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In the field of intensive care, clinical data registries are commonly used to support clinical audit and develop evidence-based practice. However, they are often restricted to the intensive care unit episode only, limiting their ability to follow long-term patient outcomes and identify patient readmissions. Data linkage can be used to supplement existing data, but a lack of unique patient identifiers may compromise the accuracy of the linkage process. The aim of this study was to assess the quality of linking the Australia/New Zealand critical care registry to a state financial claims database using a method without direct patient identifiers and to identify possible sources of bias from this method. We used a linkage method relying on indirect patient identifiers and compared the accuracy of this method to one that also included the patient medical record number and date of birth. The overall linkage rate using the method with indirect identifiers was 92.3% compared to 94.5% using the method with direct identifiers. Factors most strongly associated with not being a correct link in the first method included patients at one study hospital, admissions in 2002 and 2003 and having a hospital length of stay of 20 days or more. Linking the Australia/New Zealand critical care without direct patient identifiers is a valid linkage method that will enable the measurement of long-term patient survival and readmissions. While some sources of bias have been identified, this method provides sufficient quality linkage that will support broad analyses designed to signal future in-depth research. [ABSTRACT FROM AUTHOR]

Background: Patient sex affects treatment and outcomes in critical illness. Previous studies of sex differences in critical illness compared female and male patients. In this study, we describe the group of patients classified as a third sex admitted to ICUs in Australia and New Zealand., Research Question: What are the admission characteristics and outcomes of ICU patients classified as belonging to a third sex group compared with patients classified as female or male?, Study Design and Methods: Retrospective observational study of admissions to 200 ICUs, recorded in the Australian and New Zealand Intensive Care Society's Adult Patient Database from 2018 to 2022. We undertook mixed effect logistic regression to compare hospital mortality across the sex groups, adjusted for illness severity, diagnosis, treatment limitation, year, and hospital., Results: We examined 892,161 admissions, of whom 525 (0.06%) were classified as third sex. Patients classified as third sex were represented across all diagnostic categories, jurisdictions, and hospital types. On average, they were younger than the groups classified as female (59.2 ± 20.0 vs 61.3 ± 18.4 years; P = .02) or male (63.2 ± 16.7 years; P < .001), respectively. Patients classified as third sex were more likely to be admitted after orthopedic surgery (10.1% third sex admissions [95% CI, 7.7%-13.0%]; 6.2% female [95% CI, 6.1%-6.3%]; 4.8% male [95% CI, 4.7%-4.9%]) and drug overdose (8.8% third sex admissions [95% CI, 6.5%-11.5%]; 4.2% female [95% CI, 4.1%-4.2%]; 3.1% male [95% CI, 3.0%-3.1%]). There was no difference in the adjusted hospital mortality of patients classified as third sex compared with the other groups., Interpretation: Patients classified as third sex composed a small minority group of adult ICU patients. This group had a different diagnostic case mix but similar outcomes to the groups classified as female or male. Further characterizing a third sex group will require improved processes for recording sex and gender in health records., Competing Interests: Financial/Nonfinancial Disclosures The authors have reported to CHEST the following: L. J. M. is a member of the Women in Intensive Care Medicine Network (WIN-ANZICS). M. N. C. is Executive Director of Intersex Human Rights Australia, a signatory to the Darlington Statement and a member of the Australian Bureau of Statistics Reference Group for the standard on sex, gender, variations of sex characteristics, and sexual orientation. M. N. C. is also a member of the New South Wales Ministry of Health, Australia, reference group on sex and gender. None declared (A. M. H., D. V. P., A. S. C., M. B., S. Z., R. B.)., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

Rationale: Frailty is an increasingly recognized aspect of chronic obstructive pulmonary disease (COPD). The impact of frailty on long-term survival after admission to an intensive care unit (ICU) due to an exacerbation of COPD has not been described., Objective: The objective was to quantify the impact of frailty on time to death up to 4 years after admission to the ICU in Australia and New Zealand for an exacerbation of COPD., Methods: We performed a multicenter retrospective cohort study of adult patients admitted to 179 ICUs with a primary diagnosis of an exacerbation of COPD using the Australian and New Zealand Intensive Care Society Adult Patient Database from January 1, 2018, through December 31, 2020, in New Zealand, and March 31, 2022, in Australia. Frailty was measured using the clinical frailty scale (CFS). The primary outcome was survival up to 4 years after ICU admission. The secondary outcome was readmission to the ICU due to an exacerbation of COPD., Measurements and Main Results: We examined 7126 patients of which 3859 (54.1%) were frail (CFS scores of 5-8). Mortality in not-frail individuals versus frail individuals at 1 and 4 years was 19.8% versus 40.4%, and 56.8% versus 77.3% respectively (both p<0.001). Frailty was independently associated with a shorter time to death (adjusted hazard ratio 1.66; 95% confidence interval 1.54-1.80).There was no difference in the proportion of survivors with or without frailty who were readmitted to the ICU during a subsequent hospitalization., Conclusions: Frailty was independently associated with poorer long-term survival in patients admitted to the ICU with an exacerbation of COPD., (JCOPDF © 2024.)

Objectives: Critically ill women may receive less vital organ support than men but the mortality impact of this differential treatment remains unclear. We aimed to quantify sex differences in vital organ support provided to adult ICU patients and describe the relationship between sex, vital organ support, and mortality., Design: In this retrospective observational study, we examined the provision of invasive ventilation (primary outcome), noninvasive ventilation, vasoactive medication, renal replacement therapy, extracorporeal membrane oxygenation (ECMO), or any one of these five vital organ supports in women compared with men. We performed logistic regression investigating the association of sex with each vital organ support, adjusted for illness severity, diagnosis, preexisting treatment limitation, year, and hospital. We performed logistic regression for hospital mortality adjusted for the same variables, stratified by vital organ support (secondary outcome)., Setting and Patients: ICU admissions in the Australia and New Zealand Intensive Care Society Adult Patient Database 2018-2021. This registry records admissions from 90% of ICUs in the two nations., Interventions: None., Measurements and Main Results: We examined 699,535 ICU admissions (43.7% women) to 199 ICUs. After adjustment, women were less likely than men to receive invasive ventilation (odds ratio [OR], 0.64; 99% CI, 0.63-0.65) and each other organ support except ECMO. Women had lower adjusted hospital mortality overall (OR, 0.94; 99% CI, 0.91-0.97). Among patients who did not receive any organ support, women had significantly lower adjusted hospital mortality (OR, 0.82; 99% CI, 0.76-0.88); among patients who received any organ support women and men were equally likely to die (OR, 1.01; 99% CI, 0.97-1.04)., Conclusions: Women received significantly less vital organ support than men in ICUs in Australia and New Zealand. However, our findings suggest that women may not be harmed by this conservative approach to treatment., Competing Interests: Dr. Modra received funding from the Graeme Clark Institute of the University of Melbourne-Women in Science Technology and Mathematics Award, and the Australia and New Zealand Intensive Care Society-Peter Hicks Fellowship Award; she disclosed that she is a member of the Women in Intensive Care Medicine Network of the Australia and New Zealand Intensive Care Society. Dr Higgins received funding from a National Health and Medical Research Council Emerging Leader Fellowship (Grant #2008447). The remaining authors have disclosed that they do not have any potential conflicts of interest., (Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the Society of Critical Care Medicine and Wolters Kluwer Health, Inc.)

