanical ventilation strategy. However, the method by which the optimal PEEP is determined and titrated varies widely. Methods for determining optimal PEEP have been assessed using a variety of different study designs and patient populations. We will conduct a scoping review to systematically identify all methods for determining optimal PEEP, and to identify the patient populations, outcomes measured and study designs used for each method. The goal will be to identify gaps in the optimal PEEP literature and identify areas where there may be an opportunity to further systematically synthesise and meta-analyse existing literature.

METHODS AND ANALYSIS

Using scoping review methodology, we will generate a comprehensive search strategy based on inclusion and exclusion criteria generated using the population, concept, context framework. Five different databases will be searched (MEDLINE, EMBASE, CENTRAL, Web of Science and Scopus). Three investigators will independently screen titles and abstracts, and two investigators will independently complete full-text review and data extraction. Included citations will be categorised in terms of PEEP method, study design, patient population and outcomes measured. The methods for PEEP titration will be described in detail, including strengths and limitations.

ETHICS AND DISSEMINATION

Given this is a synthesis of existing literature, ethics approval is not required. The results will be disseminated to stakeholders via presentation at local, regional and national levels, as well as publication in a high-impact critical care journal. There is also the potential to impact local clinical care protocols and inform broader clinical practice guidelines undertaken by societies.

Incidence and outcomes of critical illness in indigenous peoples: a systematic review and meta-analysis

BACKGROUND

Indigenous Peoples experience health inequities and racism across the continuum of health services. We performed a systematic review and meta-analysis of the incidence and outcomes of critical illness among Indigenous Peoples.

METHODS

We searched Ovid MEDLINE/PubMed, Ovid EMBASE, Google Scholar, and Cochrane Central Register of Controlled Trials (inception to October 2022). Observational studies, case series of > 100 patients, clinical trial arms, and grey literature reports of Indigenous adults were eligible. We assessed risk of bias using the Newcastle-Ottawa Scale and appraised research quality from an Indigenous perspective using the Aboriginal and Torres Strait Islander Quality Assessment Tool. ICU mortality, ICU length of stay, and invasive mechanical ventilation (IMV) were compared using risk ratios and mean difference (MD) for dichotomous and continuous outcomes, respectively. ICU admission was synthesized descriptively.

RESULTS

Fifteen studies (Australia and/or New Zealand [n = 12] and Canada [n = 3]) were included. Risk of bias was low in 10 studies and moderate in 5, and included studies had minimal incorporation of Indigenous perspectives or consultation. There was no difference in ICU mortality between Indigenous and non-Indigenous (RR 1.14, 95%CI 0.98 to 1.34, I2 = 87%). We observed a shorter ICU length of stay among Indigenous (MD - 0.25; 95%CI, - 0.49 to - 0.00; I2 = 95%) and a higher use for IMV among non-Indigenous (RR 1.10; 95%CI, 1.06 to 1.15; I2 = 81%).

CONCLUSION

Research on Indigenous Peoples experience with critical care is poorly characterized and has rarely included Indigenous perspectives. ICU mortality between Indigenous and non-Indigenous populations was similar, while there was a shorter ICU length of stay and less mechanical ventilation use among Indigenous patients. Systematic Review Registration PROSPERO CRD42021254661; Registered: 12 June, 2021.

Systemic Nonsteroidal Anti-Inflammatories for Analgesia in Postoperative Critical Care Patients: A Systematic Review and Meta-Analysis of Randomized Control Trials

While opioids are part of usual care for analgesia in the ICU, there are concerns regarding excess use. This is a systematic review of nonsteroidal anti-inflammatory drugs (NSAIDs) use in postoperative critical care adult patients.

DATA SOURCES

We searched Medical Literature Analysis and Retrieval System Online, Excerpta Medica database, Cumulative Index to Nursing and Allied Health Literature, Cochrane Library, trial registries, Google Scholar, and relevant systematic reviews through March 2023.

STUDY SELECTION

Titles, abstracts, and full texts were reviewed independently and induplicate by two investigators to identify eligible studies. We included randomized control trials (RCTs) that compared NSAIDs alone or as an adjunct to opioids for systemic analgesia. The primary outcome was opioid utilization.

DATA EXTRACTION

In duplicate, investigators independently extracted study characteristics, patient demographics, intervention details, and outcomes of interest using predefined abstraction forms. Statistical analyses were conducted using Review Manager software Version 5.4. (The Cochrane Collaboration, Copenhagen, Denmark).

