Zealand Intensive Care Units Research Articles

Opinions and practice of stress ulcer prophylaxis in Australian and New Zealand intensive care units

Opinions and practice of stress ulcer prophylaxis in Australian and New Zealand intensive care units

Mortality related to after-hours discharge from intensive care in Australia and New Zealand, 2005-2012.

After-hours discharge from the intensive care unit (ICU) is associated with adverse patient outcomes including increased ICU readmissions and mortality. Since Australian and New Zealand data were last published, overall ICU patient mortality has decreased; however it is unknown whether changes in discharge practices have contributed to these improved outcomes. Our aim was to examine trends over time in discharge timing and the contemporary associations with mortality and ICU readmission. Retrospective cohort study using data from the Australian and New Zealand Intensive Care Society Adult Patient Database (ANZICS APD) for patients admitted to Australian and New Zealand ICUs between January 2005 and December 2012. Data collected included patient characteristics, time of ICU discharge, hospital mortality and ICU readmissions. Between 1 January 2005 and 31 December 2012, there were 710,535 patients available for analysis, of whom 109,384 (15.4 %) were discharged after-hours (1800-0600 hours). There were no changes in timing of ICU discharge over the 8 years of the study. Patients discharged after-hours had a higher hospital mortality (6.4 versus 3.6 %; P < 0.001) and more ICU readmissions (5.1 versus 4.5 %; P < 0.001) than patients discharged in-hours. Although post-ICU mortality for all patients declined during the study period, the risk associated with after-hours discharge remained elevated throughout (odds ratio 1.34, 95 % confidence intervals 1.30-1.38). After-hours discharge remains an important independent predictor of hospital mortality and readmission to ICU. Despite widespread dissemination this evidence has not translated into fewer after-hours discharges or reduction in risk in Australian and New Zealand hospitals.

Variability of infusion preparation in Australian and New Zealand intensive care units

Variability of infusion preparation in Australian and New Zealand intensive care units

Letter by Eastwood et al Regarding Article, “Association Between Postresuscitation Partial Pressure of Arterial Carbon Dioxide and Neurological Outcome in Patients With Post–Cardiac Arrest Syndrome”

We read the article by Roberts and colleagues1 with interest. Although we agree that hypocapnia has been demonstrated to be common and is a predictor of poor neurological outcome after cardiac arrest, we are concerned that the findings may lack external validity. In a recent study involving 16 542 patients admitted to 125 Australian and New Zealand intensive care units after cardiac arrest between 2000 and 2011,2 we found that hypocapnia and …

Risk prediction of hospital mortality for adult patients admitted to Australian and New Zealand intensive care units: Development and validation of the Australian and New Zealand Risk of Death model

PurposeThe purpose of this study is to develop and validate a new mortality prediction model (Australian and New Zealand Risk of Death [ANZROD]) for Australian and New Zealand intensive care units (ICUs) and compare its performance with the existing Acute Physiology and Chronic Health Evaluation (APACHE) III-j. Materials and MethodsAll ICU admissions from 2004 to 2009 were extracted from the Australian and New Zealand Intensive Care Society Adult Patient Database. Hospital mortality was modeled using logistic regression with training (two third) and validation (one third) data sets. Predictor variables included APACHE III score components, source of admission to ICU and hospital, lead time, elective surgery, treatment limitation, ventilation status, and APACHE III diagnoses. Model performance was assessed by standardized mortality ratio, Hosmer-Lemeshow C and H statistics, Brier score, Cox calibration regression, area under the receiver operating characteristic curve, and calibration curves. ResultsThere were 456605 patients available for model development and validation. Observed mortality was 11.3%. Performance measures (standardized mortality ratio, Hosmer-Lemeshow C and H statistics, and receiver operating characteristic curve) for the ANZROD and APACHE III-j model in the validation data set were 1.01, 104.9 and 111.4, and 0.902; 0.84, 1596.6 and 2087.3, and 0.885, respectively. ConclusionsThe ANZROD has better calibration; discrimination compared with the APACHE III-j. Further research is required to validate performance over time and in specific subgroups of ICU population.

