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.

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.

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.

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.

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.

The timing of discharge from the intensive care unit and subsequent mortality. A prospective, multicenter study.

RATIONALE: Previous studies suggested an association between after-hours intensive care unit (ICU) discharge and increased hospital mortality. Their retrospective design and lack of correction for patient factors present at the time of discharge make this association problematic. OBJECTIVES: To determine factors independently associated with mortality after ICU discharge. METHODS: This was a prospective, multicenter, binational observational study involving 40 ICUs in Australia and New Zealand. Participants were consecutive adult patients discharged alive from the ICU between September 2009 and February 2010. MEASUREMENTS AND MAIN RESULTS: We studied 10,211 patients discharged alive from the ICU. Median age was 63 years (interquartile range, 49-74), 6,224 (61%) were male, 5,707 (56%) required mechanical ventilation, and their median Acute Physiology and Chronic Health Evaluation III risk of death was 9% (interquartile range, 3-25%). A total of 8,539 (83.6%) patients were discharged in-hours (06:00-18:00) and 1,672 (16.4%) after-hours (18:00-06:00). Of these, 408 (4.8%) and 124 (7.4%), respectively, subsequently died in hospital (P < 0.001). After risk adjustment for markers of illness severity at time of ICU discharge including limitations of medical therapy (LOMT) orders, the time of discharge was no longer a significant predictor of mortality. The presence of a LOMT order was the strongest predictor of death (odds ratio, 35.4; 95% confidence interval, 27.5-45.6). CONCLUSIONS: In this large, prospective, multicenter, binational observational study, we found that patient status at ICU discharge, particularly the presence of LOMT orders, was the chief predictor of hospital survival. In contrast to previous studies, the timing of discharge did not have an independent association with mortality.

Paracetamol therapy and outcome of critically ill patients: a multicenter retrospective observational study.

INTRODUCTION: In this study, we aimed to examine the association between paracetamol administration in the intensive care unit (ICU) and mortality in critically ill patients. METHODS: We conducted a multicenter retrospective observational study in four ICUs. We obtained information on paracetamol use, body temperature, demographic, clinical and outcome data from each hospital's clinical information system and admissions and discharges database. We performed statistical analysis to assess the association between paracetamol administration and hospital mortality. RESULTS: We studied 15,818 patients with 691,348 temperature measurements at 4 ICUs. Of these patients, 10,046 (64%) received at least 1 g of paracetamol. Patients who received paracetamol had lower in-hospital mortality (10% vs. 20%, P <0.001), and survivors were more likely to have received paracetamol (66% vs. 46%; P <0.001). However, patients treated with paracetamol were also more likely to be admitted to the ICU after surgery (70% vs. 51%; P <0.001) and/or after elective surgery (55% vs. 37%; P <0.001). In multivariate logistic regression analysis including a propensity score for paracetamol treatment, we found a significant and independent association between the use of paracetamol and reduced in-hospital mortality (adjusted odds ratio =0.60 (95% confidence interval (CI), 0.53 to 0.68), P <0.001). Cox proportional hazards analysis showed that patients who received paracetamol also had a significantly longer time to death (adjusted hazard ratio =0.51 (95% CI, 0.46 to 0.56), P <0.001). The association between paracetamol and decreased mortality and/or time to death was broadly consistent across surgical and medical patients. It remained present after adjusting for paracetamol administration as a time-dependent variable. However, when such time-dependent analysis was performed, the association of paracetamol with outcome lost statistical significance in the presence of fever and suspected infection and in patients in the lower tertiles of Acute Physiology and Chronic Health Evaluation II scores. CONCLUSIONS: Paracetamol administration is common in the ICU and appears to be independently associated with reduced in-hospital mortality and time to death after adjustment for multiple potential confounders and propensity score. This association, however, was modified by the presence of fever, suspected infection and lesser illness severity and may represent the effect of indication bias.

Changing clinical guidelines from delayed to early aperient administration for enterally fed intensive care patients was associated with increased diarrhoea: a before-and-after, intention-to-treat evaluation.

BACKGROUND: The 14-bed intensive care unit of a tertiary referral hospital adopted a guideline to start docusate sodium with sennosides when enteral nutrition was started. This replaced a guideline to start aperients after 24h of enteral nutrition if no bowel action had occurred. We sought to determine the effect of this change on the incidence of diarrhoea and constipation in intensive care. METHODS: Retrospective audit of the medical records of consecutive adult patients admitted to intensive care and given enteral nutrition, excluding those with a primary gastrointestinal system diagnosis, between Jan-Aug 2011 (the delayed group, n=175) and Jan-Aug 2012 (the early group, n=175). The early aperient guideline was implemented during Sep-Dec 2011. RESULTS: The early and delayed groups were similar in age (median 62 years vs. 64 years; P=0.17), sex (males 65% vs. 63%; P=0.91), and postoperative cases (31% vs. 33%; P=0.82) and had similar proportions who received mechanical ventilation (95% vs. 95%; P=1.00), an inotrope or vasopressor (63% vs. 70%; P=0.17), renal replacement therapy (8% vs. 10%; P=0.71), opiates (77% vs. 80%; P=0.60), antibiotics (89% vs. 91%; P=0.72) and metoclopramide (46% vs. 55%; P=0.11). A significantly larger proportion of the early group received an aperient (54% vs. 29%, P<0.001) and experienced diarrhoea (38% vs. 27%, P=0.04), but the groups had similar proportions affected by constipation (42% vs. 43%, P=0.91). CONCLUSIONS: Changing guidelines from delayed to early aperient administration was associated with an increase in the incidence of diarrhoea but was not associated with the incidence of constipation. These findings do not support changing guidelines from delayed to early aperient administration.

