Measured Energy Expenditure Compared With Best-Practice Recommendations for Obese, Critically Ill Patients-A Prospective Observational Study.

BACKGROUND: This study aimed to compare recommendations in the American Society for Parenteral and Enteral Nutrition (ASPEN) Guidelines for the Provision and Assessment of Nutrition Support Therapy in the Adult Critically Ill Patient with measured energy expenditure in obese, critically ill adults. METHODS: After enrollment, measured energy expenditure was attempted at baseline and twice weekly to extubation or day 14. Data are reported as median [interquartile range]. RESULTS: Twenty patients were included. The median baseline and subsequent measured energy expenditures were 2438 [1807-2703] kcal and 2919 [2318-3362] kcal, respectively. Baseline measured energy expenditures were -491 [-788 to -323] kcal lower than subsequent measurements, and week 1 measurements were lower than those of week 2. The median bias between the guideline recommendation of 11-14 kcal/kg of actual body weight and measured expenditure at baseline was -950 [-1254 to -595] kcal/d and -1618 [-1820 to -866] kcal/d at subsequent measurements. CONCLUSION: Clinically significant variation was observed between measured expenditure and guideline recommendations at all time points.

Does Propofol Sedation Contribute to Overall Energy Provision in Mechanically Ventilated Critically Ill Adults? A Retrospective Observational Study.

BACKGROUND: Propofol sedation is common in critically ill patients, providing energy of 1.1 kcal/mL when administered as a 1% solution. We aimed to determine the proportion of energy administered as propofol on days 1-5 in the intensive care unit (ICU) and any association with outcomes. METHODS: Retrospective observational study in a quaternary ICU from January-December 2012. Inclusion criteria were length of stay (LOS) ≥5 days, age ≥18 years, and provision of mechanical ventilation (MV) for ≥5 days. Outcome measures included proportion of total daily energy provided as propofol, overall energy balance, hospital mortality, duration of MV, and ICU LOS. RESULTS: Data from 370 patients were analyzed, 87.8% (n = 325) of whom received propofol during days 1-5 in ICU. A median [interquartile range (IQR)] of 119 [50-730] kcal was provided as propofol per patient-day. Proportion of energy provided by propofol as a percentage of total energy delivered was 55.4%, 15.4%, 9.3%, 7.9%, and 9.9% days 1-5, respectively. Patients administered propofol received a greater proportion of their total daily energy prescription compared with those who were not (P < .01). Proportion of energy provided as propofol was not significantly different based on hospital mortality (P = .62), duration of MV (P = .50), or ICU LOS (P = .15). CONCLUSION: Propofol contributes to overall energy intake on days 1-5 of ICU admission. Energy balance was higher in those receiving propofol. No association was found between the proportion of energy delivered as propofol and outcomes.

Propofol sedation substantially increases the caloric and lipid intake in critically ill patients.

OBJECTIVE: The amount of lipid delivered to patients varies considerably depending on the non-nutritional intake from sedation, and on the feeding solution. The aim of this study was to quantify the magnitude and proportion of lipids and energy provided from propofol sedation in intensive care unit (ICU) patients. METHODS: This was a retrospective analysis of prospectively collected data in consecutive patients admitted to the ICUs of two university hospitals. Inclusion criterion included an ICU stay >5 d. Data were collected for a maximum of 10 d. Propofol sedation using 1% or 2% propofol solutions was defined as >100 mg/d. Nutritional management was per protocol in both centers, recommending enteral feeding. Data are shown as means ± standard deviation. RESULTS: In all, 701 admissions (687 patients, ages 59 ± 16 y, SAPS II 51 ± 17) and 6485 d, including 3484 propofol sedation days were analyzed. Energy targets were 1987 ± 411 kcal/d; mean energy delivery was 1362 ± 811 kcal/d (70% ± 38% of prescription) including propofol and dextrose. Enteral feeding dominated (75% of days) and progressed similarly in both ICUs. Mean propofol sedation dose was 2045 ± 1650 mg/d, resulting in 146 ± 117 kcal/d. Fat from propofol constituted 17% of total energy (up to 100% during the first days). Fat delivery (40 ± 23 g/d: maximum 310 g/d) was significantly increased by the combination of propofol sedation, the 1% solution, and high-fat-containing feeds. In survivors, high-fat proportion was associated with prolonged ventilation time (P < 0.0001). CONCLUSION: Propofol sedation resulted in large doses of lipids being delivered to patients, some receiving pure lipids during the first days. As the metabolic effects of high proportions of fat are unknown, further research is warranted.

