Definitions for sepsis and organ failure and guidelines for the use of innovative therapies in sepsis. The ACCP/SCCM Consensus Conference Committee. American College of Chest Physicians/Society of Critical Care Medicine

Impaired neutrophil adherence as an early marker of systemic inflammatory response syndrome and severe sepsis

STUDY OBJECTIVE

To determine whether neutrophil adherence was altered in the presence of systemic inflammatory response syndrome (SIRS) and infection or severe sepsis.

METHODS

We conducted a prospective study of a convenience sample of adults presenting to an academic urban ED to be admitted with SIRS and infection or with severe sepsis. Serial phlebotomy was performed in the ED and 12 and 24 hours into the hospital stay. We used an adherence assay that involves adding 1-mL aliquots of heparinized blood to pipettes packed with nylon. Cell count and differential on the eluates and a control tube were carried out to determine the percentage of adhering neutrophils. We reviewed charts for parameters of clinical progression.

RESULTS

Adherence values among patients with SIRS and severe sepsis were 27% +/- 17% (n = 19) and 13% +/- 16% (n = 4), respectively, significantly less than mean adherence in normal controls (47% +/- 10%; P = .0006 and .0007, ANOVA). Adherence among patients with severe sepsis and those who clinically progressed were not significantly different from that in all SIRS cases. Serial values did not differ from initial values.

CONCLUSION

Neutrophil adherence was significantly decreased in patients with SIRS and severe sepsis compared with that in normal controls. A larger study enrolling consecutive SIRS subject at risk for severe sepsis may demonstrate whether this assay could be useful in managing sepsis in the ED.

The level of lipopolysaccharide-binding protein is significantly increased in plasma in patients with the systemic inflammatory response syndrome

Currently, there is no way to predict with a high degree of sensitivity and specificity which patients are likely to develop systemic inflammatory response syndrome (SIRS) following systemic infection, trauma, organ rejection, or blood loss. The level of human lipopolysaccharide-binding protein (LBP) was determined in the plasma of 22 patients with a clinical diagnosis of early SIRS. Twenty-nine plasma samples from healthy volunteers were used as controls. The mean level of LBP in the plasma of healthy volunteers was 7.7 micrograms/ml (standard deviation, 6.2 micrograms/ml). Twenty-one of 22 patients (95%) with SIRS had an LBP level on admission at least 2 standard deviations above the mean LBP level for a healthy volunteer control group (range, 4.9 to 114.2 micrograms/ml; mean, 36.6 micrograms/ml; standard deviation, 22.2 micrograms/ml; P < 0.0001). The level of LBP in the plasma of the majority of patients with early SIRS is significantly increased compared to that in healthy controls. The sensitivity, specificity, and predictive value of elevated plasma LBP levels in patients with SIRS remain to be determined.

Comparison of early IgM-enriched immunoglobulin vs polyvalent IgG administration in score-identified postcardiac surgical patients at high risk for sepsis

STUDY OBJECTIVE

To address the relevance of the IgM component in polyvalent immunoglobulins in sepsis treatment by comparison of the clinical course under polyvalent IgG vs IgGMA therapy in postcardiac surgical patients at high risk for sepsis and to reassess the prognostic validity of sequential changes in acute physiology and chronic health evaluation (APACHE II) scores during treatment.

DESIGN

Prospective, randomized clinical trial.

SETTING

Cardiac surgical ICU in a university hospital.

PATIENTS

Among 870 consecutive patients after elective open-heart surgery, 29 (3.3%) met the previously validated high-risk criterion (APACHE II score > or = 24 on the first postoperative day) with a mean APACHE II score-predicted mortality risk of 63%.

INTERVENTIONS

In addition to standard therapy, 27 of these patients were randomized to receive commercially available IV IgG (Polyglobin N, n = 14, total dosage: 18 mL/kg) or IgGMA (Pentaglobin, n = 13, total dosage: 15 mL/kg).

MEASUREMENTS AND RESULTS

The two groups were comparable in baseline disease severity and concurrent therapy. The extent of score-quantified improvement in disease severity during treatment was similar in both groups (mean fall in APACHE II scores within 4 days; IgG, -6.9; IgGMA, -5.2), as were score-defined improvement rates (rate of patients with score decrease > or = 7 within 4 days: IgG, 57%; IgGMA, 54%) and in-hospital mortality (IgG, 29%; IgGMA, 31%) (all p = NS). There was a strong association between the decrease over time in APACHE II scores during therapy and prognosis (mortality rates in patients with vs without score-assessed improvement: 0% vs 67%, p = 0.0002).

CONCLUSIONS

IgG and IgGMA were associated with a comparable improvement in disease severity in score-identified postcardiac surgical patients at high risk for sepsis. Given the design as an efficacy rather than an equivalence study, this hypothesis derived from our results needs independent validation in larger trials. Sequential APACHE II score changes were reconfirmed as a prognostically valid quantitative measure of disease progress during sepsis therapy.

Septic shock

PURPOSE

Many patients with sepsis require surgery for their management, often on an urgent or emergency basis. Anaesthetists are commonly required to manage patients with sepsis and septic shock in the operating room, past anaesthesia recovery area, and the intensive care unit. Since little has been written in the Anaesthesia literature on sepsis and septic shock, a review of this topic was considered appropriate.

SOURCE

References were obtained from computerized searches on the National Library of Medicine (English language), recent review articles and personal files. PRINCIPLES FINDINGS: Septic shock is a common cause of morbidity and mortality. Its presentation may be subtle or catastrophic. Successful management depends on an understanding of the pathophysiology of the syndrome, allowing rapid, appropriate resuscitation. This often requires aggressive correction of volume deficit, maintenance of adequate perfusion pressure with inotropic and vasopressor therapy, mechanical ventilation and correction of coagulopathy. Appropriate cultures must be taken and antibiotic therapy started, often empirically. Anaesthetic management should include careful haemodynamic monitoring. Anaesthesia induction and maintenance must be tailored to the haemodynamically unstable patient.

CONCLUSIONS

The management of the septic patient in the perioperative period presents a challenge for the anaesthetist. Haemodynamic and respiratory instability should be anticipated. Management requires multisystem intervention and careful anesthetic management.

Erythropoietin in patients with acute renal failure and continuous veno-venous haemofiltration

Erythropoietin (Epo) is a glycoprotein hormone produced in the kidney in response to hypoxia or anaemia. In acute renal failure (ARF) anaemia also occurs and current opinion is that Epo production is depressed with inappropriately low plasma levels throughout the uraemic phase. Our study was designed to determine the excretion of Epo in patients with ARF. Fifty-nine ventilated patients were studied, 39 with ARF and continuous veno-venous haemofiltration therapy (group 1) and 13 patients with normal renal function who served as a control group (group 2). All patients with ARF were anaemic and needed a mean transfusion of 0.6 units/day. Values for vitamin B12, folic acid, serum iron and ferritin were normal. While patients with normal renal function had Epo values within the normal range, patients with ARF had significantly higher values at the onset of haemofiltration therapy. Mean Epo (mean +/- SEM) values on days 0-2 were 92.6 +/- 11.7 mU/ml in group 1 and 16.5 +/- 6.4 mU/ml in group 2 (p < 0.0002). Epo levels declined in group 1 to 49 +/- 10.5 mU/ml on days 9 and 10 compared to 23 +/- 9.1 mU/ml in group 2 (ns). These values were maintained until the end of the observation period. No differences were seen between oliguric and non-oliguric patients. Our data show that patients with ARF have increased Epo levels at the beginning of the disease with a strong tendency to decrease, suggesting that there might be inadequate Epo levels during the course of acute renal failure.

