Customized probability models for early severe sepsis in adult intensive care patients. Intensive Care Unit Scoring Group

Circadian Rhythmicity of Vital Signs at Intensive Care Unit Discharge and Outcome of Traumatic Brain Injury

BACKGROUND

Physiological functions with circadian rhythmicity are often disrupted during illness.

OBJECTIVE

To assess the utility of circadian rhythmicity of vital signs in predicting outcome of traumatic brain injury (TBI).

METHODS

A retrospective single-center cohort study of adult intensive care unit (ICU) patients with largely isolated TBI to explore the relationship between the circadian rhythmicity of vital signs during the last 24 hours before ICU discharge and clinical markers of TBI severity and score on the Glasgow Outcome Scale 6 months after injury (GOS-6).

RESULTS

The 130 study participants had a median age of 39.0 years (IQR, 23.0-59.0 years), a median Glasgow Coma Scale score at the scene of 8.0 (IQR, 3.0-13.0), and a median Rotterdam score on computed tomography of the head of 3 (IQR, 3-3), with 105 patients (80.8%) surviving to hospital discharge. Rhythmicity was present for heart rate (30.8% of patients), systolic blood pressure (26.2%), diastolic blood pressure (20.0%), and body temperature (26.9%). Independent predictors of a dichotomized GOS-6 ≥4 were the Rotterdam score (odds ratio [OR], 0.38 [95% CI, 0.18-0.81]; P = .01), Glasgow Coma Scale score at the scene (OR, 1.22 [95% CI, 1.05-1.41]; P = .008), age (OR, 0.95 [95% CI, 0.92-0.98]; P = .003), oxygen saturation <90% in the first 24 hours (OR, 0.19 [95% CI, 0.05-0.73]; P = .02), serum sodium level <130 mmol/L (OR, 0.20 [95% CI, 0.05-0.70]; P = .01), and active intracranial pressure management (OR, 0.16 [95% CI, 0.04-0.62]; P = .008), but not rhythmicity of any vital sign.

CONCLUSION

Circadian rhythmicity of vital signs at ICU discharge is not predictive of GOS-6 in patients with TBI.

Predicting severe clinical events by learning about life-saving actions and outcomes using distant supervision

Medical error is a leading cause of patient death in the United States. Among the different types of medical errors, harm to patients caused by doctors missing early signs of deterioration is especially challenging to address due to the heterogeneity of patients' physiological patterns. In this study, we implemented risk prediction models using the gradient boosted tree method to derive risk estimates for acute onset diseases in the near future. The prediction model uses physiological variables as input signals and the time of the administration of outcome-related interventions and discharge diagnoses as labels. We examine four categories of acute onset illness: acute heart failure (AHF), acute lung injury (ALI), acute kidney injury (AKI), and acute liver failure (ALF). To develop and test the model, we consider data from two sources: 23,578 admissions to the Intensive Care Unit (ICU) from the MIMIC-3 dataset (Beth-Israel Hospital) and 16,612 ICU admissions on hospitals affiliated with our institution (University of Washington Medical Center and Harborview Medical Center, the UW-CDR dataset). We systematically identify outcome-related interventions for each acute organ failure, then use them, along with discharge diagnoses, to label proxy events to train gradient boosted trees. The trained models achieve the highest F1 score with a value of 0.6018 when predicting the need for life-saving interventions for ALI within the next 24 h in the MIMIC-3 dataset while showing a median F1 score of 0.3850 from all acute organ failures in both datasets. The approach also achieves the highest F1 score of 0.6301 when classifying a patient's ALI status at the time of discharge from the MIMIC-3 dataset, with a median F1 score of 0.4307 in both datasets. This study shows the potential for using the time of outcome-related intervention administrations and discharge diagnoses as labels to train supervised machine learning models that predict the risk of acute onset illnesses.

Clinical Trajectories and Causes of Death in Septic Patients with a Low APACHE II Score

Clinical course and mortality in septic patients with low disease severity remain poorly understood and is worth further investigation. We enrolled septic patients admitted to intensive care units (ICUs) between 2010 and 2014 with Acute Physiology and Chronic Health Evaluation II (APACHE II) scores of ≤15. We sought to determine their clinical trajectories and causes of death, and to analyze risk factors associated with in-hospital mortality. A total of 352 patients were included, of whom 89 (25%) did not survive to hospital discharge, at a rate higher than predicted (<21%) by the APACHE II score. Approximately one third (31/89) of non-survivors succumbed to index sepsis; however, more patients (34/89) died of subsequent sepsis. New-onset ICU sepsis developed in 99 (28%) patients and was an independent risk factor for mortality. In addition, septic patients with comorbid malignancy or index infection acquired in the hospital settings were more likely to have in-hospital mortality than those without. In conclusion, septic patients with low APACHE II scores were at a higher mortality risk than expected, and subsequent sepsis rather than index sepsis was the primary cause of death. This study provides insight into unexpected clinical trajectories and outcomes of septic patients with low disease severity at ICU admission and highlights the need for more research and clinical attention in this patient population.

A machine learning-based model for 1-year mortality prediction in patients admitted to an Intensive Care Unit with a diagnosis of sepsis

INTRODUCTION

Sepsis is associated to a high mortality rate, and its severity must be evaluated quickly. The severity of illness scores used are intended to be applicable to all patient populations, and generally evaluate in-hospital mortality. However, patients with sepsis continue to be at risk of death after hospital discharge.

OBJECTIVE

To develop a model for predicting 1-year mortality in critical patients diagnosed with sepsis.

PATIENTS

The data corresponding to 5650 admissions of patients with sepsis from the Medical Information Mart for Intensive Care (MIMIC-III) database were evaluated, randomly divided as follows: 70% for training and 30% for validation.

DESIGN

A retrospective register-based cohort study was carried out. The clinical information of the first 24h after admission was used to develop a 1-year mortality prediction model based on Stochastic Gradient Boosting (SGB) methodology. Variable selection was addressed using Least Absolute Shrinkage and Selection Operator (LASSO) and SGB variable importance methodologies. The predictive power was evaluated using the area under the ROC curve (AUROC).

RESULTS

An AUROC of 0.8039 (95% confidence interval (CI): [0.8033 0.8045]) was obtained in the validation subset. The model exceeded the predictive performances obtained with traditional severity of disease scores in the same subset.

CONCLUSION

The use of assembly algorithms, such as SGB, for the generation of a customized model for sepsis yields more accurate 1-year mortality prediction than the traditional scoring systems such as SAPS II, SOFA or OASIS.

Early Hospital Mortality Prediction using Vital Signals

Early hospital mortality prediction is critical as intensivists strive to make efficient medical decisions about the severely ill patients staying in intensive care units (ICUs). As a result, various methods have been developed to address this problem based on clinical records. However, some of the laboratory test results are time-consuming and need to be processed. In this paper, we propose a novel method to predict mortality using features extracted from the heart signals of patients within the first hour of ICU admission. In order to predict the risk, quantitative features have been computed based on the heart rate signals of ICU patients suffering cardiovascular diseases. Each signal is described in terms of 12 statistical and signal-based features. The extracted features are fed into eight classifiers: decision tree, linear discriminant, logistic regression, support vector machine (SVM), random forest, boosted trees, Gaussian SVM, and K-nearest neighborhood (K-NN). To derive insight into the performance of the proposed method, several experiments have been conducted using the well-known clinical dataset named Medical Information Mart for Intensive Care III (MIMIC-III). The experimental results demonstrate the capability of the proposed method in terms of precision, recall, F1-score, and area under the receiver operating characteristic curve (AUC). The decision tree classifier satisfies both accuracy and interpretability better than the other classifiers, producing an F1-score and AUC equal to 0.91 and 0.93, respectively. It indicates that heart rate signals can be used for predicting mortality in patients in the care units especially coronary care units (CCUs), achieving a comparable performance with existing predictions that rely on high dimensional features from clinical records which need to be processed and may contain missing information.

