Bengt Gårdlund

Drotrecogin Alfa (Activated) in Adults with Septic Shock

BACKGROUND There have been conflicting reports on the efficacy of recombinant human activated protein C, or drotrecogin alfa (activated) (DrotAA), for the treatment of patients with septic shock. METHODS In this randomized, double-blind, placebo-controlled, multicenter trial, we assigned 1697 patients with infection, systemic inflammation, and shock who were receiving fluids and vasopressors above a threshold dose for 4 hours to receive either DrotAA (at a dose of 24 μg per kilogram of body weight per hour) or placebo for 96 hours. The primary outcome was death from any cause 28 days after randomization. RESULTS At 28 days, 223 of 846 patients (26.4%) in the DrotAA group and 202 of 834 (24.2%) in the placebo group had died (relative risk in the DrotAA group, 1.09; 95% confidence interval [CI], 0.92 to 1.28; P=0.31). At 90 days, 287 of 842 patients (34.1%) in the DrotAA group and 269 of 822 (32.7%) in the placebo group had died (relative risk, 1.04; 95% CI, 0.90 to 1.19; P=0.56). Among patients with severe protein C deficiency at baseline, 98 of 342 (28.7%) in the DrotAA group had died at 28 days, as compared with 102 of 331 (30.8%) in the placebo group (risk ratio, 0.93; 95% CI, 0.74 to 1.17; P=0.54). Similarly, rates of death at 28 and 90 days were not significantly different in other predefined subgroups, including patients at increased risk for death. Serious bleeding during the treatment period occurred in 10 patients in the DrotAA group and 8 in the placebo group (P=0.81). CONCLUSIONS DrotAA did not significantly reduce mortality at 28 or 90 days, as compared with placebo, in patients with septic shock. (Funded by Eli Lilly; PROWESS-SHOCK ClinicalTrials.gov number, NCT00604214.).

Postoperative mediastinitis in cardiac surgery — microbiology and pathogenesis

OBJECTIVE During 1992-2000, postoperative mediastinitis developed after 126 (1.32%) of 9557 consecutive cardiac surgery procedures. The study was done to describe the variation in clinical characteristics and microbiological etiology in mediastinitis. METHODS The records of 126 cases of postoperative mediastinitis were reviewed. RESULTS The median time from operation to the development of mediastinitis was 7 days. Sternal dehiscence was seen in 86 patients (68%). Coagulase negative staphylococci (CNS) were isolated in 46% of the cases with a verified microbiological etiology, Staphylococcus aureus in 26% and gram-negative bacteria in 18%. CNS were more frequently isolated in patients with sternal dehiscence (44/80, 55%) than in patients with stable sternum (10/38, 26%) (P=0.003). However, S. aureus was more frequent in patients with stable sternum (18/38, 47%) than in patients with sternal dehiscence (13/80, 16%) (P<0.001). High body mass index was associated with coagulase negative staphylococci (P<0.001) and with sternal dehiscence (P=0.008). Chronic obstructive pulmonary disease was also associated with sternal dehiscence (P<0.001) and with coagulase negative staphylococci (P=0.04). Patients who had been reoperated before onset of mediastinitis tended to have an increased risk for a gram-negative etiology (32 vs. 15% in patients not reoperated, P=0.06). The overall 90-day all cause mortality in patients with mediastinitis was 19%. High age, need for reoperation before mediastinitis, and a long primary operation time was associated with increased mortality (P=0.02, P=0.007 and P=0.001, respectively). No specific bacterial etiology was associated with increased mortality nor was the presence of bacteriemia. CONCLUSIONS Three different types of postoperative mediastinitis can be distinguished: (1) mediastinitis associated with obesity, chronic obstructive pulmonary disease, and sternal dehiscence, typically caused by coagulase negative staphylococci; (2) mediastinitis following peroperative contamination of the mediastinal space, often caused by S. aureus, and (3) mediastinitis mainly caused by spread from concomitant infections in other sites during the postoperative period, often caused by gram negative rods. The proposed classification of mediastinitis into three groups with different pathogenic mechanisms may be useful in understanding which prophylactic counter measures have the potentials to be effective in a given situation.

Randomized, placebo-controlled trial of the anti-tumor necrosis factor antibody fragment afelimomab in hyperinflammatory response during severe sepsis: The RAMSES study

