Patterns and early evolution of organ failure in the intensive care unit and their relation to outcome

Introduction

Recognition of patterns of organ failure may be useful in characterizing the clinical course of critically ill patients. We investigated the patterns of early changes in organ dysfunction/failure in intensive care unit (ICU) patients and their relation to outcome.

Methods

Using the database from a large prospective European study, we studied 2,933 patients who had stayed more than 48 hours in the ICU and described patterns of organ failure and their relation to outcome. Patients were divided into three groups: patients without sepsis, patients in whom sepsis was diagnosed within the first 48 hours after ICU admission, and patients in whom sepsis developed more than 48 hours after admission. Organ dysfunction was assessed by using the sequential organ failure assessment (SOFA) score.

Results

A total of 2,110 patients (72% of the study population) had organ failure at some point during their ICU stay. Patients who exhibited an improvement in organ function in the first 24 hours after admission to the ICU had lower ICU and hospital mortality rates compared with those who had unchanged or increased SOFA scores (12.4 and 18.4% versus 19.6 and 24.5%, P < 0.05, pairwise). As expected, organ failure was more common in sepsis than in nonsepsis patients. In patients with single-organ failure, in-hospital mortality was greater in sepsis than in nonsepsis patients. However, in patients with multiorgan failure, mortality rates were similar regardless of the presence of sepsis. Irrespective of the presence of sepsis, delta SOFA scores over the first 4 days in the ICU were higher in nonsurvivors than in survivors and decreased significantly over time in survivors.

Conclusions

Early changes in organ function are strongly related to outcome. In patients with single-organ failure, in-hospital mortality was higher in sepsis than in nonsepsis patients. However, in multiorgan failure, mortality rates were not influenced by the presence of sepsis.     

Mortality after discharge from intensive care: the impact of organ system failure and nursing workload use at discharge

OBJECTIVES: Mortality after ICU discharge accounts for approx. 20-30% of deaths. We examined whether post-ICU discharge mortality is associated with the presence and severity of organ dysfunction/failure just before ICU discharge. PATIENTS AND METHODS: The study used the database of the EURICUS-II study, with a total of 4,621 patients, including 2,958 discharged alive to the general wards (post-ICU mortality 8.6%). Over a 4-month period we collected clinical and demographic characteristics, including the Simplified Acute Physiology Score (SAPS II), Nine Equivalents of Nursing Manpower Use Score, and Sequential Organ Failure Assessment (SOFA) score. RESULTS: Those who died in the hospital after ICU discharge had a higher SAPS II score, were more frequently nonoperative, admitted from the ward, and had stayed longer in the ICU. Their degree of organ dysfunction/failure was higher (admission, maximum, and delta SOFA scores). They required more nursing workload resources while in the ICU. Both the amount of organ dysfunction/failure (especially cardiovascular, neurological, renal, and respiratory) and the amount of nursing workload that they required on the day before discharge were higher. The presence of residual CNS and renal dysfunction/failure were especially prognostic factors at ICU discharge. Multivariate analysis showed only predischarge organ dysfunction/failure to be important; thus the increased use of nursing workload resources before discharge probably reflects only the underlying organ dysfunction/failure. CONCLUSIONS: It is better to delay the discharge of a patient with organ dysfunction/failure from the ICU, unless adequate monitoring and therapeutic resources are available in the ward.     

Evaluation of the SOFA score: a single-center experience of a medical intensive care unit in 303 consecutive patients with predominantly cardiovascular disorders