Anti-inflammatory effects of human embryonic stem cell-derived mesenchymal stem cells secretome preconditioned with diazoxide, trimetazidine and MG-132 on LPS-induced systemic inflammation mouse model

Systemic inflammatory response syndrome is a complex pathophysiologic and immunologic response to an insult. Sepsis is a life-threatening condition happening when the body's response to infection causes injury to its own tissues and organs. Stem cell therapy is a new approach to modulate immune responses. Mesenchymal stem cells (MSCs) establish a regenerative niche by secreting secretome and modulating immune responses. MSC secretome can be leveraged for therapeutic applications if production of secretary molecules were optimized. Pharmacological preconditioning using small molecules can increase survival of MSCs after transplantation. The aim of this study was to investigate the effect of secretome of human embryonic-derived mesenchymal stem cells (hESC-MSCs) preconditioned with MG-132,Trimetazidine (TMZ) and Diazoxide (DZ) on immunomodulatory efficiency of these cells in Lipo polysaccharide (LPS) challenged mice models. Mice were injected intraperitoneally with LPS and groups of animals were intraperitoneally given 1 ml 30× secretome 6 h after LPS injection. Serum levels of biochemical parameters were then measured by an auto analyser and serum inflammatory cytokine levels were analysed using commercially available RayBio Mouse Inflammation Antibody Array. Ultimately, histopathology and survival studies were conducted. The results showed that TMZ and DZ-conditioned medium significantly increasing the survival and improvement of histopathological score. We found that MG-132-conditioned medium failed to show significant outcomes. This study demonstrated that human MSC secretome has the potential to control inflammation.

Real-Time Automated Sampling of Electronic Medical Records Predicts Hospital Mortality

BACKGROUND

Real-time automated continuous sampling of electronic medical record data may expeditiously identify patients at risk for death and enable prompt life-saving interventions. We hypothesized that a real-time electronic medical record-based alert could identify hospitalized patients at risk for mortality.

METHODS

An automated alert was developed and implemented to continuously sample electronic medical record data and trigger when at least 2 of 4 systemic inflammatory response syndrome criteria plus at least one of 14 acute organ dysfunction parameters was detected. The systemic inflammatory response syndrome and organ dysfunction alert was applied in real time to 312,214 patients in 24 hospitals and analyzed in 2 phases: training and validation datasets.

RESULTS

In the training phase, 29,317 (18.8%) triggered the alert and 5.2% of such patients died, whereas only 0.2% without the alert died (unadjusted odds ratio 30.1; 95% confidence interval, 26.1-34.5; P < .0001). In the validation phase, the sensitivity, specificity, area under the curve, and positive and negative likelihood ratios for predicting mortality were 0.86, 0.82, 0.84, 4.9, and 0.16, respectively. Multivariate Cox-proportional hazard regression model revealed greater hospital mortality when the alert was triggered (adjusted hazards ratio 4.0; 95% confidence interval, 3.3-4.9; P < .0001). Triggering the alert was associated with additional hospitalization days (+3.0 days) and ventilator days (+1.6 days; P < .0001).

CONCLUSION

An automated alert system that continuously samples electronic medical record data can be implemented, has excellent test characteristics, and can assist in the real-time identification of hospitalized patients at risk for death.

A comparison of adipose and bone marrow-derived mesenchymal stromal cell secreted factors in the treatment of systemic inflammation

BACKGROUND

Bone marrow-derived mesenchymal stromal cells (BMSCs) are a cell population of intense exploration for therapeutic use in inflammatory diseases. Secreted factors released by BMSCs are responsible for the resolution of inflammation in several pre-clinical models. New studies have uncovered that adipose tissue also serves as a reservoir of multipotent, non-hematopoietic stem cells, termed adipose-derived stromal/stem cells (ASCs), with many common characteristics to BMSCs. We hypothesized that ASC and BMSC secreted factors would lead to a comparable benefit in the context of generalized inflammation.

FINDINGS

Proteomic profiling of conditioned media revealed that BMSCs express significantly higher levels of sVEGFR1 and sTNFR1, two soluble cytokine receptors with known therapeutic activity in sepsis. In a prophylactic study of endotoxin-induced inflammation in mice, we observed that BMSC secreted factors provided a greater survival benefit and tissue protection of endotoxemic mice compared to ASCs. Neutralization of sVEGFR1 and sTNFR1 did not significantly affect the survival benefit experienced by mice treated with BMSC secreted factors.

CONCLUSIONS

Our findings suggest that BMSCs may be more effective as a cell therapeutic for use in endotoxic shock and that ASCs may be positioned for continued exploration in immunomodulatory diseases. Soluble cytokine receptors can distinguish stromal cells from different tissue origins, though they may not be the sole contributors to the therapeutic benefit of BMSCs. Furthermore, other secreted factors not discussed in this study may also differentiate these stromal cell populations from one another.

A modified sequential organ failure assessment score for critical care triage

OBJECTIVE

The Sequential Organ Failure Assessment (SOFA) score has been recommended for triage during a mass influx of critically ill patients, but it requires laboratory measurement of 4 parameters, which may be impractical with constrained resources. We hypothesized that a modified SOFA (MSOFA) score that requires only 1 laboratory measurement would predict patient outcome as effectively as the SOFA score.

METHODS

After a retrospective derivation in a prospective observational study in a 24-bed medical, surgical, and trauma intensive care unit, we determined serial SOFA and MSOFA scores on all patients admitted during the 2008 calendar year and compared the ability to predict mortality and the need for mechanical ventilation.

RESULTS

A total of 1770 patients (56% male patients) with a 30-day mortality of 10.5% were included in the study. Day 1 SOFA and MSOFA scores performed equally well at predicting mortality with an area under the receiver operating curve (AUC) of 0.83 (95% confidence interval 0.81-.85) and 0.84 (95% confidence interval 0.82-.85), respectively (P = .33 for comparison). Day 3 SOFA and MSOFA predicted mortality for the 828 patients remaining in the intensive care unit with an AUC of 0.78 and 0.79, respectively. Day 5 scores performed less well at predicting mortality. Day 1 SOFA and MSOFA predicted the need for mechanical ventilation on day 3, with an AUC of 0.83 and 0.82, respectively. Mortality for the highest category of SOFA and MSOFA score (>11 points) was 53% and 58%, respectively.

CONCLUSIONS

The MSOFA predicts mortality as well as the SOFA and is easier to implement in resource-constrained settings, but using either score as a triage tool would exclude many patients who would otherwise survive.

Pharmacokinetics of colistin in cerebrospinal fluid after intraventricular administration of colistin methanesulfonate

Intraventricular colistin, administered as colistin methanesulfonate (CMS), is the last resource for the treatment of central nervous system infections caused by panresistant Gram-negative bacteria. The doses and daily regimens vary considerably and are empirically chosen; the cerebrospinal fluid (CSF) pharmacokinetics of colistin after intraventricular administration of CMS has never been characterized. Nine patients (aged 18 to 73 years) were treated with intraventricular CMS (daily doses of 2.61 to 10.44 mg). Colistin concentrations were measured using a selective high-performance liquid chromatography (HPLC) assay. The population pharmacokinetics analysis was performed with the P-Pharm program. The pharmacokinetics of colistin could be best described by the one-compartment model. The estimated values (means ± standard deviations) of apparent CSF total clearance (CL/Fm, where Fm is the unknown fraction of CMS converted to colistin) and terminal half-life (t(1/2λ)) were 0.033 ± 0.014 liter/h and 7.8 ± 3.2 h, respectively, and the average time to the peak concentration was 3.7 ± 0.9 h. A positive correlation between CL/Fm and the amount of CSF drained (range 40 to 300 ml) was observed. When CMS was administered at doses of ≥5.22 mg/day, measured CSF concentrations of colistin were continuously above the MIC of 2 μg/ml, and measured values of trough concentration (C(trough)) ranged between 2.0 and 9.7 μg/ml. Microbiological cure was observed in 8/9 patients. Intraventricular administration of CMS at doses of ≥5.22 mg per day was appropriate in our patients, but since external CSF efflux is variable and can influence the clearance of colistin and its concentrations in CSF, the daily dose of 10 mg suggested by the Infectious Diseases Society of America may be more prudent.

