Changes in hospital mortality for United States intensive care unit admissions from 1988 to 2012

Balancing digital information-sharing and patient privacy when engaging families in the intensive care unit

Patients in intensive care units (ICUs) may lack decisional capacity and may depend on proxy decision makers (PDMs) to make medical decisions on their behalf. High-quality information-sharing with PDMs, including through such means as health information technology, could improve communication and decision making and could potentially minimize the psychological consequences of an ICU stay for both patients and their family members. However, alongside these anticipated benefits of information-sharing are risks of unwanted disclosure of sensitive information. Approaches to identifying the optimal balance between access to digital health information to facilitate engagement and protecting patient privacy are urgently needed. We identified eight themes that should be considered in balancing health information access and patient privacy: 1) potential benefits to patients from PDM data access; 2) potential harms to patients from such access; 3) the moral status of families within the patient-clinician relationship; 4) the scope of relevant information provided to PDMs; 5) issues around defining PDMs' authority; 6) methods for eliciting and documenting patient preferences about their family's information access; 7) the relevance of methods for ascertaining the identity of PDMs; and 8) the obligations of hospitals to prevent privacy breaches by PDMs. We conclude that PDMs should typically have access to health information from the current episode of care when the patient is decisionally impaired, unless the patient has previously expressed a clear preference that PDMs not have such access.

Temporal Trends of the Clinical, Resource Use and Outcome Attributes of ICU-Managed Candidemia Hospitalizations: A Population-Level Analysis

BACKGROUND

There are mixed findings on the longitudinal patterns of the incidence of intensive care unit (ICU)-managed candidemia, with scarcity of reports on the corresponding evolving patterns of patients' clinical characteristics and outcomes. No population-level data were reported on the temporal trends of the attributes, care and outcomes of ICU-managed adults with candidemia.

METHODS

The Texas Inpatient Public Use Data File was used to identify hospitalizations aged 18 years or older with a diagnosis of candidemia and ICU admission (C-ICU hospitalizations) between 2001 and 2010. Temporal trends of the demographics, clinical features, use of healthcare resources, and short-term outcomes were examined. Average annual percent changes (AAPCs) were derived.

RESULTS

C-ICU hospitalizations (n = 7,552) became (AAPC) increasingly younger (age ≥ 65 years: -1.0%/year). The Charslon comorbidity index rose 4.2%/year, while the mean number of organ failures (OFs) increased by 8.2%/year, with a fast rise in the rate of those developing ≥ 3 OFs (+15.5%/year). Between 2001 and 2010, there was no significant change in utilization of mechanical ventilation and new hemodialysis among C-ICU hospitalizations with reported respiratory and renal failures (68.9% vs. 73.3%, P = 0.3653 and 15.5% vs. 21.8%, P = 0.8589, respectively). Hospital length of stay or total hospital charges remained unchanged during study period. Hospital mortality decreased between 2001 and 2010 from 39.3% to 23.8% (-5.2%/year). The majority of hospital survivors (61.6%) were discharged to another facility, and increasingly to long-term acute care hospitals, with routine home discharge decreasing to 11% by 2010.

CONCLUSIONS

C-ICU hospitalizations demonstrated increasing comorbidity burden and rising development of OF, and matching rise in use of selected life-support interventions, though with unchanged in-hospital fiscal impact. There has been marked decrease in hospital mortality, but survivors had substantial residual morbidity with the majority discharged increasingly to another post-acute care facility.

A pilot study of selective lipopolysaccharide adsorption and coupled plasma filtration and adsorption in adult patients with severe sepsis

AIM

To evaluate the safety and effectiveness of combined extracorporeal therapy in patients with severe sepsis after cardiac surgery.

MATERIALS AND METHODS

Twenty patients received combined extracorporeal therapy (LPS-adsorption with Toraymyxin columns + CPFA). The inclusion criteria were clinical signs of severe sepsis, EAA = 0.6, and PCT >2 ng/ml. 20 comparable patients in the control group received only standard therapy.