Effect of hemofiltration on hemodynamics and systemic concentrations of anaphylatoxins and cytokines in human sepsis

OBJECTIVE

To determine whether hemofiltration (HF) can eliminate cytokines and complement components and alter systemic hemodynamics in patients with severe sepsis.

DESIGN

Prospective observation study.

SETTING

Surgical intensive care unit of a university hospital.

PATIENTS

16 patients with severe sepsis.

INTERVENTIONS

Continuous zero-balanced HF without dialysis (ultrafiltrate rate 2 l/h) was performed in addition to pulmonary artery catheterization, arterial cannulation, and standard intensive care treatment.

MEASUREMENTS AND MAIN RESULTS

Plasma and ultrafiltrate concentrations of cytokines (the interleukins IL-1 beta, IL-6, IL-8, and tumor necrosis factor alpha) and of complement components (C3adesArg, C5adesArg) were measured after starting HF (t0) and 4 h (t4) and 12 h later (t12). Hemodynamic variables including mean arterial pressure (MAP), mean central venous pressure, mean pulmonary artery pressure, pulmonary capillary wedge pressure, and cardiac output were serially determined. During HF, cytokine plasma concentrations remained constant. However, C3adesArg and C5adesArg plasma concentrations showed a significant decline during 12-h HF (C3adesArg: t0 = 676.9 +/- 99.7 ng/ml vs t12 = 467.8 +/- 71, p < 0.01; C5adesArg: 26.6 +/- 4.7 ng/ml vs 17.6 +/- 6.2, p < 0.01). HF resulted in a significant increase over time in systemic vascular resistance (SVR) and MAP (SVR at t0: 669 +/- 85 dyne.s/cm5 vs SVR at t12: 864 +/- 75, p < 0.01; MAP at t0: 69.9 +/- 3.5 mmHg vs MAP at t12: 82.2 +/- 3.7, p < 0.01).

CONCLUSIONS

HF effectively eliminated the anaphylatoxins C3adesArg and C5adesArg during sepsis. There was also a significant rise in SVR and MAP during high volume HF. Therefore, HF may represent a new modality for removal of anaphylatoxins and may, thereby, deserve clinical testing in patients with severe sepsis.

Nitric oxide (NO) production correlates with renal insufficiency and multiple organ dysfunction syndrome in severe sepsis

OBJECTIVE

To investigate whether the production of nitric oxide (NO) relates to the development of renal insufficiency and multiple organ dysfunction syndrome (MODS) in patients with severe sepsis.

DESIGN

Prospective study in 23 patients with severe sepsis.

SETTING

Medical and surgical intensive care units (ICU) of three hospitals.

MEASUREMENTS AND RESULTS

Serum nitrate levels, as an indirect parameter of the production of NO in vivo, and scores for renal insufficiency and MODS were determined in patients with severe sepsis during a 1-week period after admission to the ICU. The highest serum nitrate levels were found at 4 h (mean 52 +/- 16 mumol/l) after entry into the study and the levels gradually declined thereafter. Patients with renal insufficiency had considerably higher serum nitrate levels during the study period that patients who did not develop renal sufficiency (MANOVA, p < 0.05). Serum nitrate levels correlated with scores for renal insufficiency (r = 0.60, p < 0.001), and far exceeded the levels that can be explained solely by reduced renal clearance of nitrate. Further analysis showed that serum nitrate levels significantly and positively correlated with scores for MODS (r = 0.44, p < 0.001).

CONCLUSION

Our results indicate that the production of NO correlates with renal insufficiency and MODS in patients with severe sepsis and that this reactive nitrogen intermediate could be involved in the pathogenesis of organ failure in these critically ill patients.

Serum MIP-1 alpha and IL-8 in septic patients

We studied blood MIP-1 alpha and IL-8 in 38 septic patients and 5 healthy volunteers. Both chemokines were undetectable in the healthy volunteers. In sepsis, serum MIP-1 alpha was detected in 45% of the patients and Il-8 in 84%. The levels of MIP-1 alpha, but not of IL-8, correlated with CRP, IL-6 and TNF alpha levels. Complications, including various organ failures and mortality, showed no correlation with serum MIP-1 alpha levels. In contrast, we found increased levels of serum IL-8 in septic patients with disseminated intravascular coagulation, central nervous system (CNS) dysfunction or renal failure, and the mortality rate was higher in the IL-8 detectable group than in the IL-8 undetectable group (50% vs 0%, p < 0.05). In conclusion, the production of both MIP-1 alpha and IL-8 was increased and initially detectable levels of circulating IL-8 predicted high mortality in sepsis.

OBJECTIVE

To determine the significance of the C-C chemokine MIP-1 alpha and the C-X-C chemokine IL-8 in sepsis.

DESIGN

Prospective study.

SETTING

Clinical investigation, emergency department and general intensive care unit of university hospital.

PATIENTS AND PARTICIPANTS

38 septic patients and 5 healthy volunteers were studied. Sepsis was diagnosed following the criteria formulated by ACCP/SCCM.

INTERVENTIONS

10-20 ml of blood was drawn from each patient at the time of initial diagnosis of sepsis.

MEASUREMENTS AND RESULTS

MIP-1 alpha and IL-8 were determined by sandwich ELISA. Both chemokines were undetectable in the healthy volunteers. In sepsis, serum MIP-1 alpha was detected in 45% of the patients and IL-8 was detected in 84%. The levels of MIP-1 alpha, but not of IL-8, correlated with CRP, IL-6 and TNF alpha levels. Complications, including various organ failures and mortality, showed no correlation with serum MIP-1 alpha levels. In contrast, we found increased levels of serum IL-8 in patients with disseminated intravascular coagulation (DIC) (p < 0.05), central nervous system (CNS) dysfunction (p < 0.05), renal failure (p < 0.01) and the mortality rates were higher in the IL-8 detectable group than in the IL-8 undetectable group (50% vs 0%, p < 0.05).

CONCLUSIONS

The production of MIP-1 alpha and IL-8 was increased in sepsis. Furthermore, an initially detectable level of circulating IL-8, but not MIP-1 alpha, predicted a high mortality in sepsis diagnosed according to the ACCP/SCCM criteria.

Plasma proinflammatory cytokine concentrations, Acute Physiology and Chronic Health Evaluation (APACHE) III scores and survival in patients in an intensive care unit

OBJECTIVE

To more clearly define the relationships between plasma proinflammatory cytokine concentrations, physiologic disturbance, and survival in severely ill patients.

DESIGN

Prospective, longitudinal, cohort analytic study.

SETTING

Teaching hospital intensive care unit (ICU).

