Blunted erythropoietic response to anemia in multiply traumatized patients

OBJECTIVES

To assess the relations between anemia, serum erythropoietin (EPO), iron status, and inflammatory mediators in multiply traumatized patients.

DESIGN

Prospective observational study.

SETTING

Intensive care unit.

PATIENTS

Twenty-three patients suffering from severe trauma (injury severity score > or =30).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Blood samples were collected within 12 hrs after the accident (day 1) and in the morning on days 2, 4, 6, and 9 to determine blood cell status, serum EPO, tumor necrosis factor-alpha (TNF-alpha), soluble tumor necrosis factor-receptor I (sTNF-rI), interleukin-1 receptor antagonist (IL1-ra), interleukin-6 (IL-6), neopterin, and iron status, respectively. Hemoglobin concentration was low at admission (mean, 10.0 g/dL; range, 6.8-12.9 g/dL) and did not increase during the observation time. Serum EPO concentration was 49.8 U/L (mean value) on day 1 and did not show significant increases thereafter. No correlation was found between EPO and hemoglobin concentrations. TNF-alpha remained within the normal range. sTNF-rI was high at admission and increased further. IL1-ra was above the normal range. IL-6 was very high at admission and did not decrease thereafter. The initial neopterin concentration was normal, but increased until day 9. Serum iron was significantly decreased on day 2 posttrauma and remained low during the study. Serum ferritin increased steadily from day 2, reaching its maximum on day 9. In contrast, concentrations of transferrin were low from admission onward.

CONCLUSIONS

Multiply traumatized patients exhibit an inadequate EPO response to low hemoglobin concentrations. Thus, anemia in severe trauma is the result of a complex network of bleeding, blunted EPO response to low hemoglobin concentrations, inflammatory mediators, and a hypoferremic state.

Risk factors associated with new onset tachyarrhythmias after cardiac surgery--a retrospective analysis

BACKGROUND

Tachyarrhythmias (TA) represent a frequent and serious problem after cardiac surgery. We retrospectively analyzed 987 cardiac surgery patients admitted to a surgical intensive care unit between 1996 and 1999 to assess incidence and risk factors associated with development of postoperative TA in the intensive care unit.

METHODS

TA (n=149) were defined as non-sinus rhythm with a heart rate (HR) > or =100 bpm in patients with preoperative sinus rhythm or as heart rate > or =130 bpm in patients with preoperative atrial fibrillation. A total of 787 patients served as controls (C). Demographic, premorbidity and perioperative data, admission SAPS and MODS-score, presence of clinical syndromes systemic inflammatory response syndrome (SIRS) and sepsis were univariately compared between groups. For prediction of independent risk factors for TA-development two multiple logistic regression models were finally established.

RESULTS

Concerning TA, atrial fibrillation and flutter (76%) were observed most frequently, followed by paroxysmal supraventricular tachycardia (15%) and ventricular tachycardia/fibrillation (11%). Age, a history or presence of congestive heart failure, development of SIRS and sepsis, severity of multiple organ dysfunction syndrome and in particular severity of cardiovascular failure proved to be independent risk factors for development of TA.

CONCLUSION

In cardiac surgery patients, age, a history or presence of congestive heart failure, postoperative development of a systemic inflammatory response syndrome or sepsis and the severity of multiple organ function syndrome were independent predictors for development of TA in the intensive care unit. The association of severity of cardiovascular dysfunction with TA strongly suggests a causal relationship between catecholamine therapy and TA-development.

Reisethrombose 2001

Anlässlich einer Tagung in Wien im Juni 2001 hat eine Gruppe von Experten aus Deutschland, der Schweiz und aus Österreich ein Dokument ausgearbeitet, in welchem eine Definition der Reisethrombose gegeben und Vorbeugemaßnahmen vorgeschlagen wurden, die an drei Risikogruppen angepasst sind.