RESULTS

Each patient in the study group received 2 daily treatments of combined extracorporeal therapy. In contrast to controls, we noted an increase in the values of MAP from 73 to 82 mm Hg, (p < 0.001) and the mean oxygenation index (from 180 to 246, p < 0.001), decrease of EAA from 0.77 to 0.55, p < 0.001, and PCT (from 6.23 to 2.83 ng/ml, p < 0.001). The 28-day survival rate was 65 and 35% in the study and control groups respectively, p = 0.11.

CONCLUSION

The combined use of LPS-adsorption and CPFA in a single circuit with standard therapy is a safe and possibly effective adjunctive method for treating severe sepsis.

Establishment and Validation of GV-SAPS II Scoring System for Non-Diabetic Critically Ill Patients

BACKGROUND AND AIMS

Recently, glucose variability (GV) has been reported as an independent risk factor for mortality in non-diabetic critically ill patients. However, GV is not incorporated in any severity scoring system for critically ill patients currently. The aim of this study was to establish and validate a modified Simplified Acute Physiology Score II scoring system (SAPS II), integrated with GV parameters and named GV-SAPS II, specifically for non-diabetic critically ill patients to predict short-term and long-term mortality.

METHODS

Training and validation cohorts were exacted from the Multiparameter Intelligent Monitoring in Intensive Care database III version 1.3 (MIMIC-III v1.3). The GV-SAPS II score was constructed by Cox proportional hazard regression analysis and compared with the original SAPS II, Sepsis-related Organ Failure Assessment Score (SOFA) and Elixhauser scoring systems using area under the curve of the receiver operator characteristic (auROC) curve.

RESULTS

4,895 and 5,048 eligible individuals were included in the training and validation cohorts, respectively. The GV-SAPS II score was established with four independent risk factors, including hyperglycemia, hypoglycemia, standard deviation of blood glucose levels (GluSD), and SAPS II score. In the validation cohort, the auROC values of the new scoring system were 0.824 (95% CI: 0.813-0.834, P< 0.001) and 0.738 (95% CI: 0.725-0.750, P< 0.001), respectively for 30 days and 9 months, which were significantly higher than other models used in our study (all P < 0.001). Moreover, Kaplan-Meier plots demonstrated significantly worse outcomes in higher GV-SAPS II score groups both for 30-day and 9-month mortality endpoints (all P< 0.001).

CONCLUSIONS

We established and validated a modified prognostic scoring system that integrated glucose variability for non-diabetic critically ill patients, named GV-SAPS II. It demonstrated a superior prognostic capability and may be an optimal scoring system for prognostic evaluation in this patient group.

Anxiety symptoms in survivors of critical illness: a systematic review and meta-analysis

OBJECTIVES

To evaluate the epidemiology of and postintensive care unit (ICU) interventions for anxiety symptoms after critical illness.

METHODS

We searched five databases (1970-2015) to identify studies assessing anxiety symptoms in adult ICU survivors. Data from studies using the most common assessment instrument were meta-analyzed.

RESULTS

We identified 27 studies (2880 patients) among 27,334 citations. The Hospital Anxiety and Depression Scale-Anxiety (HADS-A) subscale was the most common instrument (81% of studies). We pooled data at 2-3, 6 and 12-14month time-points, with anxiety symptom prevalences [HADS-A≥8, 95% confidence interval (CI)] of 32%(27-38%), 40%(33-46%) and 34%(25-42%), respectively. In a subset of studies with repeated assessments in the exact same patients, there was no significant change in anxiety score or prevalence over time. Age, gender, severity of illness, diagnosis and length of stay were not associated with anxiety symptoms. Psychiatric symptoms during admission and memories of in-ICU delusional experiences were potential risk factors. Physical rehabilitation and ICU diaries had potential benefit.

CONCLUSIONS

One third of ICU survivors experience anxiety symptoms that are persistent during their first year of recovery. Psychiatric symptoms during admission and memories of in-ICU delusional experiences were associated with post-ICU anxiety. Physical rehabilitation and ICU diaries merit further investigation as possible interventions.

