Epidemiology of Intensive Care Patients Classified as a Third Sex in Australia and New Zealand

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.

The Long-Term Impact of Frailty After an Intensive Care Unit Admission Due to Chronic Obstructive Pulmonary Disease

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.

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.

The impact of body mass index on long-term survival after ICU admission due to COVID-19: A retrospective multicentre study

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/m2. Patients with a BMI ≥30 kg/m2 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/m2. 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/m2 (35.4%) and 18.5-24.9 kg/m2 (31.1%), while lowest for BMI ≥40 kg/m2 (14.5%). After adjusting for confounders and with BMI 18.5-24.9 kg/m2 category as a reference, only the BMI ≥40 kg/m2 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/m2 was associated with a higher survival time of up to two years.

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.

Thirty years of ANZICS CORE: A clinical quality success story

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.

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.

Incidence of death or disability at 6 months after extracorporeal membrane oxygenation in Australia: a prospective, multicentre, registry-embedded cohort study

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.

A prediction model to determine the untapped lung donor pool outside of the DonateLife network in Victoria

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.

Genomic dissection of Klebsiella pneumoniae infections in hospital patients reveals insights into an opportunistic pathogen

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.

Klebsiella pneumoniae is an opportunistic pathogen of increasing public health concern due to the prevalence of antimicrobial resistance. Here, the authors provide insight into the resistance profiles, bacterial genome features and virulence genes, in a year-long prospective study of K. pneumoniae clinical isolates.

Hospital-acquired complications in critically ill patients

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.

Assessment of a novel marker of ICU strain, the ICU Activity Index, during the COVID-19 pandemic in Victoria, Australia

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.

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.

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.

Early metabolic acidosis in critically ill patients: a binational multicentre study

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 Paco2 ≤ 45 mmHg and HCO3- ≤ 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 Paco2 ≤ 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.

Acidemia subtypes in critically ill patients: An international cohort study

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 (PaCO₂ > 42 mmHg only), and combined (both SBE < -2 mEq/L and PaCO₂ > 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 PaCO₂, 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 PaCO₂ in respiratory acidemia.

A Retrospective Review of Declined Lung Donors: Estimating the Potential of Ex Vivo Lung Perfusion

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.

Common Criteria for Ex Vivo Lung Perfusion Have No Significant Impact on Posttransplant Outcomes

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.

A survey of extracorporeal membrane oxygenation practice in 23 Australian adult intensive care units

In Australia, extracorporeal membrane oxygenation (ECMO) is one of the most expensive diagnosis-related groups, costing $305 463 per complex admission to the intensive care unit(ICU). Mortality in this group of patients is high, about 43% for respiratory failure and 68% for cardiac failure. ECMO is associated with significant risk to the patient and requires specialist training andexpertise. Variation in clinical practice for patients supported with ECMO may compromise patient care and outcomes.

Intensive care admissions and outcomes associated with short-term exposure to ambient air pollution: a time series analysis

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/m³ increase]. This association was more pronounced in those aged 65 and over (RR 1.33, 95% CI 1.11-1.58, per 10 µg/m³).

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.

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.

Prevalence of low-normal body temperatures and use of active warming in emergency department patients presenting with severe infection

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.

Early dysglycemia and mortality in traumatic brain injury and subarachnoid hemorrhage

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.

Predicting medical emergency team calls, cardiac arrest calls and re-admission after intensive care discharge: creation of a tool to identify at-risk patients