DATA SYNTHESIS

We included 15 RCTs (n = 1,621 patients) for admission to the ICU for postoperative management after elective procedures. Adjunctive NSAID therapy to opioids reduced 24-hour oral morphine equivalent consumption by 21.4 mg (95% CI, 11.8-31.0 mg reduction; high certainty) and probably reduced pain scores (measured by Visual Analog Scale) by 6.1 mm (95% CI, 12.2 decrease to 0.1 increase; moderate certainty). Adjunctive NSAID therapy probably had no impact on the duration of mechanical ventilation (1.6 hr reduction; 95% CI, 0.4 hr to 2.7 reduction; moderate certainty) and may have no impact on ICU length of stay (2.1 hr reduction; 95% CI, 6.1 hr reduction to 2.0 hr increase; low certainty). Variability in reporting adverse outcomes (e.g., gastrointestinal bleeding, acute kidney injury) precluded their meta-analysis.

CONCLUSIONS

In postoperative critical care adult patients, systemic NSAIDs reduced opioid use and probably reduced pain scores. However, the evidence is uncertain for the duration of mechanical ventilation or ICU length of stay. Further research is required to characterize the prevalence of NSAID-related adverse outcomes.

Antimicrobial stewardship, procalcitonin testing, and rapid blood-culture identification to optimize sepsis care in critically ill adult patients: A quality improvement initiative

We examined the effect of an antimicrobial stewardship program (ASP), procalcitonin testing and rapid blood-culture identification on hospital mortality in a prospective quality improvement project in critically ill septic adults. Secondarily, we have reported antimicrobial guideline concordance, acceptance of ASP interventions, and antimicrobial and health-resource utilization.

Fluid Therapy for Critically Ill Adults With Sepsis: A Review

Importance

Approximately 20% to 30% of patients admitted to an intensive care unit have sepsis. While fluid therapy typically begins in the emergency department, intravenous fluids in the intensive care unit are an essential component of therapy for sepsis.

Observations

For patients with sepsis, intravenous fluid can increase cardiac output and blood pressure, maintain or increase intravascular fluid volume, and deliver medications. Fluid therapy can be conceptualized as 4 overlapping phases from early illness through resolution of sepsis: resuscitation (rapid fluid administered to restore perfusion); optimization (the risks and benefits of additional fluids to treat shock and ensure organ perfusion are evaluated); stabilization (fluid therapy is used only when there is a signal of fluid responsiveness); and evacuation (excess fluid accumulated during treatment of critical illness is eliminated). Among 3723 patients with sepsis who received 1 to 2 L of fluid, 3 randomized clinical trials (RCTs) reported that goal-directed therapy administering fluid boluses to attain a central venous pressure of 8 to 12 mm Hg, vasopressors to attain a mean arterial blood pressure of 65 to 90 mm Hg, and red blood cell transfusions or inotropes to attain a central venous oxygen saturation of at least 70% did not decrease mortality compared with unstructured clinical care (24.9% vs 25.4%; P = .68). Among 1563 patients with sepsis and hypotension who received 1 L of fluid, an RCT reported that favoring vasopressor treatment did not improve mortality compared with further fluid administration (14.0% vs 14.9%; P = .61). Another RCT reported that among 1554 patients in the intensive care unit with septic shock treated with at least 1 L of fluid compared with more liberal fluid administration, restricting fluid administration in the absence of severe hypoperfusion did not reduce mortality (42.3% vs 42.1%; P = .96). An RCT of 1000 patients with acute respiratory distress during the evacuation phase reported that limiting fluid administration and administering diuretics improved the number of days alive without mechanical ventilation compared with fluid treatment to attain higher intracardiac pressure (14.6 vs 12.1 days; P < .001), and it reported that hydroxyethyl starch significantly increased the incidence of kidney replacement therapy compared with saline (7.0% vs 5.8%; P = .04), Ringer lactate, or Ringer acetate.

Conclusions and Relevance

Fluids are an important component of treating patients who are critically ill with sepsis. Although optimal fluid management in patients with sepsis remains uncertain, clinicians should consider the risks and benefits of fluid administration in each phase of critical illness, avoid use of hydroxyethyl starch, and facilitate fluid removal for patients recovering from acute respiratory distress syndrome.

Fluid Management for Critically Ill Patients with Acute Kidney Injury Receiving Kidney Replacement Therapy: An International Survey

BACKGROUND

In critically ill patients receiving KRT, high ultrafiltration rates and persistent fluid accumulation are associated with adverse outcomes. The purpose of this international survey was to evaluate current practices and evidence gaps related to fluid removal with KRT in critically ill patients.

