Sepsis, SIRS and infection

A probabilistic model for the prediction of intra-abdominal infection after colorectal surgery

AIM

Predicting intra-abdominal infections (IAI) after colorectal surgery by means of clinical signs is challenging. A naïve logistic regression modeling approach has some limitations, for which reason we study two potential alternatives: the use of Bayesian networks, and that of logistic regression model.

METHODS

Data from patients that had undergone colorectal procedures between 2010 and 2017 were used. The dataset was split into two subsets: (i) that for training the models and (ii) that for testing them. The predictive ability of the models proposed was tested (i) by comparing the ROC curves from days 1 and 3 with all the subjects in the test set and (ii) by studying the evolution of the abovementioned predictive ability from day 1 to day 5.

RESULTS

In day 3, the predictive ability of the logistic regression model achieved an AUC of 0.812, 95% CI = (0.746, 0.877), whereas that of the Bayesian network was 0.768, 95% CI = (0.695, 0.840), with a p-value for their comparison of 0.097. The ability of the Bayesian network model to predict IAI does present significant difference in predictive ability from days 3 to 5: AUC(Day 3) = 0.761, 95% CI = (0.680, 0.841) and AUC(Day 5) = 0.837, 95% CI = (0.769, 0.904), with a p-value for their comparison of 0.006.

CONCLUSIONS

Whereas at postoperative day 3, a logistic regression model with imputed data should be used to predict IAI; at day 5, when the predictive ability is almost identical, the Bayesian network model should be used.

Heart rate variability in dairy cows with postpartum fever during night phase

Autonomic nervous function evaluated by heart rate variability (HRV) and blood characteristics were compared between Holstein Friesian cows that developed postpartum fever (PF; n = 5) and clinically healthy (CH; n = 6) puerperal cows in this case-control study. A cow was defined as having PF when its rectal temperature rose to ≥39.5°C between 1 and 3 days postpartum. We recorded electrocardiograms during this period using a Holter-type electrocardiograph and applied power spectral analysis of HRV. Comparisons between the groups were analyzed by t test or Mann-Whitney U test, and the relationship between rectal temperature and each parameter was analyzed using multiple regression analysis. Heart rate was higher in PF cows than in CH cows (Mean ± SE, 103.3 ± 2.7 vs. 91.5 ± 1.7 bpm). This result suggested that PF cows had a relatively dominant sympathetic nervous function. Total (44,472 ± 2,301 vs. 55,373 ± 1,997 ms) and low frequency power (24.5 ± 3.8 vs. 39.9 ± 5.3 ms) were lower in PF cows than in CH cows. These findings were possibly caused by a reduction in autonomic nervous function. The total white blood cell count (54.3 ± 5.1 vs. 84.5 ± 6.4 ×10²/μL) and the serum magnesium (2.1 ± 0.1 vs. 2.4 ± 0.1 mg/dL) and iron (81.5 ± 8.0 vs. 134.4 ± 9.1 μg/dL) concentrations were lower and the serum amyloid A concentration (277 ± 33 vs. 149 ± 21 μg/mL) was higher in PF cows than in CH cows. These results imply that more inflammation was present in PF cows than in CH cows. Multiple regression analysis showed that both of low frequency power and concentration of serum iron were associated with rectal temperature. We found differences in changes in hematologic results, biochemical findings, and HRV patterns between PF cows and CH cows.

Epidemiology of the Systemic Inflammatory Response Syndrome (SIRS) in the emergency department

Introduction: Consensus guidelines recommend sepsis screening for adults with systemic inflammatory response syndrome (SIRS), but the epidemiology of SIRS among adult emergency department (ED) patients is poorly understood. Recent emphasis on cost-effective, outcomes-based healthcare prompts the evaluation of the performance of large-scale efforts such as sepsis screening. We studied a nationally representative sample to clarify the epidemiology of SIRS in the ED and subsequent category of illness.

Methods: This was a retrospective analysis of ED visits by adults from 2007 to 2010 in the National Hospital Ambulatory Medical Care Survey (NHAMCS). We estimated the incidence of SIRS using initial ED vital signs and a Bayesian construct to estimate white blood cell count based on test ordering. We report estimates with Bayesian modified credible intervals (mCIs).