Antithrombin III enhances inducible nitric oxide synthase gene expression in vascular smooth muscle cells

Evidence suggests that antithrombin III (ATIII) exerts anti-inflammatory properties in addition to its anti-coagulative mechanisms. In animal models of sepsis, ATIII affected cytokine plasma concentrations with a decrease of pro-inflammatory cytokines. In addition to cytokines, excessive production of nitric oxide (NO) derived from inducible nitric oxide synthase (iNOS) might represent another important mediator of the cytotoxic events during sepsis. Regarding ATIII as a potential anti-inflammatory modulator, one may speculate that ATIII inhibits the synthesis of iNOS-derived NO. However, our data demonstrate that ATIII further stimulates iNOS gene expression when applied together with either interleukin-1 beta or the combination of lipopolysaccharide plus interferon-gamma. The most prominent synergistic effects on NO synthesis were found when ATIII was given at higher concentrations (1, 5, and 10 U/ml). Although the mechanisms of ATIII signal transduction remain to be established, intensification of interleukin-1 beta or interferon-gamma/lipopolysaccharide-induced NO synthesis by ATIII does not attribute to the anti-inflammatory properties of ATIII.

Recombinant granulocyte colony-stimulating factor (G-CSF) in infectious diseases: still a debate

Granulocyte colony-stimulating factor (G-CSF), a central mediator of the endogenous response to infection and inflammation, is approved for use in the prevention of infection-related complications in patients with nonmyeloid malignancies during antineoplastic therapy associated with high risk of severe neutropenia. Administration of granulocyte colony-stimulating factor results in improvement of host defence paired with anti-inflammatory effects. There is evidence from animal and clinical studies that administration of granulocyte colony-stimulating factor may also be beneficial in non-neutropenic infections. This review focuses mainly on the results of different animal and clinical studies of granulocyte colony stimulating factor used in the treatment of severe infections and sepsis.

In vitro modulation of inducible nitric oxide synthase gene expression and nitric oxide synthesis by procalcitonin

OBJECTIVE

Serum procalcitonin (PCT) concentration was recently introduced as valuable diagnostic marker for systemic bacterial infection and sepsis. At present, the cellular sources and biological properties of PCT are unclear. During sepsis and septic shock, inducible nitric oxide synthase (iNOS) gene expression is stimulated followed by the release of large amounts of nitric oxide (NO). We investigated the possible association between PCT and iNOS gene expression in an in vitro cell culture model.

DESIGN

Prospective, controlled in vitro cell culture study.

SETTING

University research laboratories.

INTERVENTIONS

Confluent rat vascular smooth muscle cells (VSMC) were incubated for 24 hrs and 48 hrs with PCT (1 ng/mL, 10 ng/mL, 100 ng/mL, 1,000 ng/mL, 5,000 ng/mL) alone or with the combination of tumor necrosis factor-alpha (TNF-alpha, 500 U/mL) plus interferon-gamma (IFN-gamma, 100 U/mL). iNOS gene expression was measured by qualitative as well as quantitative polymerase chain reaction analysis, NO release was estimated by the modified Griess method.

MEASUREMENTS AND MAIN RESULTS

PCT in increasing concentrations had no effect on iNOS gene expression and nitrite/nitrate release for 24 hrs and 48 hrs, respectively. However, PCT ameliorated TNF-alpha/IFN-gamma-induced iNOS gene expression in a dose-dependent manner (maximal inhibition at PCT 100 ng/mL by -66% for 24 hrs and -80% for 48 hrs). This was accompanied by a significantly reduced release of nitrite/nitrate into the cell culture supernatant (maximal reduction at PCT 100 ng/mL by -56% and -45% for 24 hrs and 48 hrs, respectively).

CONCLUSIONS

We conclude that recombinant PCT inhibits the iNOS-inducing effects of the proinflammatory cytokines TNF-alpha/ IFN-gamma in a dose-dependent manner. This might be a counter-regulatory mechanism directed against the large production of NO and the concomitant systemic hypotension in severe sepsis and septic shock.