ObjectiveThis study investigated whether treatment with the anti-tumor necrosis factor-&agr; monoclonal antibody afelimomab would improve survival in septic patients with serum interleukin (IL)-6 concentrations of >1000 pg/mL. DesignMulticenter, double-blind, randomized, placebo-controlled study. SettingEighty-four intensive care units in academic medical centers in Europe and Israel. PatientsA total of 944 septic patients were screened and stratified by the results of a rapid qualitative immunostrip test for serum IL-6 concentrations. Patients with a positive test kit result indicating IL-6 concentrations of >1000 pg/mL were randomized to receive either afelimomab (n = 224) or placebo (n = 222). Patients with a negative IL-6 test (n = 498) were not randomized and were followed up for 28 days. InterventionsTreatment consisted of 15-min infusions of 1 mg/kg afelimomab or matching placebo every 8 hrs for 3 days. Standard surgical and intensive care therapy was otherwise delivered. Measurements and Main Results The study was terminated prematurely after an interim analysis estimated that the primary efficacy end points would not be met. The 28-day mortality rate in the nonrandomized patients (39.6%, 197 of 498) was significantly lower (p < .001) than that found in the randomized patients (55.8%, 249 of 446). The mortality rates in the IL-6 test kit positive patients randomized to afelimomab and placebo were similar, 54.0% (121 of 224) vs. 57.7% (128 of 222), respectively. Treatment with afelimomab was not associated with any particular adverse events. ConclusionsThe IL-6 immunostrip test identified two distinct sepsis populations with significantly different mortality rates. A small (3.7%) absolute reduction in mortality rate was found in the afelimomab-treated patients. The treatment difference did not reach statistical significance.

Design, conduct, analysis and reporting of a multi-national placebo-controlled trial of activated protein C for persistent septic shock.

The role of drotrecogin alfa (activated) (DAA) in severe sepsis remains controversial and clinicians are unsure whether or not to treat their patients with DAA. In response to a request from the European Medicines Agency, Eli Lilly will sponsor a new placebo-controlled trial and history suggests the results will be subject to great scrutiny. An academic steering committee will oversee the conduct of the study and will write the study manuscripts. The steering committee intends that the study will be conducted with the maximum possible transparency; this includes publication of the study protocol and a memorandum of understanding which delineates the role of the sponsor. The trial has the potential to provide clinicians with valuable data but patients will only benefit if clinicians have confidence in the conduct, analysis and reporting of the trial. This special article describes the process by which the trial was developed, major decisions regarding trial design, and plans for independent analysis, interpretation and reporting of the data.

Plasmic degradation products of human fibrinogen. I. Isolation and characterization of fragments E and D and their relation to “disulfide knots”

Abstract Separation of degradation products from human fibrinogen (Fragments A–E) after digestion with plasmin has been performed, using gel filtration in 10 % acetic acid on Sephadex G-100. Fragments D and E have been partly characterized and related to “disulfide knots” obtained from cyanogen bromide (CNBr) treated fibrinogen. Fragment E seems to contain three pairs of polypeptide chains, linked together by disulfide bonds, forming a dimeric molecule with a molecular weight of about 50 000. Immunologically and chemically it was found to have similarities with the NH2-terminal disulfide knot (N-DSK). Fragment D was found to be heterogeneous with a molecular weight range of 86 000 – 96 000. It seems to be built up by three polypeptide chains linked by disulfide bridges. Two or three hydrophobic disulfide containing products can be obtained from Fragment D after cleavage of this with CNBr. These products are similar with the three hydrophobic disulfide knots (H1-DSK, H2-DSK and H3-DSK), isolated from native fibrinogen after cleavage with CNBr. Furthermore our results suggest that Fragment D is located in a close proximity to N-DSK.

Fibrinogen and fibrin formation

Abstract The present day concept of the primary structure of fibrinogen is outlined. Cleavage of the molecule with CNBr and plasmin has yielded a number of fragments which account for almost all of the structure of the chains (Aα, Bβ and γ) of the molecule. The three chains are linked together by disulfide bridges forming a structure with a unit weight of 170,000. This half-molecule is then joined to another identical half-molecule by means of symmetrical disulfides at the NH 2 -terminal ends. Consequently fibrinogen is a dimeric structure satisfying the formula (Aα, Bβ, γ) 2 . Fibrinogen is activated by thrombin-catalyzed hydrolysis, during which two peptides (fibrinopeptide A and B) are released from the NH 2 -terminal portion of the Aα-and Bβ-chains, respectively. Kinetic studies have shown, by and large, that in its proteolytic action, thrombin recognizes only the first 51 amino acid residues of the Aα-chain of fibrinogen. Recognition of the Bβ-chain with release of fibrinopeptide B appears to occur only after polymerization has commenced. There exist two functional domains in fibrinogen, the interaction of which are of importance for fibrin formation. One functional domain (A-A′) is located in the NH 2 -terminal portion of the molecule. This domain, which includes the fibrinopeptide structures, requires activation with thrombin in order to become functionable. The other domain (a-a′) is located in the carboxyterminal region of the molecule and is active already in fibrinogen as it circulates in blood. The ordered alignment of fibrinogen units in the fibrin fiber can be explained by the interaction between the NH 2 -terminal domain (A or A′) of one molecule with the carboxyterminal domain (a or a′) of another molecule.