Prognostic categorization of intensive care septic patients

Sepsis is one of the leading worldwide causes of morbidity and mortality in critically-ill patients. Prediction of outcome in patients with sepsis requires repeated clinical interpretation of the patients’ conditions, clinical assessment of tissue hypoxia and the use of severity scoring systems, because the prognostic categorization accuracy of severity scoring indices alone, is relatively poor. Generally, such categorization depends on the severity of the septic state, ranging from systemic inflammatory response to septic shock. Now, there is no gold standard for the clinical assessment of tissue hypoxia which can be achieved by both global and regional oxygen extractabilities, added to prognostic pro-inflammatory mediators. Because the technology used to identify the genetic make-up of the human being is rapidly advancing, the structure of 30 000 genes which make-up the human DNA bank is now known. This would allow easy prognostic categorization of critically-ill patients including those suffering from sepsis. The present review spots lights on the main severity scoring systems used for outcome prediction in septic patients. For morbidity prediction, it discusses the Multiple Organ Dysfunction score, the sequential organ failure assessment score, and the logistic organ dysfunction score. For mortality/survival prediction, it discusses the Acute Physiology and Chronic Health Evaluation scores, the Therapeutic Intervention Scoring System, the Simplified acute physiology score and the Mortality Probability Models. An ideal severity scoring system for prognostic categorization of patients with systemic sepsis is far from being reached. Scoring systems should be used with repeated clinical interpretation of the patients’ conditions, and the assessment of tissue hypoxia in order to attain satisfactory discriminative performance and calibration power.

Urinary L-type fatty acid-binding protein as a new biomarker of sepsis complicated with acute kidney injury

OBJECTIVE

This study is aimed to examine whether urinary L-type fatty acid-binding protein can detect the severity of sepsis with animal sepsis models and septic shock patients complicated with established acute kidney injury.

DESIGN

Experimental animal models and a clinical, prospective observational study.

SETTING

University laboratory and tertiary hospital.

SUBJECTS AND PATIENTS

One hundred fourteen human L-type fatty acid-binding protein transgenic mice and 145 septic shock patients with established acute kidney injury.

INTERVENTIONS

Animals were challenged by abdominal (cecal ligation and puncture) and pulmonary (intratracheal lipopolysaccharide injection) sepsis models with different severities that were confirmed by survival analysis (n = 24) and bronchoalveolar lavage fluid analysis (n = 38).

MEASUREMENTS AND MAIN RESULTS

In animal experiments, significant increases of urinary L-type fatty acid-binding protein levels were induced by sepsis (severe cecal ligation and puncture 399.0 ± 226.8 μg/g creatinine [n = 12], less-severe cecal ligation and puncture 89.1 ± 25.3 [n = 11], sham 13.4 ± 3.4 [n = 10] at 6 hrs, p < .05 vs. sham; 200 μg of lipopolysaccharide 190.6 ± 77.4 μg/g creatinine [n = 6], 50 μg of lipopolysaccharide 145.4 ± 32.6 [n = 8], and saline 29.9 ± 14.9 [n = 5] at 6 hrs, p < .05 vs. saline). Urinary L-type fatty acid-binding protein predicted severity more accurately than blood urea nitrogen, serum creatinine, and urinary N-acetyl-d-glucosaminidase levels. In clinical evaluation, urinary L-type fatty acid-binding protein measured at admission was significantly higher in the nonsurvivors of septic shock with established acute kidney injury than in the survivors (4366 ± 192 μg/g creatinine [n = 68] vs. 483 ± 71 [n = 77], p < .05). Urinary L-type fatty acid-binding protein showed the higher value of area under the receiver operating characteristic curve for mortality compared with Acute Physiology and Chronic Health Evaluation (APACHE) II and Sepsis-related Organ Failure Assessment (SOFA) scores (L-type fatty acid-binding protein 0.994 [0.956-0.999], APACHE II 0.927 [0.873-0.959], and SOFA 0.813 [0.733-0.873], p < .05).

CONCLUSIONS

Our results suggest that urinary L-type fatty acid-binding protein can be a useful biomarker for sepsis complicated with acute kidney injury for detecting its severity.

How to treat esophageal perforations when determinants and predictors of mortality are considered

BACKGROUND

Published lethality rates of esophageal perforation (EP) vary depending on patient- and disease-related factors. This study was designed to evaluate how these factors impact death. Furthermore, we calculated the predictive accuracy of the Mortality Prediction Model (MPM II) and the Simplified Acute Physiology Score (SAPS II) for in-hospital death. Conclusions about treatment decisions were drawn based on our data and analysis of recent literature.

METHODS

Every patient who was treated for EP at our department from December 2001 to July 2008 is included in this study. Logistic regression analyses of various risk factors, such as etiology, time interval, size, comorbidities, localization, type of treatment, and preexisting pathologies of the esophagus on death, were performed.

RESULTS

Of the 41 patients diagnosed with EP, nine died (21%). The most important risk factor concerning death was cirrhosis of the liver (0 vs. 89% mortality; odds ratio, 208; P<0.001). Accuracy for lethality risk prediction was calculated with MPM II and SAPS II on admission, and afterward the characteristic increase that occurred was evaluated by using receiver operator characteristic curves. Optimal results were achieved by using a characteristic SAPS II increase (AUC 0.86; P: 0.009) after the patient was admitted to the intensive care unit.

CONCLUSIONS

Our study was the first to demonstrate that a rapid or continuous increase more than 40 of the daily SAPS II clearly indicates that a high risk of death is imminent. This should be used as a reevaluation factor when choosing a treatment strategy.

[POSSUM scoring system for predicting mortality in surgical patients]

This study evaluated the use of the POSSUM (Physiological and Operative Severity Score for Enumeration of Mortality and Morbidity) score for predicting mortality in surgical practice. In this study, 416 surgical patients admitted into ICUs for post-surgical care were analyzed. Both predicted and actual mortality rates were compared, according to four risk groups: 0-4%, 5-14%, 15-49%, 50% and over, and the area under the ROC curve of the POSSUM and APACHE II for mortality. The POSSUM and APACHE II scores overestimated the risk of death. The area under the ROC curve of the POSSUM was 0.762, and under APACHE II was 0.737, suggesting the use of POSSUM as an auxiliary tool to predict the risk of death in surgical patients.

[Severe sepsis and disseminated intravascular coagulation. Supplementation with antithrombin]

Administration of high-dose antithrombin (AT) was investigated on a large collective of patients with severe sepsis in the KyberSept study. In the total study the administration of AT resulted in no significant reduction of the mortality rate in comparison to a placebo. However, in the protocol of this study subgroups were predefined, which when analyzed revealed that the group of patients who received AT but not simultaneously heparin did show a reduction of the mortality rate in comparison to the placebo group. The reduction of the absolute mortality rate of 15% reached statistical significance on day 90. Even patients classified as risk group grade II according to the Simplified Acute Physiology Score (SAPS), showed a significant reduction of the mortality rate of approximately 22% after 90 days without simultaneous administration of heparin. Such a positive result for administration of AT without simultaneous heparin treatment can also be found when severe sepsis complicated by disseminated intravascular coagulation (DIC) is present. Coagulation diagnostic assists the recognition of latent or fulminant DIC and also in surveillance of the course and development. The results of AT supplementation for severe sepsis and DIC are in agreement with earlier studies on smaller patient collectives and suggest that a randomized controlled clinical study should be carried out on a subcollective of severely ill patients.