We aimed to develop a predictive model for intensive care unit (ICU)-discharged patients at risk of post-ICU deterioration. We performed a retrospective, single-centre cohort observational study by linking the hospital admission, patient pathology, ICU, and medical emergency team (MET) databases. All patients discharged from the Alfred Hospital ICU to wards between July 2012 and June 2014 were included. The primary outcome was a composite endpoint of any MET call, cardiac arrest call or ICU re-admission. Multivariable logistic regression analysis was used to identify predictors of outcome and develop a risk-stratification model. Four thousand, six hundred and thirty-two patients were included in the study. Of these, 878 (19%) patients had a MET call, 51 (1.1%) patients had cardiac arrest calls, 304 (6.5%) were re-admitted to ICU during the same hospital stay, and 964 (21%) had MET calls, cardiac arrest calls or ICU re-admission. A discriminatory predictive model was developed (area under the receiver operating characteristic curve 0.72 [95% confidence intervals {CI} 0.70 to 0.73]) which identified the following factors: increasing age (odds ratio [OR] 1.012 [95% CI 1.007 to 1.017] <i>P</i> <0.001), ICU admission with subarachnoid haemorrhage (OR 2.26 [95% CI 1.22 to 4.16] <i>P</i>=0.009), admission to ICU from a ward (OR 1.67 [95% CI 1.31 to 2.13] <i>P</i> <0.001), Acute Physiology and Chronic Health Evaluation (APACHE) III score without the age component (OR 1.005 [95% CI 1.001 to 1.010] <i>P</i>=0.025), tracheostomy on ICU discharge (OR 4.32 [95% CI 2.9 to 6.42] <i>P</i> <0.001) and discharge to cardiothoracic (OR 2.43 [95%CI 1.49 to 3.96] <i>P</i> <0.001) or oncology wards (OR 2.27 [95% CI 1.05 to 4.89] <i>P</i>=0.036). Over the two-year period, 361 patients were identified as having a greater than 50% chance of having post-ICU deterioration. Factors are identifiable to predict patients at risk of post-ICU deterioration. This knowledge could be used to guide patient follow-up after ICU discharge, optimise healthcare resources, and improve patient outcomes and service delivery.

The use of a simple three-level bronchoscopic assessment of inhalation injury to predict in-hospital mortality and duration of mechanical ventilation in patients with burns

Major burn centres in Australia use bronchoscopy to assess severity of inhalation injuries despite limited evidence as to how best to classify severity of inhalational injury or its relationship to patient outcomes. All patients with burns who were admitted to the intensive care unit (ICU) at The Alfred Hospital between February 2010 and July 2014 and underwent bronchoscopy to assess inhalational injury, were reviewed. Age, total body surface area burnt, severity of illness indices and mechanisms of injury were extracted from medical histories and local ICU and burns registries. Inhalational injury was classified based on the Abbreviated Injury Score and then grouped into three categories (none/mild, moderate, or severe injury). Univariable and multivariable analyses were undertaken to examine the relationship between inhalational injury and outcomes (in-hospital mortality and duration of mechanical ventilation). One hundred and twenty-eight patients were classified as having none/mild inhalational injury, 81 moderate, and 13 severe inhalation injury. Mortality in each group was 2.3% (3/128), 7.4% (6/81) and 30.7% (4/13) respectively. Median (interquartile range) duration of mechanical ventilation in each group was 26 (11-82) hours, 84 (32-232) hours and 94 (21-146) hours respectively. After adjusting for age, total body surface area burnt and severity of illness, only the severe inhalation injury group was independently associated with increased mortality (odds ratio 20.4 [95% confidence intervals {CI} 1.74 to 239.4], <i>P</i>=0.016). Moderate inhalation injury was independently associated with increased duration of ventilation (odds ratio 2.25 [95% CI 1.53 to 3.31], <i>P</i> <0.001), but not increased mortality. This study suggests that stratification of bronchoscopically-assessed inhalational injury into three categories can provide useful prognostic information about duration of ventilation and mortality. Larger multicentre prospective studies are required to validate these findings.

Early glycemia and mortality in critically ill septic patients: Interaction with insulin-treated diabetes

PURPOSE

To investigate the relationship between dysglycemia and hospital mortality in patients with and without a preadmission diagnosis of insulin treated diabetes mellitus (ITDM).

MATERIALS AND METHODS

An observational multicentre cohort study using the ANZICS-APD database on adult patients admitted to ICU with sepsis between January 1st 2006 and December 31st 2015. Four domains of dysglycemia were investigated (highest, mean and lowest blood glucose levels and glycemic variability: the absolute difference between the highest and lowest level). The association between a preadmission diagnosis of ITDM and hospital mortality in each domain was analysed.

RESULTS

We studied 90,644 septic patients including 5127 patients with ITDM. We found that septic ICU patients with ITDM have lower adjusted hospital mortality with higher peak blood glucose levels in the first 24 h while non-ITDM patients have increased mortality (interaction p 0.012). We found that this significant difference was replicated when assessing glycemic variability (interaction p 0.048).