Evaluating the performance of Australian and New Zealand intensive care units in 2009 and 2010

The Australian and New Zealand Intensive Care Society Adult Patient Database (ANZICS APD) is one of the largest databases of its kind in the world and collects individual admissions' data from intensive care units (ICUs) around Australia and New Zealand. Use of this database for monitoring and comparing the performance of ICUs, quantified by the standardised mortality ratio, poses several theoretical and computational challenges, which are addressed in this paper. In particular, the expected number of deaths must be appropriately estimated, the ICU casemix adjustment must be adequate, statistical variation must be fully accounted for, and appropriate adjustment for multiple comparisons must be made. Typically, one or more of these issues have been neglected in ICU comparison studies. Our approach to the analysis proceeds by fitting a random coefficient hierarchical logistic regression model for the inhospital death of each patient, with patients clustered within ICUs. We anticipate the majority of ICUs will be estimated as performing 'usually' after adjusting for important clinical covariates. We take as a starting point the ideas in Ohlssen et al and estimate an appropriate null model that we expect these ICUs to follow, taking a frequentist rather than a Bayesian approach. This methodology allows us to rigorously account for the aforementioned statistical issues and to determine if there are any ICUs contributing to the Australian and New Zealand Intensive Care Society database that have comparatively unusual performance. In addition to investigating the yearly performance of the ICUs, we also estimate changes in individual ICU performance between 2009 and 2010 by adjusting for regression-to-the-mean.

Performance of Apache III over Time in Australia and New Zealand: A Retrospective Cohort Study

The Acute Physiology and Chronic Health Evaluation (APACHE) III-j model has been used for benchmarking intensive care unit (ICU) outcomes in Australia and New Zealand for over a decade. This study assessed performance of the APACHE III-j model in adult patients admitted to Australasian ICUs during a ten-year period. Data were extracted from the Australian and New Zealand Intensive Care Society Adult Patient Database. Performance of APACHE III-j at different time points and within different age strata was evaluated by dividing the whole cohort into five 'two-year' groups. Calibration and discrimination were assessed by the Brier score, Hosmer-Lemeshow C and H statistics, Standardised Mortality Ratio (SMR), Cox calibration regression, calibration curves and area under the receiver operating characteristic curve (AUROC). Model performance within diagnostic categories was evaluated. Between 1 January 2000 and 31 December 2009, 558,585 ICU admissions which met inclusion criteria were included in the analysis. The mean (standard deviation) age was 60.8 (18.4) years and 58.3% were male. Overall observed mortality was 12.6%. The mean (standard deviation) APACHE III-j predicted mortality was 14.5% (21.8). Although discrimination (as measured by AUROC) was preserved over time, all other markers of model performance showed deterioration. There was a significant decrease in SMR in eight of ten most common diagnoses examined. This study demonstrates that performance of APACHE III-j model has deteriorated in Australasian hospitals and there is now a clear need for an updated modelling approach to improve mortality prediction, performance monitoring and quality of research undertaken in Australian and New Zealand ICUs.

Enteral nutrition in Australian and New Zealand intensive care units: a point-prevalence study of prescription practices

Enteral nutrition in Australian and New Zealand intensive care units: a point-prevalence study of prescription practices

Mortality and intensive care volume in ventilated patients from 1995 to 2009 in the Australian and New Zealand binational adult patient intensive care database*