Objective: To evaluate the use of the Sequential Organ Failure Assessment (SOFA) score, the total maximum SOFA (TMS) score, and a derived variable, the ΔSOFA (TMS score minus total SOFA score on day 1) in medical, cardiovascular patients as a means for describing the incidence and severity of organ dysfunction and the prognostic value regarding outcome. Design: Prospective, clinical study. Setting: Medical intensive care unit in a university hospital. Patients: A total of 303 consecutive patients were included (216 men, 87 women; mean age 62 ± 12.6 years; SAPS II 26.2 ± 12.7). They were evaluated 24 h after admission and thereafter every 24 h until ICU discharge or death between November 1997 and March 1998. Readmissions and patients with an ICU stay shorter than 12 h were excluded. Main outcome measure: Survival status at hospital discharge, incidence of organ dysfunction/failure. Interventions: Collection of clinical and demographic data and raw data for the computation of the SOFA score every 24 h until ICU discharge. Measurements and main results: Length of ICU stay was 3.7 ± 4.7 days. ICU mortality was 8.3 % and hospital mortality 14.5 %. Nonsurvivors had a higher total SOFA score on day 1 (5.9 ± 3.7 vs. 1.9 ± 2.3, p < 0.001) and thereafter until day 8. High SOFA scores for any organ system and increasing number of organ failures (SOFA score ≥ 3) were associated with increased mortality. Cardiovascular and neurological systems (day 1) were related to outcome and cardiovascular and respiratory systems, and admission from another ICU to length of ICU stay. TMS score was higher in nonsurvivors (1.76 ± 2.55 vs. 0.58 ± 1.39, p < 0.01), and ΔSOFA/total SOFA on day 1 was independently related to outcome. The area under the receiver-operating characteristic curve was 0.86 for TMS, 0.82 for SOFA on day 1, and 0.77 for SAPS II. Conclusions: The SOFA, TMS, and ΔSOFA scores provide the clinician with important information on degree and progression of organ dysfunction in medical, cardiovascular patients. On day 1 both SOFA score and TMS score had a better prognostic value than SAPS II score. The model is closely related to outcome and identifies patients who are at increased risk for prolonged ICU stay. Received: 6 August 1999 Final revision received: 3 January 2000 Accepted: 28 March 2000     

The Multiple Organ Dysfunction Score (MODS) versus the Sequential Organ Failure Assessment (SOFA) score in outcome prediction

OBJECTIVE: To compare outcome prediction using the Multiple Organ Dysfunction Score (MODS) and the Sequential Organ Failure Assessment (SOFA), two of the systems most commonly used to evaluate organ dysfunction in the intensive care unit (ICU). DESIGN: Prospective, observational study. SETTING: Thirty-one-bed, university hospital ICU. PATIENTS AND PARTICIPANTS: Nine hundred forty-nine ICU patients. MEASUREMENTS AND RESULTS: The MODS and the SOFA score were calculated on admission and every 48 h until ICU discharge. The Acute Physiology and Chronic Health Evaluation (APACHE) II score was calculated on admission. Areas under receiver operating characteristic (AUROC) curves were used to compare initial, 48 h, 96 h, maximum and final scores. Of the 949 patients, 277 died (mortality rate 29.1%). Shock was observed in 329 patients (mortality rate 55.3%). There were no significant differences between the two scores in terms of mortality prediction. Outcome prediction of the APACHE II score was similar to the initial MODS and SOFA score in all patients, and slightly worse in patients with shock. Using the scores' cardiovascular components (CV), outcome prediction was better for the SOFA score at all time intervals (initial AUROC SOFA CV 0.750 vs MODS CV 0.694, p<0.01; 48 h AUROC SOFA CV 0.732 vs MODS CV 0.675, p<0.01; and final AUROC SOFA CV 0.781 vs MODS CV 0.674, p<0.01). The same tendency was observed in patients with shock. There were no significant differences in outcome prediction for the other five organ systems. CONCLUSIONS: MODS and SOFA are reliable outcome predictors. Cardiovascular dysfunction is better related to outcome with the SOFA score than with the MODS.     

