Epidemiological and Clinical Characteristics of Community-Acquired Severe Sepsis and Septic Shock: A Prospective Observational Study in 12 University Hospitals in Korea

A prospective multicenter observational study was performed to investigate the epidemiology and outcomes of community-acquired severe sepsis and septic shock. Subjects included 1,192 adult patients admitted to the 22 participating intensive care units (ICUs) of 12 university hospitals in the Korean Sepsis Registry System from April, 2005 through February, 2009. Male accounted for 656 (55%) patients. Mean age was 65.0 ± 14.2 yr. Septic shock developed in 740 (62.1%) patients. Bacteremia was present in 422 (35.4%) patients. The 28-day and in-hospital mortality rates were 23.0% and 28.0%, respectively. Men were more likely to have comorbid illnesses and acute organ dysfunctions, and had higher mortality and clinical severity compared to women. While respiratory sources of sepsis were common in men, urinary sources were predominant in women. In the multivariate logistic regression analysis, cancer (odds ratio 1.89; 95% confidence interval 1.13-3.17), urinary tract infection (0.25; 0.13-0.46), APACHE II score (1.05; 1.02-1.09), SOFA score on day 1 (1.13; 1.06-1.21) and metabolic dysfunction (2.24, 1.45-3.45) were independent clinical factors for gender-related in-hospital mortality. This study provided epidemiological and clinical characteristics of community-acquired severe sepsis and septic shock in ICUs in Korea, and demonstrated the impact of clinical factors on gender difference in mortality.     

血流动力学参数与脓毒症休克患者容量反应性的预测及相关性分析

目的 探讨容量负荷试验前后脓毒症休克患者血流动力学参数的变化及对患者发生容量反应的预测价值。方法 选取脓毒症休克患者 98 例进行临床研究,根据补液治疗前后患者的每搏输出量变化值(ΔSV)分为容量负荷阳性组(ΔSV≥15% )53 例、容量负荷阴性组(ΔSV<15% )45 例,对比两组患者容量负荷试验前后脉搏指数连续心 输出量( pulse-indicated continuous cardiac output,PICCO)、超声心动图相关指标,并采用受试者工作曲线( receiveroperating curve,ROC)分析具有统计学意义的指标对于脓毒症休克患者发生容量负荷试验反应性的价值,采用Logistics 回归模型分析各项参数与容量负荷试验反应的关系。 结果 在容量负荷试验前,两组患者心排量( cardiacoutput,CO)、心脏指数( cardiac index,CI)、每搏输出量变异量( stroke volume variation,SVV)、中心静脉压( centralvenous pressure,CVP)、心率(heart rate, HR)测定值比较,差异均无统计学意义(P>0. 05);试验后,容量负荷阳性组CO、CI、CVP 测定值均高于容量负荷阴性组(P<0. 05),HR、SVV 均低于容量负荷阴性组(P<0. 05)。 容量负荷试验前,两组患者左室流出道(left ventricular outflow tract, LVOT)内径时间积分(VTI)峰值流速呼吸变异度、VEpeak 测定值比较,差异均无统计学意义(P>0. 05);试验后,容量负荷阳性组 LVOT VTI 测定值高于容量负荷阴性组(P<0. 05),LVOT 峰值流速呼吸变异度低于容量负荷阴性组(P<0. 05);ROC 曲线结果显示,HR、CO、CI、CVP、SVV、LVOT 峰值流速呼吸变异度、LVOT VTI 各项指标预测容量负荷反应阳性的曲线下面积(area under the curve, AUC)分别为 0. 515、0. 560、0. 556、0. 499、0. 898、0. 912、0. 922;Logistic 回归模型结果显示,APACHEⅡ评分越高、SOFA 评分越高、CO 越低、CI 越低、CVP 越低、SVV 越高、LVOT VTI 越低、LVOT 峰值流速呼吸变异度越大,是脓毒症休克患者容量负荷试验阴性的独立危险因素(P<0. 05)。 结论 密切监测脓毒症休克患者的相关血流动力学参数,对于预测患者容量负荷反应性具有临床价值,可以指导患者临床液体复苏。     

Hemodynamic and hormonal responses to lower body negative pressure in men with varying profiles of strength and aerobic power