Swedish guidelines for diagnosis and treatment of infective endocarditis

Swedish guidelines for diagnosis and treatment of infective endocarditis (IE) by consensus of experts are based on clinical experience and reports from the literature. Recommendations are evidence based. For diagnosis 3 blood cultures should be drawn; chest X-ray, electrocardiogram, and echocardiography preferably transoesophageal should be carried out. Blood cultures should be kept for 5 d and precede intravenous antibiotic therapy. In patients with native valves and suspicion of staphylococcal aetiology, cloxacillin and gentamicin should be given as empirical treatment. If non-staphylococcal etiology is most probable, penicillin G and gentamicin treatment should be started. In patients with prosthetic valves treatment with vancomycin, gentamicin and rifampicin is recommended. Patients with blood culture negative IE are recommended penicillin G (changed to cefuroxime in treatment failure) and gentamicin for native valve IE and vancomycin, gentamicin and rifampicin for prosthetic valve IE, respectively. Isolates of viridans group streptococci and enterococci should be subtyped and MIC should be determined for penicillin G and aminoglycosides. Antibiotic treatment should be chosen according to sensitivity pattern given 2–6 weeks intravenously. Cardiac valve surgery should be considered early, especially in patients with left-sided IE and/or prosthetic heart valves. Absolute indications for surgery are severe heart failure, paravalvular abscess, lack of response to antibiotic therapy, unstable prosthesis and multiple embolies. Follow-up echocardiography should be performed on clinical indications.

Plasmapheresis in the Treatment of Primary Septic Shock in Humans

14 patients (mean age 25.5 yrs) with life-threatening primary septic shock were eligible for treatment with acute plasmapheresis in a prospective study. They had a short history of sepsis and had no severe underlying disease. 10/14 patients had systemic meningococcal disease. All patients were severely ill with a mean APACHE II score of 25.0. 12/14 patients were treated with plasmapheresis exchanging 1 plasma volume within hours of admission. 11/14 patients survived without major sequelae and 3 (21%) died of irreversible septic shock. This mortality is lower than that predicted from the APACHE II scores (55.2%). A subgroup of plasmapheresis-treated patients with septic shock and extensive petechiae were compared to a historical control group. The mortality in the treatment group was 1/7 (14%) versus 8/21 (38%) in the control group. We conclude that acute plasmapheresis may be a therapeutic option in the early stages of severe primary non-surgical septic shock.

Postoperative surgical site infections in cardiac surgery : an overview of preventive measures

Postoperative surgical site infections are a major cause of postoperative morbidity and mortality in cardiac surgery. A surgical site infection occurs when the contaminating pathogens overcome the host defense systems and an infectious process begins. Bacteria may enter the operating site either by direct contamination from the patients skin or internal organs, through the hands and instruments of the surgical staff or by bacteria‐carrying particles that float around in the operating theatre and may land in the wound. The ability to withstand the contaminating bacteria depends on both local and systemic host defense. Successful preventive strategies are multiple and must include: 1) Minimizing the bacterial contamination of the surgical site (skin preparation, operating room ventilation, scrubbing, double gloving, etc.), 2) Minimizing the consequences of virulent contaminating bacteria by antibiotic prophylaxis (adequate dose, sort, timing, duration), 3) Minimizing injury to local host defense (atraumatic surgery, no excessive electrocautery, meticulous hemostasis, etc.), and 4) Optimizing general host defense (nutrition, tobacco smoking, weight loss, etc.). Compliance with these preventive procedures must be enforced through regular reviews of performance. Non‐compliance with hygiene routines is often due to ignorance and poor planning. Education of personnel in these issues is a continuous process.

ELISpot analysis of LPS-stimulated leukocytes: Human granulocytes selectively secrete IL-8, MIP-1β and TNF-α

Granulocytes and monocytes/macrophages represent key effector cells of the innate immune system. While human monocytes have been recognized as capable of secreting a broad spectrum of cytokines, the situation has been less clear in granulocytes with studies often showing conflicting results. In this study, lipopolysaccharide (LPS)-induced cytokine secretion from polymorphonuclear cells (PMN) and peripheral blood mononuclear cells (PBMC) was analyzed at the single cell level with the enzyme-linked immunospot (ELISpot) assay. This method allowed us to establish the cytokine profiles for both PBMC and PMN based on the frequency and pattern of cytokine secreting cells, rather than on the amount of produced cytokine detectable in solution by ELISA. As a result, low levels of contaminating mononuclear cells present in our PMN preparations could be discriminated from granulocytes. Using this technique, neutrophils were found to secrete the two chemokines, IL-8 and MIP-1beta in response to LPS. Also TNF-alpha was secreted but in lower amounts and by significantly fewer cells. However, and as opposed to several other reports, we were unable to detect secretion of IL-1beta, IL-6, IL-10, IL-12 and GM-CSF. In contrast to the limited cytokine production by PMN, PBMC secreted considerably larger amounts of the investigated cytokines with CD14(+) monocytes being the primary source of production. Finally, we believe that the cytokine ELISpot technique may provide a powerful tool by which cells of the innate immune system can be studied from a functional perspective at the single cell level.