CONCLUSIONS

Septic patients with a pre-existing diagnosis of ITDM show a different relationship between hospital mortality and highest glucose levels and glycemic variability in the first 24 h than those without ITDM. These findings provide a rationale for an ITDM-specific approach to the management of dysglycemia.

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.

Assessing contemporary intensive care unit outcome: development and validation of the Australian and New Zealand Risk of Death admission model

The Australian and New Zealand Risk of Death (ANZROD) model currently used for benchmarking intensive care units (ICUs) in Australia and New Zealand utilises physiological data collected up to 24 hours after ICU admission to estimate the risk of hospital mortality. This study aimed to develop the Australian and New Zealand Risk of Death admission (ANZROD₀) model to predict hospital mortality using data available at presentation to ICU and compare its performance with the ANZROD in Australian and New Zealand hospitals. Data pertaining to all ICU admissions between 1 January 2006 and 31 December 2015 were extracted from the Australian and New Zealand Intensive Care Society Adult Patient Database. Hospital mortality was modelled using logistic regression with development (two-thirds) and validation (one-third) datasets. All predictor variables available at ICU admission were considered for inclusion in the ANZROD₀ model. Model performance was assessed using Brier score, standardised mortality ratio and area under the receiver operating characteristic curve. The relationship between ANZROD₀ and ANZROD predicted risk of death was assessed using linear regression. After standard exclusions, 1,097,416 patients were available for model development and validation. Observed mortality was 9.5%. Model performance measures (Brier score, standardised mortality ratio and area under the receiver operating characteristic curve) for the ANZROD₀ and ANZROD in the validation dataset were 0.069, 1.0 and 0.853; 0.057, 1.0 and 0.909, respectively. There was a strong positive correlation between the mortality predictions with an overall R² of 0.73. We found that the ANZROD₀ model had acceptable calibration and discrimination. Predictions from the models had high correlations in all major diagnostic groups, with the exception of cardiac surgery and possibly trauma and sepsis.

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.

Proceedings of the 12th International Conference on Rapid Response Systems and Medical Emergency Teams

Rapid Response Teams (RRTs) have been introduced into hospitals worldwide in an effort to improve the outcomes of deteriorating hospitalised patients. Recently, there has been increased awareness of the need to develop systems other than RRTs for deteriorating patients. In May 2016, the 12th International Conference on Rapid Response Systems and Medical Emergency Teams was held in Melbourne. This represented a collaboration between the newly constituted International Society for Rapid Response Systems (iSRRS) and the Australian and New Zealand Intensive Care Society. The conference program included broad ranging presentations related to general clinical deterioration in the acute care setting, as well as deterioration in the emergency department, during pregnancy, in the paediatric setting, and deterioration in mental health status. This article briefly summarises the key features of the conference, links to presentations, and the 18 abstracts of the accepted free papers.

The Alfred Hospital experience of resumption of cardiac activity after withdrawal of life-sustaining therapy

With the advent of donation after circulatory death programs in Australia and New Zealand, greater knowledge is needed about physiologic variation in haemodynamic activity following withdrawal of cardiorespiratory support. The ANZICS Statement on Death and Organ Donation allows provision for variation in the observation times between two and five minutes after cessation of the circulation prior to declaration of death. We report our experience of two cases, the first where electrical activity and pulse returned after a 102 second pause and the second where electrical activity returned after a three minute pause; both longer than previously reported cases.

Modelling risk-adjusted variation in length of stay among Australian and New Zealand ICUs

PURPOSE

Comparisons between institutions of intensive care unit (ICU) length of stay (LOS) are significantly confounded by individual patient characteristics, and currently there is a paucity of methods available to calculate risk-adjusted metrics.

METHODS

We extracted de-identified data from the Australian and New Zealand Intensive Care Society (ANZICS) Adult Patient Database for admissions between January 1 2011 and December 31 2015. We used a mixed-effects log-normal regression model to predict LOS using patient and admission characteristics. We calculated a risk-adjusted LOS ratio (RALOSR) by dividing the geometric mean observed LOS by the exponent of the expected Ln-LOS for each site and year. The RALOSR is scaled such that values <1 indicate a LOS shorter than expected, while values >1 indicate a LOS longer than expected. Secondary mixed effects regression modelling was used to assess the stability of the estimate in units over time.