Application of SOFA score to trauma patients

Objective: To assess the ability of the SOFA score (Sequential Organ Failure Assessment) to describe the evolution of organ dysfunction/failure in trauma patients over time in intensive care units (ICU). Design: Retrospective analysis of a prospectively collected database. Setting: 40 ICUs in 16 countries. Patients: All trauma patients admitted to the ICU in May 1995. Main outcome measures and results: Incidence of dysfunction/failure of different organs during the first 10 days of stay and the relation between the dysfunction, outcome, and length of stay. Included in the SOFA study were 181 trauma patients (140 males and 41 females).The non-survivors were significantly older than the survivors (51 years ± 20 vs 38 ± 16 years, p < 0.05) and had a higher global SOFA score on admission (8 ± 4 vs 4 ± 3, p < 0.05) and throughout the 10-day stay. On admission, the non-survivors had higher scores for respiratory ( > 3 in 47 % of non-survivors vs 17 % of survivors), cardiovascular ( > 3 in 24 % of non-survivors vs 5.7 % of survivors), and neurological systems ( > 4 in 41 % of non-survivors vs 16 % of survivors); although the trend was maintained over the whole study period, the differences were greater during the first 4–5 days. After the first 4 days, only respiratory dysfunction was significantly related to outcome. A higher SOFA score, admission to the ICU from the same hospital, and the presence of infection on admission were the three major variables associated with a longer length of stay in the ICU (additive regression coefficients: 0.85 days for each SOFA point, 4.4 for admission from the same hospital, 7.26 for infection on admission). Conclusions: The SOFA score can reliably describe organ dysfunction/failure in trauma patients. Regular and repeated scoring may be helpful for identifying categories of patients at major risk of prolonged ICU stay or death. Received: 3 March 1998 Accepted: 21 December 1998     

Daily evaluation of organ function during renal replacement therapy in intensive care unit patients with acute renal failure

PurposeThe aim of this study was to assess changes in organ function in acute renal failure patients during renal replacement therapy and relate them to outcome.Materials and MethodsMedical and nursing charts from 111 patients with acute renal failure who underwent renal replacement therapy (hemodialysis or hemofiltration) from July 2000 until July 2002 on a 31-bed medicosurgical intensive care unit (ICU) at a university hospital in Belgium and in whom the Sequential Organ Failure Assessment (SOFA) score was calculated daily before the start of therapy until the seventh day, or the end of therapy, were analyzed. Changes in SOFA score over time (Δ SOFA) were calculated.ResultsOf 111 patients, 63 (57%) died in the ICU. Nonsurvivors were older (68 [52-76] vs 59 [48-70] years, P = .017) and had initially higher respiratory, cardiovascular, and total SOFA scores compared with survivors. A greater Δ renal SOFA at 24 hours was associated univariantly with a higher risk of ICU mortality (odds ratio, 1.7; 95% confidence interval, 1.2-2.6; P = .013). In a multivariate analysis with ICU outcome as the dependent variable, only age, cardiovascular SOFA score on admission, and the change in total SOFA score over the first 24 hours were independently associated with a greater risk of death.ConclusionsAssessment of these factors in the first 24 hours of renal replacement therapy could help identify patients at higher risk of mortality early during their ICU admission.     

Outcome of patients with end-stage renal disease admitted to the intensive care unit

OBJECTIVES: To describe the clinical course of patients with end-stage renal disease (ESRD) admitted to the intensive care unit (ICU) and to compare the performance of Acute Physiology and Chronic Health Evaluation (APACHE) III and Sequential Organ Failure Assessment (SOFA) in predicting their outcome. PATIENTS AND METHODS: This retrospective cohort study consisted of patients with ESRD admitted to 3 ICUs between January 1, 1997, and November 30, 2002. Data on demographics, APACHE III score, SOFA score, development of sepsis and organ failure, use of mechanical ventilation, and mortality were collected. RESULTS: Of the 476 patients with ESRD who underwent dialysis during the study period, 93 (20%) required admission to the ICU. The most common ICU admission diagnosis was gastrointestinal bleeding. The first day median (Interquartile range) APACHE III score, SOFA score, and APACHE III predicted hospital mortality rate were 64 (47-79), 6 (5-8), and 12.9% (4.2%-30.8%), respectively. The observed ICU, hospital, and 30-day mortality rates were 9%, 16%, and 22%, respectively. Nonrenal organ failure developed in 48 patients (52%) and sepsis in 15 patients (16%). Mechanical ventilation was required In 26 patients (28%). The area under the receiver operating characteristic curve for the first-day APACHE III probability of hospital death in predicting 30-day mortality was 0.78 (95% confidence interval, 0.68-0.86) compared with 0.66 (95% confidence interval, 0.55-0.76) for the SOFA score (P = .16). CONCLUSIONS: The observed hospital mortality of patients with ESRD admitted to the ICU is relatively low. There is no statistically significant difference in the performance of APACHE III and SOFA prognostic models in discriminating between 30-day survivors and nonsurvivors.     

