Simvastatin in Critically Ill Patients with Covid-19.

BACKGROUND: The efficacy of simvastatin in critically ill patients with coronavirus disease 2019 (Covid-19) is unclear. METHODS: In an ongoing international, multifactorial, adaptive platform, randomized, controlled trial, we evaluated simvastatin (80 mg daily) as compared with no statin (control) in critically ill patients with Covid-19 who were not receiving statins at baseline. The primary outcome was respiratory and cardiovascular organ support-free days, assessed on an ordinal scale combining in-hospital death (assigned a value of -1) and days free of organ support through day 21 in survivors; the analyis used a Bayesian hierarchical ordinal model. The adaptive design included prespecified statistical stopping criteria for superiority (>99% posterior probability that the odds ratio was >1) and futility (>95% posterior probability that the odds ratio was <1.2). RESULTS: Enrollment began on October 28, 2020. On January 8, 2023, enrollment was closed on the basis of a low anticipated likelihood that prespecified stopping criteria would be met as Covid-19 cases decreased. The final analysis included 2684 critically ill patients. The median number of organ support-free days was 11 (interquartile range, -1 to 17) in the simvastatin group and 7 (interquartile range, -1 to 16) in the control group; the posterior median adjusted odds ratio was 1.15 (95% credible interval, 0.98 to 1.34) for simvastatin as compared with control, yielding a 95.9% posterior probability of superiority. At 90 days, the hazard ratio for survival was 1.12 (95% credible interval, 0.95 to 1.32), yielding a 91.9% posterior probability of superiority of simvastatin. The results of secondary analyses were consistent with those of the primary analysis. Serious adverse events, such as elevated levels of liver enzymes and creatine kinase, were reported more frequently with simvastatin than with control. CONCLUSIONS: Although recruitment was stopped because cases had decreased, among critically ill patients with Covid-19, simvastatin did not meet the prespecified criteria for superiority to control. (REMAP-CAP ClinicalTrials.gov number, NCT02735707.).

Oxygenation During Venoarterial Extracorporeal Membrane Oxygenation: Physiology, Current Evidence, and a Pragmatic Approach to Oxygen Titration.

OBJECTIVES: This review aims to: 1) identify the key circuit and patient factors affecting systemic oxygenation, 2) summarize the literature reporting the association between hyperoxia and patient outcomes, and 3) provide a pragmatic approach to oxygen titration, in patients undergoing peripheral venoarterial extracorporeal membrane oxygenation (ECMO). DATA SOURCES: Searches were performed using PubMed, SCOPUS, Medline, and Google Scholar. STUDY SELECTION: All observational and interventional studies investigating the association between hyperoxia, and clinical outcomes were included, as well as guidelines from the Extracorporeal Life Support Organization. DATA EXTRACTION: Data from relevant literature was extracted, summarized, and integrated into a concise narrative review. For ease of reference a summary of relevant studies was also produced. DATA SYNTHESIS: The extracorporeal circuit and the native cardiorespiratory circuit both contribute to systemic oxygenation during venoarterial ECMO. The ECMO circuit's contribution to systemic oxygenation is, in practice, largely determined by the ECMO blood flow, whereas the native component of systemic oxygenation derives from native cardiac output and residual respiratory function. Interactions between ECMO outflow and native cardiac output (as in differential hypoxia), the presence of respiratory support, and physiologic parameters affecting blood oxygen carriage also modulate overall oxygen exposure during venoarterial ECMO. Physiologically those requiring venoarterial ECMO are prone to hyperoxia. Hyperoxia has a variety of definitions, most commonly Pa o2 greater than 150 mm Hg. Severe hypoxia (Pa o2 > 300 mm Hg) is common, seen in 20%. Early severe hyperoxia, as well as cumulative hyperoxia exposure was associated with in-hospital mortality, even after adjustment for disease severity in both venoarterial ECMO and extracorporeal cardiopulmonary resuscitation. A pragmatic approach to oxygenation during peripheral venoarterial ECMO involves targeting a right radial oxygen saturation target of 94-98%, and in selected patients, titration of the fraction of oxygen in the mixture via the air-oxygen blender to target postoxygenator Pa o2 of 150-300 mm Hg. CONCLUSIONS: Hyperoxia results from a range of ECMO circuit and patient-related factors. It is common during peripheral venoarterial ECMO, and its presence is associated with poor outcome. A pragmatic approach that avoids hyperoxia, while also preventing hypoxia has been described for patients receiving peripheral venoarterial ECMO.

Extracorporeal cardiopulmonary resuscitation for refractory cardiac arrest in Australia: a narrative review.