Predictive factors of bleeding events in adults undergoing extracorporeal membrane oxygenation.

BACKGROUND: Bleeding is the most frequent complication associated with extracorporeal membrane oxygenation (ECMO) support in critically ill patients. Nonetheless, risk factors for bleeding have been poorly described especially those associated with coagulation anomalies and anticoagulant therapy during ECMO support. The aim of this study is to describe bleeding complications in critically ill patients undergoing ECMO and to identify risk factors for bleeding events. METHODS: We retrospectively analysed ICU charts of adults who received either veno-venous (VV) or veno-arterial (VA) ECMO support in two participating ICUs between 2010 and 2013. Characteristics of patients with and without bleeding complications, as per the Extracorporeal Life Support Organisation (ELSO) definition, were compared, and the impact of bleeding complications on patient outcomes was assessed using survival analysis. Variables that were independently associated with bleeding, including daily clinical and biological variables during ECMO courses, were modelled. RESULTS: Of the 149 ECMO episodes (111 VA ECMO and 38 VV ECMO) performed in 147 adults, 89 episodes (60 %) were complicated by at least one bleeding event. The most common bleeding sources were: ECMO cannula (37 %), haemothorax or cardiac tamponade (17 %) and ear-nose and throat (16 %). Intra-cranial haemorrhage occurred in five (2.2 %) patients. Bleeding complications were independently associated with worse survival [adjusted hazard ratio (HR) 2.17, 95 % confidence interval (CI) 1.07-4.41, P = 0.03]. Higher activated partial thromboplastin time (aPTT) [adjusted odds ratio (OR) 3.00, 95 % CI 1.64-5.47, P < 0.01], APACHE III score [adjusted OR 1.01, 95 % CI 1.01-1.02, P = 0.01] and ECMO following surgery [adjusted OR 3.04, 95 % CI 1.62-5.69, P < 0.01] were independently associated with greater risk of bleeding occurrence. A similar association between bleeding and higher aPTT was found when non-post-surgical VA ECMO was considered separately. CONCLUSIONS: Bleeding events based on the ELSO bleeding definition occurred in more than 60 % of ECMO episodes and were associated with hospital mortality. We identified higher aPTT prior bleeding as an independent risk factor for bleeding event, suggesting that better control of the aPTT (through a better control of either coagulopathy or anticoagulation) may improve patients' outcome.

Insurance status and mortality in critically ill patients.

OBJECTIVE: The association between insurance status and outcome in critically ill patients is uncertain. We aimed to determine if there was an independent relationship between the presence or absence of compensable insurance status and mortality, after admission to the intensive care unit. METHODS: We performed a retrospective cohort study in five public hospitals in Victoria, comprising adult patients admitted to the ICU between 2007 and 2012. We obtained data on demographics, severity of illness, chronic health status, insurance category, length of stay (LOS) and mortality. We matched socio-economic indices (collected from the Australian Bureau of Statistics) to postcodes. The primary outcome measured was in-hospital mortality. Secondary outcomes were ICU mortality, and ICU and hospital LOS, measured in days. RESULTS: We studied 33 306 patients. Compensable patients comprised 21.2% of the study population (7046). Personal private insurance accounted for 13.4% (4451) and Transport Accident Commission insurance for 5.1% (1701) of compensable patients. Unadjusted in-hospital mortality was higher in publicly insured patients (13.4% v 10.6%, P < 0.0001). After adjusting for age, severity of illness, diagnosis and socio-economic status, being a compensable patient in a public hospital ICU was independently associated with a reduction in mortality (odds ratio, 0.73; 95% CI, 0.65-0.80; P < 0.001). CONCLUSIONS: Among ICU patients treated in public hospitals in Victoria, being a compensable patient appears to be independently associated with a reduction in mortality. Further studies are needed to confirm and validate these findings elsewhere in Australia.

The Association Between Low Admission Peak Plasma Creatinine Concentration and In-Hospital Mortality in Patients Admitted to Intensive Care in Australia and New Zealand.