Results: We used 103,701 raw patient encounters in NHAMCS to estimate 372,844,465 ED visits over the 4-year period. The moderate estimate of SIRS in the ED was 17.8% (95% mCI: 9.7 to 26%). This yields a national moderate estimate of approximately 16.6 million adult ED visits with SIRS per year. Adults with and without SIRS had similar demographic characteristics, but those with SIRS were more likely to be categorized as emergent in triage (17.7% versus 9.9%, p<0.001), stay longer in the ED (210 minutes versus 153 minutes, p<0.0001), and were more likely to be admitted (31.5% versus 12.5%, p<0.0001). Infection accounted for only 26% of SIRS patients. Traumatic causes of SIRS comprised 10% of presentations; other traditional categories of SIRS were rare.

Conclusion: SIRS is very common in the ED. Infectious etiologies make up only a quarter of adult SIRS cases. SIRS may be more useful if modified by clinician judgment when used as a screening test in the rapid identification and assessment of patients with the potential for sepsis. [West J Emerg Med. 2014;15(3):329–336.]

Shock index and early recognition of sepsis in the emergency department: pilot study

INTRODUCTION

Screening for severe sepsis in adult emergency department (ED) patients may involve potential delays while waiting for laboratory testing, leading to postponed identification or over-utilization of resources. The systemic inflammatory response syndrome (SIRS) criteria are inaccurate at predicting clinical outcomes in sepsis. Shock index (SI), defined as heart rate / systolic blood pressure, has previously been shown to identify high risk septic patients. Our objective was to compare the ability of SI, individual vital signs, and the systemic inflammatory response syndrome (SIRS) criteria to predict the primary outcome of hyperlactatemia (serum lactate ≥ 4.0 mmol/L) as a surrogate for disease severity, and the secondary outcome of 28-day mortality.

METHODS

We performed a retrospective analysis of a cohort of adult ED patients at an academic community trauma center with 95,000 annual visits, from February 1st, 2007 to May 28th, 2008. Adult patients presenting to the ED with a suspected infection were screened for severe sepsis using a standardized institutional electronic order set, which included triage vital signs, basic laboratory tests and an initial serum lactate level. Test characteristics were calculated for two outcomes: hyperlactatemia (marker for morbidity) and 28-day mortality. We considered the following covariates in our analysis: heart rate >90 beats/min; mean arterial pressure < 65 mmHg; respiratory rate > 20 breaths/min; ≥ 2 SIRS with vital signs only; ≥2 SIRS including white blood cell count; SI ≥ 0.7; and SI ≥ 1.0. We report sensitivities, specificities, and positive and negative predictive values for the primary and secondary outcomes.

RESULTS

2524 patients (89.4%) had complete records and were included in the analysis. 290 (11.5%) patients presented with hyperlactatemia and 361 (14%) patients died within 28 days. Subjects with an abnormal SI of 0.7 or greater (15.8%) were three times more likely to present with hyperlactatemia than those with a normal SI (4.9%). The negative predictive value (NPV) of a SI ≥ 0.7 was 95%, identical to the NPV of SIRS.

CONCLUSION

In this cohort, SI ≥ 0.7 performed as well as SIRS in NPV and was the most sensitive screening test for hyperlactatemia and 28-day mortality. SI ≥ 1.0 was the most specific predictor of both outcomes. Future research should focus on multi-site validation, with implications for early identification of at-risk patients and resource utilization.

The practicality of including the systemic inflammatory response syndrome in the definition of polytrauma: experience of a level one trauma centre

BACKGROUND

The systemic inflammatory response syndrome (SIRS) has been advocated as a significant predictor of outcome in trauma. Recent trauma literature has proposed SIRS as a surrogate for physiological derangements characteristic of polytrauma with some authors recommending its inclusion into the definition of polytrauma. The practicality of daily SIRS collection outside of specifically designed prospective trials is unknown. The purpose of this study was to assess the availability of SIRS variables and its appropriateness for inclusion into a definition of polytrauma. We hypothesised SIRS variables would be readily available and easy to collect, thus represent an appropriate inclusion into the definition of polytrauma.

METHOD

A prospective observational study of all trauma team activation patients over 7-months (August 2009 to February 2010) at a University affiliated level-1 urban trauma centre. SIRS data (temperature>38°C or <36°C; Pulse >90 bpm; RR>20/min or a PaCO(2)<32 mmHg; WCC>12.0×10(9)L(-1), or <4.0×10(9)L(-1), or the presence of >10 immature bands) collected from presentation, at 24 h intervals until 72 h post injury. Inclusion criteria were all patients generating a trauma team activation response age >16.