Objectives: ICU resource strain leads to adverse patient outcomes. Simple, well-validated measures of ICU strain are lacking. Our objective was to assess whether the "Activity index," an indicator developed during the COVID-19 pandemic, was a valid measure of ICU strain., Design: Retrospective national registry-based cohort study., Setting: One hundred seventy-five public and private hospitals in Australia (June 2020 through March 2022)., Subjects: Two hundred seventy-seven thousand seven hundred thirty-seven adult ICU patients., Interventions: None., Measurements and Main Results: Data from the Australian and New Zealand Intensive Care Society Adult Patient Database were matched to the Critical Health Resources Information System. The mean daily Activity index of each ICU (census total of "patients with 1:1 nursing" + "invasive ventilation" + "renal replacement" + "extracorporeal membrane oxygenation" + "active COVID-19," divided by total staffed ICU beds) during the patient's stay in the ICU was calculated. Patients were categorized as being in the ICU during very quiet (Activity index < 0.1), quiet (0.1 to < 0.6), intermediate (0.6 to < 1.1), busy (1.1 to < 1.6), or very busy time-periods (≥ 1.6). The primary outcome was in-hospital mortality. Secondary outcomes included after-hours discharge from the ICU, readmission to the ICU, interhospital transfer to another ICU, and delay in discharge from the ICU. Median Activity index was 0.87 (interquartile range, 0.40-1.24). Nineteen thousand one hundred seventy-seven patients died (6.9%). In-hospital mortality ranged from 2.4% during very quiet to 10.9% during very busy time-periods. After adjusting for confounders, being in an ICU during time-periods with higher Activity indices, was associated with an increased risk of in-hospital mortality (odds ratio [OR], 1.49; 99% CI, 1.38-1.60), after-hours discharge (OR, 1.27; 99% CI, 1.21-1.34), readmission (OR, 1.18; 99% CI, 1.09-1.28), interhospital transfer (OR, 1.92; 99% CI, 1.72-2.15), and less delay in ICU discharge (OR, 0.58; 99% CI, 0.55-0.62): findings consistent with ICU strain., Conclusions: The Activity index is a simple and valid measure that identifies ICUs in which increasing strain leads to progressively worse patient outcomes., Competing Interests: The authors have disclosed that they do not have any potential conflicts of interest., (Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the Society of Critical Care Medicine and Wolters Kluwer Health, Inc.)

Objective: The impact of obesity on long-term survival after intensive care unit (ICU) admission with severe coronavirus disease 2019 (COVID-19) is unclear. We aimed to quantify the impact of obesity on time to death up to two years in patients admitted to Australian and New Zealand ICUs., Design: Retrospective multicentre study., Setting: 92 ICUs between 1st January 2020 through to 31st December 2020 in New Zealand and 31st March 2022 in Australia with COVID-19, reported in the Australian and New Zealand Intensive Care Society adult patient database., Participants: All patients with documented height and weight to estimate the body mass index (BMI) were included. Obesity was classified patients according to the World Health Organization recommendations., Interventions and Main Outcome Measures: The primary outcome was survival time up to two years after ICU admission. The effect of obesity on time to death was assessed using a Cox proportional hazards model. Confounders were acute illness severity, sex, frailty, hospital type and jurisdiction for all patients., Results: We examined 2,931 patients; the median BMI was 30.2 (IQR 25.6-36.0) kg/m 2 . Patients with a BMI ≥30 kg/m 2  were younger (median [IQR] age 57.7 [46.2-69.0] vs. 63.0 [50.0-73.6]; p < 0.001) than those with a BMI <30 kg/m 2 . Most patients (76.6%; 2,244/2,931) were discharged alive after ICU admission. The mortality at two years was highest for BMI categories <18.5 kg/m 2  (35.4%) and 18.5-24.9 kg/m 2  (31.1%), while lowest for BMI ≥40 kg/m 2  (14.5%). After adjusting for confounders and with BMI 18.5-24.9 kg/m 2  category as a reference, only the BMI ≥40 kg/m 2  category patients had improved survival up to 2 years (hazard ratio = 0.51; 95%CI: 0.34-0.76)., Conclusions: The obesity paradox appears to exist beyond hospital discharge in critically ill patients with COVID-19 admitted in Australian and New Zealand ICUs. A BMI ≥40 kg/m 2 was associated with a higher survival time of up to two years., Competing Interests: The authors declare the following financial interests/personal relationships that may be considered as potential competing interests: n/a If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors.)

Objectives: To validate a real-time Intensive Care Unit (ICU) Activity Index as a marker of ICU strain from daily data available from the Critical Health Resource Information System (CHRIS), and to investigate the association between this Index and the need to transfer critically ill patients during the coronavirus disease 2019 (COVID-19) pandemic in Victoria, Australia. Design: Retrospective observational cohort study. Setting: All 45 hospitals with an ICU in Victoria, Australia. Participants: Patients in all Victorian ICUs and all critically ill patients transferred between Victorian hospitals from 27 June to 6 September 2020. Main outcome measure: Acute interhospital transfer of one or more critically ill patients per day from one site to an ICU in another hospital. Results: 150 patients were transported over 61 days from 29 hospitals (64%). ICU Activity Index scores were higher on days when critical care transfers occurred (median, 1.0 [IQR, 0.4-1.7] v 0.6 [IQR, 0.3-1.2]; P < 0.001). Transfers were more common on days of higher ICU occupancy, higher numbers of ventilated or COVID-19 patients, and when more critical care staff were unavailable. The highest ICU Activity Index scores were observed at hospitals in north-western Melbourne, where the COVID-19 disease burden was greatest. After adjusting for confounding factors, including occupancy and lack of available ICU staff, a rising ICU Activity Index score was associated with an increased risk of a critical care transfer (odds ratio, 4.10; 95% CI, 2.34-7.18; P < 0.001). Conclusions: The ICU Activity Index appeared to be a valid marker of ICU strain during the COVID-19 pandemic. It may be useful as a real-time clinical indicator of ICU activity and predict the need for redistribution of critical ill patients., Competing Interests: No relevant disclosures., (© 2021 College of Intensive Care Medicine of Australia and New Zealand.)

Background: The national hospital-acquired complications (HAC) system has been promoted as a method to identify health care errors that may be mitigated by clinical interventions. Objectives: To quantify the rate of HAC in multiday stay adults admitted to major hospitals. Design: Retrospective observational analysis of 5-year (July 2014 - June 2019) administrative dataset abstracted from medical records. Setting: All 47 hospitals with on-site intensive care units (ICUs) in the State of Victoria. Participants: All adults (aged ≥ 18 years) stratified into planned or unplanned, surgical or medical, ICU or other ward, and by hospital peer group (tertiary referral, metropolitan, regional). Main outcome measures: HAC rates in ICU compared with ward, and mixed-effects regression estimates of the association between HAC and i) risk of clinical deterioration, and ii) admission hospital site (intraclass correlation coefficient [ICC] > 0.3). Results: 211 120 adult ICU separations with mean hospital mortality of 7.3% (95% CI, 7.2-7.4%) reported 110 132 (42.6%) HAC events (commonly, delirium, infection, arrhythmia and respiratory failure) in 62 945 records (29.8%). Higher HAC rates were reported in elective (cardiac [50.3%] and non-cardiac [40.6%]) surgical subgroups compared with emergency medical subgroup (23.9%), and in tertiary (35.4%) compared with non-tertiary (22.7%) hospitals. HAC was strongly associated with on-admission patient characteristics ( P < 0.001), but was weakly associated with hospital site (ICC, 0.08; 95% CI, 0.05-0.11). Conclusions: Critically ill patients have a high burden of HAC events, which appear to be associated with patient admission characteristics. HAC may an indicator of hospital admission complexity rather than hospital-acquired complications., Competing Interests: No relevant disclosures., (© 2021 College of Intensive Care Medicine of Australia and New Zealand.)

Objective: We aimed to measure the incidence, prevalence, characteristics and outcomes of intensive care unit (ICU) patients with early (first 24 hours) metabolic acidosis (MA) according to two different levels of severity with a focus on recent data. Design: We retrospectively applied two diagnostic criteria to our analysis based on literature for early MA: i) severe MA criteria (pH ≤ 7.20 and Paco 2 ≤ 45 mmHg and HCO 3 - ≤ 20 mmol/L with total Sequential Organ Failure Assessment [SOFA] score ≥ 4 or lactate ≥ 2 mmol/L), and ii) moderate MA criteria (pH < 7.30 and base excess < -4 mmol/L and Paco 2 ≤ 45 mmHg). Setting: ICUs in the Australian and New Zealand Intensive Care Society Adult Patient Database program. Participants: Adult patients registered to the database from 2008 to 2018. Main outcome measures: Incidence, prevalence, and hospital mortality of patients with MA by the two criteria. Results: We screened 1 076 087 patients. Given the Australian and New Zealand population during the study period, we estimated the incidence of severe MA at 39.5 per million per year versus 349.2-411.5 per million per year for moderate MA. In the most recent 2 years, we observed early severe MA in 1.5% (1350/87 110) of patients compared with 8.4% (20 679/244 740) for moderate MA. Overall, hospital mortality for patients with early severe MA was 48.3% (652/1350) compared with 21.5% (4444/20 679) for moderate MA. Conclusions: Early severe MA is uncommon in Australian and New Zealand ICUs and carries a very high mortality. Moderate MA is over seven-fold more common and still carries a high mortality., Competing Interests: None declared., (© 2021 College of Intensive Care Medicine of Australia and New Zealand.)

