Outcomes associated with a variable rate insulin infusion diabetic ketoacidosis protocol.

AIMS: To relate adverse events with glucose correction rates in diabetic ketoacidosis (DKA) using variable rate intravenous insulin-infusions (VRIII). METHODS: Retrospective, observational study in adults with DKA who received insulin infusions between 2012 and 2017 at St Vincent's Hospital, Melbourne. Early correction of hyperglycaemia (<10 mmol/L) was evaluated for association with hypoglycaemia (<4.0 mmol/L), hypokalaemia (potassium <3.3 mmol/L) and clinical outcomes via regression analysis. RESULTS: The study involved 97 patients, with 93 % having type 1 diabetes. The mean age was 38 years, 47 % were women and 35 % were admitted to intensive care. Hypoglycaemia rates during 12 and 24 h of treatment were 6.2 % and 8.2 %, respectively with 58 % of patients recording their first BGL <10 mmol/L within 12 h and 88 % within 24 h. Ketone clearance time averaged at 15.6 h. Hyperglycaemia correction rates to <10 mmol/L were not different in those with/without hypoglycaemia at 12/24 h, in multivariate analysis including admission BGL. Hypokalaemia occurred in 40.2 % of patients and was associated with lower pH but not BGL correction rates. CONCLUSION: The VRIII protocol achieved early hyperglycaemia correction and ketoacidosis reversal with low hypoglycaemia risk. However, high hypokalaemia rates suggest the need for aggressive potassium replacement, especially in markedly acidotic patients.

Modelling of intensive care unit (ICU) length of stay as a quality measure: a problematic exercise.

BACKGROUND: Intensive care unit (ICU) length of stay (LOS) and the risk adjusted equivalent (RALOS) have been used as quality metrics. The latter measures entail either ratio or difference formulations or ICU random effects (RE), which have not been previously compared. METHODS: From calendar year 2016 data of an adult ICU registry-database (Australia & New Zealand Intensive Care Society (ANZICS) CORE), LOS predictive models were established using linear (LMM) and generalised linear (GLMM) mixed models. Model fixed effects quality-metric formulations were estimated as RALOSR for LMM (geometric mean derived from log(ICU LOS)) and GLMM (day) and observed minus expected ICU LOS (OMELOS from GLMM). Metric confidence intervals (95%CI) were estimated by bootstrapping; random effects (RE) were predicted for LMM and GLMM. Forest-plot displays of ranked quality-metric point-estimates (95%CI) were generated for ICU hospital classifications (metropolitan, private, rural/regional, and tertiary). Robust rank confidence sets (point estimate and 95%CI), both marginal (pertaining to a singular ICU) and simultaneous (pertaining to all ICU differences), were established. RESULTS: The ICU cohort was of 94,361 patients from 125 ICUs (metropolitan 16.9%, private 32.8%, rural/regional 6.4%, tertiary 43.8%). Age (mean, SD) was 61.7 (17.5) years; 58.3% were male; APACHE III severity-of-illness score 54.6 (25.7); ICU annual patient volume 1192 (702) and ICU LOS 3.2 (4.9). There was no concordance of ICU ranked model predictions, GLMM versus LMM, nor for the quality metrics used, RALOSR, OMELOS and site-specific RE for each of the ICU hospital classifications. Furthermore, there was no concordance between ICU ranking confidence sets, marginal and simultaneous for models or quality metrics. CONCLUSIONS: Inference regarding adjusted ICU LOS was dependent upon the statistical estimator and the quality index used to quantify any LOS differences across ICUs. That is, there was no "one best model"; thus, ICU "performance" is determined by model choice and any rankings thereupon should be circumspect.

Assessment of a Non-Invasive Brain Pulse Monitor to Measure Intra-Cranial Pressure Following Acute Brain Injury.