Outcome prediction in critical care: the Simplified Acute Physiology Score models

PURPOSE OF REVIEW

Outcome prediction models measuring severity of illness of patients admitted to the intensive care unit should predict hospital mortality. This review describes the state-of-the-art of Simplified Acute Physiology Score models from the clinical and managerial perspectives. Methodological issues concerning the effects of differences between new samples and original databases in which the models were developed are considered.

RECENT FINDINGS

The progressive lack of fit of the Simplified Acute Physiology Score II in independent intensive care unit populations induced investigators to propose customizations and expansions as potential evolutions for Simplified Acute Physiology Score II. We do not know whether those solutions did solve the issue because there are no demonstrations of consistent good fit in new databases. The recently developed Simplified Acute Physiology Score 3 Admission Score with customization for geographical areas is discussed. The points shared by the Simplified Acute Physiology Score models and the pros and cons for each of them are introduced.

SUMMARY

Comparisons of intensive care unit performance should take into account not only the patient severity of illness, but also the effect of the 'intensive care unit variable', that is, differences in human resources, structure, equipment, management and organization of the intensive care unit. In the future, moving from patient and geographical area adjustment to resource use could allow the user to adjust for differences in healthcare provision.

Risk scoring and bloodstream infections

Risk-scoring systems are utilised in patients with bloodstream infections (BSI) to quantify disease-associated morbidity and mortality based on simple clinical or laboratory data usually obtained early in the course of illness. In order to reduce BSI-associated mortality, specific scores were elaborated to allow early diagnosis and prompt and appropriate antibiotic therapy. Risk scoring was also successfully derived and validated to identify patients at higher risk for antibiotic-resistant BSI, or colonisation, mainly due to methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci. However, a major limitation of risk-scoring systems is the relevance to the local epidemiological environment and the difficulty in generalising results from a single study. Intelligence technology recently utilised scores to predict risks for specific pathogens causing BSI. An example of this innovation, the TREAT system, was able to significantly reduce mortality, length of hospitalisation and costs in patients with BSI. New randomised clinical trials are needed to study the efficacy of clinical scores in reducing BSI-associated morbidity and mortality.

Simple triage scoring system predicting death and the need for critical care resources for use during epidemics

OBJECTIVES

In the event of pandemic influenza, the number of critically ill victims will likely overwhelm critical care capacity. To date, no standardized method for allocating scarce resources when the number of patients in need far exceeds capacity exists. We sought to derive and validate such a triage scheme.

DESIGN

: Retrospective analysis of prospectively collected data.

SETTING

Emergency departments of two urban tertiary care hospitals.

PATIENTS

Three separate cohorts of emergency department patients with suspected infection, comprising a total of 5,133 patients.

INTERVENTIONS

None.

MEASUREMENTS

A triage decision rule for use in an epidemic was developed using only those vital signs and patient characteristics that were readily available at initial presentation to the emergency department. The triage schema was derived from a cohort at center 1, validated on a second cohort from center 1, and then validated on a third cohort of patients from center 2. The primary outcome for the analysis was in-hospital mortality. Secondary outcomes were intensive care unit admission and use of mechanical ventilation.

MAIN RESULTS

Multiple logistic regression demonstrated the following as independent predictors of death: a) age of >65 yrs, b) altered mental status, c) respiratory rate of >30 breaths/min, d) low oxygen saturation, and e) shock index of >1 (heart rate > blood pressure). This model had an area under the receiver operating characteristic curve of 0.80 in the derivation set and 0.74 and 0.76 in the validation sets. When converted to a simple rule assigning 1 point per covariate, the discrimination of the model remained essentially unchanged. The model was equally effective at predicting need for intensive care unit admission and mechanical ventilation.

CONCLUSIONS

If, as expected, patient demand far exceeds the capability to provide critical care services in an epidemic, a fair and just system to allocate limited resources will be essential. The triage rule we have developed can serve as an initial guide for such a process.

Assessment of three different mortality prediction models in four well-defined critical care patient groups at two points in time: a prospective cohort study

BACKGROUND AND OBJECTIVE

Mortality prediction systems have been calculated and validated from large mixed ICU populations. However, in daily practice it is often more important to know how a model performs in a patient subgroup at a specific ICU. Thus, we assessed the performance of three mortality prediction models in four well-defined patient groups in one centre.

METHODS

A total of 960 consecutive adult patients with either severe head injury (n = 299), multiple injuries (n = 208), abdominal aortic aneurysm (n = 267) or spontaneous subarachnoid haemorrhage (n = 186) were included. Calibration, discrimination and standardized mortality ratios were determined for Simplified Acute Physiology Score II, Mortality Probability Model II (at 0 and 24 h) and Injury Severity Score. Effective mortality was assessed at hospital discharge and after 1 yr.

RESULTS

Eight hundred and fifty-five (89%) patients survived until hospital discharge. Over all four patient groups, Mortality Probability Model II (24 h) had the best predictive accuracy (standardized mortality ratio 0.62) and discrimination (area under the receiver operating characteristic curve 0.9), but Simplified Acute Physiology Score II performed well for patients with subarachnoid haemorrhage. Overall calibration was poor for all models (Hosmer-Lemeshow Type C-values between 20 and 26). Injury Severity Score had the worst discrimination in trauma patients. All models over-estimated hospital mortality in all four patient groups, and these estimates were more like the mortality after 1 yr.

CONCLUSIONS

In our surgical ICU, Mortality Probability Model II (24 h) performed slightly better than Simplified Acute Physiology Score II in terms of overall mortality prediction and discrimination; Injury Severity Score was the worst model for mortality prediction in trauma patients.

Performance and customization of 4 prognostic models for postoperative onset of nausea and vomiting in ear, nose, and throat surgery

OBJECTIVE

To evaluate the performance of 4 published prognostic models for postoperative onset of nausea and vomiting (PONV) by means of discrimination and calibration and the possible impact of customization on these models.

DESIGN

Prospective, observational study.

SETTING

Tertiary care university hospital.

PATIENTS

748 adult patients (>18 years old) enrolled in this study. Severe obesity (weight > 150 kg or body mass index > 40 kg/m) was an exclusion criterion.

INTERVENTIONS

All perioperative data were recorded with an anesthesia information management system. A standardized patient interview was performed on the postoperative morning and afternoon.

MEASUREMENTS

Individual PONV risk was calculated using 4 original regression equations by Koivuranta et al, Apfel et al, Sinclair et al, and Junger et al Discrimination was assessed using receiver operating characteristic (ROC) curves. Calibration was tested using Hosmer-Lemeshow goodness-of-fit statistics. New predictive equations for the 4 models were derived by means of logistic regression (customization). The prognostic performance of the customized models was validated using the "leaving-one-out" technique.

MAIN RESULTS

Postoperative onset of nausea and vomiting was observed in 11.2% of the specialized patient population. Discrimination could be demonstrated as shown by areas under the receiver operating characteristic curve of 0.62 for the Koivuranta et al model, 0.63 for the Apfel et al model, 0.70 for the Sinclair et al model, and 0.70 for the Junger et al model. Calibration was poor for all 4 original models, indicated by a P value lower than 0.01 in the C and H statistics. Customization improved the accuracy of the prediction for all 4 models. However, the simplified risk scores of the Koivuranta et al model and the Apfel et al model did not show the same efficiency as those of the Sinclair et al model and the Junger et al model. This is possibly a result of having relatively few patients at high risk for PONV in combination with an information loss caused by too few dichotomous variables in the simplified scores.

CONCLUSIONS

The original models were not well validated in our study. An antiemetic therapy based on the results of these scores seems therefore unsatisfactory. Customization improved the accuracy of the prediction in our specialized patient population, more so for the Sinclair et al model and the Junger et al model than for the Koivuranta et al model and the Apfel et al model.