In 2023, the Australian and New Zealand Intensive Care Society (ANZICS) Registry run by the Centre for Outcomes and Resources Evaluation (CORE) turns 30 years old. It began with the Adult Patient Database, the Australian and New Zealand Paediatric Intensive Care Registry, and the Critical Care Resources Registry, and it now includes Central Line Associated Bloodstream Infections Registry, the Extra-Corporeal Membrane Oxygenation Database, and the Critical Health Resources Information System. The ANZICS Registry provides comparative case-mix reports, risk-adjusted clinical outcomes, process measures, and quality of care indicators to over 200 intensive care units describing more than 200 000 adult and paediatric admissions annually. The ANZICS CORE outlier management program has been a major contributor to the improved patient outcomes and provided significant cost savings to the healthcare sector. Over 200 peer-reviewed papers have been published using ANZICS Registry data. The ANZICS Registry was a vital source of information during the COVID-19 pandemic. Upcoming developments include reporting of long-term survival and patient-reported outcome and experience measures., (© 2023 The Authors. Published by Elsevier B.V. on behalf of College of Intensive Care Medicine of Australia and New Zealand.)

Rationale: Women have worse outcomes than men in several conditions more common in men, including cardiac surgery and burns. Objectives: To describe the relationship between sex balance within each diagnostic group of ICU admissions, defined as the percentage of patients who were women, and hospital mortality of women compared with men with that same diagnosis. Methods: We studied ICU patients in the Australian and New Zealand Intensive Care Society's Adult Patient Database (2011-2020). We performed mixed effects logistic regression for hospital mortality adjusted for sex, illness severity, ICU lead time, admission year, and hospital site. We compared sex balance with the adjusted hospital mortality of women compared with men for each diagnosis using weighted linear regression. Measurements and Main Results: There were 1,450,782 admissions (42.1% women), with no difference in the adjusted hospital mortality of women compared with men overall (odds ratio, 0.99; 99% confidence interval [CI], 0.97 to 1). As the percentage of women within each diagnosis increased, the adjusted mortality of women compared with men with that same diagnosis decreased (regression coefficient, -0.015; 99% CI; -0.020 to -0.011; P  < 0.001), and the illness severity of women compared with men at ICU admission decreased (regression coefficient, -0.0026; 99% CI, -0.0035 to -0.0018; P  < 0.001). Conclusions: Sex balance in diagnostic groups was inversely associated with both the adjusted mortality and illness severity of women compared with men. In diagnoses with relatively few women, women were more likely than men to die. In diagnoses with fewer men, men were more likely than women to die.

Objectives: To determine common "bed-to-physician" ratios during weekday hours across ICUs and assess factors associated with variability in this ratio., Design: Retrospective cohort study., Setting: All ICUs in Australia/New Zealand that participated in a staffing survey administered in 2017-2018., Patients: ICU admissions from 2016 to 2018., Methods: We linked survey data with patient-level data. We defined: 1) bed-to-intensivist ratio as the number of usually available ICU beds divided by the number of onsite weekday daytime intensivists; and 2) bed-to-physician ratio as the number of available ICU beds divided by the total number of physicians (intensivists + nonintensivists, including trainees). We calculated the median and interquartile range (IQR) of bed-to-intensivist ratio and bed-to-physician ratios during weekday hours. We assessed variability in each by type of hospital and ICU and by severity of illness of patients, defined by the predicted hospital mortality., Interventions: None., Measurements and Main Results: Of the 123 (87.2%) of Australia/New Zealand ICUs that returned staffing surveys, 114 (92.7%) had an intensivist present during weekday daytime hours, and 116 (94.3%) reported at least one nonintensivist physician. The median bed-to-intensivist ratio was 8.0 (IQR, 6.0-11.4), which decreased to a bed-to-physician ratio of 3.0 (IQR, 2.2-4.9). These ratios varied with mean severity of illness of the patients in the unit. The median bed-to-intensivist ratio was highest (13.5) for ICUs with a mean predicted mortality > 2-4%, and the median bed-to-physician ratio was highest (5.7) for ICUs with a mean predicted mortality of > 4-6%. Both ratios decreased and plateaued in ICUs with a mean predicted mortality for patients greater than 8% (median bed-to-intensivist ratio range, 6.8-8.0, and bed-to-physician ratio range of 2.4-2.7)., Conclusions: Weekday bed-to-physician ratios in Australia/New Zealand ICUs are lower than the bed-to-intensivist ratios and have a relatively fixed ratio of less than 3 for units taking care of patients with a higher average severity of illness. These relationships may be different in other countries or healthcare systems., Competing Interests: Dr. Wunsch received funding from the Canada Research Chair (Tier 2) in Critical Care Organization and Outcomes. Dr. Gershengorn’s institution received funding from the National Heart, Lung, and Blood Institute; she received funding from the University of Miami Hospital and Clinics through the Data Analytics Research Team, Gilead Sciences, the American Thoracic Society, and Southeastern Critical Care Summit. The remaining authors have disclosed that they do not have any potential conflicts of interest., (Copyright © 2022 by the Society of Critical Care Medicine and Wolters Kluwer Health, Inc. All Rights Reserved.)