PATIENTS

Two hundred fifty-one consecutive nonselected patients admitted to the ICU.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Daily Acute Physiology and Chronic Health Evaluation (APACHE) III scores were calculated from clinical and laboratory data. In concurrent blood samples, plasma concentrations were measured of four proinflammatory cytokines (tumor necrosis factor-[TNF] alpha, interleukin [IL]-1 beta, IL-6, and IL-8), all of which are believed to be of central importance in host proinflammatory and immune responses. Plasma TNF concentrations were increased in 42 patients, plasma IL-1 beta in 15 patients, IL-6 in 194 patients, and IL-8 in 52 patients at presentation. Although admission plasma IL-1 beta, IL-6, and IL-8 concentrations were higher in patients who died in the ICU compared with survivors (n = 33; p < .02, p < .01, p < .02, respectively), only admission plasma IL-8 concentrations were higher in patients with a fatal outcome if all in-hospital deaths were considered (n = 53; p = .05). APACHE III score was the best predictor of mortality (odds ratio 11.41; p = .003). Detection, but not the absolute level, of TNF bioactivity in plasma was a weak independent predictor of death (odds ratio 3.17; p = .02). There was no relationship between bacteremia or presence of the systemic inflammatory response syndrome and plasma cytokine concentrations. Nineteen patients were in the ICU for > or = 10 days, and of these 19 patients, 16 patients had prolonged increases of plasma cytokines. Two patients with persistently increased plasma TNF concentrations died. Otherwise, persistently increased plasma cytokine concentrations had a variable relation to daily APACHE scores and to mortality.

CONCLUSIONS

Plasma cytokine concentrations fluctuate in serious illness and have a poor correlation with derangement of whole body physiology in seriously ill patients. Only the presence of bioactive TNF in plasma was an independent predictor of mortality. Daily measurement of plasma proinflammatory cytokine concentrations is unlikely to have clinical application in the ICU setting, except possibly in specific subgroups of patients.

The Relationship of the ACCP/SCCM Consensus Conference Classification of Sepsis to Mortality and Multiorgan Dysfunction among Medical ICU Patients

To determine the relation between the proposed ACCP/SCCM Consensus Conference classification of sepsis and hospital outcomes, we conducted a single-center, prospective observational study at Barnes Hospital, St. Louis, MO, an academic tertiary care hospital. A total of 324 consecutive patients admitted to the medical intensive care unit (ICU) were studied for prospective patient surveillance and data collection. The main outcome measures were the number of acquired organ system derangements and hospital mortality. Fifty-seven (17.6%) patients died during the study period. The proposed classifications of sepsis (e.g., systemic inflammatory response syndrome [SIRS], sepsis, severe sepsis, septic shock) correlated with hospital mortality ( r = 0.330; p < 0.001) and development of an Organ System Failure Index (OSFI) of 3 or greater ( r = 0.426; p < 0.001). Independent determinants of hospital mortality for this patient cohort ( p < 0.05) were development of an OSFI of 3 or greater (adjusted odds ratio [AOR], 13.9; 95% confidence interval [CI], 6.4–30.2; p < 0.001); presence of severe sepsis or septic shock (AOR, 2.6; 95% CI, 1.2–5.6; p = 0.002), and an APACHE II score ≥ of 18 or greater (AOR, 2.4; 95% CI, 1.0–5.8; p = 0.045). Intra-abdominal infection (AOR, 19.1; 95% CI, 1.6–230.1; p = 0.011), an APACHE II score ≥ of 18 or greater (AOR, 8.9; 95% CI, 4.2–18.6; p < 0.001), and presence of severe sepsis or septic shock (AOR, 2.9; 95% CI, 1.5–5.4; p = 0.001) were independently associated with development of an OSFI of 3 or greater. These data confirm that acquired multiorgan dysfunction is the most important predictor of mortality among medical ICU patients. In addition, they identify the proposed ACCP/SCCM Consensus Conference classification of sepsis as an additional independent determinant of both hospital mortality and multiorgan dysfunction.

High tumor necrosis factor serum level is associated with increased survival in patients with abdominal septic shock: a prospective study in 59 patients

BACKGROUND

In several studies including patients with septic shock of various origins, high serum cytokine levels have been reported to correlate with poor outcome. The aim of this prospective study was to assess the prognostic value of cytokine serum levels in a group of patients with perioperative septic shock of digestive origin.

METHODS

From January 1992 to December 1994, 59 patients were evaluated (mean age, 68 +/- 15 years). From the first day of septic shock to day 7, blood was drawn every day to measure the conventional biologic parameters (white blood cell count, platelet count, hematocrit, blood urea nitrogen level, serum electrolytes level, pH, blood gases, serum lactate level, coagulation parameters, liver function tests) and tumor necrosis factor (TNF), interleukin-1, and interleukin-6.

RESULTS

No difference was observed between the 26 survivors and the 33 nonsurvivors with regard to age, gender, and cause of sepsis. On admission, mean platelet count was significantly higher in the survivors than in the nonsurvivors (260 +/- 142 versus 177 +/- 122 10(9)/L; p = 0.01). Mean blood urea nitrogen level was significantly lower in the survivors than in the nonsurvivors (9.6 +/- 9 versus 12 +/- 7 mmol/L; p = 0.04). No difference was observed between survivors and nonsurvivors for the other conventional biologic parameters and for serum interleukin-1 and interleukin-6 levels. Mean serum TNF level tended to be higher in survivors than in nonsurvivors (565 +/- 1325 versus 94 +/- 69 pg/ml; not significant). In the group survivor 9 (35%) of 26 patients had a serum TNF level greater than 200 pg/ml versus 2 (6%) of 33 patients in the nonsurvivor group (p < 0.02). Survival was noted in 6 (100%) of 6 patients who had both a serum TNF level greater than 200 pg/ml and a platelet count greater than 100.10(9)/L versus 1 (11%) of 9 in patients with neither of these criteria (p < 0.01).

CONCLUSIONS

In our patients with abdominal septic shock, high serum TNF levels were associated with increased survival. The high serum level of TNF may reflect the efficacy of peritoneal inflammatory response against abdominal sepsis. Although this possibility must be further explored, a score combining the serum TNF level and platelet count could be helpful for the prognostic assessment of patients with abdominal septic shock.

Focal neurologic deficits in infective endocarditis and other septic diseases

INTRODUCTION

Focal neurologic deficits in sepsis frequently result from parenchymal lesions due to cerebral embolism. The aim of this study was to characterize clinical, laboratory and radiologic patterns of those patients.

PATIENTS AND METHODS

Medical records of 30 patients with focal neurologic symptoms during sepsis were analyzed retrospectively.

RESULTS

24 patients (22 with infective endocarditis) had ischemic stroke. Cerebrospinal fluid (CSF) analyses revealed inflammation in 11 of 12 patients. Patients who died (11/24) suffered more frequently from secondary intracerebral hemorrhage (p = 0.0031), which was significantly associated with intravenous high-dose anticoagulation (p = 0.0059). Six patients had slowly progressive focal neurologic deficits without evidence for stroke. All showed CSF inflammation and three developed multiple cerebral abscesses.

CONCLUSIONS

There are two distinctive groups of patients with focal neurologic deficits during sepsis. One presents with stroke and CNS inflammation (septic embolic focal encephalitis). The other group develops slowly progressive focal neurologic deficits and sometimes multiple cerebral abscesses (septic metastatic focal encephalitis).