Ethical, legal and organizational issues in the ICU: prediction of outcome

PURPOSE OF REVIEW

Since the development of the first general outcome prediction models, these instruments have been widely used in the intensive care unit. Last updated in the early 1990s, these models are now severely outdated.

RECENT FINDINGS

In recent months, researchers and users assisted in several attempts at improving the existing models through customization or expansion or in the development of new models, such as the Simplified Acute Physiology Score (SAPS) 3 and the Acute Physiology and Chronic Health Evaluation (APACHE) IV.

SUMMARY

Although not similar, especially in the choice of the reference population, these models aim at replacing older general outcome models, the predictions from which no longer reflect the current case-mix outcomes of intensive care. The objective of this review is to present and discuss, to the clinician working in the intensive care unit, these different strategies and to give an updated version of the general outcome prediction models available in 2006.

Cost-effectiveness of drotrecogin alfa (activated) in the treatment of severe sepsis with multiple organ failure

OBJECTIVES

The aim of this study was to estimate the expected cost and clinical benefits associated with the use of drotrecogin alfa (activated) (Xigris; Eli Lilly and Company; Indianapolis, IN) in the French hospital setting.

METHODS

The recombinant human activated PROtein C Worldwide Evaluation in Severe Sepsis (PROWESS) study results (1271 patients with multiple organ failure) were adjusted to 9,948 hospital stays from a database of Parisian area intensive-care units (ICUs)-the CubRea (Intensive Care Database User Group) database. The analysis features a decision tree with a probabilistic sensitivity analysis.

RESULTS

The cost per life year gained (LYG) of drotrecogin treatment for severe sepsis with multiple organ failure (European indication) was estimated to be dollars 11,812. At the hospital level, the drug is expected to induce an additional cost of dollars 7545 per treated patient. The incremental cost-effectiveness ratio ranges from dollars 7873 per LYG for patients receiving three organ supports during ICU stay to dollars 17,704 per LYG for patients receiving less than two organ supports.

CONCLUSIONS

Drotrecogin alfa (activated) is cost-effective in the treatment of severe sepsis with multiple organ failure when added to best standard care. The cost-effectiveness of the drug increases with baseline disease severity, but it remains cost-effective for all patients when used in compliance with the European approved indication.

High-dose antithrombin III in the treatment of severe sepsis in patients with a high risk of death: efficacy and safety

OBJECTIVE

To explore if patients with severe sepsis and with a predicted high risk of death (according to the Simplified Acute Physiology Score II) might have a treatment benefit from high-dose antithrombin III.

DESIGN

Subgroup analysis of a randomized, placebo-controlled, double-blind, prospective phase III study.

SETTING

Unifactorial and multifactorial reanalysis of prospectively defined populations from the KyberSept trial.

PATIENTS

We studied 1,008 patients (43.6% of the overall intention-to-treat population, n = 2,314) with a predicted mortality rate of 30-60% at study entry as defined by the Simplified Acute Physiology Score II.

INTERVENTIONS

Patients were randomized in a 1:1 fashion to receive either high-dose antithrombin III (30,000 IU intravenously over the period of 4 days) or placebo.

MEASUREMENTS AND MAIN RESULTS

In a Kaplan-Meier analysis of patients with a predicted mortality of 30-60%, the survival time when followed up for 90 days after admission was increased in the high-dose antithrombin III group compared with placebo (p = .04). If heparin was avoided during the 4-day treatment phase with high-dose antithrombin III (n = 140) or placebo (n = 162), the treatment effect appeared to be even more pronounced: 28-day mortality rate, 35.7% vs. 44.4% (risk ratio, 0.804; 95% confidence interval, 0.607-1.064); 56-day mortality rate, 39.9% vs. 52.2% (risk ratio, 0.764; 95% confidence interval, 0.593-0.984); 90-day mortality rate, 42.8% vs. 55.1% (risk ratio, 0.776; 95% confidence interval, 0.614-0.986). Like in the overall population, the percentage with any bleeding was increased in patients receiving high-dose antithrombin III compared with placebo. Survival rates were in favor of high-dose antithrombin III in patients both with and without bleeding complications.

CONCLUSIONS

Treatment with high-dose antithrombin III may increase survival time up to 90 days in patients with severe sepsis and high risk of death. This benefit may even be stronger when concomitant heparin is avoided.

Determinants of mortality in patients with severe sepsis

OBJECTIVE

To evaluate the relative importance of predictors of in-hospital mortality in severe sepsis and compare the performance of generic and disease-specific mortality prediction models.

METHODS

The author used data from all 826 patients receiving placebo in the Recombinant Human Activated Protein C Worldwide Evaluation in Severe Sepsis (PROWESS) trial. After a variety of clinical factors were examined for their univariate association with in-hospital mortality, logistic regression models incorporating successively more inclusive sets of predictors were created and compared. For each model, discrimination was assessed and the relative contribution of each model component to overall model explanatory power evaluated. The accuracy of using the Acute Physiology and Chronic Health Evaluation (APACHE) II score in isolation as an indicator of "high risk" was assessed by comparing model predictions from APACHE-only models to those of disease-specific models.

RESULTS

Age, a number of laboratory values, and APACHE II score were significant univariate predictors of mortality. In multivariable models, age and laboratory values contributed the most information to model predictions; the contribution of the APACHE II score, in particular, the acute physiology component, was modest at best. A risk model including only the total APACHE II score had a c-statistic of 0.686, whereas the best performing disease-specific model had a c-statistic of 0.787. Use of the APACHE II score alone to establish high risk versus low risk resulted in misclassification of 26% of patients.

CONCLUSIONS

Individual severe sepsis patient outcomes depend on an array of clinical predictors. Models incorporating sepsis disease-specific risk factors may predict mortality more accurately than generic ICU severity measures.

Variation in pediatric intensive care therapies and outcomes by race, gender, and insurance status

CONTEXT

The differential allocation of medical resources to adult patients according to characteristics such as race, gender, and insurance status raises the serious concern that such issues apply to critically ill children as well.

OBJECTIVE

This study examined whether medical resources and outcomes for children admitted to pediatric intensive care units differed according to race, gender, or insurance status.

DESIGN

An observational analysis was conducted with use of prospectively collected data from a multicenter cohort. Data were collected on 5,749 consecutive admissions for children from three pediatric intensive care units located in large urban children's hospitals.

PARTICIPANTS

Children aged </=18 years admitted over an 18-month period beginning in June 1996 formed the study sample.

MAIN OUTCOME MEASURES

Hospital mortality, length of hospital stay, and overall resource use were examined in relation to severity of illness. Standardized ratios were formed with generalized regression analyses that included the Pediatric Index of Mortality for risk adjustment.

RESULTS

After adjustment for differences in illness severity, standardized mortality ratios and overall resource use were similar with regard to race, gender, and insurance status, but uninsured children had significantly shorter lengths of stay in the pediatric intensive care unit. Uninsured children also had significantly greater physiologic derangement on admission (mortality probability, 8.1%; 95% confidence interval [CI], 6.2-10.0) than did publicly insured (3.6%; 95% CI, 3.2-4.0) and commercially insured patients (3.7%; 95% CI, 3.3-4.1). Consistent with greater physiologic derangement, hospital mortality was higher among uninsured children than insured children.

CONCLUSIONS

Risk-adjusted mortality and resource use for critically ill children did not differ according to race, gender, or insurance status. Policies to expand health insurance to children appear more likely to affect physiologic derangement on admission rather than technical quality of care in the pediatric intensive care unit setting.

Treatment effects of high-dose antithrombin without concomitant heparin in patients with severe sepsis with or without disseminated intravascular coagulation

BACKGROUND

Disseminated intravascular coagulation (DIC) is a serious complication of sepsis that is associated with a high mortality.