Background: Extracorporeal membrane oxygenation (ECMO) is an invasive procedure used to support critically ill patients with the most severe forms of cardiac or respiratory failure in the short term, but long-term effects on incidence of death and disability are unknown. We aimed to assess incidence of death or disability associated with ECMO up to 6 months (180 days) after treatment., Methods: This prospective, multicentre, registry-embedded cohort study was done at 23 hospitals in Australia from Feb 15, 2019, to Dec 31, 2020. The EXCEL registry included all adults (≥18 years) in Australia who were admitted to an intensive care unit (ICU) in a participating centre at the time of the study and who underwent ECMO. All patients who received ECMO support for respiratory failure, cardiac failure, or cardiac arrest during their ICU stay were eligible for this study. The primary outcome was death or moderate-to-severe disability (defined using the WHO Disability Assessment Schedule 2.0, 12-item survey) at 6 months after ECMO initiation. We used Fisher's exact test to compare categorical variables. This study is registered with ClinicalTrials.gov, NCT03793257., Findings: Outcome data were available for 391 (88%) of 442 enrolled patients. The primary outcome of death or moderate-to-severe disability at 6 months was reported in 260 (66%) of 391 patients: 136 (67%) of 202 who received veno-arterial (VA)-ECMO, 60 (54%) of 111 who received veno-venous (VV)-ECMO, and 64 (82%) of 78 who received extracorporeal cardiopulmonary resuscitation (eCPR). After adjustment for age, comorbidities, Acute Physiology and Chronic Health Evaluation (APACHE) IV score, days between ICU admission and ECMO start, and use of vasopressors before ECMO, death or moderate-to-severe disability was higher in patients who received eCPR than in those who received VV-ECMO (VV-ECMO vs eCPR: risk difference [RD] -32% [95% CI -49 to -15]; p&lt;0·001) but not VA-ECMO (VA-ECMO vs eCPR -8% [-22 to 6]; p=0·27)., Interpretation: In our study, only a third of patients were alive without moderate-to-severe disability at 6 months after initiation of ECMO. The finding that disability was common across all areas of functioning points to the need for long-term, multidisciplinary care and support for surviving patients who have had ECMO. Further studies are needed to understand the 180-day and longer-term prognosis of patients with different diagnoses receiving different modes of ECMO, which could have important implications for the selection of patients for ECMO and management strategies in the ICU., Funding: The National Health and Medical Research Council of Australia., Competing Interests: Declaration of interests CLH leads the bi-national EXCEL registry, with funding from the Australian National Health and Medical Research Council (NHMRC) and the Heart Foundation of Australia (HFA), holds an NHMRC investigator grant, and is on the executive committee of the International ECMO Network (ECMONet). AMH, AJCB, and DJC receive research support from NHMRC. AMH, MJB, SB, BJF, NJL, DJC, DJG, IKH, DVP, TVT, and AAU received funding for the EXCEL registry from NHMRC and HFA. DB is Chair of the Executive Committee of ECMONet and President-elect of ELSO, receives research support from ALung Technologies, and has been on medical advisory boards for Abiomed, Xenios, Medtronic, and Cellenkos. DJC holds an NHMRC practitioner fellowship. EF is on the executive committee of ECMONet and the steering committee of the Extracorporeal Life Support Organization (ELSO). JFF and VAP are on the Executive Committee of ECMONet. JFF is President of the Asia-Pacific Chapter of ELSO, Chair of the Queensland Cardiovascular Research Network, co-founder of BiVACOR, and receives research support from Xenios, Mallenkrodt Getinge, and MERA (all ECMO companies). DS received research support from a HFA fellowship. AAU is on the executive committee of the Australian and New Zealand Intensive Care Society Clinical Trials Group. All other authors declare no competing interests., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Lung transplantation is limited by a lack of suitable lung donors. In Australia, the national donation organisation (DonateLife) has taken a major role in optimising organ donor identification. However, the potential outside the DonateLife network hospitals remains uncertain. We aimed to create a prediction model for lung donation within the DonateLife network and estimate the untapped lung donors outside of the DonateLife network. We reviewed all deaths in the state of Victoria's intensive care units using a prospectively collected population-based intensive care unit database linked to organ donation records. A logistic regression model derived using patient-level data was developed to characterise the lung donors within DonateLife network hospitals. Consequently, we estimated the expected number of lung donors in Victorian hospitals outside the DonateLife network and compared the actual number. Between 2014 and 2018, 291 lung donations occurred from 8043 intensive care unit deaths in DonateLife hospitals, while only three lung donations occurred from 1373 ICU deaths in non-DonateLife hospitals. Age, sex, postoperative admission, sepsis, neurological disease, trauma, chronic respiratory disease, lung oxygenation and serum creatinine were factors independently associated with lung donation. A highly discriminatory prediction model with area under the receiver operator characteristic curve of 0.91 was developed and accurately estimated the number of lung donors. Applying the model to non-DonateLife hospital data predicted only an additional five lung donors. This prediction model revealed few additional lung donor opportunities outside the DonateLife network, and the necessity of alternative and novel strategies for lung donation. A donor prediction model could provide a useful benchmarking tool to explore organ donation potential across different jurisdictions, hospitals and transplanting centres.

Klebsiella pneumoniae is a major cause of opportunistic healthcare-associated infections, which are increasingly complicated by the presence of extended-spectrum beta-lactamases (ESBLs) and carbapenem resistance. We conducted a year-long prospective surveillance study of K. pneumoniae clinical isolates in hospital patients. Whole-genome sequence (WGS) data reveals a diverse pathogen population, including other species within the K. pneumoniae species complex (18%). Several infections were caused by K. variicola/K. pneumoniae hybrids, one of which shows evidence of nosocomial transmission. A wide range of antimicrobial resistance (AMR) phenotypes are observed, and diverse genetic mechanisms identified (mainly plasmid-borne genes). ESBLs are correlated with presence of other acquired AMR genes (median n = 10). Bacterial genomic features associated with nosocomial onset are ESBLs (OR 2.34, p = 0.015) and rhamnose-positive capsules (OR 3.12, p < 0.001). Virulence plasmid-encoded features (aerobactin, hypermucoidy) are observed at low-prevalence (<3%), mostly in community-onset cases. WGS-confirmed nosocomial transmission is implicated in just 10% of cases, but strongly associated with ESBLs (OR 21, p < 1 × 10 -11 ). We estimate 28% risk of onward nosocomial transmission for ESBL-positive strains vs 1.7% for ESBL-negative strains. These data indicate that K. pneumoniae infections in hospitalised patients are due largely to opportunistic infections with diverse strains, with an additional burden from nosocomially-transmitted AMR strains and community-acquired hypervirulent strains., (© 2022. The Author(s).)

Rationale: Frailty in critically ill patients is associated with higher mortality and prolonged length of stay; however, little is known about the impact on the duration of mechanical ventilation. Objectives: To identify the relationship between frailty and total duration of mechanical ventilation and the interaction with patients' age. Methods: This retrospective population-based cohort study was performed using data submitted to the Australian and New Zealand Intensive Care Society Adult Patient Database between 2017 and 2020. We analyzed adult critically ill patients who received invasive mechanical ventilation within the first 24 hours of intensive care unit admission. Results: Of 59,319 available patients receiving invasive mechanical ventilation, 8,331 (14%) were classified as frail. Patients with frailty had longer duration of mechanical ventilation compared with patients without frailty. Duration of mechanical ventilation increased with higher frailty score. Patients with frailty had longer intensive care unit and hospital stay with higher mortality than patients without frailty. After adjustment for relevant covariates in multivariate analyses, frailty was significantly associated with a reduced probability of cessation of invasive mechanical ventilation (adjusted hazard ratio, 0.57 [95% confidence interval, 0.51-0.64]; P  < 0.001). Sensitivity and subgroup analyses suggested that frailty could prolong mechanical ventilation in survivors, and the relationship was especially strong in younger patients. Conclusions: Frailty score was independently associated with longer duration of mechanical ventilation and contributed to identifying patients who were less likely to be liberated from mechanical ventilation. The impact of frailty on ventilation time varied with age and was most apparent for younger patients.

Purpose: The impact of intensivist workload on intensive care unit (ICU) outcomes is incompletely described and assessed across healthcare systems and countries. We sought to examine the association of patient-to-intensivist ratio (PIR) with hospital mortality in Australia/New Zealand (ANZ) ICUs., Methods: We conducted a retrospective study of adult admissions to ANZ ICUs (August 2016-June 2018) using two cohorts: "narrow", based on previously used criteria including restriction to ICUs with a single daytime intensivist; and "broad", refined by individual ICU daytime staffing information. The exposure was average daily PIR and the outcome was hospital mortality. We used summary statistics to describe both cohorts and multilevel multivariable logistic regression models to assess the association of PIR with mortality. In each, PIR was modeled using restricted cubic splines to allow for non-linear associations. The broad cohort model included non-PIR physician and non-physician staffing covariables., Results: The narrow cohort of 27,380 patients across 67 ICUs (predicted mortality: median 1.2% [IQR 0.4-1.4%]; mean 5.9% [sd 13.2%]) had a median PIR of 10.1 (IQR 7-14). The broad cohort of 91,206 patients across 73 ICUs (predicted mortality: 1.9% [0.6-6.5%]; 7.6% [14.9%]) had a median PIR of 7.8 (IQR 5.8-10.2). We found no association of PIR with mortality in either the narrow (PIR 1st spline term odds ratio [95% CI]: 1 [0.94, 1.06], Wald testing of spline terms p = 0.61) or the broad (1.02 [0.97, 1.07], p = 0.4) cohort., Conclusion: We found no association of PIR with hospital mortality across ANZ ICUs. The low cohort predicted mortality may limit external validity., (© 2021. Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: In Australia, increased organ donation and subsequent lung transplantation (LTx) rates have followed enhanced donor identification, referral and management, as well as the introduction of a donation after circulatory death (DCD) pathway. However, the number of patients waiting for LTx still continues to exceed the number of lung donors and the search for further suitable donors is critical., Methods: All 2014-2018 Victorian DonateLife hospital deaths after intensive care unit (ICU) admission were analysed retrospectively to quantify unrecognised lung donors using current criteria, as well as novel time-extended (90 mins-24 hrs post-withdrawal) DCD lung donors., Results: Using standard lung donor eligibility criteria, we identified 473 potential lung donors and a further 122 time-extended DCD potential lung donors among 3,538 patients meeting general eligibility criteria. Detailed review of end-of-life discussions with patient families and the reasons why they were not offered donation revealed several categories of additional lung donors-traditional lung donors missed in current practice (n=2); hepatitis C infected lung donors potentially treatable with direct-acting antivirals (n=14), time-extended DCD lung donors (n=60); donor lungs potentially suitable for transplant with use of ex-vivo lung perfusion (EVLP) (n=7)., Conclusion: While the number of lung donor opportunities missed under existing DonateLife donor identification and management processes was limited, a time-extended DCD lung donation pathway could substantially expand the lung donor pool. The use of hepatitis C infected donors, and the possibility of EVLP to solve donor graft assessment or logistic issues, could also provide small additional lung donor opportunities., (Copyright © 2021 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.)