Hemodynamic, cardiac, and hormonal responses to lower-body negative pressure (LBNP) were examined in 24 healthy men to test the hypothesis that responsiveness of reflex control of blood pressure during orthostatic challenge is associated with interactions between strength and aerobic power. Subjects underwent treadmill tests to determine peak oxygen uptake ( O_2max) and isokinetic dynamometer tests to determine knee extensor strength. Based on predetermined criteria, subjects were classified into one of four fitness profiles of six subjects each, matched for age, height, and body mass: (a) low strength/average aerobic fitness, (b) low strength/high aerobic fitness, (c) high strength/average aerobic fitness, and (d) high strength/high aerobic fitness. Following 90 min of 0.11 rad (6°) head-down tilt (HDT), each subject underwent graded LBNP to –6.7 kPa or presyncope, with maximal duration 15 min, while hemodynamic, cardiac, and hormonal responses were measured. All groups exhibited typical hemodynamic, hormonal, and fluid shift responses during LBNP, with no intergroup differences between high and low strength characteristics. Subjects with high aerobic power exhibited greater (P < 0.05) stroke volume and lower (P < 0.05) heart rate, vascular peripheral resistance, and mean arterial pressure during rest, HDT, and LBNP. Seven subjects, distributed among the four fitness profiles, became presyncopal. These subjects showed greatest reduction in mean arterial pressure during LBNP, had greater elevations in vasopressin, and lesser increases in heart rate and peripheral resistance. Neither O_2max nor leg strength were associated with fall in arterial pressure or with syncopal episodes. We conclude that interactions between aerobic and strength fitness characteristics do not influence responses to LBNP challenge.     

Earliest Bedside Assessment of Hemodynamic Parameters and Cardiac Biomarkers: Their Role as Predictors of Adverse Outcome in Patients with Septic Shock

Background: Early assessment and aggressive hemodynamic treatment have been shown to increase the survival of patients in septic shock. Current and past sepsis guidelines recommend a resuscitation protocol including central venous pressure (CVP), mean arterial blood pressure (MAP), urine output and central venous oxygen saturation (ScvO₂) for resuscitation within the first six hours. Currently, the established severity score systems like APACHE II score, SOFA score or SAPS II score predict the outcome of critically ill patients on the bases of variables obtained only after the first 24 hours. The present study aims to evaluate the risk of short-term mortality for patients with septic shock by the earliest possible assessment of hemodynamic parameters and cardiac biomarkers as well as their role for the prediction of the adverse outcome.Methods: 52 consecutive patients treated for septic shock in the intensive care unit of one centre (Marien Hospital Herne, Ruhr University Bochum, Germany) were prospectively enrolled in this study. Hemodynamic parameters (MAP, CVP, ScvO₂, left ventricular ejection fraction, Hematocrit) and cardiac biomarkers (Troponin I) at the ICU admission were evaluated in regard to their influence on mortality. The primary endpoint was all-cause mortality within 28 days after the admission.Results: A total of 52 patients (31 male, 21 female) with a mean age of 71.4±8.5 years and a mean APACHE II score of 37.0±7.6 were enrolled in the study. 28 patients reached the primary endpoint (mortality 54%). Patients presenting with hypotension (MAP <65 mmHg) at ICU admission had significantly higher rates of 28-day mortality as compared with the group of patients without hypotension (28-day mortality rate 74 % vs. 32 %, p<0.01). Furthermore, the patients in the hypotension present group had significantly higher lactate concentration (p=0.002), higher serum creatinin (p=0.04), higher NTproBNP (p=0.03) and after the first 24 hours higher APACHE II scores (p=0.04). A MAP <65 mmHg was the only hemodynamic parameter significantly predicting the primary endpoint (OR: 4.1, CI: 1.1 - 14.8, p=0.008), whereas the remaining hemodynamic variables CVP, ScvO₂, Hematocrit, Troponin I and left ventricular ejection fraction (LVEF) seemed to have no influence on survival. Besides, non-survivors had a significantly higher age (74.1±9.0 vs. 68.4±6.9, p=0.01). If hypotension coincided with an age ≥72 years, the 28-day mortality rate escalated to 88%.Conclusions: In our study, we identified a risk group with an exceedingly high mortality rate: the patients with an age ≥72 years and presenting with hypotension (MAP <65 mmHg). These data can be easily obtained at the time of the very first patient contact. As a result, an aggressive and a more effective treatment can be initiated within the first minutes of the primary care, possibly reducing organ failure and short-term mortality in this risk group.     