RESULTS

336 patients met inclusion criteria. In 46% (155/336) serial SIRS scores could not be calculated due to missing data. Lowest rates of missing data observed on admission [3% (11/336)]. Stratified by ISS>15 (132/336), in 7% (9/132) serial SIRS scores could not be calculated due to missing data. In 123 patients ISS>15 with complete data, 81% (100/123) developed SIRS. For Abbreviated Injury Scale (AIS)>2 in at least 2 body regions (64/336) in 5% (3/64) serial SIRS scores could not be calculated, with 92% (56/61) of patients with complete data developing SIRS. For Direct ICU admissions [25% (85/336)] 5% (4/85) of patients could not have serial SIRS calculated [mean ISS 15(±11)] and 90% (73/81) developed SIRS at least once over 72 h.

CONCLUSION

Based on the experience of our level-1 trauma centre, the practicability of including SIRS into the definition of polytrauma as a surrogate for physiological derangement appears questionable even in prospective fashion.

Predictive ability of the ISS, NISS, and APACHE II score for SIRS and sepsis in polytrauma patients

PURPOSE

Systemic inflammatory response syndrome (SIRS) and sepsis as causes of multiple organ dysfunction syndrome (MODS) remain challenging to treat in polytrauma patients. In this study, the focus was set on widely used scoring systems to assess their diagnostic quality.

METHODS

A total of 512 patients (mean age: 39.2 ± 16.2, range: 16-88 years) who had an Injury Severity Score (ISS) ≥17 were included in this retrospective study. The patients were subdivided into four groups: no SIRS, slight SIRS, severe SIRS, and sepsis. The ISS, New Injury Severity Score (NISS), Acute Physiology and Chronic Health Evaluation II (APACHE II) scores, and prothrombin time were collected at admission. The Kruskal-Wallis test and χ(2)-test, multinomial regression analysis, and kernel density estimates were performed. Receiver operating characteristic (ROC) analysis is reported as the area under the curve (AUC). Data were considered as significant if p < 0.05.

RESULTS

All variables were significantly different in all groups (p < 0.001). The odds ratio increased with increasing SIRS severity for NISS (slight vs. no SIRS, 1.06, p = 0.07; severe vs. no SIRS, 1.07, p = 0.04; and sepsis vs. no SIRS, 1.11, p = 0.0028) and APACHE II score (slight vs. no SIRS, 0.97, p = 0.44; severe vs. no SIRS, 1.08, p = 0.02; and sepsis vs. no SIRS, 1.12, p = 0.0028). ROC analysis revealed that the NISS (slight vs. no SIRS, AUC 0.61; severe vs. no SIRS, AUC 0.67; and sepsis vs. no SIRS, AUC 0.77) and APACHE II score (slight vs. no SIRS, AUC 0.60; severe vs. no SIRS, AUC 0.74; and sepsis vs. no SIRS, AUC 0.82) had the best predictive ability for SIRS and sepsis.

CONCLUSION

Quick assessment with the NISS or APACHE II score could preselect possible candidates for sepsis following polytrauma and provide guidance in trauma surgeons' decision-making.

Effects of chronic ethanol consumption in experimental sepsis

AIMS

To evaluate the effects of chronic ethanol consumption on the development and the pathophysiology of sepsis, using an experimental model of polymicrobial peritonitis by feces i.p. injection.

METHODS

Forty-day-old male Wistar rats were divided into groups for two experiments: A and B. Experiment A was performed for determination of mortality rates, while experiment B was designed for biochemical analysis and measurement of cytokines before and after sepsis. In both the experiments, treated animals were exposed to a 10% ethanol solution as the single drinking source for 4 weeks, while untreated animals were exposed to tap water over the same period. Food was provided ad libitum. After this period, the animals underwent i.p. fecal injection for induction of sepsis.

RESULTS

Experiment A showed that higher doses of ethanol resulted in early mortality from sepsis that was correlated with the alcohol consumption (high dose = 85.7%, low dose = 14.3%, P = 0.027). In experiment B, cytokine analysis demonstrated important changes resulting from sepsis, which were further affected by ethanol exposure. In addition, glucose and creatinine levels decreased and increased, respectively, after sepsis, but a significant change occurred only in the ethanol group (P < 0.003 glucose, P < 0.01 creatinine). The levels of pro-inflammatory cytokines, interleukin-6 and tumor necrosis factor-α, increased after sepsis, but were less evident after ethanol exposure.