Survivors of intensive care with type 2 diabetes and the effect of shared care follow-up clinics: study protocol for the SWEET-AS randomised controlled feasibility study

BACKGROUND

Many patients who survive the intensive care unit (ICU) experience long-term complications such as peripheral neuropathy and nephropathy which represent a major source of morbidity and affect quality of life adversely. Similar pathophysiological processes occur frequently in ambulant patients with diabetes mellitus who have never been critically ill. Some 25 % of all adult ICU patients have diabetes, and it is plausible that ICU survivors with co-existing diabetes are at heightened risk of sequelae from their critical illness. ICU follow-up clinics are being progressively implemented based on the concept that interventions provided in these clinics will alleviate the burdens of survivorship. However, there is only limited information about their outcomes. The few existing studies have utilised the expertise of healthcare professionals primarily trained in intensive care and evaluated heterogenous cohorts. A shared care model with an intensivist- and diabetologist-led clinic for ICU survivors with type 2 diabetes represents a novel targeted approach that has not been evaluated previously. Prior to undertaking any definitive study, it is essential to establish the feasibility of this intervention.

METHODS

This will be a prospective, randomised, parallel, open-label feasibility study. Eligible patients will be approached before ICU discharge and randomised to the intervention (attending a shared care follow-up clinic 1 month after hospital discharge) or standard care. At each clinic visit, patients will be assessed independently by both an intensivist and a diabetologist who will provide screening and targeted interventions. Six months after discharge, all patients will be assessed by blinded assessors for glycated haemoglobin, peripheral neuropathy, cardiovascular autonomic neuropathy, nephropathy, quality of life, frailty, employment and healthcare utilisation. The primary outcome of this study will be the recruitment and retention at 6 months of all eligible patients.

DISCUSSION

This study will provide preliminary data about the potential effects of critical illness on chronic glucose metabolism, the prevalence of microvascular complications, and the impact on healthcare utilisation and quality of life in intensive care survivors with type 2 diabetes. If feasibility is established and point estimates are indicative of benefit, funding will be sought for a larger, multi-centre study.

TRIAL REGISTRATION

ANZCTR ACTRN12616000206426.

Prognosis of patients in a medical intensive care unit

OBJECTIVE

The aim of this study is to evaluate the demographic characteristics of critically ill patients and to determine intensive care unit (ICU) mortality and its predictors.

METHODS

This study was undertaken in the Istanbul Medeniyet University Göztepe Training and Research Hospital Medical ICU. Between May 2012 and January 2013, 111 patients (53 female, 58 male; mean age, 73.79±14.73, mean length of ICU length stay, 9.1±10.7; prevalence of geriatric patients, 77.5%) were admitted to the ICU. The common indications for ICU admission, prevalence of mechanical ventilation support, hematological and biochemical parameters and their effects on mortality were assessed.

RESULTS

The common indications for ICU admission were hemodynamic instability (48.6%), respiratory failure (27.9%) and sepsis (15.3%). Hypertension (46.8%) was the most common comorbidity. Prevalance rates of heart failure and diabetes mellitus were 32.4% and 25.2% respectively. Mortality rate was 52.3% in all patients. Approximately 80% of all deaths was observed within the first fifteen-day. In additon, mortality rate (85.7%) was prominent within patients in need of the mechanical ventilation support. Mechanical ventilation requirement, increased ferritin and vitamin B12 levels were independent risk factors for mortality in critically ill patients (p<0.01, for all).

CONCLUSION

Mortality rate was higher in medical ICU. Herein, increased prevalence of geriatric population, concomitant comorbidities and mechanical ventilation requirements may play role.

Characteristics and outcomes of patients admitted to Spanish ICU: A prospective observational study from the ENVIN-HELICS registry (2006-2011)

OBJECTIVE

To describe the case-mix of patients admitted to intensive care units (ICUs) in Spain during the period 2006-2011 and to assess changes in ICU mortality according to severity level.

DESIGN

Secondary analysis of data obtained from the ENVN-HELICS registry. Observational prospective study.

SETTING

Spanish ICU.

PATIENTS

Patients admitted for over 24h.

INTERVENTIONS

None.