The mortality outcome of mechanical ventilation, a key intervention in the critically ill, has been variously reported to be determined by intensive care patient volume. We determined the volume-(mortality)-outcome relationship of mechanically ventilated patients whose records were contributed to the Australian and New Zealand Intensive Care Society Adult Patient Database. Retrospective cohort study of 208,810 index patient admissions from 136 Australian and New Zealand intensive care units in the same number of hospitals over the course of 1995-2009. The patient-volume effect on hospital mortality, overall and at the level of patient (nonsurgical, elective surgical, and emergency surgical) and intensive care unit (rural/regional, metropolitan, tertiary, and private) descriptors, was determined by random-effects logistic regression adjusting for illness severity and demographic and geographical predictors. Annualized patient volume was modeled both as a categorical (deciles) and, with calendar year, a continuous variable using fractional polynomials. The patients were of mean age of 59 yrs (SD, 19 yrs), Acute Physiology and Chronic Health Evaluation III score 66 (32), and 39.4% female, with a hospital mortality of 22.4%. Overall and at both the patient and intensive care unit descriptor levels, no progressive decline in mortality was demonstrated across the annual patient volume range (12-932). Over the whole database, mortality odds ratio for the last volume decile (801-932 patients) was 1.26 (95% confidence interval, 1.06-1.50; p = .009) compared with the first volume decile (12-101 patients). Calendar year mortality decreases were evident (odds ratio, 0.96; 95% confidence interval, 0.94-0.98; p = .0001). Using fractional polynomials, modest curvilinear mortality increases (range, 5%-8%) across the volume range were noted over the whole database for nonsurgical patients and at the tertiary intensive care unit level. No inverse volume-(mortality)-outcome relationship was apparent for ventilated patients in the Australian and New Zealand Intensive Care Society database. Mechanisms for mortality increments with patient volume were not identified but warrant further study.

Necrotising fasciitis: an 8.5-year retrospective case review in a New Zealand intensive care unit

Necrotising fasciitis: an 8.5-year retrospective case review in a New Zealand intensive care unit

Compliance with Processes of Care in Intensive Care Units in Australia and New Zealand – A Point Prevalence Study

There are indications that compliance with routine clinical practices in intensive care units (ICU) varies widely internationally, but it is currently unknown whether this is the case throughout Australia and New Zealand. A one-day point prevalence study measured the prevalence of routine care processes being delivered in Australian and New Zealand ICUs including the assessment and/or management of: nutrition, pain, sedation, weaning from mechanical ventilation, head of bed elevation, deep venous thrombosis prophylaxis, stress ulcer prophylaxis, blood glucose, pressure areas and bowel action. Using a sample of 50 adult ICUs, prevalence data were collected for 662 patients with a median age of 65 years and a median Acute Physiology and Chronic Health Evaluation II score of 18. Wide variations in compliance were evident in several care components including: assessment of nutritional goals (74%, interquartile range [IQR] 51 to 89%), pain score (35%, IQR 17 to 62%), sedation score (89%, IQR 50 to 100%); care of ventilated patients e.g. head of bed elevation > 30 degrees (33%, IQR 7 to 62%) and setting weaning plans (50%, IQR 28 to 78%); pressure area risk assessment (78%, IQR 18 to 100%) and constipation management plan (43%, IQR 6 to 87%). Care components that were delivered more consistently included nutrition delivery (100%, IQR 100 to 100%), deep venous thrombosis (96%, IQR 89 to 100%) and stress ulcer (90%, IQR 78 to 100%) prophylaxis, and checking blood sugar levels (93%, IQR 88 to 100%). This point prevalence study demonstrated variability in the delivery of 'routine' cares in Australian and New Zealand ICUs. This may be driven in part by lack of consensus on what is best practice in intensive care units, prompting the need for further research in this area.