[Multiple organ failure following inhalation of butane gas: a case report]

Most cases of acute poisoning by butane and other volatile compounds occur in young people as a consequence of substance abuse by inhalation. Clinical symptoms are caused by asphyxia and mainly affect the cardiovascular, respiratory and central nervous system. There are also reported deaths from intoxication of butane inhalation, mostly by cardiac arrhythmia. We report the case of a healthy 14 year-old boy who inhaled butane gas from an aerosol can for refilling cigarette lighters. Despite successful resuscitation and defibrillation, he died two days later from multiple organ failure involving the central nervous system, cardiovascular system, pulmonary system and the liver. Although such incidents are rare in middle European countries, emergency and intensive care medicine staff should be instructed on the consequences and management of butane gas poisoning.

Exogenous neopterin causes cardiac contractile dysfunction in the isolated perfused rat heart

Neopterin is known in humans as a sensitive marker for diseases associated with increased activity of the cellular immune system. Recent studies report neopterin also to exhibit distinct effects: neopterin induces inducible nitric oxide synthase expression in rat vascular smooth muscle cells and activates translocation of nuclear factor- kappa B. Neopterin may also induce oxidative stress causing apoptotic cell death, or superinduce tumor necrosis factor- alpha -mediated apoptosis. Observing these effects in cell cultures, we were interested in possible consequences of neopterin on cardiac function in the isolated perfused rat heart. The influence of neopterin in three different concentrations (10 micromol/l, 50 micromol/l, 100 micromol/l) on cardiac contractility parameters and coronary vascular resistance were studied in 67 male Sprague-Dawley rats using the temperature-controlled and pressure-constant Langendorff apparatus with retrograde perfusion of the aorta with a Krebs-Henseleit buffer. Treatment with 100 micromol/l neopterin resulted in a significant decrease in coronary flow and cardiac contractility. Coronary flow decreased from 15.2 to 9.5 ml/min (P=0.002), left ventricular pressure from 80 to 52 mmHg (P=0. 002), rate of pressure fall from 1605 to 923 mmHg/s (P=0.001) and rate of pressure rise from 2862 to 1709 mmHg/s (P=0.001). Concentrations lower than 100 micromol/l neopterin had no significant effect on cardiac function. Our study demonstrates a considerable influence of exogenous neopterin on cardiac performance in the Langendorff model of isolated perfused rat hearts. This has to be considered a potential pathogenic factor of cardiac disturbances in diseases in which high concentrations of neopterin are released due to immune activation. At present the exact mechanism remains unclear.

Immunologic changes after transfusion of autologous or allogeneic buffy coat-poor versus WBC-reduced blood transfusions in patients undergoing arthroplasty. II. Activation of T cells, macrophages, and cell-mediated lympholysis

BACKGROUND

To estimate the impact of RBC preparations on the status of postoperative immune activation, the soluble cytokine receptors of TNFalpha (sTNF-R) and IL-2 (sIL-2R), as well as neopterin and cell-mediated lympholysis (CML), were measured.

STUDY DESIGN AND METHODS

Patients undergoing strictly standardized anesthesiologic management for elective orthopedic surgery were enrolled in a prospective study. The perioperative course (Days 0, 3, 7, and 10) of sTNF-R, sIL-2R, neopterin, and CML was compared after random assignment to allogeneic buffy coat-reduced (Group 2, n = 8) or WBC-reduced (Group 3, n = 11) RBC transfusion regimen. Recipients of autologous buffy coat-reduced RBC transfusions (Group 1, n = 15) served as controls. Patients receiving intraoperatively and postoperatively salvaged blood only (n = 10) were separately analyzed as Group 4.