Background: Intracranial pressure (ICP) monitoring requires placing a hole in the skull through which an invasive pressure monitor is inserted into the brain. This approach has risks for the patient and is expensive. We have developed a non-invasive brain pulse monitor that uses red light to detect a photoplethysmographic (PPG) signal arising from the blood vessels on the brain's cortical surface. The brain PPG and the invasive ICP waveform share morphological features which may allow measurement of the intracranial pressure. Methods: We enrolled critically ill patients with an acute brain injury with invasive ICP monitoring to assess the new monitor. A total of 24 simultaneous invasive ICP and brain pulse monitor PPG measurements were undertaken in 12 patients over a range of ICP levels. Results: The waveform morphologies were similar for the invasive ICP and brain pulse monitor PPG approach. Both methods demonstrated a progressive increase in the amplitude of P2 relative to P1 with increasing ICP levels. An automated algorithm was developed to assess the PPG morphological features in relation to the ICP level. A correlation was demonstrated between the brain pulse waveform morphology and ICP levels, R2=0.66, P < 0.001. Conclusion: The brain pulse monitor's PPG waveform demonstrated morphological features were similar to the invasive ICP waveform over a range of ICP levels, these features may provide a method to measure ICP levels. Trial Registration: ACTRN12620000828921.

Can nebulised HepArin Reduce morTality and time to Extubation in patients with COVID-19 Requiring invasive ventilation Meta-Trial (CHARTER-MT): Protocol and statistical analysis plan for an investigator-initiated international meta-trial of prospective randomised clinical studies.

There is significant interest in the potential for nebulised unfractionated heparin (UFH), as a novel therapy for patients with COVID-19 induced acute hypoxaemic respiratory failure requiring invasive ventilation. The scientific and biological rationale for nebulised heparin stems from the evidence for extensive activation of coagulation resulting in pulmonary microvascular thrombosis in COVID-19 pneumonia. Nebulised delivery of heparin to the lung may limit alveolar fibrin deposition and thereby limit progression of lung injury. Importantly, laboratory studies show that heparin can directly inactivate the SARS-CoV-2 virus, thereby prevent its entry into and infection of mammalian cells. UFH has additional anti-inflammatory and mucolytic properties that may be useful in this context. METHODS AND INTERVENTION: The Can nebulised HepArin Reduce morTality and time to Extubation in Patients with COVID-19 Requiring invasive ventilation Meta-Trial (CHARTER-MT) is a collaborative prospective individual patient data analysis of on-going randomised controlled clinical trials across several countries in five continents, examining the effects of inhaled heparin in patients with COVID-19 requiring invasive ventilation on various endpoints. Each constituent study will randomise patients with COVID-19 induced respiratory failure requiring invasive ventilation. Patients are randomised to receive nebulised heparin or standard care (open label studies) or placebo (blinded placebo-controlled studies) while under invasive ventilation. Each participating study collect a pre-defined minimum dataset. The primary outcome for the meta-trial is the number of ventilator-free days up to day 28 day, defined as days alive and free from invasive ventilation.

Hospital-acquired complications: the relative importance of hospital- and patient-related factors.

OBJECTIVE: To quantify the prevalence of hospital-acquired complications; to determine the relative influence of patient- and hospital-related factors on complication rates. DESIGN, PARTICIPANTS: Retrospective analysis of administrative data (Integrated South Australian Activity Collection; Victorian Admitted Episodes Dataset) for multiple-day acute care episodes for adults in public hospitals. SETTING: Thirty-eight major public hospitals in South Australia and Victoria, 2015-2018. MAIN OUTCOME MEASURES: Hospital-acquired complication rates, overall and by complication class, by hospital and hospital type (tertiary referral, major metropolitan service, major regional service); variance in rates (intra-class correlation coefficient, ICC) at the patient, hospital, and hospital type levels as surrogate measures of their influence on rates. RESULTS: Of 1 558 978 public hospital episodes (10 029 918 bed-days), 151 486 included a total of 214 286 hospital-acquired complications (9.72 [95% CI, 9.67-9.77] events per 100 episodes; 2.14 [95% CI, 2.13-2.15] events per 100 bed-days). Complication rates were highest in tertiary referral hospitals (12.7 [95% CI, 12.6-12.8] events per 100 episodes) and for episodes including intensive care components (37.1 [95% CI, 36.7-37.4] events per 100 episodes). For all complication classes, inter-hospital variation was determined more by patient factors (overall ICC, 0.55; 95% CI, 0.53-0.57) than by hospital factors (ICC, 0.04; 95% CI, 0.02-0.07) or hospital type (ICC, 0.01; 95% CI, 0.001-0.03). CONCLUSIONS: Hospital-acquired complications were recorded for 9.7% of hospital episodes, but patient-related factors played a greater role in determining their prevalence than the treating hospital.

Modelling hospital outcome: problems with endogeneity.