VARIABLES

Data for each of the participating hospitals and ICUs were recorded, as well as data that allowed to knowing the case-mix and the individual outcome of each patient. The study period was divided into two intervals, from 2006 to 2008 (period 1) and from 2009 to 2011 (period 2). Multilevel and multivariate models were used for the analysis of mortality and were performed in each stratum of severity level.

RESULTS

The study population included 142,859 patients admitted to 188 adult ICUs. There was an increase in the mean age of the patients and in the percentage of patients >79 years (11.2% vs. 12.7%, P<0.001). Also, the mean APACHE II score increased from 14.35±8.29 to 14.72±8.43 (P<0.001). The crude overall intra-UCI mortality remained unchanged (11.4%) but adjusted mortality rate in patients with APACHE II score between 11 and 25 decreased modestly in recent years (12.3% vs. 11.6%, odds ratio=0.931, 95% CI 0.883-0.982; P=0.008).

CONCLUSION

This study provides observational longitudinal data on case-mix of patients admitted to Spanish ICUs. A slight reduction in ICU mortality rate was observed among patients with intermediate severity level.

Lactate kinetics in sepsis and septic shock: a review of the literature and rationale for further research

Over the last two decades, there have been vast improvements in sepsis-related outcomes, largely resulting from the widespread adoption of aggressive fluid resuscitation and infection control. With increased understanding of the pathophysiology of sepsis, novel diagnostics and resuscitative interventions are being discovered. In recent years, few diagnostic tests like lactate have engendered more attention and research in the sepsis arena. Studies highlighting lactate’s prognostic potential for mortality and other outcomes are ubiquitous and largely focus on the early stage of sepsis management, defined as the initial 6 h and widely referred to as the “golden hours.” Additional investigations, although more representative of surgical and trauma patients, suggest that lactate measurements beyond 24 h from the initiation of resuscitation continue to have predictive and prognostic utility. This review summarizes the current research and evidence regarding lactate’s utility as a prognosticator of clinical outcomes in both early and late sepsis management, defines the mechanism of lactate production and clearance, and identifies areas warranting further research.

Update of Sepsis: Recent Evidences about Early Goal Directed Therapy

Severe sepsis and septic shock is a life-threatening disease. It is combined with multi-organ failure. In the past decade, early goal directed therapy has been proposed as an effective treatment strategy for better outcome. Recent epidemiologic studies showed that the outcome of sepsis has been improved with the introduction of early goal directed therapy. However, it is unclear which elements of early goal directed therapy contributed to the better outcome. Recent prospective and randomized trials suggested that some elements of early goal directed therapy did not have any effect on the outcome benefit. In this paper, recent articles about early goal directed therapy will be reviewed and the effectiveness of individual elements of early goal directed therapy will be discussed.

Clinical aspects of sepsis: an overview

Sepsis is one of the oldest and most elusive syndromes in medicine. With the confirmation of germ theory by Semmelweis, Pasteur, and others, sepsis was considered as a systemic infection by a pathogenic organism. Although the germ is probably the beginning of the syndrome and one of the major enemies to be identified and fought, sepsis is something wider and more elusive. In this chapter clinically relevant themes of sepsis will be approached to provide an insight of everyday clinical practice for healthcare workers often not directly involved in the patient's management.

A history of outcome prediction in the ICU

PURPOSE OF REVIEW

There are few first-hand accounts that describe the history of outcome prediction in critical care. This review summarizes the authors' personal perspectives about the development and evolution of Acute Physiology and Chronic Health Evaluation over the past 35 years.

RECENT FINDINGS

We emphasize what we have learned in the past and more recently our perspectives about the current status of outcome prediction, and speculate about the future of outcome prediction.

SUMMARY

There is increasing evidence that superior accuracy in outcome prediction requires complex modeling with detailed adjustment for diagnosis and physiologic abnormalities. Thus, an automated electronic system is recommended for gathering data and generating predictions. Support, either public or private, is required to assist users and to update and improve models. Current outcome prediction models have increasingly focused on benchmarks for resource use, a trend that seems likely to increase in the future.