Rationale, design and performance of a clinical trial to investigate interferon-gamma (Imukin) in the prophylactic treatment of severe burns-related infections

Recent advances in resuscitation therapy have increased the survival rate of patients with severe burns in the burn shock phase. Infectious complications represent the major cause of death in patients with extensive burns, however, in spite of the application of early and aggressive interventions. Extensive burn injury causes profound alterations in various essential elements of the normal host immune response and the main aim of treatment after resuscitation is to maintain or even improve host resistance. The positive anti-infective effects of interferon (IFN)-gamma observed in animal models and in clinical studies, for example in chronic granulomatous disease, provided the rationale for a study to investigate its use in patients with severe burns. A study was therefore designed to determine the efficacy and tolerance of IFN-gamma in preventing death related to infection in patients with severe burn injury who are at risk of infection. In order to avoid unnecessary risk for patients and reduce the cost, a sequential design was chosen. The primary end-point was reviewed in a group sequential manner after every 60 patients through an independent monitoring board. The study was a randomised, double-blind, Phase III multi-centre trial, conducted at 23 European Burn Centres. An interval censored survival time approach was taken, using information collected at days 8, 15, 30, 60, and 90. The trial is still blinded, but the rationale for conducting the study and its design are discussed.

Induction of diaphragmatic nitric oxide synthase after endotoxin administration in rats: role on diaphragmatic contractile dysfunction

Nitric oxide (NO), a free radical that is negatively inotropic in the heart and skeletal muscle, is produced in large amounts during sepsis by an NO synthase inducible (iNOS) by LPS and/or cytokines. The aim of this study was to examine iNOS induction in the rat diaphragm after Escherichia Coli LPS inoculation (1.6 mg/kg i.p.), and its involvement in diaphragmatic contractile dysfunction. Inducible NOS protein and activity could be detected in the diaphragm as early as 6 h after LPS inoculation. 6 and 12 h after LPS, iNOS was expressed in inflammatory cells infiltrating the perivascular spaces of the diaphragm, whereas 12 and 24 h after LPS it was expressed in skeletal muscle fibers. Inducible NOS was also expressed in the left ventricular myocardium, whereas no expression was observed in the abdominal, intercostal, and peripheral skeletal muscles. Diaphragmatic force was significantly decreased 12 and 24 h after LPS. This decrease was prevented by inhibition of iNOS induction by dexamethasone or by inhibition of iNOS activity by N(G)-methyl-L-arginine. We conclude that iNOS was induced in the diaphragm after E. Coli LPS inoculation in rats, being involved in the decreased muscular force.

Polyneuropathies in critically ill patients: a prospective evaluation

OBJECTIVE

To determine the incidence, severity and course of polyneuropathies in patients with sepsis or systemic inflammatory response syndrome combined with multiple organ failure.

DESIGN

Prospective study.

SETTING

Division of Intensive Care Medicine of the Department of Anesthesiology and Intensive Care and Intensive Care Unit of the Department of Neurology, University Hospital Innsbruck, Austria.

PATIENTS

Twenty-two patients between 23 and 77 years old with sepsis or systemic inflammatory response syndrome combined with multiple organ failure fulfilling strict inclusion and exclusion criteria.

INTERVENTIONS

Clinical neurologic examination and electro myography/nerve conduction velocity measurements during the stay on the Intensive Care Unit and 2-3 months later.

MEASUREMENTS AND RESULTS

In 9 of the 22 patients signs of polyneuropathy were found at the initial clinical investigation and in 7 patients at the follow-up investigation. Electrophysiologic investigation revealed signs of polyneuropathy in 18 patients initially and in 11 patients 2-3 months later.

CONCLUSION

In our patient population the frequency of the development of polyneuropathy was high (81.8%). Electrophysiologic investigation is superior to clinical neurologic examination in the detection of polyneuropathies.

Critical illness polyneuropathy in multiple organ dysfunction syndrome and weaning from the ventilator

BACKGROUND

Acute axonal polyneuropathy has been found in patients with multiple organ dysfunction syndrome. This 'critical illness polyneuropathy' (CIP) has been associated with difficult weaning from the ventilator in retrospective studies.

OBJECTIVE

To test the hypothesis that CIP is related to the degree and number of organ dysfunctions, and to weaning problems.

DESIGN

Prospective study of 18 months.

SETTING

A multidisciplinary intensive care unit in a general hospital

SUBJECTS

Thirty-eight patients under 75 years of age who had been mechanically ventilated for more than 7 days, without previous signs of or risk factors for polyneuropathy.

MEASURES

Organ dysfunctions were quantified using a dynamic scoring system (0-12 points). Electromyography studies were performed during mechanical ventilation to identify patients with and without CIP.

RESULTS

CIP was present in 18 out of 38 patients and associated with an increased organ dysfunction score (5.3 +/- 1.8 vs. 3.6 +/- 1.5; p = 0.003) and number of organs involved [median (range): 4 (3-5) vs. 2 (1-4); p = 0.009], in particular cardiovascular (p = 0.003), renal (p = 0.04), and hematopoietic failure (p = 0.04). Patients with polyneuropathy were ventilated longer, but this was not clearly due to more difficult weaning [median: 16.5 (1-48) vs. 9.5 (1-38) days; p = 0.26]. Polyneuropathy was present in 2 of 4 patients with normal weaning.

CONCLUSIONS

Axonal polyneuropathy is related to the severity of multiple-organ-dysfunction syndrome. Its presence does not necessarily implicate difficult weaning from artificial ventilation.

Clostridium difficile infection as a cause of severe sepsis

Although colitis is often seen in critically all patients who have received multiple broad-spectrum antibiotics, there are no reports describing severe sepsis as a result of Clostridium difficile infection. We describe three cases of severe sepsis with local intestinal Clostridium difficile infection as the only identifiable etiology. The mechanism of severe sepsis may be a derangement of the gastrointestinal barrier function. This could result in absorption of microbes or endotoxin or activation of inflammatory cascades in the submucosa of the intestine or liver.

Assessing risk in liver transplantation. Special reference to the significance of a positive cytotoxic crossmatch

OBJECTIVE

The authors determined the impact of a positive cytotoxic crossmatch on the outcome of liver transplantation.

SUMMARY BACKGROUND DATA

Liver allografts rarely undergo hyperacute rejection, but transplants performed across a positive cytotoxic crossmatch tend to follow a different clinical course, with higher intraoperative blood use, postoperative graft dysfunction, and, in some cases, graft loss. How this affects overall graft survival has not been determined.

METHODS

The authors provide a retrospective analysis of 1520 liver transplants performed between November 1989 and December 1993, with a minimum follow-up of 1 year. All cases had a cytotoxic crossmatch using serum pretreated with dithiothreitol.

RESULTS

There were 1390 negative crossmatch and 130 positive crossmatch cases. There was no difference in overall graft survival, although early survival rates were lower in the positive crossmatch group, with the maximum difference at 6 months: 0.76 (95% confidence interval, 0.74-0.78) for a negative crossmatch versus 0.68 (95% confidence interval, 0.61-0.77) for a positive crossmatch. These differences become negligible by the 2-year mark. Using stepwise logistic regression, the authors identified seven variables independently associated with outcome: 1) donor age, 2) donor gender, 3) prior liver transplant, 4) medical urgency status, 5) ischemia time, 6) indication for transplantation, and 7) primary immunosuppressant.

CONCLUSIONS

The cytotoxic crossmatch is not statistically associated with overall graft survival after liver transplantation. However, early failure rates are higher in the positive crossmatch cases, a difference that disappears by the second year.

Prevention of Jarisch-Herxheimer reactions by treatment with antibodies against tumor necrosis factor alpha

BACKGROUND

In patients with louse-borne relapsing fever (Borrelia recurrentis infection), antimicrobial treatment is often followed by sudden fever, rigors, and persistent hypotension (Jarisch-Herxheimer reactions) that are associated with increases in plasma concentrations of tumor necrosis factor alpha (TNF-alpha), interleukin-6, and interleukin-8. We attempted to determine whether sheep polyclonal Fab antibody fragments against TNF-alpha (anti-TNF-alpha Fab) could suppress the Jarisch-Herxheimer reaction.