OBJECTIVES

Using the adapted International Society on Thrombosis and Haemostasis (ISTH) diagnostic scoring algorithm for DIC, we evaluated the treatment effects of high-dose antithrombin (AT) in patients with severe sepsis with or without DIC.

PATIENTS AND METHODS

From the phase III clinical trial in severe sepsis (KyberSept), 563 patients were identified (placebo, 277; AT, 286) who did not receive concomitant heparin and had sufficient data for DIC determination.

RESULTS

At baseline, 40.7% of patients (229 of 563) had DIC. DIC in the placebo-treated patients was associated with an excess risk of mortality (28-day mortality: 40.0% vs. 22.2%, P < 0.01). AT-treated patients with DIC had an absolute reduction in 28-day mortality of 14.6% compared with placebo (P = 0.02) whereas in patients without DIC no effect on 28-day mortality was seen (0.1% reduction in mortality; P = 1.0). Bleeding complications in AT-treated patients with and without DIC were higher compared with placebo (major bleeding rates: 7.0% vs. 5.2% for patients with DIC, P = 0.6; 9.8% vs. 3.1% for patients without DIC, P = 0.02).

CONCLUSIONS

High-dose AT without concomitant heparin in septic patients with DIC may result in a significant mortality reduction. The adapted ISTH DIC score may identify patients with severe sepsis who potentially benefit from high-dose AT treatment.

Identifying risk factors for two complication types for neonatal intensive care patients (NICU)

This paper discusses the results of applying artificial neural networks to predicting complication for neonatal intensive care patients. Risk factors that lead to necrotizing entero-colitis or broncho-pulmonary dysplasia were identified. Future work will expand this work to other outcomes and add probability information to the estimations.

Incidence and impact of organ dysfunctions associated with sepsis

OBJECTIVE

To study the incidence and severity of organ dysfunction associated with sepsis.

DESIGN

Comprehensive review of prospectively collected data from intensive care patients hospitalized between 1997 and 2001.

SETTING

Thirty-five ICUs in nonuniversity and university hospitals located in the Paris area.

PATIENTS

All patients hospitalized in the ICU for > 24 h meeting the criteria for severe sepsis (SS), either with only one organ dysfunction present during the ICU stay (SS1; n = 5,675) or with at least two organ dysfunction present during the ICU stay (SS2; n = 12,598), were compared to all other patients hospitalized for > 24 h in the ICU over the same time period (n = 47,637).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We collected information on demographic characteristics, type of admission, underlying disease, organ dysfunction, organ support, McCabe and Charlson-Deyo scores, simplified acute physiology score II, length of stay, and outcome. The incidence of SS was 27.7% (8.6% for SS1 and 19.1 for SS2). Compared with non-SS patients, those with SS were significantly older, were more frequently men, required organ support more frequently, had higher severity scores, and stayed longer in the ICU and hospital. Respiratory and cardiovascular dysfunction and fungal infection were strong independent risk factors for death in SS patients, with 5.64-fold, 4.35-fold, and 2.0-fold increased risks, respectively. SS2 is significantly different from SS1: older age, more surgical stays and admission from external transfer, greater number of organ supports, site of infection (less pulmonary and urinary tract infections, and more abdominal and cardiovascular infections), type of bacteria (more methicillin-resistant Staphylococcus aureus, Pseudomonas, and fungus), ICU length of stay (20.4 d vs 11.6 d), hospital length of stay (33 d vs 27.9 d), ICU mortality (42.7% vs 5.5%), and hospital mortality (49% vs 11.3%).

CONCLUSIONS

Our study identifies a subgroup of patients with an ICU stay > 24 h and SS with at least two organ dysfunctions. This group of patients requires special attention since their ICU mortality is > 40% and they occupy almost 40% of all ICU beds.

Adverse effect on a referral intensive care unitʼs performance of accepting patients transferred from another intensive care unit*

OBJECTIVE

To determine whether observed and predicted mortality for intensive care unit (ICU) transfer admissions is different from non-ICU transfer admissions and how that might affect ICU performance evaluation.

DESIGN, SETTING, AND PATIENTS

We retrospectively analyzed the charts of 3,416 patients admitted to our tertiary referral ICU from January 1995 to December 2001 and evaluated the effect on our performance (based on the Simplified Acute Physiology Score II risk model) of accepting patients transferred from another hospital's ICU.

MAIN RESULTS

During the study period, 597 patients (17%) had been transferred from a non-ICU setting in another hospital (hospital transfer) and 408 (12%) from another hospital's ICU (ICU transfer). ICU mortality and standardized mortality ratios were significantly higher for ICU-transfer patients than for hospital-transfer or directly admitted patients: 34% vs. 23% vs. 17% (p < .0001) and 0.95 (95% confidence interval, 0.83-1.08), 0.82 (95% confidence interval, 0.71-0.95), and 0.62 (95% confidence interval, 0.55-0.68), respectively. ICU-transfer patients had 3.6-fold longer mean ICU stays and 1.9-fold longer durations of mechanical ventilation than directly admitted patients. Hospital-transfer (odds ratio = 1.89) and ICU-transfer patients (odds ratio = 2.41) had significantly higher mortality rates, even after adjustment for case mix and disease severity. Consequently, a benchmarking program adjusting only for these latter variables, but not admission source, would penalize our ICU by 39 excess deaths per 1,000 admissions as compared with another ICU admitting no transfer patients. Finally, patients transferred from the ward of another hospital had significantly higher mortality rates (odds ratio = 1.56) as compared with patients directly admitted from the ward of our hospital, confirming the "transfer effect" for this homogeneous patients' subgroup.

CONCLUSIONS

Admission source remains a strong and independent predictor of ICU death, despite adjustment for case mix and disease severity at ICU admission. Specifically, accepting numerous ICU-transfer patients, for whom the probability of ICU death is the most underestimated by a system adjusting only for case mix and disease severity, can adversely affect the evaluation of referral centers' performance. Future benchmarking and profiling systems should evaluate and adequately account for the ICU-transfer factor to provide healthcare payers and consumers with more accurate and valid information on the true performance of referral centers.

Clinical features and outcome of chronic dialysis patients admitted to an intensive care unit

BACKGROUND

Information about chronic dialysis (CD) patients admitted to intensive care units (ICU) is scant. This study sought to determine the epidemiology and outcome of CD patients in an ICU setting and to test the performance of the Simplified Acute Physiology Score (SAPS II) to predict hospital mortality in this population.

METHODS

All consecutive CD patients admitted to an adult, 10 bed medical/surgical ICU at a university hospital between January 1996 and December 1999 were included in this prospective observational study. Demographics, characteristics of the underlying renal disease, admission diagnosis, the number of organ system failures (OSFs) excluding renal failure and SAPS II, both calculated 24 h after admission, the duration of mechanical ventilation, ICU survival and survival status at hospital discharge and 6 months after discharge were recorded.

RESULTS

A total of 92 CD patients, 16 on peritoneal dialysis and 76 on haemodialysis, were included. The main reason for ICU admission was sepsis and the mean ICU length of stay 6.2+/-9.9 days. ICU mortality was 26/92 (28.3%) and was associated in multivariate analysis with SAPS II (P<0.001), duration of mechanical ventilation (P<0.01) and abnormal values of serum phosphorus (high or low; P<0.05). Hospital mortality was 35/92 (38.0%) and was accurately predicted by SAPS II [receiver operating characteristics curve: 0.86+/-0.04; goodness-of-fit test: C = 6.86, 5 degrees of freedom (df), P = 0.23 and H = 4.78, 5 df, P = 0.44]. The 6 month survival rate was 48/92 (52.2%).

CONCLUSIONS

CD patients admitted to the ICU are a subgroup of patients with high mortality and SAPS II can be used to assess their probability of hospital mortality. The severity of the acute illness responsible for ICU admission and an abnormal value of serum phosphorus are determinants for ICU mortality.