Objectives: To investigate the association of socioeconomic status as measured by the average socioeconomic status of the area where a person resides on short-term mortality in adults admitted to an ICU in Queensland, Australia., Design: Secondary data analysis using de-identified data from the Australian and New Zealand Intensive Care Society Centre for Outcome and Resource Evaluation linked to the publicly available area-level Index of Relative Socioeconomic Advantage and Disadvantage from the Australian Bureau of Statistics., Setting: Adult ICUs from 35 hospitals in Queensland, Australia, from 2006 to 2015., Patients: A total of 218,462 patient admissions., Interventions: None., Measurements and Main Results: The outcome measure was inhospital mortality. The main study variable was decile of Index of Relative Socioeconomic Advantage and Disadvantage. The overall crude inhospital mortality was 7.8%; 9% in the most disadvantaged decile and 6.9% in the most advantaged decile (p < 0.001). Increasing socioeconomic disadvantage was associated with increasing severity of illness as measured by Acute Physiology and Chronic Health Evaluation III score, admission with a diagnosis of sepsis or trauma, cardiac, respiratory, renal, and hepatic comorbidities, and remote location. Increasing socioeconomic advantage was associated with elective surgical admission, hematological and oncology comorbidities, and admission to a private hospital (all p < 0.001). After excluding patients admitted after elective surgery, in the remaining 106,843 patients, the inhospital mortality was 13.6%, 13.3% in the most disadvantaged, and 14.1% in the most advantaged. There was no trend in mortality across deciles of socioeconomic status after excluding elective surgery patients. In the logistic regression model adjusting for severity of illness and diagnosis, there was no statistically significant difference in the odds ratio of inhospital mortality for the most disadvantaged decile compared with other deciles. This suggests variables used for risk adjustment may lie on the causal pathway between socioeconomic status and outcome in ICU patients., Conclusions: Socioeconomic status as defined as Index of Relative Socioeconomic Advantage and Disadvantage of the area in which a patient lives was associated with ICU admission diagnosis, comorbidities, severity of illness, and crude inhospital mortality in this study. Socioeconomic status was not associated with inhospital mortality after excluding elective surgical patients or when adjusted for severity of illness and admission diagnosis. Commonly used measures for risk adjustment in intensive care improve understanding of the pathway between socioeconomic status and outcomes., Competing Interests: The authors have disclosed that they do not have any potential conflicts of interest., (Copyright © 2021 by the Society of Critical Care Medicine and Wolters Kluwer Health, Inc. All Rights Reserved.)

Background: There are limited published data on the epidemiology of skin and soft tissue infections (SSTIs) requiring intensive care unit (ICU) admission. This study intended to describe the annual prevalence, characteristics, and outcomes of critically ill adult patients admitted to the ICU for an SSTI., Methods: This was a registry-based retrospective cohort study, using data submitted to the Australian and New Zealand Intensive Care Society Adult Patient Database for all admissions with SSTI between 2006 and 2017. The inclusion criteria were as follows: primary diagnosis of SSTI and age ≥16 years. The exclusion criteria were as follows: ICU readmissions (during the same hospital admission) and transfers from ICUs from other hospitals. The primary outcome was in-hospital mortality, and the secondary outcomes were ICU mortality and length of stay (LOS) in the ICU and hospital with independent predictors of outcomes., Results: Admissions due to SSTI accounted for 10 962 (0.7%) of 1 470 197 ICU admissions between 2006 and 2017. Comorbidities were present in 25.2% of the study sample. The in-hospital mortality was 9% (991/10 962), and SSTI necessitating ICU admission accounted for 0.07% of in-hospital mortality of all ICU admissions between 2006 and 2017. Annual prevalence of ICU admissions for SSTI increased from 0.4% to 0.9% during the study period, but in-hospital mortality decreased from 16.1% to 6.8%. The median ICU LOS was 2.1 days (interquartile range = 3.4), and the median hospital LOS was 12.1 days (interquartile range = 20.6). ICU LOS remained stable between 2006 and 2017 (2.0-2.1 days), whereas hospital LOS decreased from 15.7 to 11.2 days. Predictors for in-hospital mortality included Australian and New Zealand Risk of Death scores [odds ratio (OR): 1.07; confidence interval (CI) (1.05, 1.09); p < 0.001], any comorbidity except diabetes [OR: 2.00; CI (1.05, 3.79); p = 0.035], and admission through an emergency response call [OR: 2.07; CI (1.03, 4.16); p = 0.041]., Conclusions: SSTIs are uncommon as primary ICU admission diagnosis. Although the annual prevalence of ICU admissions for SSTI has increased, in-hospital mortality and hospital LOS have decreased over the last decade., Competing Interests: Conflict of Interest The authors declare that they have no competing interests., (Copyright © 2021 Australian College of Critical Care Nurses Ltd. Published by Elsevier Ltd. All rights reserved.)

Background: Even in the extended-criteria era, the reasons for declining lung donors are not always clear. Furthermore, it has not been determined how many actual declined lungs would be retrieved by ex vivo lung perfusion (EVLP) beyond that already achieved in centers with an existing high utilization rate., Methods: This retrospective study reviewed all lung donor referrals between 2014 and 2018, including detailed formal referrals and preliminary notifications. This study categorized reasons for lung donor non-acceptance and estimated how many declined grafts could have been theoretically retrievable by using EVLP., Results: In total, 966 lung donor candidates were referred, including 313 transplanted donors, 336 declined donors after detailed referrals (group A) and 258 preliminary declined. In group A, the primary reasons for refusal were lung quality issues (49%), general medical issues (25%), and organization issues (26%), combined with secondary reasons in many cases. Main lung quality issues were an extensive smoking history, abnormal chest radiography, and underlying lung disease. Although 73 declined lung donors had indications for EVLP, the retrievable lungs decreased to only 30 cases after considering the details of all clinical contraindications and organizational issues. Nevertheless, 59 intended donation after circulatory death donors did not progress to death after withdrawal of cardiorespiratory support in the required timeframe, and EVLP may have an emerging additional role here., Conclusions: Based on commonly cited criteria for EVLP indication, the number of EVLP retrievable lung donors represented only a small portion of declined donor lungs referred to our center from the state donation network., (Copyright © 2021 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Purpose: To study the prevalence, characteristic, outcome, and acid-base biomarker predictors of outcome for different acidemia subtypes., Methods: We used national intensive care databases from three countries and classified acidemia subtypes as metabolic (standard base excess [SBE] < -2 mEq/L only), respiratory (PaCO 2  > 42 mmHg only), and combined (both SBE < -2 mEq/L and PaCO 2  > 42 mmHg) based on blood gas analysis in the first 24 h after ICU admission. To investigate acid-base predictors for hospital mortality, we applied the area under the receiver operating characteristic curve approach., Results: We screened 643,689 ICU patients (2014-2018) and detected acidemia in 57.8%. The most common subtype was metabolic (42.9%), followed by combined (30.3%) and respiratory (25.9%). Combined acidemia had a mortality of 12.7%, compared with 11% for metabolic and 5.5% for respiratory. For combined acidemia, the best predictor of hospital mortality was pH. However, for metabolic or respiratory acidemia, it was SBE or PaCO 2 , respectively., Conclusions: In ICU patients with acidemia, mortality differs according to subtype and is highest in the combined subtype. Best acid-base predictors of mortality also differ according to subtype with best performance for pH in combined, SBE in metabolic, and PaCO 2 in respiratory acidemia., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Third-generation cephalosporin-resistant Gram-negatives (3GCR-GN) and vancomycin-resistant enterococci (VRE) are common causes of multi-drug resistant healthcare-associated infections, for which gut colonisation is considered a prerequisite. However, there remains a key knowledge gap about colonisation and infection dynamics in high-risk settings such as the intensive care unit (ICU), thus hampering infection prevention efforts., Methods: We performed a three-month prospective genomic survey of infecting and gut-colonising 3GCR-GN and VRE among patients admitted to an Australian ICU. Bacteria were isolated from rectal swabs (n = 287 and n = 103 patients ≤2 and > 2 days from admission, respectively) and diagnostic clinical specimens between Dec 2013 and March 2014. Isolates were subjected to Illumina whole-genome sequencing (n = 127 3GCR-GN, n = 41 VRE). Multi-locus sequence types (STs) and antimicrobial resistance determinants were identified from de novo assemblies. Twenty-three isolates were selected for sequencing on the Oxford Nanopore MinION device to generate completed reference genomes (one for each ST isolated from ≥2 patients). Single nucleotide variants (SNVs) were identified by read mapping and variant calling against these references., Results: Among 287 patients screened on admission, 17.4 and 8.4% were colonised by 3GCR-GN and VRE, respectively. Escherichia coli was the most common species (n = 36 episodes, 58.1%) and the most common cause of 3GCR-GN infection. Only two VRE infections were identified. The rate of infection among patients colonised with E. coli was low, but higher than those who were not colonised on admission (n = 2/33, 6% vs n = 4/254, 2%, respectively, p = 0.3). While few patients were colonised with 3GCR- Klebsiella pneumoniae or Pseudomonas aeruginosa on admission (n = 4), all such patients developed infections with the colonising strain. Genomic analyses revealed 10 putative nosocomial transmission clusters (≤20 SNVs for 3GCR-GN, ≤3 SNVs for VRE): four VRE, six 3GCR-GN, with epidemiologically linked clusters accounting for 21 and 6% of episodes, respectively (OR 4.3, p = 0.02)., Conclusions: 3GCR-E. coli and VRE were the most common gut colonisers. E. coli was the most common cause of 3GCR-GN infection, but other 3GCR-GN species showed greater risk for infection in colonised patients. Larger studies are warranted to elucidate the relative risks of different colonisers and guide the use of screening in ICU infection control., (© 2021. The Author(s).)