Extracorporeal cardiopulmonary resuscitation (ECPR) in patients with prolonged or refractory out-of-hospital cardiac arrest (OHCA) is likely to be beneficial when used as part of a well developed emergency service system. ECPR is technically challenging to initiate and resource-intensive, but it has been found to be cost-effective in hospital-based ECPR programs. ECPR expansion within Australia has thus far been reactive and does not provide broad coverage or equity of access for patients. Newer delivery strategies that improve access to ECPR for patients with OHCA are being trialled, including networked hospital-based ECPR and pre-hospital ECPR programs. The efficacy, scalability, sustainability and cost-effectiveness of these programs need to be assessed. There is a need for national collaboration to determine the most cost-effective delivery strategies for ECPR provision along with its place in the OHCA survival chain.

Beta-blockade for the treatment of refractory hypoxaemia during venovenous extracorporeal membrane oxygenation: An in-silico study.

INTRODUCTION: Venovenous extracorporeal membrane oxygenation (VV ECMO) is used for refractory hypoxemia, although despite this, in high cardiac output states, hypoxaemia may persist. The administration of beta-blockers has been suggested as an approach in this scenario, however the physiological consequences of this intervention are not clear. METHODS: We performed an in-silico study using a previously described mathematical model to evaluate the effect of beta-blockade on mixed venous and arterial saturations (Sv¯O2, SaO2), in three different clinical scenarios and considered the potential effects of beta-blockers on, cardiac output, oxygen consumption and recirculation. Additionally we assessed the interaction of beta-blockade with haemoglobin concentration. RESULTS: In scenario 1: simulating a patient with high cardiac output and partial lung shunt Sv¯O2 decreased from increased 53.5% to 44.7% despite SaO2 rising from 74.2% to 79.2%. In scenario 2 simulating a patient with high cardiac output and complete lung shunt Sv¯O2 remained unchanged at 52.2% and SaO2 rose from 71.9% to 85%. In scenario 3 a patient with normal cardiac output and high recirculation Sv¯O2 fell from 50.8% to 25.5% and also fell from 82.4% to to 78.3%. Across the remaining modelling examples the effect on Sv¯O2 varied but oxygen delivery was consistently reduced across all scenarios. CONCLUSION: The administration of beta-blockers for refractory hypoxemia during VV ECMO are unpredictable and may reduce oxygen delivery, although this will vary with patient and circuit features. This study does not support the use of beta-blockers for this indication.

Flow capabilities of arterial and drainage cannulae during venoarterial extracorporeal membrane oxygenation: A simulation model.

BACKGROUND: Large cannulae can increase cannula-related complications during venoarterial extracorporeal membrane oxygenation (VA ECMO). Conversely, the ability for small cannulae to provide adequate support is poorly understood. Therefore, we aimed to evaluate a range of cannula sizes and VA ECMO flow rates in a simulated patient under various disease states. METHODS: Arterial cannulae sizes between 13 and 21 Fr and drainage cannula sizes between 21 and 25 Fr were tested in a VA ECMO circuit connected to a mock circulation loop simulating a patient with severe left ventricular failure. Systemic and pulmonary hypertension, physiologically normal, and hypotension were simulated by varying systemic and pulmonary vascular resistances (SVR and PVR, respectively). All cannula combinations were evaluated against all combinations of SVR, PVR, and VA ECMO flow rates. RESULTS: A 15 Fr arterial cannula combined with a 21 Fr drainage cannula could provide >4 L/min of total flow and a mean arterial pressure of 81.1 mmHg. Changes in SVR produced marked changes to all measured parameters, while changes to PVR had minimal effect. Larger drainage cannulae only increased maximum circuit flow rates when combined with larger arterial cannulae. CONCLUSION: Smaller cannulae and lower flow rates could sufficiently support the simulated patient under various disease states. We found arterial cannula size and SVR to be key factors in determining the flow-delivering capabilities for any given VA ECMO circuit. Overall, our results challenge the notion that larger cannulae and high flows must be used to achieve adequate ECMO support.

Cardiogenic Shock Challenges and Priorities: A Clinician Survey.

BACKGROUND: Cardiogenic shock (CS) is common and survival outcomes have not substantially improved. Australia's geography presents unique challenges in the management of CS. The challenges and research priorities for clinicians pertaining to CS identification and management have yet to be described. METHOD: We used an exploratory sequential mixed methods design. Semi-structured interviews were conducted with 10 clinicians (medical and nursing) to identify themes for quantitative evaluation. A total of 143 clinicians undertook quantitative evaluation through online survey. The interviews and surveys addressed current understanding of CS, status of cardiogenic systems and future research priorities. RESULTS: There were 143 respondents: 16 (11%) emergency, cardiology 22 (16%), 37 (26%) intensive care, 54 (38%) nursing. In total, 107 (75%) believe CS is under-recognised. Thirteen (13; 9%) of respondents indicated their hospital had existing CS teams, all from metropolitan hospitals, and 40% thought additional access to mechanical circulatory support devices was required. Five (5; 11%) non-tertiary hospital respondents had not experienced a delay in transfer of a patient in CS. All respondents felt additional research, particularly into the management of CS, was required. CONCLUSIONS: Clinicians report that CS is under-recognised and further research into CS management is required. Access to specialised CS services is still an issue and CS protocolised pathways may be of value.