CONCLUSION

These differences may be the result of either early mortality or an increase in the severity of the septic process. Taking into account the high mortality rate and the extreme severity of sepsis after alcohol consumption, often encouraged by advertising, a caution should be given to patients with severe infections and a history of alcohol abuse.

Systemic inflammatory response syndrome score at admission predicts injury severity, organ damage and serum neutrophil elastase production in trauma patients

BACKGROUND

Systemic inflammatory response syndrome (SIRS) is a clinical condition representing the culmination of the activation of a complex network of acute endogenous mediators.

MATERIALS AND METHODS

We investigated both the relationship between the results of SIRS assessments in 212 trauma patients at the time of hospital arrival and measures of trauma severity determined using the Injury Severity Score (ISS) and the Revised Trauma Score (RTS). We then considered the possibility of whether this assessment could be used to predict the development of organ dysfunction as a complication in trauma patients after admission. The serum neutrophil elastase (SNE) level was also measured in 47 cases.

RESULTS

The cases with SIRS had a significantly higher ISS and a lower RTS. Organ dysfunction occurred in 22 cases, and a significant correlation was noted between the development of organ dysfunction and the presence of SIRS (86.4%; 19 cases/22 cases, p=0.0007) at the time of arrival. The SNE level was significantly higher among the patients who fulfilled the four SIRS criteria than among the other patients (p=0.0301).

CONCLUSION

We concluded that the greater the SIRS score at the time of hospital arrival, the greater the anatomical and physiological severity of the trauma patient's condition.

Src family kinases as mediators of endothelial permeability: effects on inflammation and metastasis

Src family kinases (SFKs) are signaling enzymes that have long been recognized to regulate critical cellular processes such as proliferation, survival, migration, and metastasis. Recently, considerable work has elucidated mechanisms by which SFKs regulate normal and pathologic processes in vascular biology, including endothelial cell proliferation and permeability. Further, when inappropriately activated, SFKs promote pathologic inflammatory processes and tumor metastasis, in part through their effects on the regulation of endothelial monolayer permeability. In this review, we discuss the roles of aberrantly activated SFKs in mediating endothelial permeability in the context of inflammatory states and tumor cell metastasis. We further summarize recent efforts to translate Src-specific inhibitors into therapy for systemic inflammatory conditions and numerous solid organ cancers.

Systemic Inflammatory Response Syndrome and Nosocomial Infection in Trauma

BACKGROUND

Admission systemic inflammatory response syndrome (SIRS) score has been previously reported to be an accurate predictor of infection and outcome in trauma. However, the data were limited to the first 7 days of admission. Our objective in this follow-up study was to prospectively evaluate the utility of daily SIRS scores in the second and third week of admission as compared with the first week in prediction of nosocomial infection and outcome in high-risk trauma patients.

METHODS

Prospective data were collected on 1,277 consecutive trauma patients admitted during a 28-month period to the intensive care unit. SIRS scores were calculated daily for the first week and every other day for the following 2 weeks. Patients were categorized into SIRS occurring "early" (week 1), "middle" (week 2), and "late" (week 3). Centers for Disease Control and Prevention guidelines were used for the diagnosis of infection. Multivariate linear and logistic regression analyses were utilized for statistical analyses, controlling for the covariates of age, Injury Severity Score, and admission Glasgow Coma Scale score.

RESULTS

The trauma cohort included patients with blunt injuries (84%) and penetrating injuries (16%). The mean age was 43 +/- 21 years with an overall mortality of 14.7%. Nosocomial infection developed in 580 (45.4%) of the study patients (respiratory site most common) with a total of 1,001 infections (some patients with multiple infections). SIRS (defined as SIRS score >/=2) was common, with 92.4% of patients manifesting SIRS at admission. SIRS was most prevalent during the first week postinjury (91% of patients manifesting SIRS), decreasing to 69% and 50% during postinjury weeks 2 and 3. SIRS was more common in patients who acquired nosocomial infections compared with noninfected patients. Logistic regression analysis confirmed that patients with "middle" SIRS during week 2 (odds ratio [OR] 17.62, confidence interval [CI] 12.95-23.97, p < 0.0001, receiver operating characteristic [ROC] 0.83) and "late" SIRS during week 3 (OR18.12, CI 12.71-25.84, p < 0.0001, ROC 0.81) had significantly greater risk for nosocomial infection compared with patients with "early" SIRS during week 1 (OR 4.55, CI 2.57-8.06, p < 0.0001, ROC 0.65) postinjury.