OBJECTIVE: To evaluate the independent association between low peak admission plasma creatinine concentrations and in-hospital mortality in patients requiring critical care in Australia and New Zealand. DESIGN: Multicenter, binational, retrospective cohort study. SETTING: Data were extracted from the Australian and New Zealand Intensive Care Society Centre for Outcome and Resource Evaluation adult patient database. PATIENTS: All available records for the period 2000 to 2013 were utilized. The following exclusion criteria were applied: all readmission episodes (within the same hospital stay), missing in-hospital mortality, admission post kidney transplantation, chronic renal replacement therapy (hemodialysis or peritoneal dialysis), and missing peak plasma creatinine concentration. Demographic, anthropometric, admission, illness severity, laboratory, and outcome data were then extracted. Patients were categorized on the basis of their peak (maximum) plasma creatinine concentration recorded in the first 24 hours of ICU admission. Illness severity-adjusted associations with in-hospital mortality relative to a reference category of 70-79 µmol/L were then determined using multivariate logistic regression. INTERVENTIONS: Nil. MEASUREMENTS AND MAIN RESULTS: Data pertaining to 1,250,449 admissions were available for the study period. Following exclusions, 1,045,718 patients were included. Regression analysis identified that peak plasma creatinine concentrations less than 60 µmol/L measured in the first 24 hours after ICU admission imply a steadily increasing adjusted in-hospital mortality risk. In cases where this value is markedly low (< 30 µmol/L), the adjusted odds of dying in-hospital is over two-fold higher than the reference category and exceeds the risk implied with elevated (≥ 180 µmol/L) values. This finding was also independent of anthropometric data. CONCLUSIONS: In a large heterogenous cohort of critically ill patients, low admission peak plasma creatinine concentrations are independently associated with increased risk-adjusted in-hospital mortality. Further research should now focus on the potential mechanisms underpinning this finding, such as a low skeletal muscle mass and/or fluid overload.

Predicting survival after ECMO for refractory cardiogenic shock: the survival after veno-arterial-ECMO (SAVE)-score.

RATIONALE: Extracorporeal membrane oxygenation (ECMO) may provide mechanical pulmonary and circulatory support for patients with cardiogenic shock refractory to conventional medical therapy. Prediction of survival in these patients may assist in management of these patients and comparison of results from different centers. AIMS: To identify pre-ECMO factors which predict survival from refractory cardiogenic shock requiring ECMO and create the survival after veno-arterial-ECMO (SAVE)-score. METHODS AND RESULTS: Patients with refractory cardiogenic shock treated with veno-arterial ECMO between January 2003 and December 2013 were extracted from the international Extracorporeal Life Support Organization registry. Multivariable logistic regression was performed using bootstrapping methodology with internal and external validation to identify factors independently associated with in-hospital survival. Of 3846 patients with cardiogenic shock treated with ECMO, 1601 (42%) patients were alive at hospital discharge. Chronic renal failure, longer duration of ventilation prior to ECMO initiation, pre-ECMO organ failures, pre-ECMO cardiac arrest, congenital heart disease, lower pulse pressure, and lower serum bicarbonate (HCO3) were risk factors associated with mortality. Younger age, lower weight, acute myocarditis, heart transplant, refractory ventricular tachycardia or fibrillation, higher diastolic blood pressure, and lower peak inspiratory pressure were protective. The SAVE-score (area under the receiver operating characteristics [ROC] curve [AUROC] 0.68 [95%CI 0.64-0.71]) was created. External validation of the SAVE-score in an Australian population of 161 patients showed excellent discrimination with AUROC = 0.90 (95%CI 0.85-0.95). CONCLUSIONS: The SAVE-score may be a tool to predict survival for patients receiving ECMO for refractory cardiogenic shock (www.save-score.com).

Mechanical ventilation management during extracorporeal membrane oxygenation for acute respiratory distress syndrome: a retrospective international multicenter study.