不同时点序贯器官衰竭评估评分对重症医学科患者院内死亡的预测价值比较

目的比较不同时点序贯器官衰竭评估（SOFA）评分对重症医学科（ICU）患者院内死亡的预测价值,以期为实际临床工作中合理选用SOFA评分指标提供一定的研究证据。 方法从美国重症监护数据库中选择住院时间>72 h的成年ICU患者,提取其基本信息与相关检验指标并计算不同时点SOFA评分,以院内死亡为结局指标,采用多因素Logistic回归分析不同时点SOFA评分与院内死亡的关联,绘制受试者工作特征（ROC）曲线并计算曲线下面积（AUC）以评价各指标的预后预测价值。 结果共有11 968例患者纳入最终分析,其中男性患者占56.15%,平均年龄为（64.75±16.63）岁,院内病死率为10.41%（1246/11 968）。多因素Logistic回归分析显示不同时点SOFA评分均与院内死亡密切相关（P均<0.0001）,ROC曲线分析显示不同时点SOFA评分预测院内死亡的能力存在差异,以T₇₂最高（AUC=0.7246,95%CI：0.7101~0.7391）。 结论对于住院时间>72 h的成年ICU患者,入院后72 h的SOFA评分可能具有更好的预后预测价值。     

Glasgow Coma Scale score dominates the association between admission Sequential Organ Failure Assessment score and 30-day mortality in a mixed intensive care unit population

Objective

The Sequential Organ Failure Assessment (SOFA) score, a measure of multiple-organ dysfunction syndrome, is used to predict mortality in critically ill patients by assigning equally weighted scores across 6 different organ systems. We hypothesized that specific organ systems would have a greater association with mortality than others.

Design

We retrospectively studied patients admitted over a period of 4.2 years to a mixed-profile intensive care unit (ICU). We recorded age and comorbidities, and calculated SOFA organ scores. The primary outcome was 30-day all-cause mortality. We determined which organ subscores of the SOFA score were most associated with mortality using multiple analytic methods: random forests, conditional inference trees, distanced-based clustering techniques, and logistic regression.

Setting

A 24-bed mixed-profile adult ICU that cares for medical, surgical, and trauma (level 1) patients at an academic referral center.

Patients

All patients' first admission to the study ICU during the study period.

Measurements and Main Results

We identified 9120 first admissions during the study period. Overall 30-day mortality was 12%. Multiple analytical methods all demonstrated that the best initial prediction variables were age and the central nervous system SOFA subscore, which is determined solely by Glasgow Coma Scale score.

Conclusions

In a mixed population of critically ill patients, the Glasgow Coma Scale score dominates the association between admission SOFA score and 30-day mortality. Future research into outcomes from multiple-organ dysfunction may benefit from new models for measuring organ dysfunction with special attention to neurologic dysfunction.     

冠脉搭桥病人术后器官功能评分和预后分析

目的　采用序贯器官衰竭估计 (SOFA)评价急诊和择期冠状动脉搭桥 (CABG)术后的器官功能并对预后进行分析。方法　急诊CABG和择期CABG病人各 4 2例 ,进行回顾性分析。根据SOFA评分标准 ,确定术后在重症监护病房 (ICU)期间每天的器官功能评分 ,比较两组病人SOFA总分 (totalSOFAscore) ,分析总的最高SOFA评分 (TMS)以及各器官最差SOFA评分与预后的关系。结果　急诊组的死亡率高于择期组 (P <0 0 5 )。急诊组术后前 5d的SOFA总分均高于择期组 (P <0 0 1) ,死亡病例的TMS、除肝脏外的器官最差评分均高于存活病例 (P <0 0 5或 P <0 0 1) ,Logistic回归分析发现呼吸、心血管和中枢神经系统与死亡相关 (P <0 0 1)。急诊组存活病例的TMS高于择期组 (P <0 0 1) ,心血管支持时间和ICU停留时间较长 (P <0 0 5或P <0 0 1)。存活病例的ICU停留时间和TMS之间存在相关性 ,相关系数为 0 4 5 2 (P <0 0 1)。结论　SOFA是反映CABG病人预后的指标。急诊CABG术后器官功能评分较高 ,预后较差 ,与呼吸、心血管和中枢神经系统功能障碍有关。     