METHODS

We conducted a randomized, double-blind, placebo-controlled trial in 49 patients with proven louse-borne relapsing fever. Immediately before the intramuscular injection of penicillin, the patients received an intravenous infusion of either anti-TNF-alpha Fab or a control solution.

RESULTS

Ten of the 20 patients given anti-TNF-alpha Fab had Jarisch-Herxheimer reactions with rigors, as compared with 26 of the 29 control patients (P = 0.006). The controls had significantly greater mean maximal increases in temperature (1.5 vs. 0.8 degrees C, P < 0.001), pulse rate (31 vs. 13 per minute, P < 0.001), and systolic blood pressure (25 vs. 15 mm Hg, P < 0.003), as well as higher mean peak plasma concentrations of interleukin-6 (50 vs. 17 micrograms per liter) and interleukin-8 (2000 vs 205 ng per liter) (P < 0.001 for both comparisons). Levels of TNF-alpha were undetectable after treatment with anti-TNF-alpha Fab.

CONCLUSIONS

Pretreatment with sheep anti-TNF-alpha Fab suppresses Jarisch-Herxheimer reactions that occur after penicillin treatment for louse-borne relapsing fever, reduces the associated increases in plasma concentrations of interleukin-6 and interleukin-8, and may be useful in other forms of sepsis.

The immune system: relation to sepsis and multiple organ failure

The immune system plays a dual role in the pathogenesis of sepsis and organ failure, intended for host defense but also possessing significant cytodestructive capacity. As the understanding of the epidemiology and pathophysiology of these disorders improves, so too does the appreciation for the complexity of this system. No longer is the immune response viewed as simply cellular or humoral but rather as a network of cells, chemical mediators, and molecular elements. The interactions between these various components serve to regulate and coordinate the inflammatory response. When this fine balance is lost, the inflammatory response becomes pathologic and self-destructive. Organ injury ensues, and with this injury, further escalation of the inflammatory response occurs; becoming a self-perpetuating process. Conventional therapy is limited to supportive care and has been ineffective in improving mortality. To date, efforts to modulate the inflammatory response by inhibition of specific components have been unsuccessful. In the future, better patient selection, combination therapy (perhaps using strategies of early augmentation followed by inhibition), and alternative techniques such as blood purification may prove to be more effective.

Lactic acidosis during sepsis is related to increased pyruvate production, not deficits in tissue oxygen availability

OBJECTIVE

The purpose of this study was to quantitate the derangements in intermediary carbohydrate metabolism and oxygen use in severely septic patients in comparison with healthy volunteers.

SUMMARY BACKGROUND DATA

It commonly has been assumed that the development of lactic acidosis during sepsis results from a deficit in tissue oxygen availability. Dichloroacetate (DCA), which is known to increase pyruvate oxidation but only when tissue oxygen is available, provides a means to assess the role of hypoxia in lactate production.

METHODS

Stable isotope tracer methodology and indirect calorimetry was used to determine the rates of intermediary carbohydrate metabolism and oxygen use in five severely septic patients with lactic acidosis and six healthy volunteers before and after administration of DCA.

RESULTS

Oxygen consumption and the rates of glucose and pyruvate production and oxidation were substantially greater (p < 0.05) in the septic patient compared with healthy volunteers. Administration of DCA resulted in a further increase in oxygen consumption and the percentage of glucose and pyruvate directed toward oxidation. Dichloroacetate also decreased glucose and pyruvate production, with a corresponding decrease in plasma lactate concentration.

CONCLUSIONS

These findings clearly indicate that the accumulation of lactate during sepsis is not the result of limitations in tissue oxygenation, but is a sequelae to the markedly increased rate of pyruvate production. Furthermore, the substantially higher rate of pyruvate oxidation in the septic patients refutes the notion of a sepsis-induced impairment in pyruvate dehydrogenase activity.

Current concepts of sepsis and acute lung injury

Acute respiratory distress syndrome continues to be a vexing clinical problem with no specific therapy. Epidemiologic and basic sciences have advanced our understanding of the clinical syndrome and have brought us to the brink of effective intervention strategies. This article carefully examines the current state of knowledge, with reference to acute lung injury and current efforts, to arrive at effective pharmacologic approaches.

Bradykinin and nitric oxide in infectious disease and cancer

Vascular pathophysiology at the sites of bacterial infection and cancerous tissues share numerous common events similar to inflammatory tissue. Among them enhanced vascular permeability is the universal and hallmark event mediated by bradykinin. All 16 or more bacterial or fungal proteases we have examined activated one or more steps of the kinin generating Hageman-factor-kallikrein cascade. In the meantime, most of the microbial proteases rapidly inactivated various plasma inhibitors such as alpha 1-protease inhibitor and alpha 2-macroglobulin. In addition to the extracellular proteases, bacterial cell wall components (negatively charged LPS) of gram-negative bacteria and teichoic acid moieties of gram-positive bacteria activate the Hageman-factor-kallikrein system and exert hypotensive effects via kinin generation. Endotoxin (LPS) also induces nitric oxide synthase (NOS) which appears to exhibit a rather slow, but significant, effect in relaxing the vascular tone of the infected animal (thus hypotension). Furthermore, bacterial proteases can activate the matrix metalloproteinase (collagenase) resulting in exacerbation of tissue injury in the diseased animal. Many tumor cells or tissues excrete plasminogen activator, and hence activate plasminogen. The plasmin thus generated activates procollagenases, as well as the Hageman-factor-kallikrein system, resulting in pronounced extravasation. Fluid accumulation in pleural and ascitic carcinomatoses is largely due to the activated bradykinin-generating system. We can also demonstrate and control enhanced vascular permeability using kallikrein inhibitors, especially the polymer-conjugated soybean trypsin inhibitor which exhibits a prolonged plasma t1/2, kinin antagonists, NOS inhibitors, NO scavengers, inhibitors of prostaglandins and others. Bacterial proteases induce shock in mice which can be prevented by the soybean trypsin inhibitor by blocking the kallikrein-kinin cascade. Therapeutic use of kinin antagonists and a kallikrein inhibitor has been made for infectious diseases such as septicemia and in tumor pathology.

Pathophysiology of the burn wound and pharmacological treatment. The Rudi Hermans Lecture, 1995

The body's reaction to thermal injury is much more than an initial, local inflammatory response. The burn wound is a continuous, severe threat against the rest of the body due to invasion of infectious agents, antigen challenge and repeated additional trauma caused by wound cleaning and excision. The inflammatory mediators which control blood supply and microvascular permeability in the wound have been extensively studied and are largely understood. Attempts to suppress the inflammatory reaction by different drugs, have, however, been less successful. Extensive thermal injury and sepsis also results in immunosuppression. The defects causing immunosuppression are still very much under consideration. An understanding of these defects is essential for the development of therapies. The increasing interest in the control of the inflammatory reactions by cytokines may, in the near future, be of great importance.

The sepsis syndrome. Definition and general approach to management

Sepsis is the systemic response to severe infection in critically ill patients. Sepsis, sepsis syndrome, and septic shock represent the increasingly severe stages of the same disease. Severe sepsis and septic shock occur in persons with preexisting illness or trauma. If sepsis is not diagnosed and treated early, it can become self-perpetuating, and elderly persons, in particular, are at a greater risk of death from sepsis.