CONCLUSION

SIRS is predictive of nosocomial infection in trauma through postinjury day 21. Nosocomial infection should be considered as a treatable cause of SIRS in trauma patients, and early diagnostic interventions should be initiated to evaluate for potential causes.

Systemic inflammatory response syndrome (SIRS): molecular pathophysiology and gene therapy

In recent years, extensive basic science research has led to a clear understanding of the molecular mechanisms contributing to the pathophysiology of sepsis. Sepsis is now defined as a systemic inflammatory response syndrome (SIRS) in which there is an identifiable focus of infection. SIRS can be also precipitated by non-infective events such as trauma, pancreatitis, and surgery. As a consequence of an overactive SIRS response, the function of various organ systems may be compromised, resulting in multiple organ dysfunction syndrome (MODS) and death. Production and activation of multiple proinflammatory genes are likely to play a key role in the pathogenesis of MODS development. This review article focuses on the molecular mechanisms and components involved in the pathogenesis of severe sepsis. This includes cellular targets of sepsis-inducing bacterial products and their signaling pathways with a major emphasis on transcription factors and new therapeutic approaches to severe sepsis.

Effects of single dose of dexamethasone on patients with systemic inflammatory response

CONTEXT AND OBJECTIVE

Systemic inflammatory response syndrome (SIRS) is a very common condition among critically ill patients. SIRS, sepsis, septic shock and multiple organ dysfunction syndrome (MODS) can lead to death. Our aim was to investigate the efficacy of a single dose of dexamethasone for blocking the progression of systemic inflammatory response syndrome.

DESIGN AND SETTING

Prospective, randomized, double-blind, single-center study in a postoperative intensive care unit (Surgical Support Unit) at Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo.

METHODS

The study involved 29 patients with SIRS. All eligible patients were prospectively randomized to receive either a single dose of 0.2 mg/kg of dexamethasone or placebo, after SIRS was diagnosed. The patients were monitored over a seven-day period using Sequential Organ Failure Assessment score (SOFA).

RESULTS

The respiratory system showed an improvement on the first day after dexamethasone was administered, demonstrated by the improved PaO2/FiO2 ratio (p < 0.05). The cardiovascular system of patients requiring vasopressor therapy also improved over the first two days, with a better evolution in the dexamethasone group (p < 0.05). Non-surviving patients presented higher lactate assays than did survivors (p < 0.05) during this period.

CONCLUSIONS

Dexamethasone enhanced the effects of vasopressor drugs and evaluation of the respiratory system showed improvements (better PaO2/FiO2 ratio), one day after its administration. Despite these improvements, the single dose of dexamethasone did not block the evolution of SIRS.

Definitions of bloodstream infection in the newborn

OBJECTIVE

To develop definitions of bloodstream infections in the newborn that would enable clinicians to identify infection early, so patients can be enrolled in clinical trials. The definitions should be useful for surveillance and epidemiologic purposes.

METHOD

Search of EMBASE, MEDLINE, and Cochrane Library using age and English language limited key words sepsis, septicemia, and shock. Extensive study of textbook of neonatology and discussions with experts in the field.

RESULTS

The search identified >2,000 references. The most appropriate were selected and reviewed. Definitions of bloodstream infection were developed after consultation with an international faculty.

CONCLUSION

Current definitions of neonatal infection (and associated categories) used by neonatal clinicians and researchers have been either adapted/modified from definitions developed for adults or generated by individuals to suit their local needs or the needs of a particular study. It is clear that definitions generated for adults are not applicable to children or to newborn infants. In addition, developing and using unique definitions to suit individual or local needs make comparisons of outcome data and result of studies very difficult. This article proposes a set of definitions that are based as much as possible on current evidence. These definitions may be applicable widely for daily management of an infant with an infection and for research and epidemiologic studies.