Experience with High Frequency Oscillation Ventilation during the 2009 H1N1 Influenza Pandemic in Australia and New Zealand

During the 2009 H1N1 pandemic, large numbers of patients had severe respiratory failure. High frequency oscillation ventilation was used as a salvage technique for profound hypoxaemia. Our aim was to compare this experience with high frequency oscillation ventilation during the 2009 H1N1 pandemic with the same period in 2008 by performing a three-month period prevalence study in Australian and New Zealand intensive care units. The main study end-points were clinical demographics, care delivery and survival. Nine intensive care units contributed data. During 2009 there were 22 H1N1 patients (17 adults, five children) and 10 non-H1N1 patients (five adults, five children), while in 2008, 18 patients (two adults, 16 children) received high frequency oscillation ventilation. The principal non-H1N1 high frequency oscillation ventilation indication was bacterial or viral pneumonia (56%). For H1N1 patients, the median duration of high frequency oscillation ventilation was 3.7 days (interquartile range 1.8 to 5) with concomitant therapies including recruitment manoeuvres (22%), prone ventilation (41%), inhaled prostacyclins (18%) and inhaled nitric oxide (36%). Seven patients received extracorporeal membrane oxygenation, six having H1N1. Three patients had extracorporeal membrane oxygenation concurrently, two as salvage therapy following the commencement of high frequency oscillation ventilation. In 2008, no high frequency oscillation ventilation patient received extracorporeal membrane oxygenation. Overall hospital survival was 77% in H1N1 patients, while survival in patients having adjunctive extracorporeal membrane oxygenation was similar to those receiving high frequency oscillation ventilation alone (65% compared to 71%, P = 1.00). Survival rates were comparable to published extracorporeal membrane oxygenation outcomes. High frequency oscillation ventilation was used successfully as a rescue therapy for severe respiratory failure. High frequency oscillation ventilation was only available in a limited number of intensive care units during the H1N1 pandemic.

Clinical Prediction of Weaning and Extubation in Australian and New Zealand Intensive Care Units

Our objective was to describe, in Australian and New Zealand adult intensive care units, the relative frequency in which various clinical criteria were used to predict weaning and extubation, and the weaning methods employed. Participant intensivists at 55 intensive care units completed a self-administered questionnaire, using visual analogue scales (0 = not at all predictive, 10 = perfectly predictive, not used = null score) to record the perceived utility of 30 potential predictors. Survey response rate was 71% (164/230). Those variables thought most predictive of weaning readiness were respiratory rate (median score 8.0, interquartile range 7.0 to 8.6) effective cough (7.3, 5.9 to 8.2) and pressure support setting (7.2, 6.0 to 8.0). The most highly rated predictors of extubation success were effective cough (8.0, 7.0 to 9.0), respiratory rate (8.0, 7.0 to 8.5) and Glasgow Coma Score (7.9, 6.1 to 8.3). Variables perceived least predictive of weaning and extubation success were P0.1, Acute Physiological and Chronic Health Evaluation score II, mean arterial pressure, electrolytes and maximum inspiratory pressure (individual median scores < 5). Most popular clinical criteria were those perceived to have high predictive accuracy, both for weaning (respiratory rate 96%, pressure support setting 94% and Glasgow coma score 91%) and extubation readiness (respiratory rate 98%, effective cough 94% and Glasgow Coma Score 92%). Weaning mostly employed pressure support ventilation (55%), with less use of synchronised intermittent mandatory ventilation (32%) and spontaneous breathing trials (13%). Classic ventilatory performance predictors including respiratory rate and effective cough were reported to be of greater clinical utility than other more recently proposed measures.

Defining and evaluating the role of dietitians in intensive care: State of play

Summary Background & aims Intensive Care is a relatively new work area for dietitians in Australia and New Zealand. It is unclear how many dietitians are working in intensive care units (ICUs) and what their level of involvement is. Methods The study was a complete population study, surveying all 182 adult Australian and New Zealand ICUs on a list obtained from the Australian and New Zealand Intensive Care Society (ANZICS). An 18-question telephone survey was implemented to explore dietitians’ practices in ICU. Results At least one dietitian from each of the 182 hospitals participated in the survey (100% response rate). Thirteen ICUs had no dietitian service. In the remainder there was wide variation in dietitians’ involvement, ranging from occasional consulting to daily attendance at the ICU round, identifying and assessing patients requiring dietitian input, prescribing parenteral, enteral or oral nutrition support, ordering laboratory tests, and contributing to all nutrition-related decision-making in the ICU. Conclusions The wide variation in dietitians’ roles and responsibilities in the intensive care units across Australasia reflects the rapid recent growth in this area. The results of this survey may suggest some useful strategies that dietitians could implement to increase their involvement in the ICU setting.