Nitric oxide production in critically ill patients

OBJECTIVE

To measure serum nitrite and nitrate levels in critically ill children as indicators of endogenous nitric oxide (NO) production.

HYPOTHESIS

Endogenous NO production is increased in children with conditions characterised by immune stimulation.

DESIGN

Prospective descriptive study in a multidisciplinary paediatric intensive care unit.

PATIENTS

137 consecutive critically ill children with a variety of clinical conditions.

INTERVENTIONS

Using a rapid microtitre plate technique, daily serum nitrite and nitrate levels were measured from serum samples that remained in the clinical laboratory after daily routine phlebotomy. Clinical and laboratory information was also gathered daily for each patient.

RESULTS

The maximum serum nitrite plus nitrate levels (microM) reached by children with infection (41.8 (SD 18.1)), sepsis syndrome (85.1 (39.9)), shock without sepsis (36.4 (19.1)), transplantation alone (61.0 (43.4)), transplantation with sepsis (200.7 (150.5)), or rejection (161.7 (70.4)), were higher than in controls (18.1 (9.3)). In the absence of exogenous NO donors, levels greater than 80 microM were reached only in children with the sepsis syndrome, organ transplantation, or acute rejection.

CONCLUSIONS

Increased endogenous NO production occurs in children with clinical conditions associated with immune stimulation. Further investigation is warranted to determine the value of this simple and rapid test as a clinically useful diagnostic tool and therapeutic monitor in the evaluation of children at risk for the sepsis syndrome or acute allograft rejection.

New perspectives on the management of septic shock in the cancer patient

Septic shock is a common life-threatening problem, usually presenting with fever, tachycardia, tachypnea, and often a source of infection. The cardiac index is increased, with a decreased systemic vascular resistance, and a reversibly decreased ejection fraction with an increased end diastolic volume. The myocardial depression is most likely caused by a circulating humoral substance that depresses myocardial contractility. The initial treatment of septic shock is aggressive fluid resuscitation and antibiotic therapy, with vasopressors and inotropes being indicated in those patients who do not respond adequately to fluids. Therapy directed against the mediators of septic shock is theoretically promising, but to date has not been successful.

Hepatic Retransplantation--an analysis of risk factors associated with outcome

Hepatic retransplantation is controversial because the results are inferior to primary transplants and organs are so scarce. To determine the factors that are associated with poor outcome within the first year following retransplantation, we performed a multivariate analysis, using stepwise logistic regression, of 418 hepatic retransplantations performed at a single institution from November 1987 to December 1993. The minimum follow-up was 1 year. Seven variables were found to be independently associated with subsequent graft failure (defined as either patient death or retransplantation): donor age (odds ratio 2.2 for each 10-year increase over age 45, 95% CI 1.3 to 3.7), female donor sex (odds ratio 1.7, 95% CI 1.05 to 2.7), recipient age (odds ratio 1.6 for each 10-year increase over age 45,95% CI 1.2 to 2.8), need for preoperative mechanical ventilation (odds ratio 1.8, 95% CI 1.1 to 2.9), pretransplant serum creatinine (odds ratio 1.24 for each increase of 1 mg/dl, 95% CI 1.1 to 1.4), pretransplant total serum bilirubin (odds ratio 1.4 for each 10-mg/dl increase over 15 mg/dl, 95% CI 1.1 to 1.8), and the primary immunosuppressant, using tacrolimus as the reference category (odds ratio for cyclosporine-based immunosuppression 3.9, 95% CI 2.3 to 6.8). Although not part of the logistic regression model, the timing of retransplantation was also found to be important, with the overall probability of failure increasing from 0.58 on day 0 to a peak of 0.8 on day 38 and decreasing slowly after that. The implications of these results regarding the appropriateness of retransplantation are discussed.

Comparison of flomoxef with latamoxef in the treatment of sepsis and/or Gram-negative bacteremia in adult patients

The safety and efficacy of flomoxef and latamoxef were compared in the treatment of hospitalized patients with sepsis and/or Gram-negative bacteremia in a prospective, open-labelled clinical trial. Patients were randomized to receive 1 to 2 g intravenous doses of either flomoxef every 6 to 12 h, or latamoxef every 8 to 12 h. Data from 21 patients given flomoxef and 23 patients given latamoxef were included in the evaluation of efficacy. Flomoxef produced clinical cure and satisfactory microbiological responses in 85.7% and 100% of patients, respectively. These results were similar to those obtained with latamoxef (87% and 100%, respectively). In addition, no significant difference was found in mean age, sex, severity of infection, distribution of pathogens and focus of infection between the two groups. However, the flomoxef group included more patients with ultimately fatal diseases. Six patients given flomoxef and two patients given latamoxef developed superinfections caused by yeast, enterococci and Pseudomonas aeruginosa in the urinary tract. Mild and reversible adverse reactions probably related to flomoxef and latamoxef were noted in 14.3% and 13% of patients, respectively. The results of this study demonstrated that flomoxef is a safe and effective antimicrobial agent in the treatment of patients with sepsis and/or Gram-negative bacteremia.

Utility of illness severity scoring for prediction of prolonged surgical critical care

OBJECTIVE

To determine whether APACHE III and multiple organ dysfunction syndrome scores can predict a prolonged length of stay for critically ill surgical patients in the intensive care unit.

DESIGN

Prospective, inception-cohort study.

SETTING

Surgical intensive care unit (SICU) of an urban, tertiary care hospital.

PATIENTS

2,295 consecutive admissions for critical surgical illness, postoperative complications, or postoperative monitoring in 2,058 patients.

INTERVENTIONS

Calculation of Acute Physiology and Chronic Health Evaluation (APACHE) II and APACHE III scores 24 hours after admission to the SICU. Serial quantitation of organ dysfunction for the duration of hospitalization according to the multiple organ dysfunction score. Patients were stratified by survival and time intervals for the duration of critical care, and followed until discharge or death.

MAIN OUTCOME MEASURES

Hospital mortality and length of stay in the SICU.

RESULTS

The mean APACHE II and APACHE III scores were 14.0 +/- 0.2 and 45.2 +/- 0.6 points, respectively (mean +/- SEM). The incidence of organ dysfunction was 43%, and the hospital mortality was 9.7%. The mean ICU length of stay was 6.1 +/- 0.2 days, but decreased progressively from 6.8 +/- 0.5 days in 1991 to 5.3 +/- 0.6 days in 1995 (p < 0.01) with no change in either illness severity or the number of admissions. By univariate analysis, increased length of stay in the ICU was associated with increasing APACHE scores, an increased incidence of emergency admissions, and the incidence and magnitude of organ dysfunction (all p < 0.01). Severity indices appeared to plateau in magnitude in patients whose ICU stay ultimately exceeded 21 days. By multivariate analysis of variance (MANOVA), independent predictors of a prolonged stay in the SICU were APACHE III (p = 0.0023), emergency admission (p = 0.0007), and the magnitude of organ dysfunction (p < 0.00001), but not APACHE II. Only an emergency admission (p = 0.0005) and the magnitude of organ dysfunction (p < 0.00001) predicted a prolonged stay independently in survivors. In contrast, only the admission APACHE III score(p = < 0.0001) and the magnitude of organ dysfunction (p = 0.0001) were independently predictive of mortality by MANOVA.