OBJECTIVE: To describe mechanical ventilation settings in adult patients treated for an acute respiratory distress syndrome with extracorporeal membrane oxygenation and assess the potential impact of mechanical ventilation settings on ICU mortality. DESIGN: Retrospective observational study. SETTING: Three international high-volume extracorporeal membrane oxygenation centers. PATIENTS: A total of 168 patients treated with extracorporeal membrane oxygenation for severe acute respiratory distress syndrome from January 2007 to January 2013. INTERVENTIONS: We analyzed the association between mechanical ventilation settings (i.e. plateau pressure, tidal volume, and positive end-expiratory pressure) on ICU mortality using multivariable logistic regression model and Cox-proportional hazards model. MEASUREMENT AND MAIN RESULTS: We obtained detailed demographic, clinical, daily mechanical ventilation settings and ICU outcome data. One hundred sixty-eight patients (41 ± 14 years old; PaO2/FIO2 67 ± 19 mm Hg) fulfilled our inclusion criteria. Median duration of extracorporeal membrane oxygenation and ICU stay were 10 days (6-18 d) and 28 days (16-42 d), respectively. Lower positive end-expiratory pressure levels and significantly lower plateau pressures during extracorporeal membrane oxygenation were used in the French center than in both Australian centers (23.9 ± 1.4 vs 27.6 ± 3.7 and 27.8 ± 3.6; p < 0.0001). Overall ICU mortality was 29%. Lower positive end-expiratory pressure levels (until day 7) and lower delivered tidal volume after 3 days on extracorporeal membrane oxygenation were associated with significantly higher mortality (p < 0.05). In multivariate analysis, higher positive end-expiratory pressure levels during the first 3 days of extracorporeal membrane oxygenation support were associated with lower mortality (odds ratio, 0.75; 95% CI, 0.64-0.88; p = 0.0006). Other independent predictors of ICU mortality included time between ICU admission and extracorporeal membrane oxygenation initiation, plateau pressure greater than 30 cm H2O before extracorporeal membrane oxygenation initiation, and lactate level on day 3 of extracorporeal membrane oxygenation support. CONCLUSIONS: Protective mechanical ventilation strategies were routinely used in high-volume extracorporeal membrane oxygenation centers. However, higher positive end-expiratory pressure levels during the first 3 days on extracorporeal membrane oxygenation support were independently associated with improved survival. Further prospective trials on the optimal mechanical ventilation strategy during extracorporeal membrane oxygenation support are warranted.

Randomised trial of software algorithm driven regional citrate anticoagulation versus heparin in continuous renal replacement therapy: the Filter Life in Renal Replacement Therapy pilot trial.

OBJECTIVE: The effectiveness of continuous renal replacement therapy (CRRT) increases when unplanned circuit failure is prevented. Adequate anticoagulation is an important component. Although heparin is the predominating anticoagulant, calcium chelation with citrate is an alternative, but systemic calcium monitoring and supplementation increase the complexity of CRRT. We assessed efficacy and safety of citrate delivery via integrated software algorithms against an established regional heparin protocol. DESIGN: Prospective computer randomisation allocated eligible patients to regional citrate or heparin between April and December 2012. Citrate fluids were Prismocitrate 18 mmol/L predilution and Prism0cal B22 dialysate. Hemosol B0 was the default fluid for heparin. The primary outcome was filter running time. Electively terminated circuits were censored. Intention-totreat (ITT) and per-protocol analyses were performed. Filter survival was compared by log-rank tests and hazard ratios were explored with a mixed-effects Cox model. RESULTS: 221 filters were analysed from 30 patients (of whom 19 were randomly allocated to citrate filters and 11 to heparin filters). Patients randomly allocated to citrate were older, sicker, with a higher male:female ratio, but of similar weight. Mortality was 37% in the citrate arm and 27% in the heparin arm. All deaths were attributed to underlying disease. Significant crossover occurred from the citrate arm to use of heparin. Median filter survival, by ITT, was not significantly different (citrate, 34 hours; heparin, 30.7 hours; P=0.58). Per-protocol survival favoured citrate (citrate, 42.1 hours; heparin, 24 hours; χ(2)=8.1; P=0.004). Considerable variation in filter life existed between patients, and between vascular access sites within patients. Safety end points were reached in one heparin and three citrate patients. CONCLUSION: Although the per-protocol results favoured citrate when it was actually delivered, the significant crossover between treatment arms hampered more definitive conclusions. Until further studies support improved patient outcomes, increased complexity and complications suggest that anticoagulation choice be made using patient-specific indications.

Impact of fluid balance on outcome of adult patients treated with extracorporeal membrane oxygenation.