Although the use of donation after circulatory death (DCD) donors has increased lung transplant activity, 25-40% of intended DCD donors do not convert to actual donation because of no progression to asystole in the required time frame after withdrawal of cardiorespiratory support (WCRS). No studies have specifically focussed on DCD lung donor progression. This retrospective study reviewed intended DCD lung donors to make a prediction model of the likelihood of progression to death using logistic regression and classification and regression tree (CART). Between 2014 and 2018, 159 of 334 referred DCD donors were accepted, with 100 progressing to transplant, while 59 (37%) did not progress. In logistic regression, a length of ICU stay ≤ 5 days, severe infra-tentorial brain damage on imaging and use of vasopressin were related with the progression to actual donation. CART modelling of the likelihood of death within 90-minute post-WCRS provided prediction with a sensitivity of 1.00 and positive predictive value of 0.56 in the validation data set. In the nonprogressed DCD group, 26 died within 6 h post-WCRS. Referral received early after ICU admission, with nonspontaneous ventilatory mode, deep coma and severe infra-tentorial damage were relevant predictors. The CART model is useful to exclude DCD donor candidates with low probability of progression., (© 2021 Steunstichting ESOT. Published by John Wiley & Sons Ltd.)

Background: Although it is intense in health care resources, by facilitating assessment and reconditioning, ex vivo lung perfusion (EVLP) has the potential to expand the donor pool and improve lung transplant outcomes. However, inclusion criteria used in EVLP trials have not been validated., Methods: This retrospective study from 2014 to 2018 reviewed our local state-based donation organization donor records as well as subsequent recipient outcomes to explore the relation between EVLP indications used in clinical trials and recipient outcomes. The primary outcome was primary graft dysfunction grade 3 at 24 hours, with 30-day mortality and posttransplant survival time as secondary outcomes, compared with univariate and multivariate analysis., Results: From 705 lung donor referrals, 304 lung transplantations were performed (use rate of 42%); 212 of recipients (70%) met at least 1 of the commonly cited EVLP initiation criteria. There was no significant difference in primary graft dysfunction grade 3 or 30-day mortality between recipients with or without an EVLP indication (10.2% versus 7.8%, P = .51; and 2.4% versus 0%, P = .14, respectively). Multivariate analyses showed no significant relationship between commonly cited EVLP criteria and primary graft dysfunction grade 3 or survival time. Recipient outcomes were significantly associated with recipient diagnosis., Conclusions: At least 1 commonly cited criterion for EVLP initiation was present in 70% of the transplanted donors, and yet it did not predict clinical results; acceptable outcomes were seen in both subgroups. To discover the true utility of EVLP beyond good clinical management and focus EVLP on otherwise unacceptable lungs, a reconsideration of EVLP inclusion criteria is required., (Copyright © 2021 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: Coronavirus disease 2019 (COVID-19) pandemic has caused unprecedented pressure on healthcare system globally. Lack of high-quality evidence on the respiratory management of COVID-19-related acute respiratory failure (C-ARF) has resulted in wide variation in clinical practice., Methods: Using a Delphi process, an international panel of 39 experts developed clinical practice statements on the respiratory management of C-ARF in areas where evidence is absent or limited. Agreement was defined as achieved when > 70% experts voted for a given option on the Likert scale statement or > 80% voted for a particular option in multiple-choice questions. Stability was assessed between the two concluding rounds for each statement, using the non-parametric Chi-square (χ 2 ) test (p < 0·05 was considered as unstable)., Results: Agreement was achieved for 27 (73%) management strategies which were then used to develop expert clinical practice statements. Experts agreed that COVID-19-related acute respiratory distress syndrome (ARDS) is clinically similar to other forms of ARDS. The Delphi process yielded strong suggestions for use of systemic corticosteroids for critical COVID-19; awake self-proning to improve oxygenation and high flow nasal oxygen to potentially reduce tracheal intubation; non-invasive ventilation for patients with mixed hypoxemic-hypercapnic respiratory failure; tracheal intubation for poor mentation, hemodynamic instability or severe hypoxemia; closed suction systems; lung protective ventilation; prone ventilation (for 16-24 h per day) to improve oxygenation; neuromuscular blocking agents for patient-ventilator dyssynchrony; avoiding delay in extubation for the risk of reintubation; and similar timing of tracheostomy as in non-COVID-19 patients. There was no agreement on positive end expiratory pressure titration or the choice of personal protective equipment., Conclusion: Using a Delphi method, an agreement among experts was reached for 27 statements from which 20 expert clinical practice statements were derived on the respiratory management of C-ARF, addressing important decisions for patient management in areas where evidence is either absent or limited., Trial Registration: The study was registered with Clinical trials.gov Identifier: NCT04534569.

Background: Donor smoking histories are common in the lung donor pool, which are known to adversely affect post-lung transplant (LTx) outcomes. However, no evidence is available about smoking status (current/former), cumulative dose effect, or the combined effect of tobacco with marijuana., Methods: We retrospectively reviewed our local state-based donation organization records and subsequent LTx recipient outcomes. The primary outcome was 3-year graft survival, with cause of death as secondary outcomes. Univariate and multivariate Cox regression analyses were used to explore smoking status or cumulative dose effect., Results: Between 2014 and 2018, 304 LTxs were performed: 133 (44%) LTxs were from never-smoker donors, 68 (22%) from former-smoker donors, and 103 (34%) from current-smoker donors. Of the current-smoker donors, 48% had a marijuana use history. There was no significant difference in early mortality, although recipients who received transplants from current-smoker donors had a lower 3-year graft survival than those who received transplants from never smokers. Multivariate modeling showed that current tobacco smoking (hazard ratio: 2.13, 95% CI: 1.13-3.99) and a more than 5-year weekly marijuana use (hazard ratio: 2.97, 95% CI: 1.29-6.87) were independent donor factors affecting graft survival. Chronic lung allograft dysfunction accounted for a higher proportion of the causes of death within 3 years after LTx where lungs from current/former smokers were utilized compared with those from never smokers (chronic lung allograft dysfunction-cause mortality: 11%, 7%, 0%, respectively)., Conclusions: More than 50% of LTx donors had smoking histories. Current tobacco use or more than 5-year weekly marijuana smoking history adversely affected 3-year graft survival. Our findings support the importance of obtaining a detailed donor tobacco and marijuana smoking history., (Copyright © 2020 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.)