Efficacy and safety of the monoclonal anti-tumor necrosis factor antibody F(ab′)2 fragment afelimomab in patients with severe sepsis and elevated interleukin-6 levels*

OBJECTIVE

To evaluate whether administration of afelimomab, an anti-tumor necrosis factor F(ab')2 monoclonal antibody fragment, would reduce 28-day all-cause mortality in patients with severe sepsis and elevated serum levels of IL-6.

DESIGN

Prospective, randomized, double-blind, placebo-controlled, multiple-center, phase III clinical trial.

SETTING

One hundred fifty-seven intensive care units in the United States and Canada.

PATIENTS

Subjects were 2,634 patients with severe sepsis secondary to documented infection, of whom 998 had elevated interleukin-6 levels.

INTERVENTIONS

Patients were stratified into two groups by means of a rapid qualitative interleukin-6 test kit designed to identify patients with serum interleukin-6 levels above (test positive) or below (test negative) approximately 1000 pg/mL. Of the 2,634 patients, 998 were stratified into the test-positive group, 1,636 into the test-negative group. They were then randomly assigned 1:1 to receive afelimomab 1 mg/kg or placebo for 3 days and were followed for 28 days. The a priori population for efficacy analysis was the group of patients with elevated baseline interleukin-6 levels as defined by a positive rapid interleukin-6 test result.

MEASUREMENTS AND MAIN RESULTS

In the group of patients with elevated interleukin-6 levels, the mortality rate was 243 of 510 (47.6%) in the placebo group and 213 of 488 (43.6%) in the afelimomab group. Using a logistic regression analysis, treatment with afelimomab was associated with an adjusted reduction in the risk of death of 5.8% (p = .041) and a corresponding reduction of relative risk of death of 11.9%. Mortality rates for the placebo and afelimomab groups in the interleukin-6 test negative population were 234 of 819 (28.6%) and 208 of 817 (25.5%), respectively. In the overall population of interleukin-6 test positive and negative patients, the placebo and afelimomab mortality rates were 477 of 1,329 (35.9%)and 421 of 1,305 (32.2%), respectively. Afelimomab resulted in a significant reduction in tumor necrosis factor and interleukin-6 levels and a more rapid improvement in organ failure scores compared with placebo. The safety profile of afelimomab was similar to that of placebo.

CONCLUSIONS

Afelimomab is safe, biologically active, and well tolerated in patients with severe sepsis, reduces 28-day all-cause mortality, and attenuates the severity of organ dysfunction in patients with elevated interleukin-6 levels.

Outcome prediction in a surgical ICU using automatically calculated SAPS II scores

The objective of this study was to establish a complete computerized calculation of the Simplified Acute Physiology Score (SAPS) II within 24 hours after admission to a surgical intensive care unit (ICU) based only on routine data recorded with a patient data management system (PDMS) without any additional manual data entry. Score calculation programs were developed using SQL scripts (Structured Query Language) to retrospectively compute the SAPS II scores of 524 patients who stayed in ICU for at least 24 hours between April 1, 1999 and March 31, 2000 out of the PDMS database. The main outcome measure was survival status at ICU discharge. Score evaluation was modified in registering missing data as being not pathological and using surrogates of the Glasgow Coma Scale (GCS). Computerized score calculation was possible for all investigated patients. The 459 (87.6%) survivors had a median SAPS II of 28 (interquartile range (IQR) 13) whereas the 65 (12.4%) decreased patients had a median score of 43 (IQR 16; P < 0.001). Of the physiological variables for SAPS II score calculation, bilirubin was missing in 84%, followed by PaO2/FiO2 ratio (34%), and neurological status (34%). Using neurological diagnoses and examinations as surrogates for the GCS, a pathological finding was seen in only 8.8% of all results. The discriminative power of the computerized SAPS II checked with a receiver operating characteristic (ROC) curve was 0.81 (95% confidence interval (CI): 0.74-0.87). The Hosmer-Lemeshow goodness-of-fit statistics showed good calibration (H = 5.55, P = 0.59, 7 degrees of freedom; C = 5.55, P = 0.68, 8 degrees of freedom). The technique used in this study for complete automatic data sampling of the SAPS II score seems to be suitable for predicting mortality rate during stay in a surgical ICU. The advantage of the described method is that no additional manual data recording is required for score calculation.

Administration of the nitric oxide synthase inhibitor NG-methyl-L-arginine hydrochloride (546C88) by intravenous infusion for up to 72 hours can promote the resolution of shock in patients with severe sepsis: results of a randomized, double-blind, placebo-controlled multicenter study (study no. 144-002)

OBJECTIVE

To assess the safety and efficacy of the nitric oxide synthase inhibitor 546C88 in patients with septic shock. The predefined primary efficacy objective was resolution of shock, defined as a mean arterial pressure > or =70 mm Hg in the absence of both conventional vasopressors and study drug, determined at the end of the 72-hr treatment period.

DESIGN

Multicentered, randomized, placebo-controlled, safety and efficacy study.

SETTING

Forty-eight intensive care units in Europe, North America, and Australia.

PATIENTS

A total of 312 patients with septic shock diagnosed within 24 hr before randomization.

INTERVENTIONS

Patients were randomly allocated to receive either 546C88 or placebo (5% dextrose) by intravenous infusion for up to 72 hrs. Conventional vasoactive therapy was restricted to norepinephrine, dopamine, and dobutamine. Study drug was initiated at 0.1 mL/kg/hr (5 mg/kg/hr 546C88) and titrated according to response up to a maximum rate of 0.4 mL/kg/hr with the objective to maintain mean arterial pressure at 70 mm Hg while attempting to withdraw any concurrent vasopressor(s).

MEASUREMENTS AND MAIN RESULTS

Requirement for vasopressors, systemic hemodynamics, indices of organ function and safety (including survival up to day 28) were assessed. The median mean arterial pressure for both groups was maintained >70 mm Hg. Administration of 546C88 was associated with a decrease in cardiac index while stroke index was maintained. Resolution of shock at 72 hr was achieved by 40% and 24% of the patients in the 546C88 and placebo cohorts, respectively (p =.004). There was no evidence that treatment with 546C88 had any major adverse effect on pulmonary, hepatic, or renal function. Day 28 survival was similar for both groups.

CONCLUSIONS

In this study, treatment with the nitric oxide synthase inhibitor 546C88 promoted the resolution of shock in patients with severe sepsis. This was associated with an acceptable overall safety profile.

Multiple-center, randomized, placebo-controlled, double-blind study of the nitric oxide synthase inhibitor 546C88: effect on survival in patients with septic shock

OBJECTIVE

To assess the safety and efficacy of the nitric oxide synthase inhibitor 546C88 in patients with septic shock. The predefined primary efficacy objective was survival at day 28.

DESIGN

Multiple-center, randomized, two-stage, double-blind, placebo-controlled, safety and efficacy study.

SETTING

A total of 124 intensive care units in Europe, North America, South America, South Africa, and Australasia.

PATIENTS

A total of 797 patients with septic shock diagnosed for <24 hrs.

INTERVENTIONS

Patients with septic shock were allocated to receive 546C88 or placebo (5% dextrose) for up to 7 days (stage 1) or 14 days (stage 2) in addition to conventional therapy. Study drug was initiated at 0.05 mL.kg(-1).hr(-1) (2.5 mg.kg(-1).hr(-1) 546C88) and titrated up to a maximum rate of 0.4 mL.kg(-1).hr(-1) to maintain mean arterial pressure between 70 and 90 mm Hg while attempting to withdraw concurrent vasopressors.