Observed differences in nutrition management at two time points spanning a decade in critically ill trauma patients with and without head injury.

BACKGROUND: Nutritional needs of trauma patients admitted to the intensive care unit may differ from general critically ill patients, but most current evidence is based on large clinical trials recruiting mixed populations. OBJECTIVE: The aim of the study was to investigate nutrition practices at two time points that span a decade in trauma patients with and without head injury. METHODS: This observational study recruited adult trauma patients receiving mechanical ventilation and artificial nutrition from a single-centre intensive care unit between February 2005 to December 2006 (cohort 1), and December 2018 to September 2020 (cohort 2). Patients were categorised into head injury and non-head injury subgroups. Data regarding energy and protein prescription and delivery were collected. Data are presented as median [interquartile range]. Wilcoxon rank-sum test assessed the differences between cohorts and subgroups, with a P value ≤ 0.05. The protocol was registered with the Australian and New Zealand Clinical Trials Registry (Trial ID: ACTRN12618001816246). RESULTS: Cohort 1 included 109 patients, and 112 patients were included in cohort 2 (age: 46 ± 19 vs 50 ± 19 y; 80 vs 79% M). Overall, nutrition practice did not differ between head-injured and non-head-injured subgroups (all P > 0.05). Energy prescription and delivery decreased from time point one to time point two, regardless of subgroup (Prescription: 9824 [8820-10 581] vs 8318 [7694-9071] kJ; Delivery: 6138 [5130-7188] vs 4715 [3059-5996] kJ; all P < 0.05). Protein prescription did not change from time point one to time point two. Although protein delivery remained constant from time point one to time point two in the head injury group, protein delivery reduced in the non-head injury subgroup (70 [56-82] vs 45 [26-64] g/d, P < 0.05). CONCLUSION: In this single-centre study, energy prescription and delivery in critically ill trauma patients reduced from time point one to time point two. Protein prescription did not change, but protein delivery reduced from time point one to time point two in non-head injury patients. Reasons for these differing trajectories require exploration. STUDY REGISTRATION: Trial registered at www.anzctr.org.au. TRIAL ID: ACTRN12618001816246.

Nutrition delivery across hospitalisation in critically ill patients with COVID-19: An observational study of the Australian experience.

BACKGROUND: Data on nutrition delivery over the whole hospital admission in critically ill patients with COVID-19 are scarce, particularly in the Australian setting. OBJECTIVES: The objective of this study was to describe nutrition delivery in critically ill patients admitted to Australian intensive care units (ICUs) with coronavirus disease 2019 (COVID-19), with a focus on post-ICU nutrition practices. METHODS: A multicentre observational study conducted at nine sites included adult patients with a positive COVID-19 diagnosis admitted to the ICU for >24 h and discharged to an acute ward over a 12-month recruitment period from 1 March 2020. Data were extracted on baseline characteristics and clinical outcomes. Nutrition practice data from the ICU and weekly in the post-ICU ward (up to week four) included route of feeding, presence of nutrition-impacting symptoms, and nutrition support received. RESULTS: A total of 103 patients were included (71% male, age: 58 ± 14 years, body mass index: 30±7 kg/m2), of whom 41.7% (n = 43) received mechanical ventilation within 14 days of ICU admission. While oral nutrition was received by more patients at any time point in the ICU (n = 93, 91.2% of patients) than enteral nutrition (EN) (n = 43, 42.2%) or parenteral nutrition (PN) (n = 2, 2.0%), EN was delivered for a greater duration of time (69.6% feeding days) than oral and PN (29.7% and 0.7%, respectively). More patients received oral intake than the other modes in the post-ICU ward (n = 95, 95.0%), and 40.0% (n = 38/95) of patients were receiving oral nutrition supplements. In the week after ICU discharge, 51.0% of patients (n = 51) had at least one nutrition-impacting symptom, most commonly a reduced appetite (n = 25; 24.5%) or dysphagia (n = 16; 15.7%). CONCLUSION: Critically ill patients during the COVID-19 pandemic in Australia were more likely to receive oral nutrition than artificial nutrition support at any time point both in the ICU and in the post-ICU ward, whereas EN was provided for a greater duration when it was prescribed. Nutrition-impacting symptoms were common.