Antimicrobial Utilisation in 37 Australian and New Zealand Intensive Care Units

This multi-centre point prevalence study reports on antimicrobial dosing patterns, including dose, mode of administration and type of infection, in 37 Australian and New Zealand intensive care units. Of 422 patients admitted to an intensive care unit on 8 May 2007, 195 patients (46%) received antimicrobial treatment, 123 patients (29%) received no antimicrobials and 104 patients (25%) received prophylactic antimicrobials only. Dosing data were available for 331 antimicrobials used to treat 225 infections in 193 patients. Respiratory (40%), abdominal (13%) and blood stream (12%) infections were most common. For adult patients, ticarcillin/clavulanate (23% or 40/177), meropenem (20% or 35/177) and vancomycin (18% or 32/177) were the most frequently used antibiotics; vancomycin was most commonly used in children (31% or 5/16). The majority of antimicrobials were administered as bolus doses or infusions of less than two hours (98% or 317/323); only six patients received extended or continuous infusions. The mode of administration was unknown in eight cases (4.1%). The total defined daily dose for adult patients receiving antimicrobial therapy was 2051 defined daily doses per 1000 patient days. Our results confirm that the use of continuous infusions remains rare, despite increased interest in continuous infusions for time-dependent antibiotics.

Nutritional therapy in patients with acute pancreatitis requiring critical care unit management: A prospective observational study in Australia and New Zealand*

To determine nutritional therapy practices of patients with severe acute pancreatitis (defined as those receiving critical care management in an intensive care unit or high-dependency unit) in Australia and New Zealand with focus on the choice of enteral nutrition or parenteral nutrition. Prospective observational multicentered study performed at 40 sites in Australia and New Zealand over 6 months. Intensive care units or high-dependency units within Australia and New Zealand. Those with severe acute pancreatitis diagnosed by elevated lipase and/or amylase. Patients with chronic pancreatitis were excluded. The primary outcome was the proportion of patients who received enteral nutrition, parenteral nutrition, or concurrent enteral nutrition/parenteral nutrition. Secondary outcomes included other aspects of nutritional therapy and the severity and clinical outcomes of acute pancreatitis. We enrolled 121 patients and 117 were analyzed. The mean age was 61 (sd 17) years and 53% were men. Enteral nutrition was delivered to 58 (50%; 95% confidence interval [CI], 41-59%) and parenteral nutrition to 49 (42%; 95% CI, 33-51%) patients. Parenteral nutrition was more frequently used as the initial therapy (58%; 95% CI, 49-67%) than enteral nutrition (42%; 95% CI, 33-51%). The most common reason for parenteral nutrition prescription was the treating doctor's preference (60%). Enteral nutrition (74%) was more often used than parenteral nutrition (40%) on any individual study day. Concurrent enteral nutrition and parenteral nutrition occurred in 28 (24%) patients on 14% of days. Complications of acute pancreatitis requiring critical care unit management were observed in 45 (39%) patients. The median (interquartile range) duration of intensive care unit and hospital stay were 5 (2-10) and 19 (9-31) days, respectively. The hospital mortality rate was 15% (95% CI, 8-21%), and there was a tendency toward higher mortality for patients who only received parenteral nutrition than for those who only received enteral nutrition (28% vs. 7%, p=.06). For patients with acute pancreatitis requiring critical care unit management in Australian and New Zealand intensive care units, enteral nutrition is used most commonly, but parenteral nutrition is more often used as the initial route of nutritional therapy. Given that clinical practice guidelines currently recommend enteral nutrition as the initial route of nutritional therapy in severe acute pancreatitis, improved education about and dissemination of these guidelines seems warranted.