RESULTS

During the study there were a total of 662,525 admissions to 168 units (median annual admissions = 767, IQR:426-1121). The mean observed LOS was 3.21 days (median = 1.79 IQR = 0.92-3.52) over the entire period, and declined on average 1.97 hours per year (95%CI:1.76-2.18) from 2011 to 2015. The RALOSR varied considerably between units, ranging from 0.35 to 2.34 indicating large differences after accounting for case-mix.

CONCLUSIONS

There are large disparities in risk-adjusted LOS among Australian and New Zealand ICUs which may reflect differences in resource utilization.

Prognostic Accuracy of the SOFA Score, SIRS Criteria, and qSOFA Score for In-Hospital Mortality Among Adults With Suspected Infection Admitted to the Intensive Care Unit

IMPORTANCE

The Sepsis-3 Criteria emphasized the value of a change of 2 or more points in the Sequential [Sepsis-related] Organ Failure Assessment (SOFA) score, introduced quick SOFA (qSOFA), and removed the systemic inflammatory response syndrome (SIRS) criteria from the sepsis definition.

OBJECTIVE

Externally validate and assess the discriminatory capacities of an increase in SOFA score by 2 or more points, 2 or more SIRS criteria, or a qSOFA score of 2 or more points for outcomes among patients who are critically ill with suspected infection.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort analysis of 184 875 patients with an infection-related primary admission diagnosis in 182 Australian and New Zealand intensive care units (ICUs) from 2000 through 2015.

EXPOSURES

SOFA, qSOFA, and SIRS criteria applied to data collected within 24 hours of ICU admission.

MAIN OUTCOMES AND MEASURES

The primary outcome was in-hospital mortality. In-hospital mortality or ICU length of stay (LOS) of 3 days or more was a composite secondary outcome. Discrimination was assessed using the area under the receiver operating characteristic curve (AUROC). Adjusted analyses were performed using a model of baseline risk determined using variables independent of the scoring systems.

RESULTS

Among 184 875 patients (mean age, 62.9 years [SD, 17.4]; women, 82 540 [44.6%]; most common diagnosis bacterial pneumonia, 32 634 [17.7%]), a total of 34 578 patients (18.7%) died in the hospital, and 102 976 patients (55.7%) died or experienced an ICU LOS of 3 days or more. SOFA score increased by 2 or more points in 90.1%; 86.7% manifested 2 or more SIRS criteria, and 54.4% had a qSOFA score of 2 or more points. SOFA demonstrated significantly greater discrimination for in-hospital mortality (crude AUROC, 0.753 [99% CI, 0.750-0.757]) than SIRS criteria (crude AUROC, 0.589 [99% CI, 0.585-0.593]) or qSOFA (crude AUROC, 0.607 [99% CI, 0.603-0.611]). Incremental improvements were 0.164 (99% CI, 0.159-0.169) for SOFA vs SIRS criteria and 0.146 (99% CI, 0.142-0.151) for SOFA vs qSOFA (P <.001). SOFA (AUROC, 0.736 [99% CI, 0.733-0.739]) outperformed the other scores for the secondary end point (SIRS criteria: AUROC, 0.609 [99% CI, 0.606-0.612]; qSOFA: AUROC, 0.606 [99% CI, 0.602-0.609]). Incremental improvements were 0.127 (99% CI, 0.123-0.131) for SOFA vs SIRS criteria and 0.131 (99% CI, 0.127-0.134) for SOFA vs qSOFA (P <.001). Findings were consistent for both outcomes in multiple sensitivity analyses.

CONCLUSIONS AND RELEVANCE

Among adults with suspected infection admitted to an ICU, an increase in SOFA score of 2 or more had greater prognostic accuracy for in-hospital mortality than SIRS criteria or the qSOFA score. These findings suggest that SIRS criteria and qSOFA may have limited utility for predicting mortality in an ICU setting.