Current and future strategies to monitor and manage coagulation in ECMO patients.

Extracorporeal membrane oxygenation (ECMO) can provide life-saving support for critically ill patients suffering severe respiratory and/or cardiac failure. However, thrombosis and bleeding remain common and complex problems to manage. Key causes of thrombosis in ECMO patients include blood contact to pro-thrombotic and non-physiological surfaces, as well as high shearing forces in the pump and membrane oxygenator. On the other hand, adverse effects of anticoagulant, thrombocytopenia, platelet dysfunction, acquired von Willebrand syndrome, and hyperfibrinolysis are all established as causes of bleeding. Finding safe and effective anticoagulants that balance thrombosis and bleeding risk remains challenging. This review highlights commonly used anticoagulants in ECMO, including their mechanism of action, monitoring methods, strengths and limitations. It further elaborates on existing anticoagulant monitoring strategies, indicating their target range, benefits and drawbacks. Finally, it introduces several highly novel approaches to real-time anticoagulation monitoring methods including sound, optical, fluorescent, and electrical measurement as well as their working principles and future directions for research.

Inter-hospital transfer and clinical outcomes for people with COVID-19 admitted to intensive care units in Australia: an observational cohort study.

OBJECTIVES: To examine the association between inter-hospital transfer and in-hospital mortality among people with coronavirus disease 2019 (COVID-19) admitted to intensive care units (ICUs) in Australia. DESIGN: Retrospective cohort study; analysis of data collected for the Short Period Incidence Study of Severe Acute Respiratory Illness (SPRINT-SARI) Australia study. SETTING, PARTICIPANTS: People with COVID-19 admitted to 63 ICUs, 1 January 2020 - 1 April 2022. MAIN OUTCOME MEASURES: Primary outcome: in-hospital mortality; secondary outcomes: ICU and hospital lengths of stay and frequency of selected complications. RESULTS: Of 5207 people with records in the SPRINT-SARI Australia database at 1 April 2022, 328 (6.3%) had been transferred between hospitals, 305 (93%) during the third pandemic wave. Compared with patients not transferred, their median age was lower (53 years; interquartile range [IQR], 45-61 years v 60 years; IQR, 46-70 years), their median body mass index higher (32.5 [IQR, 27.2-39.0] kg/m2 v 30.1 [IQR, 25.7-35.7] kg/m2 ), and fewer had received a COVID-19 vaccine (22% v 44.9%); their median APACHE II scores were similar (14.0; IQR, 12.0-18.0 v 14.0; IQR, 10.0-19.0). Bacterial pneumonia (64.7% v 29.0%) and bacteraemia (27% v 8%) were more frequent in transferred patients, as was the need for more intensive ICU interventions, including invasive mechanical ventilation (71.2% v 38.1%) and extra-corporeal membrane oxygenation (26% v 1.7%). Crude ICU (19% v 14.9%) and in-hospital mortality (19% v 18.4%) were similar for patients who were or were not transferred; median lengths of ICU (20.0 [IQR, 11.2-40.3] days v 4.6 [IQR, 2.1-10.1] days) and hospital stay (29.7 [IQR, 18.1-49.6] days v 12.3 [IQR, 7.3-21.0] days) were longer for transferred patients. In the multivariable regression analysis, in-hospital mortality risk was lower for transferred patients (risk difference [RD], -5.0 percentage points; 95% confidence interval [CI] -10 to -0.03 percentage points), but not in the propensity score-adjusted analysis (RD, -3.4 [95% CI, -8.9 to 2.1] percentage points). CONCLUSIONS: Among people with COVID-19 admitted to ICUs, patients transferred from another hospital required more intense interventions and remained in hospital longer, but were not at greater risk of dying in hospital than the patients who were not transferred.