BACKGROUND: Mortality modelling in the critical care paradigm traditionally uses logistic regression, despite the availability of estimators commonly used in alternate disciplines. Little attention has been paid to covariate endogeneity and the status of non-randomized treatment assignment. Using a large registry database, various binary outcome modelling strategies and methods to account for covariate endogeneity were explored. METHODS: Patient mortality data was sourced from the Australian & New Zealand Intensive Society Adult Patient Database for 2016. Hospital mortality was modelled using logistic, probit and linear probability (LPM) models with intensive care (ICU) providers as fixed (FE) and random (RE) effects. Model comparison entailed indices of discrimination and calibration, information criteria (AIC and BIC) and binned residual analysis. Suspect covariate and ventilation treatment assignment endogeneity was identified by correlation between predictor variable and hospital mortality error terms, using the Stata™ "eprobit" estimator. Marginal effects were used to demonstrate effect estimate differences between probit and "eprobit" models. RESULTS: The cohort comprised 92,693 patients from 124 intensive care units (ICU) in calendar year 2016. Patients mean age was 61.8 (SD 17.5) years, 41.6% were female and APACHE III severity of illness score 54.5(25.6); 43.7% were ventilated. Of the models considered in predicting hospital mortality, logistic regression (with or without ICU FE) and RE logistic regression dominated, more so the latter using information criteria indices. The LPM suffered from many predictions outside the unit [0,1] interval and both poor discrimination and calibration. Error terms of hospital length of stay, an independent risk of death score and ventilation status were correlated with the mortality error term. Marked differences in the ventilation mortality marginal effect was demonstrated between the probit and the "eprobit" models which were scenario dependent. Endogeneity was not demonstrated for the APACHE III score. CONCLUSIONS: Logistic regression accounting for provider effects was the preferred estimator for hospital mortality modelling. Endogeneity of covariates and treatment variables may be identified using appropriate modelling, but failure to do so yields problematic effect estimates.

Incidence and management of metabolic acidosis with sodium bicarbonate in the ICU: An international observational study.

BACKGROUND: Metabolic acidosis is a major complication of critical illness. However, its current epidemiology and its treatment with sodium bicarbonate given to correct metabolic acidosis in the ICU are poorly understood. METHOD: This was an international retrospective observational study in 18 ICUs in Australia, Japan, and Taiwan. Adult patients were consecutively screened, and those with early metabolic acidosis (pH < 7.3 and a Base Excess < -4 mEq/L, within 24-h of ICU admission) were included. Screening continued until 10 patients who received and 10 patients who did not receive sodium bicarbonate in the first 24 h (early bicarbonate therapy) were included at each site. The primary outcome was ICU mortality, and the association between sodium bicarbonate and the clinical outcomes were assessed using regression analysis with generalized linear mixed model. RESULTS: We screened 9437 patients. Of these, 1292 had early metabolic acidosis (14.0%). Early sodium bicarbonate was given to 18.0% (233/1292) of these patients. Dosing, physiological, and clinical outcome data were assessed in 360 patients. The median dose of sodium bicarbonate in the first 24 h was 110 mmol, which was not correlated with bodyweight or the severity of metabolic acidosis. Patients who received early sodium bicarbonate had higher APACHE III scores, lower pH, lower base excess, lower PaCO2, and a higher lactate and received higher doses of vasopressors. After adjusting for confounders, the early administration of sodium bicarbonate was associated with an adjusted odds ratio (aOR) of 0.85 (95% CI, 0.44 to 1.62) for ICU mortality. In patients with vasopressor dependency, early sodium bicarbonate was associated with higher mean arterial pressure at 6 h and an aOR of 0.52 (95% CI, 0.22 to 1.19) for ICU mortality. CONCLUSIONS: Early metabolic acidosis is common in critically ill patients. Early sodium bicarbonate is administered by clinicians to more severely ill patients but without correction for weight or acidosis severity. Bicarbonate therapy in acidotic vasopressor-dependent patients may be beneficial and warrants further investigation.

Nebulised heparin for patients with or at risk of acute respiratory distress syndrome: a multicentre, randomised, double-blind, placebo-controlled phase 3 trial.