Assessing the utility of ICU readmissions as a quality metric: an analysis of changes mediated by residency work-hour reforms

BACKGROUND

ICU readmissions are associated with increased mortality and costs; however, it is unclear whether these outcomes are caused by readmissions or by residual confounding by illness severity. An assessment of temporal changes in ICU readmission in response to a specific policy change could help disentangle these possibilities. We sought to determine whether ICU readmission rates changed after 2003 Accreditation Council for Graduate Medical Education Resident Duty Hours reform ("reform") and whether there were temporally corresponding changes in other ICU outcomes.

METHODS

We used a difference-in-differences approach using Project IMPACT (Improved Methods of Patient Information Access of Core Clinical Tasks). Piecewise regression models estimated changes in outcomes immediately before and after reform in 274,491 critically ill medical and surgical patients in 151 community and academic US ICUs. Outcome measures included ICU readmission, ICU mortality, and in-hospital post-ICU-discharge mortality.

RESULTS

In ICUs with residents, ICU readmissions increased before reform (OR, 1.5; 95% CI, 1.22-1.84; P < .01), and decreased after (OR, 0.85; 95% CI, 0.73-0.98; P = .03). This abrupt decline in ICU readmissions after reform differed significantly from an increase in readmissions observed in ICUs without residents at this time (difference-in-differences P < .01). No comparable changes in mortality were observed between ICUs with vs without residents.

CONCLUSIONS

The changes in ICU readmission rates after reform, without corresponding changes in mortality, suggest that ICU readmissions are not causally related to other untoward patient outcomes. Instead, ICU readmission rates likely reflect operational aspects of care that are not patient-centered, making them less useful indicators of ICU quality.

Phenotypic clusters within sepsis-associated multiple organ dysfunction syndrome

INTRODUCTION

Sepsis is a devastating condition that is generally treated as a single disease. Identification of meaningfully distinct clusters may improve research, treatment and prognostication among septic patients. We therefore sought to identify clusters among patients with severe sepsis or septic shock.

METHODS

We retrospectively studied all patients with severe sepsis or septic shock admitted directly from the emergency department to the intensive care units (ICUs) of three hospitals, 2006-2013. Using age and Sequential Organ Failure Assessment (SOFA) subscores, we defined clusters utilizing self-organizing maps, a method for representing multidimensional data in intuitive two-dimensional grids to facilitate cluster identification.

RESULTS

We identified 2533 patients with severe sepsis or septic shock. Overall mortality was 17 %, with a mean APACHE II score of 24, mean SOFA score of 8 and a mean ICU stay of 5.4 days. Four distinct clusters were identified; (1) shock with elevated creatinine, (2) minimal multi-organ dysfunction syndrome (MODS), (3) shock with hypoxemia and altered mental status, and (4) hepatic disease. Mortality (95 % confidence intervals) for these clusters was 11 (8-14), 12 (11-14), 28 (25-32), and 21 (16-26) %, respectively (p < 0.0001). Regression modeling demonstrated that the clusters differed in the association between clinical outcomes and predictors, including APACHE II score.

CONCLUSIONS

We identified four distinct clusters of MODS among patients with severe sepsis or septic shock. These clusters may reflect underlying pathophysiological differences and could potentially facilitate tailored treatments or directed research.

A national survey exploring views and experience of health professionals about transferring patients from critical care home to die

BACKGROUND

Transferring critically ill patients home to die is poorly explored in the literature to date. This practice is rare, and there is a need to understand health care professionals' (HCP) experience and views.

OBJECTIVES

To examine (1) HCPs' experience of transferring patients home to die from critical care, (2) HCPs' views about transfer and (3) characteristics of patients, HCPs would hypothetically consider transferring home to die.

DESIGN

A national study developing a web-based survey, which was sent to the lead doctors and nurses in critical care units.

SETTING/PARTICIPANTS

Lead doctors and senior nurses (756 individuals) working in 409 critical care units across the United Kingdom were invited to participate in the survey.

