Sex Differences in Vital Organ Support Provided to ICU Patients.

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.

Measuring the Impact of ICU Strain on Mortality, After-Hours Discharge, Discharge Delay, Interhospital Transfer, and Readmission in Australia With the Activity Index.

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.

Sex Differences in Mortality of ICU Patients According to Diagnosis-related Sex Balance.

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.

Variation in Bed-to-Physician Ratios During Weekday Daytime Hours in ICUs in Australia and New Zealand.

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.

An Audit of Lung Donor Pool: Optimal Current Donation Strategies and the Potential of Novel Time-Extended Donation After Circulatory Death Donation.

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.

Associations Between Socioeconomic Status, Patient Risk, and Short-Term Intensive Care Outcomes.

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.

Genomic surveillance of antimicrobial resistant bacterial colonisation and infection in intensive care patients.

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.

Improving the predictability of time to death in controlled donation after circulatory death lung donors.

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.

Expert consensus statements for the management of COVID-19-related acute respiratory failure using a Delphi method.

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 (χ2) 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.

Annual prevalence, characteristics, and outcomes of intensive care patients with skin or soft tissue infections in Australia and New Zealand: A retrospective cohort study between 2006-2017.

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.

Association Between Consecutive Days Worked by Intensivists and Outcomes for Critically Ill Patients.

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.

Characteristics and Outcomes of Critically Ill Trauma Patients in Australia and New Zealand (2005-2017).

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.

Association Between Arterial Carbon Dioxide Tension and Clinical Outcomes in Venoarterial Extracorporeal Membrane Oxygenation.

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.

Exploring staff perceptions of organ donation after circulatory death.

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.

Retrieval of Adult Patients on Extracorporeal Membrane Oxygenation by an Intensive Care Physician Model.

The optimal staffing model during the inter-hospital transfer of patients on extracorporeal membrane oxygenation (ECMO) is not known. We report the complications and outcomes of patients who were commenced on ECMO at a referring hospital by intensive care physicians and compare these findings with patients who had ECMO established at an ECMO center in Australia. This was a single center, retrospective observational study based on a prospectively collected ECMO database from Melbourne, Australia. Patients with severe cardiac and/or respiratory failure failing conventional supportive treatment between 2007-2013 were placed on ECMO via a physician-led model of ECMO retrieval, including two intensivists in a four person team, using percutaneous ECMO cannulation. Patients (198) underwent ECMO over the study period, of which 31% were retrieved. Veno-venous (VV)-ECMO and veno-arterial (VA)-ECMO accounted for 27 and 73% respectively. The VA-ECMO patients had more intra-transport interventions compared with VV-ECMO transported patients, but none resulting in serious morbidity or death. There was no overall difference in survival at 6 months between retrieved and ECMO center patients: VV-ECMO (75 vs. 70%, P = 0.690) versus VA-ECMO (70 vs. 68%, P = 1.000). An intensive care physician-led team was able to safely place all critically ill patients on ECMO and retrieve them to an ECMO center. This may be an appropriate staffing model for ECMO retrieval.

Early Hyperoxia in Patients with Traumatic Brain Injury Admitted to Intensive Care in Australia and New Zealand: A Retrospective Multicenter Cohort Study.

BACKGROUND: Early hyperoxia may be an independent risk factor for mortality in critically ill traumatic brain injury (TBI) patients, although current data are inconclusive. Accordingly, we conducted a retrospective cohort study to determine the association between systemic oxygenation and in-hospital mortality, in critically ill mechanically ventilated TBI patients. METHODS: Data were extracted from the Australian and New Zealand Intensive Care Society Centre for Outcome and Resource Evaluation Adult Patient Database. All adult TBI patients receiving mechanical ventilation in 129 intensive care units between 2000 and 2016 were included in analysis. The following data were extracted: demographics, illness severity scores, physiological and laboratory measurements, institutional characteristics, and vital status at discharge. In-hospital mortality was used as the primary study outcome. The primary exposure variable was the 'worst' partial arterial pressure of oxygen (PaO2) recorded during the first 24 h in ICU; hyperoxia was defined as > 299 mmHg. Adjustment for illness severity utilized multivariable logistic regression, the results of which are reported as the odds ratio (OR) 95% CI. RESULTS: Data concerning 24,148 ventilated TBI patients were extracted. By category of worst PaO2, crude in-hospital mortality ranged from 27.1% (PaO2 40-49 mmHg) to 13.3% (PaO2 140-159 mmHg). When adjusted for patient and institutional characteristics, the only PaO2 category associated with a significantly greater risk of death was < 40 mmHg [OR 1.52, 1.03-2.25]. A total of 3117 (12.9%) patients were hyperoxic during the first 24 h in ICU, with a crude in-hospital mortality rate of 17.8%. No association was evident in between hyperoxia and mortality in adjusted analysis [OR 0.97 (0.86-1.11)]. CONCLUSIONS: In this large multicenter cohort of TBI patients, hyperoxia in the first 24 h after ICU admission was not independently associated with greater in-hospital mortality. Hypoxia remains associated with greater in-hospital mortality risk and should be avoided where possible.

Suicide right ventricle after lung transplantation for pulmonary vascular disease.

A 27-year-old female with Eisenmenger's syndrome underwent closure of a patent ductus arteriosus, closure of a perimembranous ventricular septal defect and mid muscular defect and bilateral lung transplantation. Her immediate postoperative course was complicated by severe right ventricular outflow tract (RVOT) obstruction resulting in hemodynamic collapse, a condition described as suicide right ventricle. The patient was placed on central Veno-Arterial Extra-Corporeal Membrane Oxygenation as a bridge to the relief of RVOT obstruction which included a right ventricular outflow muscle resection and a right ventricle outflow tract patch. The patient made an uneventful recovery.