Non-neurological organ dysfunction in neurocritical care

PURPOSE: To determine the incidence of non-neurological organ dysfunction in patients with severe neurological injury. MATERIALS AND METHODS: Modified daily SOFA (mSOFA) scores were retrospectively calculated for 55 consecutive patients with severe head injury or subarachnoid hemorrhage. mSOFA was defined as the sum of the 5 non-neurological component SOFA scores, maximum mSOFA as the sum of the most abnormal non-neurological SOFA component scores and delta mSOFA as the difference between maximum mSOFA and admission mSOFA. Organ failure was defined as a SOFA component score > or =3. RESULTS: Median (IQR) admission, maximum and delta mSOFA scores were 4 (3-6), 8 (6-9), and 2 (1-5), respectively. Respiratory and cardiac failure developed in 80% and 82% of patients, respectively. No patient developed renal or hepatic failure. Three patients developed hematological failure. There was no difference between survivors and nonsurvivors with respect to admission mSOFA (P =.45), maximum mSOFA (P =.54), or delta mSOFA (P =.19). There was no difference between those patients with favorable or unfavorable neurological outcome with respect to admission mSOFA (P =.24), maximum mSOFA (P =.84), or delta mSOFA (P =.20). CONCLUSIONS: Cardiopulmonary failure, as defined by SOFA, is common in intensive care unit patients with severe head injury and subarachnoid hemorrhage. In contrast to other intensive care unit patient populations, the mortality of patients with closed head injury or subarachnoid hemorrhage was not related to the severity of organ dysfunction on admission or its development during the intensive care unit stay.     

The combined use of three widely available biochemical markers as predictor of organ failure in critically ill patients

Background: We hypothesized that lactate dehydrogenase, LDH/albumin ratio in combination with or without magnesium (Mg²⁺) could predict organ failure in critically ill adult patients. The aim of this study was to describe a new risk index for organ failure or mortality in critically ill patients based on a combination of these routinely available biochemical plasma biomarkers.

Methods: Patients?≥?18 years admitted to the intensive care unit (ICU) were screened. Albumin and LDH were analyzed at the time of admission to ICU (n?=?347). Organ failure assessed with ‘Sequential Organ Failure Assessment’ (SOFA) score was used, and 30-day mortality was recorded. The predictive value of the test was calculated using the areas under the receiving operating characteristic (ROC) curve.

Results: The LDH/albumin ratio was higher in patients who developed organ failure as compared to those who did not (p?n?=?183) admitted to ICU from the emergency department, the predictive values were 0.86 and 0.80, respectively.

Conclusion: The LDH/albumin ratio at ICU admission was associated with the development of multiple organ failure and 30-day mortality in this prospective study. The clinical value of this biomarker as a predictor of organ failure in critically ill patients is yet to be defined.     

Glutamine and glutathione at ICU admission in relation to outcome

Glutamine depletion is demonstrated to be an independent predictor of hospital mortality in ICU (intensive care unit) patients. Today glutamine supplementation is recommended to ICU patients on parenteral nutrition. In addition to glutamine, glutathione may be a limiting factor in ICU patients with MOF (multiple organ failure). To study the prevalence of glutamine and glutathione depletion an observational study was performed. The results were analysed in relation to mortality and the conventional predictors of mortality outcome, APACHE II (Acute Physiology and Chronic Health Evaluation II) and SOFA (Sequential Organ Failure Assessment). Consecutive patients admitted to the ICU at Karolinska University Hospital Huddinge were studied. Patient admission scoring of APACHE II and SOFA were registered as well as mortality up to 6 months. Plasma glutamine concentration and whole blood glutathione status at admittance were analysed. The admission plasma glutamine concentrations were totally independent of the conventional risk scoring at admittance, and a subnormal concentration was an independent predictor of mortality. In addition, glutathione redox status was also an independent mortality predictor, but here a normal ratio was the risk factor. In both cases the mortality risk was mainly confined to the post-ICU period. A low plasma concentration of glutamine at ICU admission is an independent risk factor for post-ICU mortality. The possible benefit of extending glutamine supplementation post-ICU should be evaluated prospectively.     