Extracorporeal membrane oxygenation for critically ill adults.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) may provide benefit in certain populations of adults, including those with severe cardiac failure, severe respiratory failure, and cardiac arrest. However, it is also associated with serious short- and long-term complications, and there remains a lack of high-quality evidence to guide practice. Recently several large randomized controlled trials (RCTs) have been published, therefore, we undertook an update of our previous systematic review published in 2014. OBJECTIVES: To evaluate whether venovenous (VV), venoarterial (VA), or ECMO cardiopulmonary resuscitation (ECPR) improve mortality compared to conventional cardiopulmonary support in critically ill adults. SEARCH METHODS: We used standard, extensive Cochrane search methods. The latest search date was March 2022. The search was limited to English language only. SELECTION CRITERIA: We included RCTs, quasi-RCTs, and cluster-RCTs that compared VV ECMO, VA ECMO or ECPR to conventional support in critically ill adults. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcome was 1. all-cause mortality at day 90 to one year. Our secondary outcomes were 2. length of hospital stay, 3. survival to discharge, 4. disability, 5. adverse outcomes/safety events, 6. health-related quality of life, 7. longer-term health status, and 8. cost-effectiveness. We used GRADE to assess certainty of evidence. MAIN RESULTS: Five RCTs met our inclusion criteria, with four new studies being added to the original review (total 757 participants). Two studies were of VV ECMO (429 participants), one VA ECMO (41 participants), and two ECPR (285 participants). Four RCTs had a low risk of bias and one was unclear, and the overall certainty of the results (GRADE score) was moderate, reduced primarily due to indirectness of the study populations and interventions. ECMO was associated with a reduction in 90-day to one-year mortality compared to conventional treatment (risk ratio [RR] 0.80, 95% confidence interval [CI] 0.70 to 0.92; P = 0.002, I2 = 11%). This finding remained stable after performing a sensitivity analysis by removing the single trial with an uncertain risk of bias. Subgroup analyses did not reveal a significant subgroup effect across VV, VA, or ECPR modes (P = 0.73). Four studies reported an increased risk of major hemorrhage with ECMO (RR 3.32, 95% CI 1.90 to 5.82; P < 0.001), while two studies reported no difference in favorable neurologic outcome (RR 2.83, 95% CI 0.36 to 22.42; P = 0.32). Other secondary outcomes were not consistently reported across the studies. AUTHORS' CONCLUSIONS: In this updated systematic review, which included four additional RCTs, we found that ECMO was associated with a reduction in day-90 to one-year all-cause mortality, as well as three times increased risk of bleeding. However, the certainty of this result was only low to moderate, limited by a low number of small trials, clinical heterogeneity, and indirectness across studies.

Comparison of 6-Month Outcomes of Survivors of COVID-19 versus Non-COVID-19 Critical Illness.

Rationale: The outcomes of survivors of critical illness due to coronavirus disease (COVID-19) compared with non-COVID-19 are yet to be established. Objectives: We aimed to investigate new disability at 6 months in mechanically ventilated patients admitted to Australian ICUs with COVID-19 compared with non-COVID-19. Methods: We included critically ill patients with COVID-19 and non-COVID-19 from two prospective observational studies. Patients were eligible if they were adult (age ⩾ 8 yr) and received ⩾24 hours of mechanical ventilation. In addition, patients with COVID-19 were eligible with a positive laboratory PCR test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Measurements and Main Results: Demographic, intervention, and hospital outcome data were obtained from electronic medical records. Survivors were contacted by telephone for functional outcomes with trained outcome assessors using the World Health Organization Disability Assessment Schedule 2.0. Between March 6, 2020, and April 21, 2021, 120 critically ill patients with COVID-19, and between August 2017 and January 2019, 199 critically ill patients without COVID-19, fulfilled the inclusion criteria. Patients with COVID-19 were older (median [interquartile range], 62 [55-71] vs. 58 [44-69] yr; P = 0.019) with a lower Acute Physiology and Chronic Health Evaluation II score (17 [13-20] vs. 19 [15-23]; P = 0.011). Although duration of ventilation was longer in patients with COVID-19 than in those without COVID-19 (12 [5-19] vs. 4.8 [2.3-8.8] d; P < 0.001), 180-day mortality was similar between the groups (39/120 [32.5%] vs. 70/199 [35.2%]; P = 0.715). The incidence of death or new disability at 180 days was similar (58/93 [62.4%] vs. 99/150 [66/0%]; P = 0.583). Conclusions: At 6 months, there was no difference in new disability for patients requiring mechanical ventilation for acute respiratory failure due to COVID-19 compared with non-COVID-19. Clinical trial registered with www.clinicaltrials.gov (NCT04401254).

Clinical characteristics and outcomes of critically ill patients with one, two and three doses of vaccination against COVID-19 in Australia.

BACKGROUND: Vaccination has been shown to be highly effective in preventing death and severe disease from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Currently, few studies have directly compared vaccinated and unvaccinated patients with severe COVID-19 in the intensive care unit (ICU). AIMS: To compare the clinical characteristics and outcomes of vaccine recipients and unvaccinated patients with SARS-CoV-2 infection admitted to the ICU in a nationwide setting. METHODS: Data were extracted from the Short PeRiod IncideNce sTudy of Severe Acute Respiratory Infection Australia, in 57 ICU during Delta and Omicron predominant periods of the COVID-19 pandemic. The primary outcome was inhospital mortality. Secondary outcomes included duration of mechanical ventilation, ICU length of stay, hospital length of stay and ICU mortality. RESULTS: There were 2970 patients admitted to ICU across participating sites from 26 June 2021 to 8 February 2022; 1134 (38.2%) patients were vaccine recipients, and 1836 (61.8%) patients were unvaccinated. Vaccine recipients were older, more comorbid and less likely to require organ support. Unadjusted inhospital mortality was greater in the vaccinated cohort. After adjusting for age, gender and comorbid status, no statistically significant association between inhospital or ICU mortality, and vaccination status, was apparent. CONCLUSION: We found COVID-19 infection can cause severe disease and death in vaccine recipients, though comorbid status and older age were significant contributors to mortality. Organ support requirements and the number of deaths were highest in the unvaccinated cohort.