BACKGROUND: Mechanical ventilation in intensive care for 48 h or longer is associated with the acute respiratory distress syndrome (ARDS), which might be present at the time ventilatory support is instituted or develop afterwards, predominantly during the first 5 days. Survivors of prolonged mechanical ventilation and ARDS are at risk of considerably impaired physical function that can persist for years. An early pathogenic mechanism of lung injury in mechanically ventilated, critically ill patients is inflammation-induced pulmonary fibrin deposition, leading to thrombosis of the microvasculature and hyaline membrane formation in the air sacs. The main aim of this study was to determine if nebulised heparin, which targets fibrin deposition, would limit lung injury and thereby accelerate recovery of physical function in patients with or at risk of ARDS. METHODS: The Can Heparin Administration Reduce Lung Injury (CHARLI) study was an investigator-initiated, multicentre, double-blind, randomised phase 3 trial across nine hospitals in Australia. Adult intensive care patients on invasive ventilation, with impaired oxygenation defined by a PaO2/FiO2 ratio of less than 300, and with the expectation of invasive ventilation beyond the next calendar day were recruited. Key exclusion criteria were heparin allergy, pulmonary bleeding, and platelet count less than 50 X 109/L. Patients were randomly assigned 1:1, with stratification by site and using blocks of variable size and random seed, via a web-based system, to either unfractionated heparin sodium 25 000 IU in 5 mL or identical placebo (sodium chloride 0·9% 5 mL), administered using a vibrating mesh membrane nebuliser every 6 h to day 10 while invasively ventilated. Patients, clinicians, and investigators were masked to treatment allocation. The primary outcome was the Short Form 36 Health Survey Physical Function Score (out of 100) of survivors at day 60. Prespecified secondary outcomes, which are exploratory, included development of ARDS to day 5 among at-risk patients, deterioration of the Murray Lung Injury Score (MLIS) to day 5, mortality at day 60, residence of survivors at day 60, and serious adverse events. Analyses followed the intention-to-treat principle. There was no imputation of missing data. The trial is registered with the Australian and New Zealand Clinical Trials Register, number ACTRN12612000418875 . FINDINGS: Between Sept 4, 2012, and Aug 23, 2018, 256 patients were randomised. Final follow-up was on Feb 25, 2019. We excluded three patients who revoked consent and one ineligible participant who received no intervention. Of 252 patients included in data analysis, the mean age was 58 years (SD 15), 157 (62%) were men, and 118 (47%) had ARDS. 128 (51%) patients were assigned to the heparin group and 124 (49%) to the placebo group, all of whom received their assigned intervention. Survivors in the heparin group (n=97) had similar SF-36 Physical Function Scores at day 60 compared to the placebo group (n=94; mean 53·6 [SD 31·6] vs 48·7 [35·7]; difference 4·9 [95% CI -4·8 to 14·5]; p=0·32). Compared with the placebo group, the heparin group had fewer cases of ARDS develop to day 5 among the at-risk patients (nine [15%] of 62 patients vs 21 [30%] of 71 patients; hazard ratio 0·46 [95% CI 0·22 to 0·98]; p=0·0431), less deterioration of the MLIS to day 5 (difference -0·14 [-0·26 to -0·02]; p=0·0215), similar day 60 mortality (23 [18%] of 127 patients vs 18 [15%] of 123 patients; odds ratio [OR] 1·29 [95% CI 0·66 to 2·53]; p=0·46), and more day 60 survivors at home (86 [87%] of 99 patients vs 73 [73%] of 100 patients; OR 2·45 [1·18 to 5·08]; p=0·0165). A similar number of serious adverse events occurred in each group (seven [5%] of 128 patients in the heparin group vs three [2%] of 124 patients in the placebo group; OR 2·33 [0·59 to 9·24]; p=0·23), which were a transient increase in airway pressure during nebulisation (n=3 in the heparin group), major non-pulmonary bleeding (n=2 in each group), haemoptysis (n=1 in the heparin group), tracheotomy site bleeding (n=1 in the heparin group), and hypoxaemia during nebulisation (n=1 in the placebo group). INTERPRETATION: In patients with or at risk of ARDS, nebulised heparin did not improve self-reported performance of daily physical activities, but was well tolerated and exploratory outcomes suggest less progression of lung injury and earlier return home. Further research is justified to establish if nebulised heparin accelerates recovery in those who have or are at risk of ARDS. FUNDING: Rowe Family Foundation, TR and RB Ditchfield Medical Research Endowment Fund, Patricia Madigan Charitable Trust, and The J and R McGauran Trust Fund.

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.

Safety of the endotracheal tube for prolonged mechanical ventilation.