Changes in severity and organ failure scores as prognostic factors in onco-hematological malignancy patients admitted to the ICU

Objective To determine whether severity and organ failure scores over the first 3 days in an ICU predict in-hospital mortality in onco-hematological malignancy patients.Design and setting Retrospective study in a 22-bed medical ICU.Patients 92 consecutive patients with onco-hematological malignancies including 20 hematopoietic stem cell transplantation (HSCT) patients (11 with allogenic HSCT).Measurements Simplified Acute Physiology Score (SAPS) II, Organ Dysfunction and/or Infection (ODIN) score, Logistic Organ Dysfunction System (LODS), and Sequential Organ Failure Assessment (SOFA) score were recorded on admission. The change in each score (Δ score) during the first 3 days in the ICU was calculated as follows: severity or organ failure score on day 3 minus severity or organ failure score on day 1, divided by severity or organ failure score on day 1.Results In-hospital mortality was 58%. Using multivariate analysis in-hospital mortality was predicted by all scores on day 1 and all Δ scores. Areas under the receiver operating characteristics curves were similar for SAPS II (0.78), ODIN (0.78), LODS (0.83), and SOFA (0.78) scores at day 1. They were also similar for ΔSAPS II, ΔODIN, ΔLODS, and ΔSOFA. Similar results were observed when excluding patients with allogenic HSCT.Conclusion Severity and three organ failure scores on day 1 and Δ scores perform similarly in predicting in-hospital mortality in ICU onco-hematological malignancy patients but do not predict individual outcome. Decision to admit such patients to the ICU or to forgo life-sustaining therapies should not be based on these scores.Electronic supplementary material Supplementary material is available in the online version of this article at and is accesible for authorized users.     

Prospective cohort study comparing sequential organ failure assessment and acute physiology, age, chronic health evaluation III scoring systems for hospital mortality prediction in critically ill cirrhotic patients

The aim of the study was to evaluate the usefulness of sequential organ failure assessment (SOFA) and acute physiology, age, chronic health evaluation III (APACHE III) scoring systems obtained on the first day of intensive care unit (ICU) admission in predicting hospital mortality in critically ill cirrhotic patients. The study enrolled 102 cirrhotic patients consecutively admitted to ICU during a 1-year period. Twenty-five demographic, clinical and laboratory variables were analysed as predicators of survival. Information considered necessary to calculate the Child-Pugh, SOFA and APACHE III scores on the first day of ICU admission was also gathered. Overall hospital mortality was 68.6%. Multiple logistic regression analysis revealed that mean arterial pressure, SOFA and APACHE III scores were significantly related to prognosis. Goodness-of-fit was good for the SOFA and APACHE III models. Both predictive models displayed a similar degree of the best Youden index (0.68) and overall correctness (84%) of prediction. The SOFA and APACHE III models displayed good areas under the receiver-operating characteristic curve (0.917 +/- 0.028 and 0.912 +/- 0.029, respectively). Finally, a strong and significant positive correlation exists between SOFA and APACHE III scores for individual patients (r(2) = 0.628, p < 0.001). This investigation confirms the grave prognosis for cirrhotic patients admitted to ICU. Both SOFA and APACHE III scores are excellent tools to predict the hospital mortality in critically ill cirrhotic patients. The overall predictive accuracy of SOFA and APACHE III is superior to that of Child-Pugh system. The role of these scoring systems in describing the dynamic aspects of clinical courses and allocating ICU resources needs to be clarified.     

Incidence, organ dysfunction and mortality in severe sepsis: a Spanish multicentre study

Introduction

Sepsis is a leading cause of admission to non-cardiological intensive care units (ICUs) and the second leading cause of death among ICU patients. We present the first extensive dataset on the epidemiology of severe sepsis treated in ICUs in Spain.