PURPOSE: To assess the relationship between early daily fluid balance (FB) and 90-day outcome in adult patients treated with extracorporeal membrane oxygenation (ECMO). DESIGN: Retrospective observational study. SETTING: Tertiary referral centre for ECMO. PATIENTS: 115 patients treated with ECMO for refractory heart failure and 57 patients treated with ECMO for refractory respiratory failure. METHODS: We analysed the association between early daily FB versus hospital and 90-day mortality using multivariable logistic regression model, Cox proportional-hazards model and propensity score. RESULTS: We obtained detailed demographic, clinical, and biochemical data, daily FB, and continuous renal replacement days. Fifty-seven per cent of patients had acute kidney injury (AKI) at ECMO initiation, and 60 % (n = 103) of patients received continuous renal replacement therapy (CRRT) during ECMO course, beginning at a median of 1 (0-3.5) days after ECMO initiation. Overall 90-day mortality was 24 %. Survivors exhibited lower daily FB from day 3 to day 5. After adjustments, Acute Physiology and Chronic Health Evaluation (APACHE) III, CRRT during the first 3 days, major bleeding event at day 1 and positive FB on day 3 were independent predictors of 90-day mortality. Positive FB at ECMO day 3 remained an independent predictor of hospital and 90-day mortality, regardless of the statistical model used or the inclusion of a propensity score to have positive FB. CONCLUSIONS: Positive FB at ECMO day 3 is an independent predictor of 90-day mortality. Further interventional studies aimed at testing the value of strategy of tight control of FB during the early ECMO period are now warranted.

Predicting survival after extracorporeal membrane oxygenation for severe acute respiratory failure. The Respiratory Extracorporeal Membrane Oxygenation Survival Prediction (RESP) score.

RATIONALE: Increasing use of extracorporeal membrane oxygenation (ECMO) for acute respiratory failure may increase resource requirements and hospital costs. Better prediction of survival in these patients may improve resource use, allow risk-adjusted comparison of center-specific outcomes, and help clinicians to target patients most likely to benefit from ECMO. OBJECTIVES: To create a model for predicting hospital survival at initiation of ECMO for respiratory failure. METHODS: Adult patients with severe acute respiratory failure treated by ECMO from 2000 to 2012 were extracted from the Extracorporeal Life Support Organization (ELSO) international registry. Multivariable logistic regression was used to create the Respiratory ECMO Survival Prediction (RESP) score using bootstrapping methodology with internal and external validation. MEASUREMENTS AND MAIN RESULTS: Of the 2,355 patients included in the study, 1,338 patients (57%) were discharged alive from hospital. The RESP score was developed using pre-ECMO variables independently associated with hospital survival on logistic regression, which included age, immunocompromised status, duration of mechanical ventilation before ECMO, diagnosis, central nervous system dysfunction, acute associated nonpulmonary infection, neuromuscular blockade agents or nitric oxide use, bicarbonate infusion, cardiac arrest, PaCO2, and peak inspiratory pressure. The receiver operating characteristics curve analysis of the RESP score was c = 0.74 (95% confidence interval, 0.72-0.76). External validation, performed on 140 patients, exhibited excellent discrimination (c = 0.92; 95% confidence interval, 0.89-0.97). CONCLUSIONS: The RESP score is a relevant and validated tool to predict survival for patients receiving ECMO for respiratory failure.

The relationship between hypophosphataemia and outcomes during low-intensity and high-intensity continuous renal replacement therapy.

AIM: To identify risk factors for development of hypophosphataemia in patients treated with two different intensities of continuous renal replacement therapy (CRRT) and to assess the independent association of hypophosphataemia with major clinical outcomes. MATERIALS AND METHODS: We performed secondary analysis of data collected from 1441 patients during a large, multicentre randomised controlled trial of CRRT intensity. We allocated patients to two different intensities of CRRT (25mL/kg/hour vs 40 mL/kg/hour of effluent generation) and obtained daily measurement of serum phosphate levels. RESULTS: We obtained 14 115 phosphate measurements and identified 462 patients (32.1%) with hypophosphataemia, with peak incidence on Day 2 and Day 3. With lower intensity CRRT, there were 58 episodes of hypophosphataemia/1000 patient days, compared with 112 episodes/1000 patient days with higher intensity CRRT (P < 0.001). On multivariable logistic regression analysis, higher intensity CRRT, female sex, higher Acute Physiology and Chronic Health Evaluation score and hypokalaemia were independently associated with an increased odds ratio (OR) for hypophosphataemia. On multivariable models, hypophosphataemia was associated with better clinical outcomes, but when analysis was confined to patients alive at 96 hours, hypophosphataemia was not independently associated with clinical outcomes. CONCLUSIONS: Hypophosphataemia is common during CRRT and its incidence increases with greater CRRT intensity. Hypophosphataemia is not a robust independent predictor of mortality. Its greater incidence in the higher intensity CRRT arm of the Randomised Evaluation of Normal vs Augmented Level trial does not explain the lack of improved outcomes with such treatment.

Calorie intake and patient outcomes in severe acute kidney injury: findings from The Randomized Evaluation of Normal vs. Augmented Level of Replacement Therapy (RENAL) study trial.