RESULTS

In total, 180 (23.8%) completed surveys were received. A total of 65 (36.1%) respondents had been actively involved in transferring patients home to die and 28 (15.5%) had been involved in discussions that did not lead to transfer. Respondents were supportive of the idea of transfer home to die (88.8%). Patients identified by respondents as unsuitable for transfer included unstable patients (61.8%), intubated and ventilated patients (68.5%) and patients receiving inotropes (65.7%). There were statistically significant differences in views between those with and without experience and between doctors and nurses. Nurses and those with experience tended to have more positive views.

CONCLUSION

While transferring patients home to die is supported in critical care, its frequency in practice remains low. Patient stability and level of intervention are important factors in decision-making in this area. Views held about this practice are influenced by previous experience and the professional role held.

Current challenges in understanding immune cell functions during septic syndromes

BACKGROUND

Sepsis is a dynamic infectious disease syndrome characterized by dysregulated inflammatory responses.

RESULTS

Despite decades of research, improvements in the treatment of sepsis have been modest. These limited advances are likely due, in part, to multiple factors, including substantial heterogeneity in septic syndromes, significant knowledge gaps in our understanding of how immune cells function in sepsis, and limitations in animal models that accurately recapitulate the human septic milieu. The goal of this brief review is to describe current challenges in understanding immune cell functions during sepsis. We also provide a framework to guide scientists and clinicians in research and patient care as they strive to better understand dysregulated cell responses during sepsis.

CONCLUSIONS

Additional, well-designed translational studies in sepsis are critical for enhancing our understanding of the role of immune cells in sepsis.

Stress-related mucosal disease in the critically ill patient

Bleeding from stress-related mucosal disease in critically ill patients remains an important clinical management issue. Although only a small proportion (1-6%) of patients admitted to an intensive care unit (ICU) will bleed, a substantial proportion exhibit clinical risk factors (mechanical ventilation for >48 h and a coagulopathy) that predict an increased risk of bleeding. Furthermore, upper gastrointestinal mucosal lesions can be found in 75-100% of patients in ICUs. Although uncommon, stress-ulcer bleeding is a severe complication with an estimated mortality of 40-50%, mostly from decompensating an underlying condition or multiorgan failure. Although the vast majority of patients in ICUs receive stress-ulcer prophylaxis, largely with PPIs, some controversy surrounds their efficacy and safety. Indeed, no single trial has shown that stress-ulcer prophylaxis reduces mortality. Some reports suggest that the use of PPIs increases the risk of nosocomial infections. However, several meta-analyses and cost-effectiveness studies suggest PPIs to be more clinically effective and cost-effective than histamine-2 receptor antagonists, without considerable increases in nosocomial pneumonia. To help clinicians use the most appropriate strategy for treatment of patients in the ICU, this Review presents the latest information on all aspects of stress-related mucosal disease.

Mortality prediction in intensive care units with the Super ICU Learner Algorithm (SICULA): a population-based study

BACKGROUND

Improved mortality prediction for patients in intensive care units is a big challenge. Many severity scores have been proposed, but findings of validation studies have shown that they are not adequately calibrated. The Super ICU Learner Algorithm (SICULA), an ensemble machine learning technique that uses multiple learning algorithms to obtain better prediction performance, does at least as well as the best member of its library. We aimed to assess whether the Super Learner could provide a new mortality prediction algorithm for patients in intensive care units, and to assess its performance compared with other scoring systems.

METHODS

From January, 2001, to December, 2008, we used the Multiparameter Intelligent Monitoring in Intensive Care II (MIMIC-II) database (version 26) including all patients admitted to an intensive care unit at the Beth Israel Deaconess Medical Centre, Boston, MA, USA. We assessed the calibration, discrimination, and risk classification of predicted hospital mortality based on Super Learner compared with SAPS-II, APACHE-II, and SOFA. We calculated performance measures with cross-validation to avoid making biased assessments. Our proposed score was then externally validated on a dataset of 200 randomly selected patients admitted at the intensive care unit of Hôpital Européen Georges-Pompidou, Paris, France, between Sept 1, 2013, and June, 30, 2014. The primary outcome was hospital mortality. The explanatory variables were the same as those included in the SAPS II score.