METHODS

This was a multinational, web-based survey distributed by seven networks comprising nephrologists and intensivists. Physicians involved in the care of critically ill patients were invited to complete a 39-question survey about fluid management practices on KRT. The survey was distributed from September 2021 to December 2021.

RESULTS

There were 757 respondents from 96 countries (response rate of 65%). Most respondents practiced adult medicine (89%) and worked in an academic center (69%). The majority (91%) reported aiming for a 0.5- to 2-L negative fluid balance per day when fluid removal is indicated, although there was important variability in what respondents considered a safe maximal target. Intensivists were more likely than nephrologists to use adjunct volume status assessment methods ( i.e. , ultrasound, hemodynamic markers, and intra-abdominal pressure), while nephrologists were more likely to deploy cointerventions aimed at improving tolerance to fluid removal ( i.e. , osmotic agents and low-temperature dialysate). There was a broad consensus that rapid decongestion should be prioritized when fluid accumulation is present, but the prevention of hypotension was also reported as a competing priority. A majority (77%) agreed that performing trials that compare fluid management strategies would be ethical and clinically relevant.

CONCLUSIONS

We have identified multiple areas of variability in current practice of fluid management for patients receiving KRT. Most nephrologists and intensivists agreed that several knowledge gaps related to fluid removal strategies should be investigated in future randomized controlled trials.

Epidemiology and Outcomes of AKI Treated With Continuous Kidney Replacement Therapy: The Multicenter CRRTnet Study

Rationale & Objective

Continuous kidney replacement therapy (CKRT) is the predominant form of acute kidney replacement therapy used for critically ill adult patients with acute kidney injury (AKI). Given the variability in CKRT practice, a contemporary understanding of its epidemiology is necessary to improve care delivery.

Study Design

Multicenter, prospective living registry.

Setting & Population

1,106 critically ill adults with AKI requiring CKRT from December 2013 to January 2021 across 5 academic centers and 6 intensive care units. Patients with pre-existing kidney failure and those with coronavirus 2 infection were excluded.

Exposure

CKRT for more than 24 hours.

Outcomes

Hospital mortality, kidney recovery, and health care resource utilization.

Analytical Approach

Data were collected according to preselected timepoints at intensive care unit admission and CKRT initiation and analyzed descriptively.

Results

Patients' characteristics, contributors to AKI, and CKRT indications differed among centers. Mean (standard deviation) age was 59.3 (13.9) years, 39.7% of patients were women, and median [IQR] APACHE-II (acute physiologic assessment and chronic health evaluation) score was 30 [25-34]. Overall, 41.1% of patients survived to hospital discharge. Patients that died were older (mean age 61 vs. 56.8, P < 0.001), had greater comorbidity (median Charlson score 3 [1-4] vs. 2 [1-3], P < 0.001), and higher acuity of illness (median APACHE-II score 30 [25-35] vs. 29 [24-33], P = 0.003). The most common condition predisposing to AKI was sepsis (42.6%), and the most common CKRT indications were oliguria/anuria (56.2%) and fluid overload (53.9%). Standardized mortality ratios were similar among centers.

Limitations

The generalizability of these results to CKRT practices in nonacademic centers or low-and middle-income countries is limited.

Conclusions

In this registry, sepsis was the major contributor to AKI and fluid management was collectively the most common CKRT indication. Significant heterogeneity in patient- and CKRT-specific characteristics was found in current practice. These data highlight the need for establishing benchmarks of CKRT delivery, performance, and patient outcomes. Data from this registry could assist with the design of such studies.

Protocol and statistical analysis plan for the mega randomised registry trial comparing conservative vs. liberal oxygenation targets in adults with sepsis in the intensive care unit (Mega-ROX Sepsis)

Background

The effect of conservative vs. liberal oxygen therapy on 90-day in-hospital mortality in adults with sepsis receiving unplanned invasive mechanical ventilation in the intensive care unit (ICU) is uncertain.

Objective

The objective of this study was to summarise the protocol and statistical analysis plan for the Mega-ROX Sepsis trial.

Design setting and participants

The Mega-ROX Sepsis trial is an international randomised clinical trial that will be conducted within an overarching 40,000-patient registry-embedded clinical trial comparing conservative and liberal ICU oxygen therapy regimens. We anticipate that between 10,000 and 13,000 patients with sepsis who are receiving unplanned invasive mechanical ventilation in the ICU will be enrolled in this trial.

Main outcome measures

The primary outcome is in-hospital all-cause mortality up to 90 days from the date of randomisation. Secondary outcomes include duration of survival, duration of mechanical ventilation, ICU length of stay, hospital length of stay, and the proportion of patients discharged home.