RESULTS

In Group 1, a short-lasting increase in soluble cytokine receptors, a diminished cytolytic response (Day 0 vs. Day 7: sTNF-R, p = 0.0001; sIL-2R, p = 0.0004; CML, p = 0. 0238), and an elevation of neopterin (Day 0 vs. Day 3: p = 0.0064) were observed. In contrast, in allogeneically transfused patients, sTNF-R (Group 2, p = 0.0469: Group 3, p = 0.0039), sIL-2R (Group 3, p = 0.002) and neopterin (Group 3, p = 0.0164) increased further from baseline to Day 10 (Day 0 vs. Day 10), and this increase was accompanied by a diminished cytolytic response (Day 0 vs. Day 10: Group 2, p = 0.05; Group 3, p = 0.0076). Patients in Group 4 showed a short-lasting increase in sIL-2R (Day 0 vs. Day 3: p = 0.0078), neopterin (Day 0 vs. Day 3: p = 0.0156) and sTNF-R (Day 0 vs. Day 7: p = 0.0781).

CONCLUSION

Allogeneic transfusions seem to prolong the postoperative status of immune activation, even when WBC-filtered RBCs are used for the transfusion regimen.

Tachyarrhythmias in a surgical intensive care unit: a case-controlled epidemiologic study

OBJECTIVE

Incidence, types, and factors associated with new onset tachyarrhythmias (TA) in surgical intensive care patients.

DESIGN

Pairwise-matched case-controlled study.

SETTING

Surgical intensive care unit (ICU) with nine intensive care beds.

PATIENTS

During a 1-year period, all TA patients (n = 89) were included in the study. Control patients (n = 82) without TA were matched according to age, sex, and surgical region.

METHODS

TA workup included: 12-lead ECG, arterial blood gas, serum electrolyte (K+, Mg2+), and serum CK/CKMB isoenzyme analysis. Pre-existing cardiovascular and pulmonary disease, cardiovascular risk factors, preoperative regular medication, and admission SAPS were recorded in all patients. A multiple organ dysfunction syndrome (MODS) score, the presence or absence of SIRS or sepsis, and hemodynamics (MAP and CVP) before onset of TA were evaluated in TA patients, while in control patients highest MODS-score, the presence or absence of SIRS or sepsis, mean hemodynamic and laboratory values calculated from highest and lowest readings during ICU stay were used for statistical comparison. Logistic regression analysis was performed to identify variables multivariately associated with TA.

RESULTS

Eighty-nine (14.8%) of 596 patients developed TA. Atrial fibrillation was most frequent (60.7%). Presence of SIRS or sepsis (adj. OR = 36.45; 95% CI: 11.5-115.5), high admission SAPS (adj. OR = 1.25/point; 95% CI: 1.08-1.44), high CVP (adj. OR = 1.27/mmHg; 95% CI: 1.09-1.48), and low arterial oxygen tension (adj. OR = 0.97/mmHg); 95% CI: 0.95-0.99) were found to be significant predictors for development of TA.

CONCLUSIONS

In surgical patients hypoxia, high cardiac filling pressures, a greater degree of physiologic derangement at admission, and the presence of SIRS and sepsis are independent risk factors for the development of TA.

[Streptococcal toxic shock-like syndrome with necrotizing myositis]

Streptococcal toxic shocklike syndrome is caused by group A streptococci and characterized by multiorgan failure and soft-tissue necrosis, often in young patients with a bland history and at most a minor trauma. Diagnosis is reached through the clinical presentation, imaging methods and positive bacterial verification. The course is fulminant and in the case of muscle involvement, mortality reaches 80-100%. Therapy consists of immediate fasciotomy and often of debridement of affected soft tissues with high-dose antibiotics in intensive care. Sometimes an unconfirmed diagnosis must be sufficient to operate. We report the case of a 29-year-old man without an exceptional history who was forced to undergo thigh amputation, multiple soft-tissue debridements, and after a total of 240 erythrocyte concentrates, finally hip joint enucleation.