RATIONALE: The endotracheal tube (ETT) is the most common route for invasive mechanical ventilation (MV) yet controversy attends its long-term safety. OBJECTIVE: Assess the safety of ETT compared with tracheostomy tube (TT) for MV support in the intensive care unit (ICU). METHODS: Retrospective analysis of five year national dataset of 128,977 adults (age > 15-years) admitted for MV therapy with tracheostomy tube (TT; n = 4772) or without (ETT; n = 124,204), excluding those with neurological diagnoses or likely to require a surgical airway (n = 27,466), in 93 public health service ICUs across Australia, between July 2013-June 2018. MEASUREMENTS: Hospital survival (including liberation from MV) for ETT Group compared with TT Group using a probit regression model adjusted for confounding using fixed, endogenous and non-random treatment assignment covariates, and their interactions; analysed and plotted as marginal effects by duration of MV. RESULTS: Median duration of MV was 2 (IQR =1-4) days, predominantly via ETT (124,205; 96.3%), and 21,620 (16.7%) died. Temporal trend for ETT increased (OR = 1.06 per year, 95%CI =1.03-1.10) compared to TT, even for prolonged (>3 weeks) MV (38.1%). Higher risk-adjusted mortality was associated with longer duration of MV and after 9 days of MV with retention of ETT compared with TT - average (mortality) treatment effect 12.6% (95%CI =10.7-14.5). The latter was not significant after 30 days of MV. CONCLUSIONS: The safety of ETT compared with TT beyond short-term MV (≤9-days) is uncertain and requires prospective evaluation with additional data.

Frailty in very old critically ill patients in Australia and New Zealand: a population-based cohort study.

OBJECTIVE: To explore associations between frailty (Clinical Frailty Scale score of 5 or more) in very old patients in intensive care units (ICUs) and their clinical outcomes (mortality, discharge destination). DESIGN, SETTING AND PARTICIPANTS: Retrospective population cohort analysis of Australian and New Zealand Intensive Care Society (ANZICS) Adult Patient Database data for all patients aged 80 years or more admitted to participating ICUs between 1 January 2017 and 31 December 2018. MAIN OUTCOME MEASURES: Primary outcome: in-hospital mortality; secondary outcomes: length of stay (hospital, ICU), re-admission to ICU during the same hospital admission, discharge destination (including new chronic care or nursing home admission). RESULTS: Frailty status data were available for 15 613 of 45 773 patients aged 80 years or more admitted to 178 ICUs (34%); 6203 of these patients (39.7%) were deemed frail. A smaller proportion of frail than non-frail patients were men (47% v 57%), the mean illness severity scores of frail patients were slightly higher than those of non-frail patients, and they were more frequently admitted from the emergency department (28% v 21%) or with sepsis (12% v 7%) or respiratory complications (16% v 12%). In-hospital mortality was higher for frail patients (17.6% v 8.2%; adjusted odds ratio [OR], 1.87 [95% CI, 1.65-2.11]). Median lengths of ICU and hospital stay were slightly longer for frail patients, and they were more frequently discharged to new nursing home or chronic care (4.9% v 2.8%; adjusted OR, 1.61 [95% CI, 1.34-1.95]). CONCLUSIONS: Many very old critically ill patients in Australia and New Zealand are frail, and frailty is associated with considerably poorer health outcomes. Routine screening of older ICU patients for frailty could improve outcome prediction and inform intensive care and community health care planning.

Frailty is associated with reduced prospect of discharge home after in-hospital cardiac arrest.