INTRODUCTION: Current practice in the delivery of caloric intake (DCI) in patients with severe acute kidney injury (AKI) receiving renal replacement therapy (RRT) is unknown. We aimed to describe calorie administration in patients enrolled in the Randomized Evaluation of Normal vs. Augmented Level of Replacement Therapy (RENAL) study and to assess the association between DCI and clinical outcomes. METHODS: We performed a secondary analysis in 1456 patients from the RENAL trial. We measured the dose and evolution of DCI during treatment and analyzed its association with major clinical outcomes using multivariable logistic regression, Cox proportional hazards models, and time adjusted models. RESULTS: Overall, mean DCI during treatment in ICU was low at only 10.9 ± 9 Kcal/kg/day for non-survivors and 11 ± 9 Kcal/kg/day for survivors. Among patients with a lower DCI (below the median) 334 of 729 (45.8%) had died at 90-days after randomization compared with 316 of 727 (43.3%) patients with a higher DCI (above the median) (P = 0.34). On multivariable logistic regression analysis, mean DCI carried an odds ratio of 0.95 (95% confidence interval (CI): 0.91-1.00; P = 0.06) per 100 Kcal increase for 90-day mortality. DCI was not associated with significant differences in renal replacement (RRT) free days, mechanical ventilation free days, ICU free days and hospital free days. These findings remained essentially unaltered after time adjusted analysis and Cox proportional hazards modeling. CONCLUSIONS: In the RENAL study, mean DCI was low. Within the limits of such low caloric intake, greater DCI was not associated with improved clinical outcomes. TRIAL REGISTRATION: ClinicalTrials.gov number, NCT00221013.

Mechanical ventilation during extracorporeal membrane oxygenation.

The timing of extracorporeal membrane oxygenation (ECMO) initiation and its outcome in the management of respiratory and cardiac failure have received considerable attention, but very little attention has been given to mechanical ventilation during ECMO. Mechanical ventilation settings in non-ECMO studies have been shown to have an effect on survival and may also have contributed to a treatment effect in ECMO trials. Protective lung ventilation strategies established for non-ECMO-supported respiratory failure patients may not be optimal for more severe forms of respiratory failure requiring ECMO support. The influence of positive end-expiratory pressure on the reduction of the left ventricular compliance may be a matter of concern for patients receiving ECMO support for cardiac failure. The objectives of this review were to describe potential mechanisms for lung injury during ECMO for respiratory or cardiac failure, to assess the possible benefits from the use of ultra-protective lung ventilation strategies and to review published guidelines and expert opinions available on mechanical ventilation-specific management of patients requiring ECMO, including mode and ventilator settings. Articles were identified through a detailed search of PubMed, Ovid, Cochrane databases and Google Scholar. Additional references were retrieved from the selected studies. Growing evidence suggests that mechanical ventilation settings are important in ECMO patients to minimize further lung damage and improve outcomes. An ultra-protective ventilation strategy may be optimal for mechanical ventilation during ECMO for respiratory failure. The effects of airway pressure on right and left ventricular afterload should be considered during venoarterial ECMO support of cardiac failure. Future studies are needed to better understand the potential impact of invasive mechanical ventilation modes and settings on outcomes.

Hyperoxia in the intensive care unit and outcome after out-of-hospital ventricular fibrillation cardiac arrest.

BACKGROUND: Laboratory and clinical studies have suggested that hyperoxia early after resuscitation from cardiac arrest may increase neurological injury and worsen outcome. Previous clinical studies have been small or have not included relevant prehospital data. We aimed to determine in a larger cohort of patients whether hyperoxia in the intensive care unit in patients admitted after out-of-hospital cardiac arrest (OHCA) was associated with increased mortality rate after correction for prehospital variables. METHODS: Data from the Victorian Ambulance Cardiac Arrest Registry (VACAR) of patients transported to hospital after resuscitation from OHCA and an initial cardiac rhythm of ventricular fibrillation between January 2007 and December 2011 were linked to the Australian and New Zealand Intensive Care Society Adult Patient Database (ANZICS-APD). Patients were allocated into three groups (hypoxia [PaO2<60mmHg], normoxia [PaO2,60-299mmHg] or hyperoxia [PaO2≥300mmHg]) according to their most abnormal PaO2 level in the first 24 hours of ICU stay. The relationship between PaO2 and hospital mortality was investigated using multivariate logistic regression analysis to adjust for confounding prehospital and ICU factors. RESULTS: There were 957 patients identified on the VACAR database who met inclusion criteria. Of these, 584 (61%) were matched to the ANZICS-APD and had hospital mortality and oxygen data available. The unadjusted hospital mortality was 51% in the hypoxia patients, 41% in the normoxia patients and 47% in the hyperoxia patients (P=0.28). After adjustment for cardiopulmonary resuscitation by a bystander, patient age and cardiac arrest duration, hyperoxia in the ICU was not associated with increased hospital mortality (OR, 1.2; 95% CI, 0.51-2.82; P=0.83). CONCLUSIONS: Hyperoxia within the first 24 hours was not associated with increased hospital mortality in patients admitted to ICU following out-of-hospital ventricular fibrillation cardiac arrest.