Impact of pandemic (H1N1) 2009 on Australasian critical care units

Objective: To identify the resource usage by patients with influenza A H1N1 admitted to Australian and New Zealand intensive care units during the first wave of the pandemic in June, July and August 2009.Design, setting and participants: Data were collected in two separate surveys: the 2007–08 resource and activity survey and the 2009 influenza pandemic survey. Participants comprised 143 of the 189 Australian and New Zealand critical care units identified by the Australian and New Zealand Intensive Care Society Centre for Outcome and Resource Evaluation (ANZICS CORE). Mean length of stay (LOS) and ventilation data for H1N1 patients were reported by the ANZIC Influenza Investigators study from the same units over the same time period. Mean LOS for all ICU admissions was obtained from the ANZICS CORE adult patient database 10-year study.Main outcome measures: H1N1 patient admissions as a proportion of all ICU admissions; H1N1 patient bed-days as a proportion of total bed-days; ventilation resource usage by H1N1 patients; changes in ICU admissions for elective surgery during the H1N1 pandemic.Results: Over the period June–August 2009, among 30 222 ICU admissions to 133 ICUs contributing data, 704 patients (2.3%) had H1N1 influenza A. Twenty-eight units had no H1N1 patient admissions. The peak of the pandemic in Australia and New Zealand occurred in July 2009, when H1N1 patients represented 3.7% of all ICU admissions for July and 53.5% of all H1N1 patient admissions in the period June–August 2009. We estimate that H1N1 cases required approximately 12.4% of the ventilator resources and used 8.1% of total patient bed-days. During the pandemic, there was a 3.2 percentage-point reduction in elective admissions to public hospitals (from 32.5% to 29.3%).Conclusion: Low rates of admission of H1N1 patients to ICUs during the 2009 pandemic enabled the intensive care system to cope with the large demand when analysed at a jurisdictional level.

Mortality prediction and outcomes among burns patients from Australian and New Zealand intensive care units

Mortality prediction and outcomes among burns patients from Australian and New Zealand intensive care units

A survey of antibiotic prescribing practices in Australian and New Zealand intensive care units

A survey of antibiotic prescribing practices in Australian and New Zealand intensive care units

Audit of severe acute maternal morbidity describing reasons for transfer and potential preventability of admissions to ICU

Maternal mortality is a rare event in the developed world. Assessment of severe acute maternal morbidity (SAMM) is therefore an appropriate measure of the quality of maternity care. The aim of the study was to conduct a retrospective audit of SAMM cases (pregnant women admitted to a New Zealand Intensive Care Unit) to describe clinical, socio-demographic characteristics, pregnancy outcomes and preventability. Severe acute maternal morbidity cases were reviewed by a multidisciplinary panel to determine reasons for admission to ICU, to classify organ-system dysfunction and to determine whether the SAMM case was preventable or not. Inclusion criteria were: admission to ICU between 2005 and 2007 during pregnancy or within 42 days of delivery. Twenty-nine SAMM cases were reviewed, of which 10 (35%) were deemed preventable. The most common reasons for transfer to ICU were: the need for invasive vascular monitoring, hypotension and disseminated intravascular coagulation. The most frequent types of preventable events were: inadequate diagnosis/recognition of high-risk status, inappropriate treatment, communication problems and inadequate documentation. All five SAMM cases of septicaemia were deemed preventable. Of the ten preventable cases, three were Maori (50% of the Maori in total audit), four were Pacific (67% of the Pacific in total audit) and three were women of 'other' ethnicities (17.6%, 3 of 17 in the audit). An audit of SAMM cases describing reasons for transfer to ICU and preventability is feasible. We recommend that a prospective national SAMM audit process be introduced in New Zealand as a quality of care measure.