BACKGROUND: Frailty is common among acute hospital patients and might adversely affect recovery from inpatient cardiac arrest. AIM: To assess the relationship between hospital admission characteristics, including frailty, and discharge outcome after in-hospital cardiac arrest. METHODS: Prospectively collected data were retrospectively analysed for all separations from a tertiary hospital during 2008-2017 that involved rapid response team attendance for cardiac arrest. Hospital Frailty Risk Score (HFRS) and Charlson index of comorbidity were calculated from 'primary' and 'associated' International Classification of Diseases, 10th revision, Australian Modification diagnoses. HFRS ≥5 was taken to signify frailty. Discharge home from hospital and death in hospital were modelled using logistic regression. RESULTS: There were 388 in-hospital arrest patients: 91% were aged ≥50 years, 34% were previously discharged in the past 6 months, 66% were unplanned admissions, 63% were non-cardiology-cardiothoracic admissions, 45% had a Charlson comorbidity index ≥2 and 19% were identified as frail. Discharge home occurred in 22%, discharge to another hospital 17% and death 62%. Of the frail patients, only 3 (4%) were discharged home, 12 (17%) were discharged to another hospital and 57 (79%) died in hospital. Fewer frail patients were discharged home compared with non-frail patients (4 vs 26%; odds ratio (OR) 0.13, P = 0.001). On multivariable analysis, patients were less likely to be discharged home if they had frailty (OR 0.24, P = 0.02), age ≥ 50 years (OR 0.36, P = 0.01), non-cardiology-cardiothoracic unit admission (OR 0.40, P = 0.001) and unplanned admission (OR 0.57, P = 0.04). Frail patients discharged to another hospital spent a median of 15 days (interquartile range 11-23) in the hospital post-arrest before leaving to continue inpatient care elsewhere. Frailty was associated with death in hospital on univariate analysis (79 vs 58%; OR 2.80, P = 0.001) but not after controlling for other factors. CONCLUSION: Frail patients are unlikely to make a good recovery after in-hospital arrest. This should be taken into account when planning care with patients and their families.

Diabetic ketoacidosis in adult patients: an audit of factors influencing time to normalisation of metabolic parameters.

BACKGROUND: Diabetic ketoacidosis (DKA) is an acute life-threatening metabolic complication of diabetes that imposes substantial burden on our healthcare system. There is a paucity of published data in Australia assessing factors influencing time to resolution of DKA and length of stay (LOS). AIMS: To identify factors that predict a slower time to resolution of DKA in adults with diabetes. METHODS: Retrospective audit of patients admitted to St Vincent's Hospital Melbourne between 2010 to 2014 coded with a diagnosis of 'Diabetic Ketoacidosis'. The primary outcome was time to resolution of DKA based on normalisation of biochemical markers. Episodes of DKA within the wider Victorian hospital network were also explored. RESULTS: Seventy-one patients met biochemical criteria for DKA; median age 31 years (26-45 years), 59% were male and 23% had newly diagnosed diabetes. Insulin omission was the most common precipitant (42%). Median time to resolution of DKA was 11 h (6.5-16.5 h). Individual factors associated with slower resolution of DKA were lower admission pH (P < 0.001) and higher admission serum potassium level (P = 0.03). Median LOS was 3 days (2-5 days), compared to a Victorian state-wide LOS of 2 days. Higher comorbidity scores were associated with longer LOS (P < 0.001). CONCLUSIONS: Lower admission pH levels and higher admission serum potassium levels are independent predictors of slower time to resolution of DKA. This may assist to stratify patients with DKA using markers of severity to determine who may benefit from closer monitoring and to predict LOS.

Use of resuscitation plans at a tertiary Australian hospital: room for improvement.

BACKGROUND: The 'Acute Resuscitation Plan' (ARP) is a document for recording the resuscitation plans of patients at a tertiary hospital for adult patients. The ARP was introduced at the hospital in September 2014, superseding the 'Not for Cardiopulmonary Resuscitation (CPR)' form. Unlike the Not for CPR form, the ARP was relevant to patients with and without resuscitation limits. AIM: To evaluate the introduction of the ARP. METHODS: This study is a retrospective audit of the records of all admissions to the hospital from January to June 2014 (Not for CPR period) and January to June 2015 (ARP period). The main outcomes are the incidence of resuscitation plans, the proportion of ARP specifying consultation with the patient (or representative) and with senior medical staff, and the proportion of ARP among older patients and those with significant comorbidity. RESULTS: Resuscitation plans were present for 453 of 23 325 (1.9%) admissions in the Not for CPR period versus 1801 of 24 037 (7.5%) in the ARP period (odds ratio (OR) 4.1, 95% confidence interval (CI) 3.7-4.5, P < 0.001). A total of 42% of ARP specified 'care of the dying' in the event of arrest. Acknowledgement of the views of the patient (or representative) was indicated on 37% of ARP and of a senior physician on 28%. An ARP was not present for 67% of patients aged ≥90 years, 59% from aged care, 90% with metastatic cancer and 64% aged ≥80 years and with a Charlson comorbidity index ≥3. CONCLUSIONS: More patients had resuscitation plans after introducing the ARP. However, patients and senior physicians were often remote from the consultation process, and an ARP was not present for many patients likely to have a poor outcome from cardiopulmonary arrest.

Rapid response team diagnoses: frequencies and related hospital mortality.