CONCLUSIONS

The development of multiple organ dysfunction syndrome is a powerful predictor of a prolonged ICU course in critical surgical illness, even in survivors. Increased risk of a prolonged stay in the ICU plateaued at 21 days, making 21 days an appropriate definition of prolonged care for future studies. Predictive models should account for organ dysfunction and very long stays in future estimations. The combined use of APACHE III and the multiple organ dysfunction score may provide improved prediction of a prolonged stay in the ICU, but further enhancements are needed before prediction of outcome in individual patients is reliable.

Early prediction of outcome in score-identified, postcardiac surgical patients at high risk for sepsis, using soluble tumor necrosis factor receptor-p55 concentrations

OBJECTIVE

To investigate the prognostic value of increased serum concentrations of soluble tumor necrosis factor (TNF) receptors in patients at high risk for sepsis.

DESIGN

Prospective study.

SETTING

Cardiac surgical intensive care unit in a University Hospital.

PATIENTS

Those 27 of 870 consecutive postcardiac surgical patients who met a previously validated high-risk criterion for imminent sepsis (Acute Physiology and Chronic Health Evaluation II [APACHE II] score of > or = 24 on the first postoperative day [day 1]). In this population, systemic inflammatory response syndrome was present in 96% of the patients and the in-hospital mortality rate was 30%. In addition, ten postcardiac surgical patients with an uncomplicated course (mortality rate 0%) were studied for comparison.

INTERVENTIONS

Blood sampling for measurements of serum concentrations of TNF and soluble TNF receptors 55 kilodalton (TNF receptor-p55) and 75 kilodalton (TNF receptor-p75) on days 1, 2, 3, and 5.

MEASUREMENTS AND MAIN RESULTS

Compared with the ten patients with an uncomplicated course (group A), the high-risk patients had significantly higher baseline (day 1) serum concentrations of soluble TNF receptor-p55 (9.2 vs. 4.2 ng/mL) and soluble TNF receptor-p75 (9.2 vs. 5.5 ng/mL). These high-risk patients could be further differentiated into two subgroups: one (B) with a prompt decrease in APACHE II score and a good prognosis (mortality rate 0%) and another (C) with a persisting high risk of sepsis and mortality rate (40%, p < .05). Although baseline APACHE II score was similar in both high-risk subgroups, soluble TNF receptor-p55 concentrations were significantly higher in subgroup C compared with subgroup B already at baseline (10.7 vs. 4.7 ng/mL). The receiver operating characteristic curve for subgroup classification by soluble TNF receptor-p55 was in a discriminating position with an area (0.773 +/- 0.096), confirming soluble TNF receptor-p55 as a predictor of mortality. TNF and soluble TNF receptor-p75 concentrations were less predictive at baseline.

CONCLUSIONS

This study suggest that increased soluble TNF receptor-p55 concentrations in the serum of postcardiac surgical patients allow earlier prognostication of subsequent hospital course than APACHE II scores alone. This study further suggests that the combination of physiologic scores and cytokine receptor measurements could improve the predictive power of early postoperative risk stratification.

Epidemiology of sepsis and multiple organ dysfunction syndrome in children

STUDY OBJECTIVES

To determine the cumulated incidence and the density of incidence of systemic inflammatory response syndrome (SIRS), sepsis, severe sepsis, septic shock, and multiple organ dysfunction syndrome (MODS) in critically ill children; to distinguish patients with primary from those with secondary MODS.

DESIGN

Prospective cohort study.

SETTING

Pediatric ICU of a university hospital.

PATIENTS

One thousand fifty-eight consecutive hospital admissions.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

SIRS occurred in 82% (n=869) of hospital admissions, 23% (n=245) had sepsis, 4% (n=46) had severe sepsis, 2% (n=25) had septic shock; 16% (n=168) had primary MODS and 2% (n=23) had secondary MODS; 6% (n=68) of the study population died. The pediatric risk of mortality (PRISM) scores on the first day of admission to pediatric ICU were as follows: 3.9 +/- 3.6 (no SIRS), 7.0 +/- 7.0 (SIRS), 9.5 +/- 8.3 (sepsis), 8.8 +/- 7.8 (severe sepsis), 21.8 +/- 15.8 (septic shock); differences among groups (p=0.0001), all orthogonal comparisons, were significant (p<0.05), except for patients with severe sepsis. The observed mortality for the whole study population was also different according to the underlying diagnostic category (p=0.0001; p<0.05 for patients with SIRS and those with septic shock, compared with all groups). Among, patients with MODS, the difference in mortality between groups did not reach significance (p=0.057). Children with secondary MODS had a longer duration of organ dysfunction (p<0.0001), a longer stay in pediatric ICU after MODS diagnosis (p<0.0001), and a higher risk of mortality (odds ratio, 6.5 [2.7 to 15.9], p<0.0001) than patients with primary MODS.

CONCLUSIONS

SIRS and sepsis occur frequently in critically ill children. The presence of SIRS, sepsis, or septic shock is associated with a distinct risk of mortality among critically ill children admitted to the pediatric ICU; more data are needed concerning children with MODS. Secondary MODS is much less common than primary MODS, but it is associated with an increased morbidity and mortality; we speculate that distinct pathophysiologic mechanisms are involved in these two conditions.

Mediators, cytokines, and growth factors in liver-lung interactions

Multiple mediators have been implicated in the interactions between the liver and the lungs in various disease states. The best characterized mediator of liver-lung interaction is alpha 1-antitrypsin. Several cytokines and mediators may be involved in the pathogenesis of the hepatopulmonary syndrome and in the cytokine cascades that are activated in systemic inflammatory states such as acute respiratory distress syndrome. Hepatocyte growth factor or scatter factor is a recently described peptide with a broad range of biologic effects that may mediate lung-liver interactions.

Resuscitation of the critically ill in the ED: responses of blood pressure, heart rate, shock index, central venous oxygen saturation, and lactate

To describe the simultaneous responses of systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial blood pressure (MAP), heart rate (HR), shock index (SI = HR/SBP), central venous oxyhemoglobin saturation (ScvO2), and arterial blood lactate concentration (Lact) to resuscitation of critically ill patients in the emergency department (ED), an observational descriptive study was conducted in the ED of an urban teaching hospital. Thirty- six patients admitted from the ED to the medical intensive care unit were studied. Vital signs were measured immediately on arrival to the ED (phase 1). After initial resuscitation and stabilization, ie, HR between 50 and 120 beats/min and MAP between 70 and 110 mm Hg (phase 2), ScvO2 and Lact were measured and additional therapy was given in the ED to increase ScvO2 to > 65% and decrease Lact to < 2 mmol/L, if needed (phase 3). SBP, DBP, MAP, HR. SI, ScvO2, and Lact were measured. Initial resuscitation increased SBP from 103 +/- 39 to 118 +/- 29 mm Hg (P < .05) and MAP from 67 +/- 35 to 82 +/- 22 mm Hg (P < .05) but did not affect DBP (53 +/- 35 to 63 +/- 22 mm Hg, P = NS), HR (110 +/- 26 to 110 +/- 22 beats/min, P = NS) or SI (from 1.3 +/- 0.7 to 1.0 +/- 0.3, P =NS) from phase 1 to phase 2. ScvO2 remained < 65% and/or Lact > 2.0 mmol/L in 31 of 36 patients at phase 2, and additional therapy was required. Lact was decreased (from 4.6 +/- 3.8 to 2.6 +/- 2.5 mmol/L, P < .05) and ScvO2 was increased (from 52 +/- 18 to 65 +/- 13%, P < .05) without significant additional changes in SBP, DBP, MAP, HR, or SI at phase 3. The in-hospital mortality was 14% for this group of patients. It was concluded that additional therapy is required in the majority of critically ill patients to restore adequate systemic oxygenation after initial resuscitation and hemodynamic stabilization in the ED. Additional therapy to increase ScvO2 and decrease Lact may not produce substantial responses in SBP, DBP, MAP, HR, and SI. The measurement of ScvO2 and Lact can be utilized to guide this phase of additional therapy in the ED.