FINDINGS

24,508 patients were included, with median SAPS-II of 38 (IQR 27-51) and median SOFA of 5 (IQR 2-8). 3002 of 24,508 (12%) patients died in the Beth Israel Deaconess Medical Centre. We produced two sets of predictions based on the Super Learner; the first based on the 17 variables as they appear in the SAPS-II score (SL1), and the second, on the original, untransformed variables (SL2). The two versions yielded average predicted probabilities of death of 0·12 (IQR 0·02-0·16) and 0·13 (0·01-0·19), whereas the corresponding value for SOFA was 0·12 (0·05-0·15) and for SAPS-II 0·30 (0·08-0·48). The cross-validated area under the receiver operating characteristic curve (AUROC) for SAPS-II was 0·78 (95% CI 0·77-0·78) and 0·71 (0·70-0·72) for SOFA. Super Learner had an AUROC of 0·85 (0·84-0·85) when the explanatory variables were categorised as in SAPS-II, and of 0·88 (0·87-0·89) when the same explanatory variables were included without any transformation. Additionally, Super Learner showed better calibration properties than previous score systems. On the external validation dataset, the AUROC was 0·94 (0·90-0·98) and calibration properties were good.

INTERPRETATION

Compared with conventional severity scores, Super Learner offers improved performance for predicting hospital mortality in patients in intensive care units. A user-friendly implementation is available online and should be useful for clinicians seeking to validate our score.

FUNDING

Fulbright Foundation, Assistance Publique-Hôpitaux de Paris, Doris Duke Clinical Scientist Development Award, and the NIH.

Mortality related to invasive infections, sepsis, and septic shock in critically ill children in Australia and New Zealand, 2002-13: a multicentre retrospective cohort study

BACKGROUND

Severe infections kill more than 4·5 million children every year. Population-based data for severe infections in children requiring admission to intensive care units (ICUs) are scarce. We assessed changes in incidence and mortality of severe infections in critically ill children in Australia and New Zealand.

METHODS

We did a retrospective multicentre cohort study of children requiring intensive care in Australia and New Zealand between 2002 and 2013, with data from the Australian and New Zealand Paediatric Intensive Care Registry. We included children younger than 16 years with invasive infection, sepsis, or septic shock. We assessed incidence and mortality in the ICU for 2002-07 versus 2008-13.

FINDINGS

During the study period, 97 127 children were admitted to ICUs, 11 574 (11·9%) had severe infections, including 6688 (6·9%) with invasive infections, 2847 (2·9%) with sepsis, and 2039 (2·1%) with septic shock. Age-standardised incidence increased each year by an average of 0·56 cases per 100 000 children (95% CI 0·41-0·71) for invasive infections, 0·09 cases per 100 000 children (0·00-0·17) for sepsis, and 0·08 cases per 100 000 children (0·04-0·12) for septic shock. 260 (3·9%) of 6688 patients with invasive infection died, 159 (5·6%) of 2847 with sepsis died, and 346 (17·0%) of 2039 with septic shock died, compared with 2893 (3·0%) of all paediatric ICU admissions. Children admitted with invasive infections, sepsis, and septic shock accounted for 765 (26·4%) of 2893 paediatric deaths in ICUs. Comparing 2008-13 with 2002-07, risk-adjusted mortality decreased significantly for invasive infections (odds ratio 0·72, 95% CI 0·56-0·94; p=0·016), and for sepsis (0·66, 0·47-0·93; p=0·016), but not significantly for septic shock (0·79, 0·61-1·01; p=0·065).

INTERPRETATION

Severe infections remain a major cause of mortality in paediatric ICUs, representing a major public health problem. Future studies should focus on patients with the highest risk of poor outcome, and assess the effectiveness of present sepsis interventions in children.

FUNDING

National Medical Health and Research Council, Australian Resuscitation Outcomes Consortium, Centre of Research Excellence (1029983).

Metabolomic derangements are associated with mortality in critically ill adult patients

Objective

To identify metabolomic biomarkers predictive of Intensive Care Unit (ICU) mortality in adults.