Prehospital Extracorporeal Cardiopulmonary Resuscitation for Out-of-Hospital Cardiac Arrest: A Systematic Review and Meta-Analysis.

OBJECTIVES: To evaluate the available published evidence of the effects of extracorporeal cardiopulmonary resuscitation (ECPR) in the prehospital setting on clinical outcomes in patients with out-of-hospital cardiac arrest. DESIGN: A systematic review and meta-analysis designed according to the Preferred Reporting Items for Systematic Reviews an Meta-Analyses guidelines. SETTING: In the prehospital setting. PARTICIPANTS: All randomized control trials (RCTs) and observational trials using pre-hospital ECPR in adult patients (>17 years). INTERVENTIONS: Prehospital ECPR. MEASUREMENTS AND MAIN RESULTS: The study authors searched Medline, Embase, and PUBMED for all RCTs and observational trials. The studies were assessed for clinical, methodologic, and statistical heterogeneity. The primary outcome was survival at hospital discharge. The study outcomes were aggregated using random-effects meta-analysis of means or proportions as appropriate. The Grading of Recommendations Assessment, Development and Evaluation methodology was used to assess the quality of evidence. Four studies were included, with a total of 222 patients receiving prehospital ECPR (mean age = 51 years [95% CI 44-57], 81% of patients were male (CI 74-87), and 60% patients had a cardiac cause for their arrest (95% CI 43-76). Overall survival at discharge was 23.4% (95% CI 15.5-33.7; I2 = 62%). The pooled low-flow time was 61.1 minutes (95% CI 45.2-77.0; I2 = 97%). The quality of evidence was assessed to be low, and the overall risk of bias was assessed to be serious, with confounding being the primary source of bias. CONCLUSION: No definitive conclusions can be made as to the efficacy of prehospital ECPR in refractory cardiac arrest. Higher quality evidence is required.

Long-term (180-Day) Outcomes in Critically Ill Patients With COVID-19 in the REMAP-CAP Randomized Clinical Trial.

Importance: The longer-term effects of therapies for the treatment of critically ill patients with COVID-19 are unknown. Objective: To determine the effect of multiple interventions for critically ill adults with COVID-19 on longer-term outcomes. Design, Setting, and Participants: Prespecified secondary analysis of an ongoing adaptive platform trial (REMAP-CAP) testing interventions within multiple therapeutic domains in which 4869 critically ill adult patients with COVID-19 were enrolled between March 9, 2020, and June 22, 2021, from 197 sites in 14 countries. The final 180-day follow-up was completed on March 2, 2022. Interventions: Patients were randomized to receive 1 or more interventions within 6 treatment domains: immune modulators (n = 2274), convalescent plasma (n = 2011), antiplatelet therapy (n = 1557), anticoagulation (n = 1033), antivirals (n = 726), and corticosteroids (n = 401). Main Outcomes and Measures: The main outcome was survival through day 180, analyzed using a bayesian piecewise exponential model. A hazard ratio (HR) less than 1 represented improved survival (superiority), while an HR greater than 1 represented worsened survival (harm); futility was represented by a relative improvement less than 20% in outcome, shown by an HR greater than 0.83. Results: Among 4869 randomized patients (mean age, 59.3 years; 1537 [32.1%] women), 4107 (84.3%) had known vital status and 2590 (63.1%) were alive at day 180. IL-6 receptor antagonists had a greater than 99.9% probability of improving 6-month survival (adjusted HR, 0.74 [95% credible interval {CrI}, 0.61-0.90]) and antiplatelet agents had a 95% probability of improving 6-month survival (adjusted HR, 0.85 [95% CrI, 0.71-1.03]) compared with the control, while the probability of trial-defined statistical futility (HR >0.83) was high for therapeutic anticoagulation (99.9%; HR, 1.13 [95% CrI, 0.93-1.42]), convalescent plasma (99.2%; HR, 0.99 [95% CrI, 0.86-1.14]), and lopinavir-ritonavir (96.6%; HR, 1.06 [95% CrI, 0.82-1.38]) and the probabilities of harm from hydroxychloroquine (96.9%; HR, 1.51 [95% CrI, 0.98-2.29]) and the combination of lopinavir-ritonavir and hydroxychloroquine (96.8%; HR, 1.61 [95% CrI, 0.97-2.67]) were high. The corticosteroid domain was stopped early prior to reaching a predefined statistical trigger; there was a 57.1% to 61.6% probability of improving 6-month survival across varying hydrocortisone dosing strategies. Conclusions and Relevance: Among critically ill patients with COVID-19 randomized to receive 1 or more therapeutic interventions, treatment with an IL-6 receptor antagonist had a greater than 99.9% probability of improved 180-day mortality compared with patients randomized to the control, and treatment with an antiplatelet had a 95.0% probability of improved 180-day mortality compared with patients randomized to the control. Overall, when considered with previously reported short-term results, the findings indicate that initial in-hospital treatment effects were consistent for most therapies through 6 months.