Aspergillus sp. isolated in critically ill patients with extracorporeal membrane oxygenation support.

This study reports Aspergillus isolation in critically ill patients who underwent extracorporeal membrane oxygenation (ECMO) and highlights the difficulty in establishing a diagnosis of aspergillosis in this population. The diagnosis of Aspergillus infection or colonization was retrospectively performed using the proposed modified criteria of the European Organization for Research and Treatment of Cancer and the Mycoses Study Group (EORTC/MSG) adapted to critically ill patients. Between 2005 and 2011, 11 of 151 patients (7.2%) who underwent ECMO had Aspergillus sp. isolates, 10 in a pulmonary sample and 1 in a mediastinal wound sample. Five patients did not have any classical risk factors for aspergillosis. One patient had a proven invasive pulmonary aspergillosis (IPA), 2 had a putative IPA, and 1 patient had a possible Aspergillus mediastinitis, whilst in 7 patients this was considered colonization. However, the clinical relevance of Aspergillus isolation was based on an algorithm not validated in patients undergoing ECMO. Our data support the need to implement non-invasive diagnostic procedures for aspergillosis in this population.

Periprocedural cessation of nutrition in the intensive care unit: opportunities for improvement.

PURPOSE: Delivery of enteral nutrition (EN) to ICU patients is commonly interrupted for diagnostic and therapeutic procedures. We investigated this practice in a cohort of trauma and surgical ICU patients. METHODS: This was a retrospective single-center study conducted in a 15-bed trauma ICU of a university-affiliated teaching hospital. Descriptive statistics were used. RESULTS: Of 69 patients assessed, 41 had 121 planned procedures over a mean ICU length of stay of 18.7 days (SD 9.6 days). EN was stopped prior to 108 (89 %, 95 % CI 82-94 %) of these 121 procedures, and 102 of these cessation episodes were related to the planned procedure. EN was stopped in 37 patients for a mean cumulative duration of 30.8 h (SD 22.7 h) per patient, which represented 7.9 % (SD 6.9 %) of the mean total time spent in the ICU leading to a mean energy and protein deficit of 7.2 % (SD 8.5 %) and 7.7 % (SD 9.6 %), respectively. Of the 121 planned procedures, 27 (22 %, 95 % CI 16-31 %) were postponed beyond the scheduled day. For 32 (31 %, 95 % CI 23-41 %) of the 102 EN cessation episodes, EN was stopped without a documented order and 23 (23 %, 95 % CI 16-32 %) episodes were not deemed necessary based on the institution's guidelines. CONCLUSION: In this ICU cohort, EN cessation for planned procedures was frequent and led to a nutritional deficit due to long periods without EN being delivered. Postponement of procedures and clinically unnecessary EN cessation were important factors that prevented delivery of planned nutrition. EN cessation practice should be a focus for improving EN delivery in ICU patients.

Factors associated with outcomes of patients on extracorporeal membrane oxygenation support: a 5-year cohort study.