Methods

We conducted a prospective, observational, multicentre cohort study, carried out over two 3-month periods in 2002. Our aims were to determine the incidence of severe sepsis among adults in ICUs in a specific area in Spain, to determine the early (48 h) ICU and hospital mortality rates, as well as factors associated with the risk of death.

Results

A total of 4,317 patients were admitted and 2,619 patients were eligible for the study; 311 (11.9%) of these presented at least 1 episode of severe sepsis, and 324 (12.4%) episodes of severe sepsis were recorded. The estimated accumulated incidence for the population was 25 cases of severe sepsis attended in ICUs per 100,000 inhabitants per year. The mean logistic organ dysfunction system (LODS) upon admission was 6.3; the mean sepsis-related organ failure assessment (SOFA) score on the first day was 9.6. Two or more organ failures were present at diagnosis in 78.1% of the patients. A microbiological diagnosis of the infection was reached in 209 episodes of sepsis (64.5%) and the most common clinical diagnosis was pneumonia (42.8%). A total of 169 patients (54.3%) died in hospital, 150 (48.2%) of these in the ICU. The mortality in the first 48 h was 14.8%. Factors associated with early death were haematological failure and liver failure at diagnosis, acquisition of the infection prior to ICU admission, and total LODS score on admission. Factors associated with death in the hospital were age, chronic alcohol abuse, increased McCabe score, higher LODS on admission, ΔSOFA 3-1 (defined as the difference in the total SOFA scores on day 3 and on day 1), and the difference of the area under the curve of the SOFA score throughout the first 15 days.

Conclusions

We found a high incidence of severe sepsis attended in the ICU and high ICU and hospital mortality rates. The high prevalence of multiple organ failure at diagnosis and the high mortality in the first 48 h suggests delays in diagnosis, in initial resuscitation, and/or in initiating appropriate antibiotic treatment.     

Acute renal failure in the ICU: risk factors and outcome evaluated by the SOFA score

Objectives: To describe risk factors for the development of acute renal failure (ARF) in a population of intensive care unit (ICU) patients, and the association of ARF with multiple organ failure (MOF) and outcome using the sequential organ failure assessment (SOFA) score. Design: Prospective, multicenter, observational cohort analysis. Setting: Forty ICUs in 16 countries. Patients: All patients admitted to one of the participating ICUs in May 1995, except those who stayed in the ICU for less than 48 h after uncomplicated surgery, were included. After the exclusion of 38 patients with a history of chronic renal failure requiring renal replacement therapy, a total of 1411 patients were studied. Measurements and results: Of the patients, 348 (24.7 %) developed ARF, as diagnosed by a serum creatinine of 300 μmol/l (3.5 mg/dl) or more and/or a urine output of less than 500 ml/day. The most important risk factors for the development of ARF present on admission were acute circulatory or respiratory failure; age more than 65 years, presence of infection, past history of chronic heart failure (CHF), lymphoma or leukemia, or cirrhosis. ARF patients developed MOF earlier than non-ARF patients (median 24 vs 48 h after ICU admission, p < 0.05). ARF patients older than 65 years with a past history of CHF or with any organ failure on admission were most likely to develop MOF. ICU mortality was 3 times higher in ARF than in other patients (42.8 % vs 14.0 %, p < 0.01). Oliguric ARF was an independent risk factor for overall mortality as determined by a multivariate regression analysis (OR = 1.59 [CI 95 %: 1.23–2.06], p < 0.01). Infection increased the risk of death associated with all factors. Factors that increased the ICU mortality of ARF patients were a past history of hematologic malignancy, age more than 65 years, the number of failing organs on admission and the presence of acute cardiovascular failure. Conclusion: In ICU patients, the most important risk factors for ARF or mortality from ARF are often present on admission. During the ICU stay, other organ failures (especially cardiovascular) are important risk factors. Oliguric ARF was an independent risk factor for ICU mortality, and infection increased the contribution to mortality by other factors. The severity of circulatory shock was the most important factor influencing outcome in ARF patients. Received: 9 August 1999/Final revision received: 24 January 2000/Accepted: 6 April 2000     