Results and conclusions

Mega-ROX Sepsis will compare the effect of conservative vs. liberal oxygen therapy on 90-day in-hospital mortality in adults with sepsis who are receiving unplanned invasive mechanical ventilation in the ICU. The protocol and a prespecified approach to analyses are reported here to mitigate analysis bias.

The Clinical Frailty Scale for mortality prediction of old acutely admitted intensive care patients: a meta-analysis of individual patient-level data

BACKGROUND

This large-scale analysis pools individual data about the Clinical Frailty Scale (CFS) to predict outcome in the intensive care unit (ICU).

METHODS

A systematic search identified all clinical trials that used the CFS in the ICU (PubMed searched until 24th June 2020). All patients who were electively admitted were excluded. The primary outcome was ICU mortality. Regression models were estimated on the complete data set, and for missing data, multiple imputations were utilised. Cox models were adjusted for age, sex, and illness acuity score (SOFA, SAPS II or APACHE II).

RESULTS

12 studies from 30 countries with anonymised individualised patient data were included (n = 23,989 patients). In the univariate analysis for all patients, being frail (CFS ≥ 5) was associated with an increased risk of ICU mortality, but not after adjustment. In older patients (≥ 65 years) there was an independent association with ICU mortality both in the complete case analysis (HR 1.34 (95% CI 1.25-1.44), p < 0.0001) and in the multiple imputation analysis (HR 1.35 (95% CI 1.26-1.45), p < 0.0001, adjusted for SOFA). In older patients, being vulnerable (CFS 4) alone did not significantly differ from being frail. After adjustment, a CFS of 4-5, 6, and ≥ 7 was associated with a significantly worse outcome compared to CFS of 1-3.

CONCLUSIONS

Being frail is associated with a significantly increased risk for ICU mortality in older patients, while being vulnerable alone did not significantly differ. New Frailty categories might reflect its "continuum" better and predict ICU outcome more accurately.

TRIAL REGISTRATION

Open Science Framework (OSF: https://osf.io/8buwk/ ).

Protocol and statistical analysis plan for the mega randomised registry trial comparing conservative vs. liberal oxygenation targets in adults with nonhypoxic ischaemic acute brain injuries and conditions in the intensive care unit (Mega-ROX Brains)

Background

The effect of conservative vs. liberal oxygen therapy on 90-day in-hospital mortality in adults who have nonhypoxic ischaemic encephalopathy acute brain injuries and conditions and are receiving invasive mechanical ventilation in the intensive care unit (ICU) is uncertain.

Objective

The objective of this study was to summarise the protocol and statistical analysis plan for the Mega-ROX Brains trial.

Design setting and participants

Mega-ROX Brains is an international randomised clinical trial, which will be conducted within an overarching 40,000-participant, registry-embedded clinical trial comparing conservative and liberal ICU oxygen therapy regimens. We expect to enrol between 7500 and 9500 participants with nonhypoxic ischaemic encephalopathy acute brain injuries and conditions who are receiving unplanned invasive mechanical ventilation in the ICU.

Main outcome measures

The primary outcome is in-hospital all-cause mortality up to 90 d from the date of randomisation. Secondary outcomes include duration of survival, duration of mechanical ventilation, ICU length of stay, hospital length of stay, and the proportion of participants discharged home.

Results and conclusions

Mega-ROX Brains will compare the effect of conservative vs. liberal oxygen therapy regimens on 90-day in-hospital mortality in adults in the ICU with acute brain injuries and conditions. The protocol and planned analyses are reported here to mitigate analysis bias.

Trial Registration

Australian and New Zealand Clinical Trials Registry (ACTRN 12620000391976).

Indications for and Timing of Initiation of KRT

KRT is considered for patients with severe AKI and associated complications. The exact indications for initiating KRT have been debated for decades. There is a general consensus that KRT should be considered in patients with AKI and medically refractory complications ("urgent indications"). "Relative indications" are more common but defined with less precision. In this review, we summarize the latest evidence from recent landmark clinical trials, discuss strategies to anticipate the need for KRT in individual patients, and propose an algorithm for decision making. We emphasize that the decision to consider KRT should be made in conjunction with other forms of organ support therapies and important nonkidney factors, including the patient's preferences and overall goals of care. We also suggest future research to differentiate patients who benefit from timely initiation of KRT from those with imminent recovery of kidney function. Until then, efforts are needed to optimize the initiation and delivery of KRT in routine clinical practice, to minimize nonessential variation, and to ensure that patients with persistent AKI or progressive organ failure affected by AKI receive KRT in a timely manner.