Objectives: The manipulation of arterial carbon dioxide tension is associated with differential mortality and neurologic injury in intensive care and cardiac arrest patients; however, few studies have investigated this relationship in patients on venoarterial extracorporeal membrane oxygenation. We investigated the association between the initial arterial carbon dioxide tension and change over 24 hours on mortality and neurologic injury in patients undergoing venoarterial extracorporeal membrane oxygenation for cardiac arrest and refractory cardiogenic shock., Design: Retrospective cohort analysis of adult patients recorded in the international Extracorporeal Life Support Organization Registry., Setting: Data reported to the Extracorporeal Life Support Organization from all international extracorporeal membrane oxygenation centers during 2003-2016., Patients: Adult patients (≥ 18 yr old) supported with venoarterial extracorporeal membrane oxygenation., Interventions: None., Measurements and Main Results: A total of 7,168 patients had sufficient data for analysis at the initiation of venoarterial extracorporeal membrane oxygenation, 4,918 of these patients had arterial carbon dioxide tension data available at 24 hours on support. The overall in-hospital mortality rate was 59.9%. A U-shaped relationship between arterial carbon dioxide tension tension at extracorporeal membrane oxygenation initiation and in-hospital mortality was observed. Increased mortality was observed with a arterial carbon dioxide tension less than 30 mm Hg (odds ratio, 1.26; 95% CI, 1.08-1.47; p = 0.003) and greater than 60 mm Hg (odds ratio, 1.28; 95% CI, 1.10-1.50; p = 0.002). Large reductions (> 20 mm Hg) in arterial carbon dioxide tension over 24 hours were associated with important neurologic complications: intracranial hemorrhage, ischemic stroke, and/or brain death, as a composite outcome (odds ratio, 1.63; 95% CI, 1.03-2.59; p = 0.04), independent of the initial arterial carbon dioxide tension., Conclusions: Initial arterial carbon dioxide tension tension was independently associated with mortality in this cohort of venoarterial extracorporeal membrane oxygenation patients. Reductions in arterial carbon dioxide tension (> 20 mm Hg) from the initiation of extracorporeal membrane oxygenation were associated with neurologic complications. Further prospective studies testing these associations are warranted.

Purpose: Short-term exposure to outdoor air pollution has been positively associated with numerous measures of acute morbidity and mortality, most consistently as excess cardiorespiratory disease associated with fine particulate matter (PM 2.5 ), particularly in vulnerable populations. It is unknown if the critically ill, a vulnerable population with high levels of cardiorespiratory disease, is affected by air pollution., Methods: We performed a time series analysis of emergency cardiorespiratory, stroke and sepsis intensive care (ICU) admissions for the years 2008-2016, using data from the Australian and New Zealand Intensive Care Society Adult Patient Database (ANZICS-APD). Case-crossover analysis was conducted to assess the relationship between air pollution and the frequency and severity of ICU admissions having adjusted for temperature, humidity, public holidays and influenza activity., Results: 46,965 episodes in 87 separate ICUs were analysed. We found no statistically significant associations with admission counts. However, ICU admissions ending in death within 30 days were significantly positively associated with short-term exposure to PM 2.5 [RR 1.18, 95% confidence interval (CI) 1.02-1.37, per 10 µg/m 3 increase]. This association was more pronounced in those aged 65 and over (RR 1.33, 95% CI 1.11-1.58, per 10 µg/m 3 )., Conclusions: Increased ICU mortality was associated with higher levels of PM 2.5 . Larger studies are required to determine if the frequency of ICU admissions is positively associated with short-term exposure to air pollution.

Rationale: The characteristics and outcomes of patients presenting with an acute exacerbation of chronic obstructive pulmonary disease (AECOPD) requiring intensive care unit (ICU) admission are poorly understood and there are sparse epidemiological data. Objectives: The objectives were to describe epidemiology and outcomes of patients admitted to an ICU with COPD and to evaluate whether outcomes varied over time. Methods: We studied adult ICU admissions across Australia and New Zealand between 2005 and 2017 with a diagnosis of AECOPD and used an admission diagnosis of asthma as comparator for trends over time. We measured changes in characteristics and outcomes over time using logistic regression, adjusting for illness severity using the Australian New Zealand Risk of Death model. Results: We studied 31,991 admissions with AECOPD and 11,096 with asthma. Mean (standard deviation) age for AECOPD patients was 68.3 (11.2) years, with 35.4% mechanically ventilated. For patients with AECOPD, the percentage of deaths in an ICU was 8.7% and in a hospital was 15.4% of admissions, with the proportion of 69.2% discharged home and 5.6% discharged to a high-level care facility. During the study period, the proportion of ICU admissions with AECOPD per 10,000 admissions decreased at an annual rate of 2.0 (95% confidence interval [CI], 0.8-3.2; P  = 0.009) but their admission rate per million population increased annually by 4.5 (95% CI, 3.7-5.3; P  < 0.0001). There was a linear reduction in mortality for AECOPD but not for asthma admissions (odds ratio annual decline: AECOPD, 0.94 [0.93-0.95] and asthma, 1.01 [0.97-1.05]; P  = 0.001) and an increase in AECOPD admissions discharged to home (odds ratio annual increase, AECOPD, 1.04 [1.03-1.05] and asthma, 1.01 [0.99-1.03]; P  = 0.01). The reduction in mortality was sustained after adjusting for illness severity. Conclusions: Across Australia and New Zealand, the rate of ICU admissions due to AECOPD is increasing but mortality rates are decreasing, with a corresponding increase in the home discharge rates.

Objectives: To compare the characteristics of adults admitted to the ICU in Australia and New Zealand after trauma with nonelective, nontrauma admissions. To describe trends in hospital mortality and rates of discharge home among these two groups., Design: Retrospective review (2005-2017) of the Australia and New Zealand Intensive Care Society's Center for Outcome and Resource Evaluation Adult Patient Database., Setting: Adult ICUs in Australia and New Zealand., Patients: Adult (≥17 yr), nonelective, ICU admissions., Intervention: Observational study., Measurements and Main Results: We compared 77,002 trauma with 741,829 nonelective, nontrauma patients. Trauma patients were younger (49.0 ± 21.6 vs 60.6 ± 18.7 yr; p < 0.0001), predominantly male (73.1% vs 53.9%; p < 0.0001), and more frequently treated in tertiary hospitals (74.7% vs 45.8%; p < 0.0001). The mean age of trauma patients increased over time but was virtually static for nonelective, nontrauma patients (0.72 ± 0.02 yr/yr vs 0.03 ± 0.01 yr/yr; p < 0.0001). Illness severity increased for trauma but fell for nonelective, nontrauma patients (mean Australia and New Zealand risk of death: 0.10% ± 0.02%/yr vs -0.21% ± 0.01%/yr; p < 0.0001). Trauma patients had a lower hospital mortality than nonelective, nontrauma patients (10.0% vs 15.8%; p < 0.0001). Both groups showed an annual decline in the illness severity adjusted odds ratio (odds ratio) of hospital mortality, but this was slower among trauma patients (trauma: odds ratio 0.976/yr [0.968-0.984/yr; p < 0.0001]; nonelective, nontrauma: odds ratio 0.957/yr [0.955-0.959/yr; p < 0.0001]; interaction p < 0.0001). Trauma patients had lower rates of discharge home than nonelective, nontrauma patients (56.7% vs 64.6%; p < 0.0001). There was an annual decline in illness severity adjusted odds ratio of discharge home among trauma patients, whereas nonelective, nontrauma patients displayed an annual increase (trauma: odds ratio 0.986/yr [0.981-0.990/yr; p < 0.0001]; nonelective, nontrauma: odds ratio 1.014/yr [1.012-1.016/yr; p < 0.0001]; interaction: p < 0.0001)., Conclusions: The age and illness severity of adult ICU trauma patients in Australia and New Zealand has increased over time. Hospital mortality is lower for trauma than other nonelective ICU patients but has fallen more slowly. Trauma patients have become less likely to be discharged home than other nonelective ICU patients.