Plasma concentration of procalcitonin and systemic inflammatory response syndrome after colorectal surgery

BACKGROUND

To study whether plasma concentrations of procalcitonin (PCT), interleukin-6 (IL-6), complement 3a (C3a), C-reactive protein and white blood cell count (WBC) correlate with the presence of systemic inflammatory response syndrome (SIRS) during the early post-operative period after major colorectal surgery.

METHODS

Prospective, observational study during the first 24 h post-operatively. The setting for the study was the operating theatre and the recovery unit at the university hospital. Fifty consecutive patients, operated on electively with major resection of the large bowel or rectum. PCT levels increased significantly to the maximum level 18 h postoperatively. PCT levels were significantly higher in the SIRS group in comparison to the non-SIRS group of patients 6 and 12 h after surgery (P < 0.05). The IL-6 levels were increased directly after the surgery and then decreased gradually in both study groups. Twenty-four hours after the surgery, C3a levels decreased and then returned to normal levels. Twenty-four hours post-operatively, patients with SIRS had a higher plasma concentration of C3a compared with patients without SIRS (P < 0.05). CRP and WBC increased during the study period in both groups (P < 0.05).

CONCLUSIONS

During the early post-operative period after uncomplicated major abdominal surgery, SIRS was reflected by the increase in plasma PCT and C3a concentrations. IL-6, CRP and WBC increased to the same extend in both the SIRS and the non-SIRS group of patients.

Systemic inflammatory response syndrome score at admission independently predicts infection in blunt trauma patients

BACKGROUND

Systemic inflammatory response syndrome (SIRS) score has been demonstrated to be an accurate predictor of outcome in critical surgical illness. To our knowledge, there is a paucity of data using SIRS score as a tool to predict posttraumatic infection. Our goal was to determine whether the severity of SIRS score at admission is an accurate predictor of infection in trauma patients.

METHODS

Prospective data were collected on 4,887 blunt trauma patients admitted to a primary adult resource center designated trauma center over an 18-month period. Patients were stratified by age and Injury Severity Score (ISS). SIRS score was calculated at admission. SIRS was defined as an SIRS score > or = 2. Each patient was screened for infection by an infectious disease specialist. Those at high risk for infection were then monitored daily throughout their hospitalization. Centers for Disease Control and Prevention guidelines were used to diagnose infection.

RESULTS

Of the 4,887 patients, 1,850 (38%) were admitted > 24 hours and evaluated for subsequent infection (mean ISS, 16 +/- 9; mean age, 43 +/- 19, SD). Thirty-one percent (577) of the patients acquired an infection. The mean hospital length of stay (20.2 days vs. 6.5 days) and mortality (7.8% vs. 2.7%) were significantly greater in the infected group (p < 0.001). Of the four SIRS variables (temperature, heart rate, white blood cell count, and respiratory rate), hypothermia and leukocytosis were the most significant predictors of infection (p < 0.001) when adjusted for age and ISS. SIRS scores of > or = 2 were increasingly predictive of infection when analyzed by multiple logistic regression analysis.

CONCLUSION

An admission SIRS score of > or = 2 is a significant independent predictor of infection and outcome in blunt trauma. Daily SIRS scores may be a meaningful method of assessing postinjury risk of infection, and may initiate earlier diagnostic intervention for determination of infection.

Selenium, systemic immune response syndrome, sepsis, and outcome in critically ill patients

OBJECTIVES

To confirm early, marked decrease in plasma selenium concentrations in patients admitted to a surgical and medical intensive care unit (ICU), and to study this decrease according to the presence or absence of systemic inflammatory response syndrome (SIRS), sepsis, or direct ischemia-reperfusion.

DESIGN

Prospective, observational study.

SETTINGS

Collaboration between the adult ICU of a 1,100-bed general hospital and a biochemical research laboratory of a university medical center.

PATIENTS

One hundred thirty-four consecutive surgical and medical ICU patients.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