Acute respiratory failure associated with catastrophic antiphospholipid syndrome

We present a case of multiple organ dysfunction syndrome with acute respiratory failure due to alveolar haemorrhage associated with antiphospholipid antibodies in a 42-year-old woman with a medical history of antinuclear antibody-negative systemic lupus erythematosus and antiphospholipid syndrome. Severe respiratory failure, circulatory shock and acute renal failure necessitated artificial ventilation, inotropic and vasopressor therapy, and continuous venovenous haemofiltration. A tentative diagnosis of haemorrhagic lupus pneumonitis or pulmonary manifestation of antiphospholipid syndrome was made. Lupus anticoagulant, IgG anticardiolipin and anti-beta2-glycoprotein I antibodies were positive. High-dose glucocorticoid, anticoagulation with heparin, plasmapheresis and cyclophosphamide improved her clinical condition. Despite this, the patient died several days later of spontaneous intracranial haemorrhage. This case illustrates the uncommon manifestation of acute respiratory failure associated with antiphospholipid syndrome.

Increase in immune activation, vascular endothelial growth factor and erythropoietin after an ultramarathon run at moderate altitude

The present study was performed to investigate the effects of exhaustive long lasting exercise at moderate altitude on the time course of serum immunomodulatory peptides, vascular endothelial growth factor (VEGF) and serum erythropoietin (EPO). Thirteen well trained runners participated at the Swiss Alpine Marathon of Davos (distance 67 km, altitude difference 2300 m). Interleukin-6 was significantly elevated in the first 2h after the run. In contrast, tumor necrosis factor-alpha and both soluble tumor necrosis factor-a receptors I and II were increased after exercise termination and showed sustained serum concentrations the following days. Neopterin, a serum marker for the activation of the cellular immune system, was increased until day two after the run. Immediately after the run VEGF was significantly elevated and further increased 2.4-fold until day five post exercise (p = 0.005). EPO was also increased after exercise but reached its maximum 2 h after the run (2-fold increase; p = 0.004) and decreased thereafter. The main findings of our study are that prolonged strenuous exercise at moderate altitude induced a significant long lasting increase in serum VEGF and EPO which was accompanied by an activation of the immune system.

Low platelet count and elevated serum thrombopoietin after severe trauma

Platelet count is regularly low in patients after multiple trauma, mainly due to blood loss and dilution. Thrombopoietin (TPO) is the main regulator of the circulating platelet mass. Under several clinical conditions an inverse correlation between TPO and the circulating platelet mass was reported. Since platelets bind and internalize TPO, a platelet-dependent regulation of TPO was suggested. Thus, acute blood loss should be accompanied by elevated TPO. We measured serum TPO, platelets, interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF) in 17 multiple traumatized victims. Blood was collected within 12 h after trauma as well as in the morning of days 2, 4, 6 and 9 after admission at the intensive care unit. Platelet count was low at admission and remained low until day 4. Thereafter platelets increased until day 9. TPO nearly doubled within the first 2 d, reaching its maximum on day 6. IL-6 was initially very high and steadily decreased until day 9. VEGF increased 3-fold during the 9 d. Statistically significant correlations of TPO were found with platelets and IL-6, but not with VEGF. In multiple traumatized patients low platelet count is followed by a rapid increase in serum TPO. This fits into the concept of a feedback regulation between circulating TPO and platelet mass.

Neopterin-induced expression of intercellular adhesion molecule-1 (ICAM-1) in type II-like alveolar epithelial cells

Production and release of proinflammatory mediators such as tumour necrosis factor-alpha and neopterin are common events following the activation of the cellular immune system. Concerning inflammatory disorders of the lung, e.g. sepsis or sarcoidosis, high serum neopterin levels have been reported to correlate well with the severity of the disease. These situations are often associated with an increased expression of ICAM-1 reported to be induced in type II alveolar epithelial cells. In our study we investigated the potential effects of neopterin on ICAM-1 synthesis in the type II-like pneumocyte cell line L2. Detection of ICAM-1 gene expression by reverse transcriptase-polymerase chain reaction revealed a dose-dependent effect of neopterin, with maximum impact following 12-h incubations. Comparable results were obtained when ICAM-1 protein synthesis was measured via a cell-based ELISA. In a second set of experiments we were able to show that coincubation of L2 cells with pyrrolidine dithiocarbamate (PDTC) significantly suppressed neopterin-induced ICAM-1 synthesis. Since PDTC is known to be a potent inhibitor of NF-kappaB, the stimulating effects of neopterin on ICAM-1 gene expression and protein generation may be mediated by activation of this transcription factor. From these data we conclude that neopterin stimulates ICAM-1 production in L2 cells. In vivo, these effects may contribute to the prolongation of the inflammatory response, including cytotoxic cell host defence mechanisms that impair the functions of the airway epithelium.