MEASUREMENTS AND MAIN RESULTS

Hemodynamic variables, organ function data, microbiological data, concomitant therapy, and adverse event data were recorded at baseline, throughout treatment, and at follow-up. The primary end point was day-28 survival. The trial was stopped early after review by the independent data safety monitoring board. Day-28 mortality was 59% (259/439) in the 546C88 group and 49% (174/358) in the placebo group (p <.001). The overall incidence of adverse events was similar in both groups, although a higher proportion of the events was considered possibly attributable to study drug in the 546C88 group. Most of the events accounting for the disparity between the groups were associated with the cardiovascular system (e.g., decreased cardiac output, pulmonary hypertension, systemic arterial hypertension, heart failure). The causes of death in the study were consistent with those expected in patients with septic shock, although there was a higher proportion of cardiovascular deaths and a lower incidence of deaths caused by multiple organ failure in the 546C88 group.

CONCLUSIONS

In this study, the nonselective nitric oxide synthase inhibitor 546C88 increased mortality in patients with septic shock.

Cardiovascular effects of the nitric oxide synthase inhibitor NG-methyl-l-arginine hydrochloride (546C88) in patients with septic shock: Results of a randomized, double-blind, placebo-controlled multicenter study (study no. 144-002)*

OBJECTIVE

To assess the hemodynamic effects of the nitric oxide synthase inhibitor 546C88 in patients with septic shock, although this was not a stated aim of the protocol. The predefined primary efficacy objective of the protocol was resolution of shock determined at the end of a 72-hr treatment period.

DESIGN

Multicentered, randomized, placebo-controlled, safety and efficacy study.

SETTING

Forty-eight intensive care units in Europe, North America, and Australia.

PATIENTS

A total of 312 patients with septic shock diagnosed within 24 hr before randomization.

INTERVENTIONS

Patients were randomly allocated to receive either 546C88 or placebo (5% dextrose) by intravenous infusion for up to 72 hrs. Conventional vasoactive therapy was restricted to norepinephrine, dopamine, and dobutamine. Study drug was initiated at 0.1 mL/kg/hr (5 mg/kg/hr 546C88) and titrated according to response up to a maximum rate of 0.4 mL/kg/hr with the objective to maintain mean arterial pressure at 70 mm Hg while attempting to withdraw any concurrent vasopressor(s).

MEASUREMENTS AND MAIN RESULTS

Requirement for vasopressors, systemic and pulmonary hemodynamics, indices of oxygen transport, and plasma concentrations of arginine and nitrate were assessed over time. The median mean arterial pressure for both groups was maintained > or =70 mm Hg. There was an early increase in systemic and pulmonary vascular tone and oxygen extraction, whereas both cardiac index and oxygen delivery decreased for patients in the 546C88 cohort. Although these parameters subsequently returned toward baseline values, the observed differences between the treatment groups, except for pulmonary vascular resistance and oxygen extraction, persisted throughout the treatment period, despite a reduced requirement for vasopressors in the 546C88 cohort. These changes were associated with a reduction in plasma nitrate concentrations, which were elevated in both groups before the start of therapy.

CONCLUSIONS

The nitric oxide synthase inhibitor 546C88 can reduce the elevated plasma nitrate concentrations observed in patients with septic shock. In this study, treatment with 546C88 for up to 72 hrs was associated with an increase in vascular tone and a reduction in both cardiac index and oxygen delivery. The successful maintenance of a target mean arterial blood pressure > or =70 mm Hg was achieved with a reduction in the requirement for, or withdrawal of, conventional inotropic vasoconstrictor agents (i.e., dopamine and norepinephrine). There were no substantive untoward consequences accompanying these hemodynamic effects. An international, randomized, double-blind, placebo-controlled phase III study has since been conducted in patients with septic shock. Recruitment into the study was discontinued due to the emergence of increased mortality in the 546C88-treated group.

Influence of systemic inflammatory response syndrome and sepsis on outcome of critically ill infected patients

The clinical significance of the systemic inflammatory response in infected patients remains unclear. We examined risk factors for hospital mortality in 3,608 intensive care unit patients included in the European Sepsis Study. Patients were categorized as having infection without or with (i.e., sepsis) systemic inflammatory response, severe sepsis, and septic shock, on the first day of infection. Hospital mortality varied from 25 to 60% according to sepsis stage, but did not differ between the first two categories (hazard ratio, 0.94; p = 0.55), whereas there was a grading of severity from sepsis to severe sepsis (1.53, p < 10-4) and septic shock (2.64, p < 10-4). Within each stage, mortality was unaffected by the number of inflammatory response criteria. Prognostic factors identified by Cox regression included comorbid conditions, severity of acute illness and acute organ dysfunction, shock, nosocomial infection, and infection caused by aerobic gram-negative bacilli, enterobacteria, Staphylococcus aureus, and infection from a digestive or unknown source. We conclude that whereas the categorization of infection by the presence of organ dysfunction or shock has strong prognostic significance, infection and sepsis have similar outcomes, unaffected by the presence or number of inflammatory response criteria. Refinement of risk stratification of patients presenting with infection and no organ dysfunction is needed.

Monitoring the evolutionary process of quality: risk-adjusted charting to track outcomes in intensive care

OBJECTIVE

To present graphical procedures for prospectively monitoring outcomes in the intensive care unit.

DESIGN

Observational study: risk-adjusted control chart analysis of a case series.

SETTING

Tertiary referral adult intensive care unit: Princess Alexandra Hospital, Brisbane, Australia.

PATIENTS

A total of 3398 intensive care unit admissions from January 1, 1995, to January 1, 1998.

CONCLUSIONS

Risk-adjusted process control charting procedures for continuous monitoring of intensive care unit outcomes are proposed as quality management tools. A modified Shewhart p chart and cumulative sum process control chart, using the Acute Physiology and Chronic Health Evaluation III model mortality prediction for risk adjustment, are presented. The risk-adjusted p chart summarizes performance at arbitrary intervals and plots observed against predicted mortality rate to detect large changes in risk-adjusted mortality. The risk-adjusted cumulative sum procedure is a likelihood-based scoring method that adjusts for estimated risk of death, accumulating evidence from outcomes of all previous patients. It formally tests the hypothesis of a change in the odds of death. In this application, we detected a decrease from above to predicted risk-adjusted mortality. This was temporally related to increased senior staffing levels and enhanced ongoing multidisciplinary review of practice, quality improvement, and educational activities. Formulas and analyses are provided as appendices.

Outcome analysis of 189 consecutive cancer patients referred to the intensive care unit as emergencies during a 2-year period

The referral of critically ill cancer patients to an intensive care unit (ICU) is a matter of controversial debate. This study was conducted by an interdisciplinary clinical group to evaluate the outcome of ICU treatment in cancer patients according to their characteristics at the time of referral. A retrospective analysis was used to identify relevant subgroups among 189 consecutive cancer patients referred as emergencies to one of four ICUs during a 2-year period. Reasons for ICU referral were pneumonia (29.6%), sepsis (27.0%), fungal infection (11.1%), another infection (9.5%), gastrointestinal emergency (16.9%), treatment-related organ toxicity (6.9%), or other, non-infectious complications (43.9%). Vasopressor support was required in 50.3%, mechanical ventilation in 49.7%, and haemodialysis/-filtration in 26.5% of the patients. Overall, 41.3% died during ICU treatment, 12.2% died after transfer from ICU to a non-ICU ward, and 35.4% were discharged alive. Sepsis, mechanical ventilation, vasopressor support, renal replacement therapy and neutropenia were independent risk factors for fatal outcome, but no single risk factor unequivocally predicted death. All patients with fungal infection who required vasopressor support and either had sepsis (n=13) or needed mechanical ventilation (n=14) died during ICU treatment, while all non-septic patients. who did not require mechanical ventilation, were younger than 74 years of age and had a non-infectious underlying complication (n=29), survived. This analysis may help to early identify relevant subgroups of cancer patients with different prognoses under ICU treatment. A prospective study to confirm the predictive usefulness of this approach is needed. Cancer patients should not be excluded from referral to the intensive care unit in an emergency solely due to their underlying malignant disease or a single unfavourable prognostic factor.