Effect of Angiotensin-Converting Enzyme Inhibitor and Angiotensin Receptor Blocker Initiation on Organ Support-Free Days in Patients Hospitalized With COVID-19: A Randomized Clinical Trial.

IMPORTANCE: Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective: To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS: In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non-critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS: Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES: The primary outcome was organ support-free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS: On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support-free days among critically ill patients was 10 (-1 to 16) in the ACE inhibitor group (n = 231), 8 (-1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support-free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE: In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02735707.

Intravenous Vitamin C for Patients Hospitalized With COVID-19: Two Harmonized Randomized Clinical Trials.

Importance: The efficacy of vitamin C for hospitalized patients with COVID-19 is uncertain. Objective: To determine whether vitamin C improves outcomes for patients with COVID-19. Design, Setting, and Participants: Two prospectively harmonized randomized clinical trials enrolled critically ill patients receiving organ support in intensive care units (90 sites) and patients who were not critically ill (40 sites) between July 23, 2020, and July 15, 2022, on 4 continents. Interventions: Patients were randomized to receive vitamin C administered intravenously or control (placebo or no vitamin C) every 6 hours for 96 hours (maximum of 16 doses). Main Outcomes and Measures: The primary outcome was a composite of organ support-free days defined as days alive and free of respiratory and cardiovascular organ support in the intensive care unit up to day 21 and survival to hospital discharge. Values ranged from -1 organ support-free days for patients experiencing in-hospital death to 22 organ support-free days for those who survived without needing organ support. The primary analysis used a bayesian cumulative logistic model. An odds ratio (OR) greater than 1 represented efficacy (improved survival, more organ support-free days, or both), an OR less than 1 represented harm, and an OR less than 1.2 represented futility. Results: Enrollment was terminated after statistical triggers for harm and futility were met. The trials had primary outcome data for 1568 critically ill patients (1037 in the vitamin C group and 531 in the control group; median age, 60 years [IQR, 50-70 years]; 35.9% were female) and 1022 patients who were not critically ill (456 in the vitamin C group and 566 in the control group; median age, 62 years [IQR, 51-72 years]; 39.6% were female). Among critically ill patients, the median number of organ support-free days was 7 (IQR, -1 to 17 days) for the vitamin C group vs 10 (IQR, -1 to 17 days) for the control group (adjusted proportional OR, 0.88 [95% credible interval {CrI}, 0.73 to 1.06]) and the posterior probabilities were 8.6% (efficacy), 91.4% (harm), and 99.9% (futility). Among patients who were not critically ill, the median number of organ support-free days was 22 (IQR, 18 to 22 days) for the vitamin C group vs 22 (IQR, 21 to 22 days) for the control group (adjusted proportional OR, 0.80 [95% CrI, 0.60 to 1.01]) and the posterior probabilities were 2.9% (efficacy), 97.1% (harm), and greater than 99.9% (futility). Among critically ill patients, survival to hospital discharge was 61.9% (642/1037) for the vitamin C group vs 64.6% (343/531) for the control group (adjusted OR, 0.92 [95% CrI, 0.73 to 1.17]) and the posterior probability was 24.0% for efficacy. Among patients who were not critically ill, survival to hospital discharge was 85.1% (388/456) for the vitamin C group vs 86.6% (490/566) for the control group (adjusted OR, 0.86 [95% CrI, 0.61 to 1.17]) and the posterior probability was 17.8% for efficacy. Conclusions and Relevance: In hospitalized patients with COVID-19, vitamin C had low probability of improving the primary composite outcome of organ support-free days and hospital survival. Trial Registration: ClinicalTrials.gov Identifiers: NCT04401150 (LOVIT-COVID) and NCT02735707 (REMAP-CAP).