Rationale

Comprehensive metabolomic profiling of plasma at ICU admission to identify biomarkers associated with mortality has recently become feasible.

Methods

We performed metabolomic profiling of plasma from 90 ICU subjects enrolled in the BWH Registry of Critical Illness (RoCI). We tested individual metabolites and a Bayesian Network of metabolites for association with 28-day mortality, using logistic regression in R, and the CGBayesNets Package in MATLAB. Both individual metabolites and the network were tested for replication in an independent cohort of 149 adults enrolled in the Community Acquired Pneumonia and Sepsis Outcome Diagnostics (CAPSOD) study.

Results

We tested variable metabolites for association with 28-day mortality. In RoCI, nearly one third of metabolites differed among ICU survivors versus those who died by day 28 (N = 57 metabolites, p<.05). Associations with 28-day mortality replicated for 31 of these metabolites (with p<.05) in the CAPSOD population. Replicating metabolites included lipids (N = 14), amino acids or amino acid breakdown products (N = 12), carbohydrates (N = 1), nucleotides (N = 3), and 1 peptide. Among 31 replicated metabolites, 25 were higher in subjects who progressed to die; all 6 metabolites that are lower in those who die are lipids. We used Bayesian modeling to form a metabolomic network of 7 metabolites associated with death (gamma-glutamylphenylalanine, gamma-glutamyltyrosine, 1-arachidonoylGPC(20:4), taurochenodeoxycholate, 3-(4-hydroxyphenyl) lactate, sucrose, kynurenine). This network achieved a 91% AUC predicting 28-day mortality in RoCI, and 74% of the AUC in CAPSOD (p<.001 in both populations).

Conclusion

Both individual metabolites and a metabolomic network were associated with 28-day mortality in two independent cohorts. Metabolomic profiling represents a valuable new approach for identifying novel biomarkers in critically ill patients.

One-year mortality and predictors of death among hospital survivors of acute respiratory distress syndrome

PURPOSE

Advances in supportive care and ventilator management for acute respiratory distress syndrome (ARDS) have resulted in declines in short-term mortality, but risks of death after survival to hospital discharge have not been well described. Our objective was to quantify the difference between short-term and long-term mortality in ARDS and to identify risk factors for death and causes of death at 1 year among hospital survivors.

METHODS

This multi-intensive care unit, prospective cohort included patients with ARDS enrolled between January 2006 and February 2010. We determined the clinical characteristics associated with in-hospital and 1-year mortality among hospital survivors and utilized death certificate data to identify causes of death.

RESULTS

Of 646 patients hospitalized with ARDS, mortality at 1 year was substantially higher (41 %, 95% CI 37-45%) than in-hospital mortality (24%, 95% CI 21-27%), P < 0.0001. Among 493 patients who survived to hospital discharge, the 110 (22%) who died in the subsequent year were older (P < 0.001) and more likely to have been discharged to a nursing home, other hospital, or hospice compared to patients alive at 1 year (P < 0.001). Important predictors of death among hospital survivors were comorbidities present at the time of ARDS, and not living at home prior to admission. ARDS-related measures of severity of illness did not emerge as independent predictors of mortality in hospital survivors.

CONCLUSIONS

Despite improvements in short-term ARDS outcomes, 1-year mortality is high, mostly because of the large burden of comorbidities, which are prevalent in patients with ARDS.

Epidemiology of severe sepsis

Severe sepsis is a leading cause of death in the United States and the most common cause of death among critically ill patients in non-coronary intensive care units (ICU). Respiratory tract infections, particularly pneumonia, are the most common site of infection, and associated with the highest mortality. The type of organism causing severe sepsis is an important determinant of outcome, and gram-positive organisms as a cause of sepsis have increased in frequency over time and are now more common than gram-negative infections.

Recent studies suggest that acute infections worsen pre-existing chronic diseases or result in new chronic diseases, leading to poor long-term outcomes in acute illness survivors. People of older age, male gender, black race, and preexisting chronic health conditions are particularly prone to develop severe sepsis; hence prevention strategies should be targeted at these vulnerable populations in future studies.