[Implementing limited therapy methods in intensive care units: discontinuing therapy, reducing therapy and withholding therapy in intensive care units of the Innsbruck University Clinics]

INTRODUCTION

The intensive care physician is frequently confronted with the decision to withhold or withdraw therapy in patients with a poor prognosis. Apart from the legal implications, the practical management of withholding or withdrawing intensive care treatment continues to be indistinct. The subject has not been investigated in Austria or Germany. The aim of the study was to examine the different points of view of intensive care physicians and the various procedures to limit therapy in patients with a poor prognosis.

METHODS

We interviewed physicians working at different intensive care departments of the University Hospital of Innsbruck from March to April 1998.

RESULTS

Withholding treatment was given preference over withdrawing treatment. In regard of withdrawing treatment, 64% of the interviewed physicians felt more uncertain. In the decision making process the potential reversibility of disease was estimated to be more important than the wish of the patient. Hemofiltration and antibiotics were mentioned as the first measures the physicians would withdraw. The last measure that would be withheld was ventilatory support. Sixty-three per cent of the physicians felt that sedation and analgesia should be continued. In regard of withholding or withdrawing treatment 83% voted for an obligatory DNR order.

CONCLUSION

Before withholding or withdrawing intensive care therapy, a medical specialist must determine and document the futile prognosis of the patient. If the patient's wish is unknown, all further decisions should be made in agreement with all participants. The goal of the therapy is to provide the patient maximum comfort under minimal intensive care treatment.

Immunologic changes after transfusion of autologous or allogeneic buffy coat-poor versus white cell-reduced blood to patients undergoing arthroplasty. I. Proliferative T-cell responses and the balance of helper and suppressor T cells

BACKGROUND

Donor white cells (WBCs) contained in red cell (RBC) transfusions are thought to provoke down-regulation of T-cell-mediated immunity. This study investigated this topic in otherwise healthy patients receiving buffy coat-depleted or WBC-filtered RBCs and undergoing standardized perioperative management.

STUDY DESIGN AND METHODS

Patients undergoing elective orthopedic surgery (primary hip and knee replacement surgery) were enrolled in a prospective study. Perioperative changes in T-cell proliferation (stimulation with phytohemagglutinin and mixed lymphocyte culture) and T-cell balance (T-lymphocytes, helper T cells, and suppressor T cells) were compared after random assignment to allogeneic buffy coat-depleted (Group 2, n = 8) or WBC-reduced RBC (Group 3, n = 11) transfusion regimens. Recipients of autologous buffy coat-depleted RBC transfusions (n = 15) served as controls (Group 1).

RESULTS

Compared to that in autologous transfusion recipients, alloantigen-induced T-cell proliferation was significantly reduced in recipients of allogeneic WBC-reduced RBCs (Day 3, p = 0.0274). After the transfusion of allogeneic buffy coat-depleted RBCs, a weak trend toward decreased T-cell proliferation was observed (p = 0.0933) and the numbers of CD4+ T cells were also significantly lower (Day 7, p = 0.0389). On Day 10, alloantigen-induced T-cell proliferation remained significantly below baseline after transfusion of WBC-reduced RBCs (p = 0.05), the numbers of CD3+ cells decreased in allogeneic RBC recipients (Group 2, p = 0.078; Group 3, p = 0.05), and those of CD8+ cells decreased significantly after the transfusion of allogeneic buffy coat-depleted RBCs (p = 0.0234) concomitant with an increased CD4:CD8 ratio (p = 0.0391).

CONCLUSION

Results of the present study confirm the hypothesis of impaired T-cell-mediated immunity after allogeneic transfusion.