Extracorporeal membrane oxygenation and Extracorporeal Membrane Oxygenation Cardiopulmonary Resusciation (ECPR) research priorities in Australia: A clinician survey.

BACKGROUND: The use of extracorporeal membrane oxygenation (ECMO) for cardiorespiratory failure and during cardiopulmonary resuscitation has increased significantly and is resource intensive. High-quality evidence to guide management of patients on ECMO is limited. OBJECTIVES: The objective of this study was to determine the research priorities of clinicians for ECMO and Extracorporeal Membrane Oxygenation Cardiopulmonary Resusciation (ECPR) in Australia and New Zealand. METHODS: A prospective, binational survey of clinicians was conducted in May 2022. RESULTS: There were 133 respondents; 110 (84%) worked at an Australian ECMO centre; 28 (21%) were emergency, 45 (34%) were intensive care, and 41 (31%) were nursing clinicians. All aspects of ECMO care were identified by respondents as being important for further research; however, appropriate patient selection and determining long-term outcomes were ranked the highest. While most believed ECMO was efficacious, they felt that there was insufficient evidence to determine cost-effectiveness. There was uncertainty of the best model of ECPR provision. Equipoise exists for randomised studies into anticoagulation, blood product usage, and ECPR. CONCLUSIONS: This survey found strong support amongst clinicians for further research into the optimal use of ECMO and ECPR and provides a frame work for prioritising future clinical trials and research agendas.

The impact of the intensive care unit family liaison nurse role on communication during the COVID-19 pandemic: A qualitative descriptive study of healthcare professionals' perspectives.

BACKGROUND: The COVID-19 pandemic has deeply impacted patient and family communication and patient- and family-centred care in the intensive care unit (ICU). A new role-the ICU Family Liaison Nurse (FLN)-was introduced in an Australian metropolitan hospital ICU to facilitate communication between patient and family and ICU healthcare professionals, although there is limited knowledge about the impact of this from the ICU healthcare professionals' perspectives. OBJECTIVE: The aim of this study was to explore the impact of the ICU FLN role on communication with patients and their family during the COVID-19 pandemic, from the ICU healthcare professionals' perspectives. METHODS: A qualitative descriptive study was conducted. Seven participants including ICU FLNs, ICU doctors, nurses, and social workers who worked with the ICU FLNs were interviewed. Thematic analysis was used to analyse the data. RESULTS: Two main themes related to the ICU FLN role were identified. First, the COVID-19 pandemic posed challenges to patient and family communication, but it also created opportunities to improve patient and family communication. Second, the ICU FLN role brought beneficial impacts to the ICU healthcare professionals' workflow and work experience, as well as patient and family communication. The ICU FLN role has potential benefits that extend beyond the pandemic. CONCLUSION: We found that during the COVID-19 pandemic, the ICU FLN role was acceptable, beneficial, and appreciated from the ICU healthcare professionals' perspectives. Further research should continue the evaluation of the ICU FLN role during and post the pandemic.

Diabetes mellitus, glycaemic control, and severe COVID-19 in the Australian critical care setting: A nested cohort study.

BACKGROUND: Internationally, diabetes mellitus is recognised as a risk factor for severe COVID-19. The relationship between diabetes mellitus and severe COVID-19 has not been reported in the Australian population. OBJECTIVE: The objective of this study was to determine the prevalence of and outcomes for patients with diabetes admitted to Australian intensive care units (ICUs) with COVID-19. METHODS: This is a nested cohort study of four ICUs in Melbourne participating in the Short Period Incidence Study of Severe Acute Respiratory Infection (SPRINT-SARI) Australia project. All adult patients admitted to the ICU with COVID-19 from 20 February 2020 to 27 February 2021 were included. Blood glucose and glycated haemoglobin (HbA1c) data were retrospectively collected. Diabetes was diagnosed from medical history or an HbA1c ≥6.5% (48 mmol/mol). Hospital mortality was assessed using logistic regression. RESULTS: There were 136 patients with median age 58 years [48-68] and median Acute Physiology and Chronic Health Evaluation II (APACHE II) score of 14 [11-19]. Fifty-eight patients had diabetes (43%), 46 patients had stress-induced hyperglycaemia (34%), and 32 patients had normoglycaemia (23%). Patients with diabetes were older, were with higher APACHE II scores, had greater glycaemic variability than patients with normoglycaemia, and had longer hospital length of stay. Overall hospital mortality was 16% (22/136), including nine patients with diabetes, nine patients with stress-induced hyperglycaemia, and two patients with normoglycaemia. CONCLUSION: Diabetes is prevalent in patients admitted to Australian ICUs with severe COVID-19, highlighting the need for prevention strategies in this vulnerable population.