Outcomes of older people receiving intensive care in Victoria.

UNLABELLED: OBJECTIVE To assess trends in service use and outcome of critically ill older people (aged ≥ 65 years) admitted to an intensive care unit (ICU). DESIGN, PATIENTS AND SETTING: Retrospective cohort analysis of administrative data on older patients discharged from ICUs at all 23 adult public hospitals with onsite ICUs in Victoria between 1 July 1999 and 30 June 2011. Subgroups examined included those aged ≥ 80 years, major diagnosis categories, and those receiving mechanical ventilation. MAIN OUTCOME MEASURES: Resource use and hospital survival; also length of stay (LOS) and discharge destination trends. RESULTS: Over 12 years, 108,171 people aged ≥ 65 years were admitted to ICUs; of these, 49,912 (46.1%) received mechanical ventilation and 17,772 (16.4%) died. Despite an increase in the older age population (2.5% per annum) and acute care admissions (7.3% per annum) over the period studied, there was a net reversal in prevalence trends for ICU admissions (- 1.7% per annum; P = 0.04) and admissions of patients requiring mechanical ventilation (- 1.6% per annum) in the 8 years since 2004. Annual risk-adjusted mortality fell (odds ratio, 0.97 per year; 95% CI, 0.96-0.97 per year; P < 0.001) without prolongation of hospital or ICU LOS (P = 0.49) or discharge to residential aged care (RAC). Similar trends were noted in all a priori subgroups. CONCLUSIONS: Improved hospital survival without an increase in demand for ICU admission or RAC or an increase in LOS suggests there has been improvement in the care of the older age population.

Do outlier inpatients experience more emergency calls in hospital? An observational cohort study.

OBJECTIVE: To determine the effect of spending time as an outlier (ie, an inpatient who spends time away from his or her "home" ward) on the frequency of emergency calls for patients admitted to a tertiary referral hospital. DESIGN, SETTING AND PATIENTS: Observational cohort study of all patients admitted to a university-affiliated tertiary referral hospital in Melbourne, Victoria, between 1 July 2009 and 30 November 2011. MAIN OUTCOME MEASURE: The number of emergency calls per hospital admission, with reference to location within the hospital. RESULTS: There were 58,158 admissions during the study period. The median age of admitted patients was 61 years, 55% were male, and the inhospital mortality was 1.40%. In 11,034 admissions (18.97%), patients spent time as outliers. Inhospital mortality was 2.57% in the outlier group versus 1.12% in the non-outlier group (P < 0.001). After adjusting for age, same-day admission, 10-year predicted mortality, interhospital transfer and high-risk clinical units, outlier status was associated with a 53% increase in emergency calls (P < 0.001). CONCLUSIONS: This study found a strong association between time spent away from a patient's home ward and the number of emergency calls. We postulate that outlier patients are at risk as they may have therapeutic and monitoring needs that are only available on their home ward. With increasing pressure to move patients out of the emergency department, the number of outlier patients may increase.

The operating surgeon is an independent predictor of chest tube drainage following cardiac surgery.

OBJECTIVES: Bleeding into the chest is a major cause of blood transfusion and adverse outcomes following cardiac surgery. The authors investigated predictors of bleeding following cardiac surgery to identify potentially correctable factors. DESIGN: Data were retrieved from the medical records of patients undergoing cardiac surgery over the period of 2002 to 2008. Multivariate analysis was used to identify the independent predictors of chest tube drainage. SETTING: Tertiary hospital. PARTICIPANTS: Two thousand five hundred seventy-five patients. INTERVENTIONS: Cardiac surgery. RESULTS: The individual operating surgeon was independently associated with the extent of chest tube drainage. Other independent factors included internal mammary artery grafting, cardiopulmonary bypass time, urgency of surgery, tricuspid valve surgery, redo surgery, left ventricular impairment, male gender, lower body mass index and higher preoperative hemoglobin levels. Both a history of diabetes and administration of aprotinin were associated with reduced levels of chest tube drainage. CONCLUSIONS: The individual operating surgeon was an independent predictor of the extent of chest tube drainage. Attention to surgeon-specific factors offers the possibility of reduced bleeding, fewer transfusions, and improved patient outcomes.

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.

The association of blood transfusion with mortality after cardiac surgery: cause or confounding? (CME).

BACKGROUND: Bleeding into the chest is a life-threatening complication of cardiac surgery. Blood transfusion has been implicated as an important cause of harm associated with bleeding, based largely on studies demonstrating an independent association between transfusion and mortality. These studies did not, however, consider the possibility that bleeding may in itself be harmful, inasmuch as drains are inefficient at clearing blood from the chest and retained blood may compromise cardiac and lung function. STUDY DESIGN AND METHODS: We undertook a multivariate logistic regression analysis of the risk factors associated with mortality in 2599 consecutive patients undergoing cardiac surgery. Unlike previous studies the risk factors examined included the volume of chest tube drainage at 24 hours. A stratified analysis was also undertaken that compared the adjusted risk of death for patients exposed or not exposed to a postoperative blood transfusion. RESULTS: Blood transfusion was not an independent predictor of mortality (p=0.4). Chest tube drainage was the strongest independent predictor of mortality (p<0.001). In the stratified analysis, chest tube drainage remained an independent predictor of mortality for patients not exposed to a blood transfusion (p<0.01). Furthermore, the risk of death of these patients was no different from patients exposed to a blood transfusion (p=0.7 for interaction). CONCLUSIONS: Our results argue that for patients undergoing cardiac surgery bleeding contributes to mortality through mechanisms unrelated to blood transfusion.

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.