Competing Interests: Declaration of Competing Interest The authors declare that they have no competing interests.

Objective: To evaluate the association between consecutive days worked by intensivists and ICU patient outcomes., Design: Retrospective cohort study linked with survey data., Setting: Australia and New Zealand ICUs., Patients: Adults (16+ yr old) admitted to ICU in the Australia New Zealand Intensive Care Society Centre for Outcome and Resource Evaluation Registries (July 1, 2016, to June 30, 2018)., Interventions: None., Measurements and Main Results: We linked data on staffing schedules for each unit from the Critical Care Resources Registry 2016-2017 annual survey with patient-level data from the Adult Patient Database. The a priori chosen primary outcome was ICU length of stay. Secondary outcomes included hospital length of stay, ICU readmissions, and mortality (ICU and hospital). We used multilevel multivariable regression modeling to assess the association between days of consecutive intensivist service and patient outcomes; the predicted probability of death was included as a covariate and individual ICU as a random effect. The cohort included 225,034 patients in 109 ICUs. Intensivists were scheduled for seven or more consecutive days in 43 (39.4%) ICUs; 27 (24.7%) scheduled intensivists for 5 days, 22 (20.1%) for 4 days, seven (6.4%) for 3 days, four (3.7%) for 2 days, and six (5.5%) for less than or equal to 1 day. Compared with care by intensivists working 7+ consecutive days (adjusted ICU length of stay = 2.85 d), care by an intensivist working 3 or fewer consecutive days was associated with shorter ICU length of stay (3 consecutive days: 0.46 d fewer, p = 0.010; 2 consecutive days: 0.77 d fewer, p < 0.001; ≤ 1 consecutive days: 0.68 d fewer, p < 0.001). Shorter schedules of consecutive intensivist days worked were also associated with trends toward shorter hospital length of stay without increases in ICU readmissions or hospital mortality., Conclusions: Care by intensivists working fewer consecutive days is associated with reduced ICU length of stay without negatively impacting mortality.

Background and Objective: Solid organ donation remains low in Australia; however, donation after circulatory death (DCD) bolsters rates and is associated with good short- and long-term clinical outcomes among recipients, especially in lung and kidney recipients. However, its reintroduction is met with resistance within hospitals. The aim of the present study was to develop a greater understanding of DCD perceptions among staff involved., Methods: This descriptive exploratory study incorporated open-ended and scaled questions with intensive care staff at a public tertiary teaching hospital in Australia. Interviews were digitally recorded and transcribed verbatim before thematic analysis. Quantitative responses were assessed using a 10-point Likert scale., Results: Twelve participants were interviewed. Responses to the Likert scale questions were averaged. Donation after brain death was unanimously accepted (average = 10.0), whereas DCD acceptance was lower but remained supported (average = 8.8). Interview responses generated five themes, each containing subthemes. Respondents had concerns with DCD where perceptions existed that DCD would increase family distress, from either timeframes not being met or logistical delays. A second major source of concern stemmed from personal conflict relating to their role. There was difficulty transitioning from primarily sustaining life or facilitating palliation alone to advocating for DCD, especially where there was perceived potential for deviations from standard palliation in analgesia, sedation, and investigations. Overall, concerns were overcome by reliance on a supportive work environment, rationalisation of concerns over time, and reliance on protocols., Conclusions: Supportive leadership within the hospital's intensive care unit meant DCD occurred with minimal institutional resistance. However, some individual concerns surrounding DCD were identified. These may be present and amplified in other centres. More study is required in centres where institutional resistance to DCD is identified so that DCD may be further promoted to expand the donor pool., (Copyright © 2019 Australian College of Critical Care Nurses Ltd. Published by Elsevier Ltd. All rights reserved.)

The apnea test (AT) during clinical brain death (BD) testing does not account for different arterial gas tensions on veno-arterial extracorporeal membrane oxygenation (V-A ECMO). We aimed to develop a protocol and now report our experience with three patients. The protocol was developed and implemented in 2015 at a quaternary center in Australia, measures both right radial and postoxygenator carbon dioxide (CO2) and oxygen (O2) gas tensions during the AT, incorporates regular gas sampling and a gradual reduction in fresh gas flow to ensure patient oxygenation. Patient 1 remained apneic despite both right radial and postoxygenator CO2 gas tensions >60 mmHg. Patient 2, despite having CO2 levels in a right radial arterial sample high enough to diagnose BD, postoxygenator CO2 remained <60 mmHg. Patient 2 did not breathe but radiological tests confirmed BD. Patient 3 showed respiratory effort but only once CO2 levels rose high enough in both right radial and postoxygenator samples. No patient was hypoxic during the AT. Performance of a reliable AT on V-A ECMO requires measurement of both right radial and postoxygenator blood gases. A protocol, which measures both blood gas values, is feasible to implement, while being both safe and easy to perform.

Background: Traumatic brain injury (TBI) and subarachnoid hemorrhage (SAH) are the most common causes of severe acute brain injury in younger Intensive Care Unit (ICU) patients. Dysglycemia (abnormal peak glycemia, glycemic variability, mean glycemia, nadir glycemia) is common in these patients but its comparative outcome associations are unclear., Methods: In a retrospective, cross-sectional, study of adults admitted to Australian and New Zealand ICUs with TBI and SAH from 2005 to 2015, we studied the relationship between multiple aspects of early (first 24 hours) dysglycemia and mortality and compared TBI and SAH patients with the general ICU population and with each other., Results: Among 670,301 patients, 11,812 had TBI and 6,098 had SAH. After adjustment for illness severity, we found that the mortality rate increased with each quintile of glycemia for each aspect of early dysglycemia (peak glycemia, glycemic variability, mean glycemia, nadir glycemia; P<0.0001 for all). This increased risk of death was greater in TBI and SAH patients than in the general ICU population. Moreover, it was stronger for mean glycemia (increase in mortality from 9.2% in the lowest quintile to 15.1% in general ICU patients compared with an increase in mortality from 4.4% to 49.0% for TBI and SAH patients; P<0.0001). Finally, in TBI patients, this relationship was significantly stronger than in SAH patients (P<0.0001)., Conclusions: In TBI and SAH patients, greater dysglycemia is associated with greater mortality. This association is significantly stronger than in the general population and it is significantly stronger in patients with TBI compared with SAH.

Objective: To describe the prevalence of low-normal body temperatures in emergency department (ED) patients presenting with severe infection, and to determine whether active warming is used in this setting., Design, Setting and Participants: We performed a singlecentre retrospective cohort study in ED patients with community-acquired infection who required admission to the intensive care unit (ICU). Temperatures recorded from presentation up until 24 hours in the ICU were extracted from the patients' clinical records. Body temperatures were then classified as low (≤ 36.4°C), normothermic (36.5-37.9°C) or fever ≥ 38°C., Results: Over the study period, 574 patients were admitted to the ICU with infection. Of them, 151 fulfilled the inclusion criteria, and the in-hospital mortality rate for these patients was 8.6%. On presentation, 22.5% (34 patients) had a low body temperature (35-35.9°C for six patients, and < 35.0°C for three patients). In contrast, 26.5% (40 patients) had a temperature ≥ 38.0°C. Among those who presented with low temperature, the median time to reach normothermia was 7.9 hours (range, 3.3-14.0 hours). Active warming was only applied to one patient, (whose body temperature was < 35°C)., Conclusion: Among patients with community-acquired infection requiring ICU admission, about a quarter have a low temperature and active warming was essentially not applied. These findings suggest that active warming of such patients would likely achieve separation from usual care.