OBJECTIVES: To describe the frequency and hospital mortality of problems (diagnoses) encountered by a rapid response team (RRT), and to identify the most common diagnoses for RRT triggers and for treating units. DESIGN: For each RRT event in 2015 at a tertiary hospital for adults, we chose the diagnosis that best explained the RRT event from a pre-defined list after reviewing relevant test results and clinical notes. RESULTS: There were 937 RRT events during 700 admissions and there were 58 different RRT diagnoses in 11 diagnosis groups. The largest groups were neurological and consciousness problems (22.9%), circulatory problems (19.0%) and breathing problems (16.0%). The most common diagnoses were rapid atrial fibrillation (7.6%) and oversedation or narcosis (4.8%). When SpO2 < 90% triggered RRT review, the leading diagnoses were complex respiratory failure (25.9%) and pneumonia (11.4%). When decreased conscious state triggered review, the main problems were neurological, but there were 39 different diagnoses among these cases. The main problems among orthopaedic cases were post-operative hypovolaemia (19.0%) and spinal anaesthetic-related or epidural analgesicrelated hypotension (15.2%). Hospital mortality was 101/700 (14.4%). Diagnoses with high mortality included gastrointestinal bleeding (4/17, 23.5%), complex respiratory failure (8/33, 24.2%), intracranial event (8/28, 28.6%), cardiogenic shock or acute heart failure (5/17, 29.4%), pneumonia (7/21, 33.3%), chest sepsis (5/11, 45.5%) and cardiac arrest (18/26, 69.2%). CONCLUSIONS: The RRT activation trigger provides only a general indication of the diagnosis. Some problems appear preventable and could provide a focus for unit-based quality initiatives. The mortality of some diagnoses is substantial, and this may help in setting treatment goals, but more work is needed to understand the association of RRT diagnosis and outcome.

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

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

The impact of an education program and written guideline on adherence to low tidal volume ventilation.

BACKGROUND: Low tidal volume ventilation reduces mortality in patients with acute lung injury (ALI) and may reduce the risk of ALI in ventilated patients. A previous audit of our ventilation practices showed poor adherence to low tidal volume ventilation, and we subsequently introduced written ventilation guidelines and an education program to change practice. OBJECTIVES: To determine if adherence to low tidal volume ventilation (defined as mandatory tidal volumes of =?6.5 mL/ kg predicted body weight [PBW]) in ventilated patients was improved with a written guideline and staff education. DESIGN AND SETTING: Retrospective analysis of recorded mandatory ventilator settings from the clinical information system of a tertiary referral intensive care unit from 1 January 2012 to 31 December 2015, involving analysis of mandatory ventilator settings in relation to PBW to determine adherence to guidelines, and interrupted time-series analysis to assess the impact of education. MAIN OUTCOME MEASURE: Adherence to low tidal volume ventilation. RESULTS: The mean tidal volume for the cohort was 7.4 mL/ kg (SD, 1.3 mL/kg) PBW, and 760 patients (26.9%) received an average tidal volume during mandatory ventilation of ≤6.5 mL/kg PBW. Interrupted time-series analysis showed improved adherence after education, with an increase in adherence of 29.4% (95% CI, 19.3%-39.5%) from baseline. Multivariate logistic analysis found height, weight and staff education, but not sex, were associated with adherence to low tidal volume ventilation. CONCLUSION: Written protocols and education can influence clinician behaviour, with substantial improvements in adherence to low tidal volume ventilation. Efforts to improve adherence through ward-based education appear warranted and necessary. Adherence was strongly associated with patient height, which suggested that adherence was partly the result of chance rather than design.

Towards defining persistent critical illness and other varieties of chronic critical illness.

We hypothesise that there exists a substantial and growing group of "persistently critically ill" patients who appear to be intensive care unit-dependent because of a cascade of critical illnesses rather than their original ICU admitting diagnosis. These persistently critically ill patients are those who remain in the ICU because of ongoing complications of care that continue after their reason for admission has been treated and is no longer active. We believe such patients can be distinguished from patients currently labelled as "chronic critical illness" or "prolonged mechanical ventilation". We further believe that their primary problem is not simply failure to wean from mechanical ventilation due to muscle weakness and impaired gas exchange. We outline a program of clinician consultation, epidemiological research, consensus conference and validation to develop a useful definition of persistent critical illness, with the aim of supporting investigations in preventing persistence, and improving the care of patients so affected.