Secretory non-pancreatic phopholipase A2 in severe sepsis: relation to endotoxin, cytokines and thromboxane B2

Circulatory secretory non-pancreatic phospholipase A2 (snp-PLA2) was measured prospectively at the onset (day 0) of severe sepsis in 52 patients as well as on day 1 and 2 in 25 patients, in order to answer two questions: 1) does the snp-PLA2 plasma concentration differ according to the type and severity of infection? 2) what is the relation between snp-PLA2 and other mediators involved in severe sepsis, such as endotoxin, cytokines (TNF alpha, IL-1 beta, IL-6) and thromboxane B2 (the stable metabolite of thromboxane A2)? On day 0, the snp-PLA2 circulatory level was 78 +/- 17 nmol/min/ml in patients with severe sepsis as compared to 3.5 +/- 2 nmol/min/ml in 40 healthy volunteers. There was no statistical difference according to the outcome, the presence of shock, or the type of infection on day 0. However, snp-PLA2 remained elevated or even increased in patients who ultimately died, while it decreased in survivors (p = 0.01 by ANOVA). The cytokine profiles during the 2-day follow-up were similar to that of snp-PLA2, but the differences were not statistically significant between survivors and non-survivors. No correlation was found between snp-PLA2 and other mediators for either initial or peak values.

The pathogenesis of septic shock

A new age of treating patients with septic shock is rapidly approaching. A multidrug approach will likely be used to interrupt the systemic inflammatory response to infection, with use of new immune and inflammatory modulating therapies. In this article are reviewed the advances made in understanding the cellular events that cause septic shock. Critical care nurses need to update themselves on this new information to provide optimal care that patients with septic shock demand. Symptoms of septic shock, its hemodynamic characteristics, and the actions of principal inflammatory mediators that cause vasodilation and capillary leak are discussed.

Renal effects of low-dose dopamine in patients with sepsis syndrome or septic shock treated with catecholamines

OBJECTIVE

To evaluate the renal effects of low-dose dopamine in patients with sepsis syndrome or septic shock treated with catecholamines.

DESIGN

Prospective, clinical study using sequential periods.

SETTING

A 12-bed surgical intensive care unit in a university hospital.

PATIENTS

14 patients with sepsis syndrome and 15 patients with septic shock treated with exogenous catecholamines were studied. They had no diuretic treatment.

INTERVENTION

Two periods of 2 h each with and without 2 micrograms.kg-1.min-1 of dopamine infusion. Hemodynamic and renal data were obtained at the end of each period. Measurements were repeated after 48 h of dopamine infusion in patients with sepsis syndrome. All data were evaluated by the Wilcoxon rank test.

MEASUREMENTS AND RESULTS

In patients with sepsis syndrome, diuresis and creatinine clearance increased significantly by 100% and 60%, respectively, during low-dose dopamine infusion without any change in systemic hemodynamics. The renal response to dopamine decreased significantly after 48 h of dopamine infusion (P < 0.01). In patients with septic shock treated with catecholamines, no variation of either systemic hemodynamics or renal function was noted during low-dose dopamine infusion.

CONCLUSION

The renal effects of low-dose dopamine in patients with sepsis syndrome decrease with time. No renal effect of low-dose dopamine was observed in patients with septic shock treated with catecholamines. These findings suggest a desensitization of renal dopaminergic receptors.

Circulating complement proteins in patients with sepsis or systemic inflammatory response syndrome

The systemic inflammatory response of the body to invading microorganisms, termed sepsis, leads to profound activation of the complement system. Pathophysiological concepts suggest that complement activation occurs very early in this syndrome. Thus, we discuss whether the determination of concentrations of the complement components C3a, C5a, and C3 in plasma as well as of the C3a/C3 ratio might be helpful to diagnose sepsis early. For this purpose, 33 patients from an intensive care unit were monitored for 10 days. In comparison with healthy donors, C3a levels and the C3a/C3 ratio of intensive-care-unit patients were significantly elevated (P < 0.0001) on admission. In contrast, C3 levels were significantly reduced (P < 0.0001) but increased during the study. C5a levels in the plasma of healthy donors and patients were identical. Twenty-two of 33 patients fulfilled microbiological and clinical criteria of sepsis. Eleven patients had signs of systemic inflammatory response syndrome but no microbiological evidence of sepsis. The groups could be differentiated from each other by their C3a levels or their C3a/C3 ratios during the first 24 h after the clinical onset of sepsis (P < 0.05). Septic patients in shock had higher C3a levels than normotensive septic patients, although the differences were not significant. Nonsurvivors had significantly higher C3a levels on admission than survivors (P = 0.0185). No differences were found between septic patients who developed adult respiratory distress syndrome and those who did not. Thus, determination of C3a concentrations in plasma may prove useful (i) to diagnose sepsis early, (ii) to differentiate between patients with sepsis and those with systemic inflammatory response syndrome, and (iii) to assess prognosis.

Glycosylation of alpha 1-acid glycoprotein in septic shock: changes in degree of branching and in expression of sialyl Lewis(x) groups

The occurrence of differences in acute-phase response, with respect to concentration and glycosylation of alpha 1-acid glycoprotein (AGP) was studied in the sera of patients, surviving or not from septic shock. Crossed affino-immunoelectrophoresis was used with concanavalin A and Aleuria aurantia lectin for the detection of the degree of branching and fucosylation, respectively, and the monoclonal CSLEX-1 for the detection of sialyl Lewisx (SLeX) groups on AGP. Septic shock apparently induced an acute-phase response as indicated by the increased serum levels and changed glycosylation of AGP. In the survivor group a transient increase in diantennary glycan content was accompanied by a gradually increasing fucosylation and SLeX expression, comparable to those observed in the early phase of an acute-inflammatory response. Remarkably, in the non-survivor group a modest increase in diantennary glycan content was accompanied by a strong elevation of the fucosylation of AGP and the expression of SLeX groups on AGP, typical for the late phase of an acute-phase response. Our results suggest that these changes in glycosylation of AGP can have a prognostic value for the outcome of septic shock.

Bacteremia and sepsis

Recent evolution in the thinking of sepsis syndrome has provided a framework on which new clinical and basic research can be built. The separation of the inciting event and the cascade of subsequent physiologic changes has profound effects on how sepsis is thought of and ultimately how it will be treated. Early identification and treatment of infections and identifying patients at risk, to prevent SIRS, is the current role of Eps. Resuscitation of severe sepsis is more complex than other forms of shock and may require extensive resources if rapid admission or transfer to an intensive care unit is not available. As in many instances, the EP must be knowledgeable and skilled in the early identification and initial management of these patients until the definitive care can be provided. Modulation of the inflammatory response appears to be a prime prospect, but its practicality remains to be proved. Research and future roles of EPs include defining the population of ED patients at risk for SIRS and use of mediators of the inflammatory response. Emergency medicine is positioned in a critical point in the care of these patients.