Gastrointestinal Carriage Is a Major Reservoir of Klebsiella pneumoniae Infection in Intensive Care Patients.

BACKGROUND: Klebsiella pneumoniae is an opportunistic pathogen and leading cause of hospital-associated infections. Intensive care unit (ICU) patients are particularly at risk. Klebsiella pneumoniae is part of the healthy human microbiome, providing a potential reservoir for infection. However, the frequency of gut colonization and its contribution to infections are not well characterized. METHODS: We conducted a 1-year prospective cohort study in which 498 ICU patients were screened for rectal and throat carriage of K. pneumoniae shortly after admission. Klebsiella pneumoniae isolated from screening swabs and clinical diagnostic samples were characterized using whole genome sequencing and combined with epidemiological data to identify likely transmission events. RESULTS: Klebsiella pneumoniae carriage frequencies were estimated at 6% (95% confidence interval [CI], 3%-8%) among ICU patients admitted direct from the community, and 19% (95% CI, 14%-51%) among those with recent healthcare contact. Gut colonization on admission was significantly associated with subsequent infection (infection risk 16% vs 3%, odds ratio [OR] = 6.9, P < .001), and genome data indicated matching carriage and infection isolates in 80% of isolate pairs. Five likely transmission chains were identified, responsible for 12% of K. pneumoniae infections in ICU. In sum, 49% of K. pneumoniae infections were caused by the patients' own unique strain, and 48% of screened patients with infections were positive for prior colonization. CONCLUSIONS: These data confirm K. pneumoniae colonization is a significant risk factor for infection in ICU, and indicate ~50% of K. pneumoniae infections result from patients' own microbiota. Screening for colonization on admission could limit risk of infection in the colonized patient and others.

Readmissions to Intensive Care: A Prospective Multicenter Study in Australia and New Zealand.

OBJECTIVES: To determine factors independently associated with readmission to ICU and the independent association of readmission with subsequent mortality. DESIGN: Prospective multicenter observational study. SETTING: Forty ICUs in Australia and New Zealand. PATIENTS: Consecutive adult patients discharged alive from ICU to hospital wards between September 2009 and February 2010. INTERVENTIONS: Measurement of hospital mortality. MEASUREMENTS AND MAIN RESULTS: We studied 10,210 patients and 674 readmissions. The median age was 63 years (interquartile range, 49-74), and 6,224 (61%) were male. The majority of readmissions were unplanned (84.1%) but only deemed preventable in a minority (8.9%) of cases. Time to first readmission was shorter for unplanned than planned readmission (3.2 vs 6.9 d; p < 0.001). Primary diagnosis changed between admission and readmission in the majority of patients (60.2%) irrespective of planned (58.2%) or unplanned (60.6%) status. Using recurrent event analysis incorporating patient frailty, we found no association between readmissions and hospital survival (hazard ratios: first readmission 0.88, second readmission 0.90, third readmission 0.44; p > 0.05). In contrast, age (hazard ratio, 1.03), a medical diagnosis (hazard ratio, 1.43), inotrope use (hazard ratio, 3.47), and treatment limitation order (hazard ratio, 17.8) were all independently associated with outcome. CONCLUSIONS: In this large prospective study, readmission to ICU was not an independent risk factor for mortality.

Subarachnoid Hemorrhage Patients Admitted to Intensive Care in Australia and New Zealand: A Multicenter Cohort Analysis of In-Hospital Mortality Over 15 Years.

OBJECTIVE: The primary aim of this study was to describe in-hospital mortality in subarachnoid hemorrhage patients requiring ICU admission. Secondary aims were to identify clinical characteristics associated with inferior outcomes, to compare subarachnoid hemorrhage mortality with other neurological diagnoses, and to explore the variability in subarachnoid hemorrhage standardized mortality ratios. DESIGN: Multicenter, binational, retrospective cohort study. SETTING: Data were extracted from the Australian and New Zealand Intensive Care Society Centre for Outcome and Resource Evaluation Adult Patient Database. PATIENTS: All available records for the period January 2000 to June 2015. INTERVENTIONS: Nil. MEASUREMENTS AND MAIN RESULTS: A total of 11,327 subarachnoid hemorrhage patients were identified in the Australian and New Zealand Intensive Care Society Centre for Outcome and Resource Evaluation Adult Patient Database. The overall case fatality rate was 29.2%, which declined from 35.4% in 2000 to 27.2% in 2015 (p = 0.01). Older age, nonoperative admission, mechanical ventilation, higher Acute Physiology and Chronic Health Evaluation III scores, lower Glasgow Coma Scale, and admission prior to 2004 were all associated with lower hospital survival in multivariable analysis (p < 0.05). In comparison with other neurological diagnoses, subarachnoid hemorrhage patients had significantly greater risk-adjusted in-hospital mortality (odds ratio, 1.89 [95% CI, 1.79-2.00]). Utilizing data from the 5 most recent complete years (2010-2014), three sites had higher and four (including the two largest centers) had lower standardized mortality ratios than might be expected due to chance. CONCLUSIONS: Subarachnoid hemorrhage patients admitted to ICU in Australia and New Zealand have a high mortality rate. Year of admission beyond 2003 did not impact risk-adjusted in-hospital mortality. Significant variability was noted between institutions. This implies an urgent need to systematically evaluate many aspects of the critical care provided to this patient group.