INTRODUCTION: Mortality of patients on extracorporeal membrane oxygenation (ECMO) remains high. The objectives of this study were to assess the factors associated with outcome of patients undergoing ECMO in a large ECMO referral centre and to compare veno-arterial ECMO (VA ECMO) with veno-venous ECMO (VV ECMO). METHODS: We reviewed a prospectively obtained ECMO database and patients' medical records between January 2005 and June 2011. Demographic characteristics, illness severity at admission, ECMO indication, organ failure scores before ECMO and the ECMO mode and configuration were recorded. Bleeding, neurological, vascular and infectious complications that occurred on ECMO were also collected. Demographic, illness, ECMO support descriptors and complications associated with hospital mortality were analysed. RESULTS: ECMO was initiated 158 times in 151 patients. VA ECMO (66.5%) was twice as common as VV ECMO (33.5%) with a median duration significantly shorter than for VV ECMO (7 days (first and third quartiles: 5; 10 days) versus 10 days (first and third quartiles: 6; 16 days)). The most frequent complications during ECMO support were bleeding and bloodstream infections regardless of ECMO type. More than 70% of the ECMO episodes were successfully weaned in each ECMO group. The overall mortality was 37.3% (37.1% for the patients who underwent VA ECMO, and 37.7% for the patients who underwent VV ECMO). Haemorrhagic events, assessed by the total of red blood cell units received during ECMO, were associated with hospital mortality for both ECMO types. CONCLUSIONS: Among neurologic, vascular, infectious and bleeding events that occurred on ECMO, bleeding was the most frequent and had a significant impact on mortality. Further studies are needed to better investigate bleeding and coagulopathy in these patients. Interventions that reduce these complications may improve outcome.

Early acid-base and blood pressure effects of continuous renal replacement therapy intensity in patients with metabolic acidosis.

PURPOSE: In acute kidney injury patients, metabolic acidosis is common. Its severity, duration, and associated changes in mean arterial pressure (MAP) and vasopressor therapy may be affected by the intensity of continuous renal replacement therapy (CRRT). We aimed to compare key aspects of acidosis and MAP and vasopressor therapy in patients treated with two different CRRT intensities. METHODS: We studied a nested cohort of 115 patients from two tertiary intensive care units (ICUs) within a large multicenter randomized controlled trial treated with lower intensity (LI) or higher intensity (HI) CRRT. RESULTS: Levels of metabolic acidosis at randomization were similar [base excess (BE) of -8 ± 8 vs. -8 ± 7 mEq/l; p = 0.76]. Speed of BE correction did not differ between the two groups. However, the HI group had a greater increase in MAP from baseline to 24 h (7 ± 3 vs. 0 ± 3 mmHg; p < 0.01) and a greater decrease in norepinephrine dose (from 12.5 to 3.5 vs. 5 to 2.5 µg/min; p < 0.05). The correlation (r) coefficients between absolute change in MAP and norepinephrine (NE) dose versus change in BE were 0.05 and -0.37, respectively. CONCLUSIONS: Overall, LI and HI CRRT have similar acid-base effects in patients with acidosis. However, HI was associated with greater improvements in MAP and vasopressor requirements (clinical trial no. NCT00221013).

Infections acquired by adults who receive extracorporeal membrane oxygenation: risk factors and outcome.

OBJECTIVES: To analyze infectious complications that occur in patients who receive extracorporeal membrane oxygenation (ECMO), associated risk factors, and consequences on patient outcome. DESIGN: Retrospective observational survey from 2005 through 2011. PARTICIPANTS AND SETTING: Patients who required ECMO in an Australian referral center. METHODS: Cases of bloodstream infection (BSI), catheter-associated urinary tract infection (CAUTI), and ventilator-associated pneumonia (VAP) that occurred in patients who received ECMO were analyzed. RESULTS: A total of 146 ECMO procedures were performed for more than 48 hours in 139 patients, and 36 patients had a total of 46 infections (30.1 infectious episodes per 1,000 days of ECMO). They included 24 cases of BSI, 6 of them secondary to VAP; 23 cases of VAP; and 5 cases of CAUTI. The most frequent pathogens were Enterobacteriaceae (found in 16 of 46 cases), and Candida was the most common cause of BSI (in 9 of 24 cases). The Sequential Organ Failure Assessment score before ECMO initiation and the number of days of support were independently associated with a risk of BSI, with odds ratios of 1.23 (95% confidence interval [CI], 1.03-1.47; [Formula: see text]) and 1.08 (95% CI, 1.03-1.19]; [Formula: see text]), respectively. Infected patients did not have a significantly higher mortality compared with uninfected patients (41.7% vs 32%; [Formula: see text]), but intensive care unit length of stay (16 days [interquartile range, 8-26 days] vs 11 days [IQR, 4-19 days]; [Formula: see text]) and hospital length of stay (33.5 days [interquartile range, 15.5-55.5] vs 24 days [interquartile range, 9-42 days]; [Formula: see text]) were longer. CONCLUSION: The probability of infection increased with the duration of support and the severity of illness before initiation of ECMO. Infections affected length of stay but did not have an impact on mortality.