In the first 31 patients, plasma and urine selenium concentrations were measured by electrothermal atomic absorption spectrometry on admission and once weekly during their ICU stay. These values were compared first with severity scores, criteria for SIRS, sepsis, and organ system failure taken on admission, and then with nosocomial infection, organ system failure during ICU stay, and hospital mortality. An early, low mean plasma selenium concentration was observed in these patients compared with selenium laboratory reference values. Plasma selenium, measured on ICU admission, inversely correlated with Acute Physiology and Chronic Health Evaluation II or Simplified Acute Physiology II scores. Patients with SIRS had lower selenium concentrations than those without SIRS. Mean urine selenium losses were normal in the first 31 patients. Plasma selenium concentration was low in all patients with severe sepsis and septic shock (range 0.20 to 0.72 micromol/L) and in those patients with ischemia-reperfusion from aortic cross-clamping (range 0.34 to 0.68 micromol/L). Despite recommended specific selenium supplementation, plasma selenium concentrations remained low for >2 wks in patients with SIRS. However, there was a slight increase in plasma selenium concentrations in surviving SIRS patients, whereas plasma selenium concentrations decreased in nonsurviving patients. The frequency of ventilator-associated pneumonia, organ system failure, and mortality was three times higher in patients with low plasma selenium concentration at the time of admission (selenium < or =0.70 micromol/L) than for the other patients.

CONCLUSIONS

In severely ill ICU patients with SIRS, we observed an early 40% decrease in plasma selenium concentrations, reaching values observed in deleterious nutritional selenium deficiency. This prolonged decrease in selenium concentrations could explain the three-fold increase in morbidity and mortality rates in these patients compared with other ICU patients. The efficacy of selenium treatment in SIRS patients with a high gravity index score or hypoperfusion needs further investigation.

Participation of tissue factor and thrombin in posttraumatic systemic inflammatory syndrome

OBJECTIVE

To determine the roles of tissue factor and thrombin on the systemic inflammatory response syndrome (SIRS) in posttrauma patients, as well as to investigate the relationship between SIRS and sepsis.

DESIGN

Prospective, cohort study.

SETTING

General intensive care unit of a tertiary care emergency department.

PATIENTS

Forty trauma patients were classified into subgroups, according to the duration of SIRS: non-SIRS patients (n = 9); patients with SIRS for < 2 days (n = 15); and patients with SIRS for > 3 days (n = 16).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Tissue factor antigen concentration, prothrombin fragment F1+2, thrombin antithrombin complex, fibrinopeptide A, and cross-linked fibrin degradation products (D-dimer) were measured on the day of admission, and on days 1 through 4 after admission. Simultaneously, the number of SIRS criteria that the patients met and the disseminated intravascular coagulation score were determined. The results of these measurements, frequency of acute respiratory distress syndrome (ARDS), multiple organ dysfunction syndrome, sepsis, and outcome were compared among the groups. The values of all five hemostatic molecular markers in the patients with SIRS for > 3 days were significantly more increased than those molecular marker values measured in the other groups on the day of admission. These values continued to be markedly high up to day 4 of admission. The occurrence rates of disseminated intravascular coagulation in these patient groups were significantly higher than those rates in the other two groups (p = .0001), and the disseminated intravascular coagulation scores did not improve during the study period. The occurrence rates of ARDS (p < .05) and multiple organ dysfunction syndrome (p < .01) were higher in patients with SIRS for > 3 days compared with those rates in the other groups, and the patients with SIRS for > 3 days had a poor outcome. No significant difference was noted in the frequency of sepsis among the groups.

CONCLUSIONS

Sustained SIRS is the main determinant for ARDS, multiple organ dysfunction syndrome, and outcome in posttrauma patients. Disseminated intravascular coagulation associated with massive thrombin generation and its activation is involved in the pathogenesis of sustained SIRS. Sepsis has a small role in early posttrauma multiple organ dysfunction syndrome.

Plasma cytokines and endotoxin levels in patients with severe injury and their relationship with organ damage

In 17 patients plasma TNF-alpha and IL-8 were assayed with enzyme-linked immunosorbent assay. IL-6 activity in plasma was determined by bioassay with IL-6-dependent cell line 7TD1. The limulus amoebocyte lysate chromogenic test was used for plasma endotoxin assay. Plasma cytokine levels in injured patients were significantly increased. Plasma TNF-alpha was shown to be increased earlier, while an increase in plasma IL-6 and IL-8 levels occurred late, all of which were shown to be significantly positively correlated with ISS, cardiac and hepatic enzyme activities, and index of renal function. In addition, obvious endotoxaemia occurred at an early stage of injuries, which was respectively significantly correlated with ISS and plasma TNF-alpha, IL-6 and IL-8 levels. Severe injuries could induce increased successive release of TNF-alpha, IL-6 and IL-8, and obvious endotoxaemia. The post injury release of cytokines might be related to endotoxaemia, and may play an important role in the development of organ damage after injury.