轻度CLP模型大鼠在脓毒症早期即发生心肌收缩与舒张功能障碍

目的:利用轻度盲肠结扎穿孔术(CLP)复制脓毒症大鼠模型,比较脓毒症大鼠心功能与其它器官功能障碍发生的时间。方法:将大鼠随机分为假手术组和盲肠结扎穿孔术组,分别于手术后6 h、9 h和12 h用Langendorff装置检测大鼠心肌收缩与舒张功能,并测定心肌肿瘤坏死因子α(TNF-α)、细胞间黏附分子1(ICAM-1)和血管内皮细胞黏附因子1(VCAM-1)的表达;同时检测血清TNF-α水平以及大鼠肝、肾功能和肺湿/干重比值。结果:轻度CLP术后10 d,大鼠的死亡率为26.7%。CLP术后9 h与12 h左心室内压最大上升与下降速率显著低于假手术组;CLP术后6 h,心肌TNF-α、ICAM-1和VCAM-1的mRNA表达显著高于假手术组,CLP术后9 h心肌TNF-α和VCAM-1的蛋白表达显著升高。CLP术后9 h血清天冬氨酸氨基转移酶活性和12 h丙氨酸氨基转移酶活性高于假手术组。而术后6 h、9 h和12 h,大鼠血尿素氮水平、肺湿/干重比与相应时点的假手术组比较,差异没有统计学显著性。结论:轻度CLP模型大鼠在脓毒症发生后6 h心肌炎症因子表达增多,9 h后即发生心肌内在收缩与舒张功能障碍,其发生早于肝、肾功能损伤。     

Stroke Volume Variation for Prediction of Fluid Responsiveness in Patients Undergoing Gastrointestinal Surgery

Background: Stroke volume variation (SVV) has been shown to be a reliable predictor of fluid responsiveness. However, the predictive role of SVV measured by FloTrac/Vigileo system in prediction of fluid responsiveness was unproven in patients undergoing ventilation with low tidal volume. Methods: Fifty patients undergoing elective gastrointestinal surgery were randomly divided into two groups: Group C [n₁=20, tidal volume (V_t) = 8 ml/kg, frequency (F) = 12/min] and Group L [n₂=30, V_t= 6 ml/kg, F=16/min]. After anesthesia induction, 6% hydroxyethyl starch130/0.4 solution (7 ml/kg) was intravenously transfused. Besides standard haemodynamic monitoring, SVV, cardiac output, cardiac index (CI), stroke volume (SV), stroke volume index (SVI), systemic vascular resistance (SVR) and systemic vascular resistance index (SVRI) were determined with the FloTrac/Vigileo system before and after fluid loading. Results: After fluid loading, the MAP, CVP, SVI and CI increased significantly, whereas the SVV and SVR decreased markedly in both groups. SVI was significantly correlated to the SVV, CVP but not the HR, MAP and SVR. SVI was significantly correlated to the SVV before fluid loading (Group C: r = 0.909; Group L: r = 0.758) but not the HR, MAP, CVP and SVR before fluid loading. The largest area under the ROC curve (AUC) was found for SVV (Group C, 0.852; Group L, 0.814), and the AUC for other preloading indices in two groups ranged from 0.324 to 0.460. Conclusion: SVV measured by FloTrac/Vigileo system can predict fluid responsiveness in patients undergoing ventilation with low tidal volumes during gastrointestinal surgery.     

Hemodynamic response patterns: responder type differences in reactivity and recovery

We examined whether responder type groups reflecting patterns of hemodynamic reactivity might also differ in recovery responses. Cardiac output (CO), total peripheral resistance (TPR), systolic and diastolic blood pressure, heart rate, and Heather index were assessed at rest and during speech and cold pressor tasks in young adults. Participants (n = 152) were classified as myocardial, vascular, or mixed-mild responders based on CO and TPR responses to speech presentation. Vascular responders exhibited slower CO and TPR speech recovery than the myocardial and/or mixed-mild groups. Responder type differences in reactivity showed limited task-generalizability. The sustained vascular response pattern of the vascular group is consistent with that seen in hypertension. In light of associations of heightened TPR with markers of disease risk, this suggests potentially negative health implications for vascular responders.