Risk factors for acute organ failure in intensive care unit patients who receive respiratory support in the absence of non-respiratory organ failure: an international prospective cohort study

Introduction

Many supposed low-risk intensive care unit (ICU) admissions develop acute organ failure (AOF). Identifying patients at high risk of developing AOF and targeting them with preventative strategies may be effective. Our study question was: in a population of ICU patients receiving positive pressure respiratory support (invasive or non-invasive) in the absence of non-respiratory AOF, what is the 14-day incidence of, risk factors for and time to acute organ failure?

Methods

In an international prospective cohort study, patients receiving positive pressure respiratory support (invasive or non-invasive) in the absence of non-respiratory AOF were enrolled and followed for 14 days. The primary outcome measure was the incidence of any AOF (defined as SOFA 3 to 4) during follow-up.

Results

A total of 123 of 766 screened patients (16.1%) were enrolled. Data are reported for 121 patients. In total, 45 out of 121 patients (37.2%) developed AOF. Mortality rates were higher in those with AOF: 17.8% versus 4.0% OR 5.11, P = 0.019) for ICU mortality; and 28.9% versus 11.8% (OR 2.80, P = 0.019) for hospital mortality. Median ICU length of stay was also longer in those with AOF (11 versus 3.0 days; P < 0.0001). Hypoxemic respiratory failure (P = 0.001) and cardiovascular dysfunction (that is, SOFA 1 to 2; P = 0.03) were associated with AOF. The median time to first AOF was two days.

Conclusions

Patients receiving positive (invasive or non-invasive) pressure respiratory support in the absence of non-respiratory AOF are commonly admitted to ICU; AOF is frequent in these patients. Organ failure developed within a short period after admission. Hypoxemic respiratory failure and cardiovascular dysfunction were strongly associated with AOF.     

Dynamic microsimulation to model multiple outcomes in cohorts of critically ill patients

Background Existing intensive care unit (ICU) prediction tools forecast single outcomes, (e.g., risk of death) and do not provide information on timing.Objective To build a model that predicts the temporal patterns of multiple outcomes, such as survival, organ dysfunction, and ICU length of stay, from the profile of organ dysfunction observed on admission.Design Dynamic microsimulation of a cohort of ICU patients.Setting 49Forty-nine ICUs in 11 countries.Patients One thousand four hundred and forty-nine patients admitted to the ICU in May 1995.Interventions None.Model construction We developed the model on all patients (n=989) from 37 randomly-selected ICUs using daily Sequential Organ Function Assessment (SOFA) scores. We validated the model on all patients (n=460) from the remaining 12 ICUs, comparing predicted-to-actual ICU mortality, SOFA scores, and ICU length of stay (LOS).Main results In the validation cohort, the predicted and actual mortality were 20.1% (95%CI: 16.2%–24.0%) and 19.9% at 30 days. The predicted and actual mean ICU LOS were 7.7 (7.0–8.3) and 8.1 (7.4–8.8) days, leading to a 5.5% underestimation of total ICU bed-days. The predicted and actual cumulative SOFA scores per patient were 45.2 (39.8–50.6) and 48.2 (41.6–54.8). Predicted and actual mean daily SOFA scores were close (5.1 vs 5.5, P=0.32). Several organ-organ interactions were significant. Cardiovascular dysfunction was most, and neurological dysfunction was least, linked to scores in other organ systems.Conclusions Dynamic microsimulation can predict the time course of multiple short-term outcomes in cohorts of critical illness from the profile of organ dysfunction observed on admission. Such a technique may prove practical as a prediction tool that evaluates ICU performance on additional dimensions besides the risk of death.Electronic Supplementary Material Supplementary material is available in the online version of this article at http://dx.doi.org/10.1007/s00134-004-2456-5Financial support: partially supported by Eli Lilly & Company (Gilles Clermont and Derek C. Angus) and by the Stiefel-Zangger Foundation, University of Zurich, Switzerland (Vladimir Kaplan)