[Extracorporeal life support in thoracic surgery: What are the indications and the pertinence?] / Support extracorporel en chirurgie thoracique : quelles indications et quels intérêts ?

INTRODUCTION: In thoracic surgery, extracorporeal life support (ECLS) technologies are used in cases of severe and refractory respiratory failure or as intraoperative cardiorespiratory support. The objectives of this review are to describe the rationale of ECLS techniques, to review the pulmonary diseases potentially treated by ECLS, and finally to demonstrate the efficacy of ECLS, using recently published data from the literature, in order to practice evidence based medicine. STATE OF THE ART: ECLS technologies should only be undertaken in expert centers. ECLS allows a protective ventilatory strategy in severe ARDS. In the field of lung transplantation, ECLS may be used successfully as a bridge to transplantation, as intraoperative cardiorespiratory support or as a bridge to recovery in cases of severe primary graft dysfunction. In general thoracic surgery, ECLS technology seems to be safe and efficient as intraoperative respiratory support for tracheobronchial surgery or for severe respiratory insufficiency, without significant increase in perioperative risk. PERSPECTIVE: The indications for ECLS are going to increase. Future improvements both in scientific knowledge and bioengineering will improve the prognosis of patients treated with ECLS for respiratory failure. Multicenter randomized controlled trials will refine the indications for ECLS and improve the global care strategies for these patients. CONCLUSION: ECLS is an efficient therapeutic strategy that will improve the prognosis of patients suffering from, or exposed to, the risks of severe respiratory failure.

Microparticles and infectious diseases.

Membrane shedding with microvesicle (MV) release after membrane budding due to cell stimulation is a highly conserved intercellular interplay. MV can be released by micro-organisms or by host cells in the course of infectious diseases. Host MVs are divided according to cell compartment origin in microparticles (MPs) from plasma membrane and exosomes from intracellular membranes. MPs are cell fragments resulting from plasma membrane reorganization characterized by phosphatidylserine (PhtdSer) content and parental cell antigens on membrane. The role of MPs in physiology and pathophysiology is not yet well elucidated; they are a pool of bioactive molecules able to transmit a pro-inflammatory message to neighboring or target cells. The first acknowledged function of MP was the dissemination of a procoagulant potential via PhtdSer and it is now obvious than MPs bear tissue factor (TF). Such MPs have been implicated in the coagulation disorders observed during sepsis and septic shock. MPs have been implicated in the regulation of vascular tone and cardiac dysfunction in experimental sepsis. Beside a non-specific role, pathogens such as Neisseria meningitidis and Ebola Virus can specifically activate blood coagulation after TF-bearing MPs release in the bloodstream with disseminated intravascular coagulopathy and Purpura fulminans. The role of MPs in host-pathogen interactions is also fundamental in Chagas disease, where MPs could allow immune evasion by inhibiting C3 convertase. During cerebral malaria, MPs play a complex role facilitating the activation of brain endothelium that contributes to amplify vascular obstruction by parasitized erythrocytes. Phagocytosis of HIV induced MPs expressing PhtdSer by monocytes/macrophages results in cellular infection and non-inflammatory response via up-regulation of TGF-ß.

[Implication of dexamethasone adjunctive therapy after the onset of cerebral vasculitis in Streptococcus pneumoniae meningitis]. / Implication du traitement adjuvant par dexaméthasone dans la survenue d'une artérite septique cérébrale au cours d'une méningite à Streptococcus pneumoniae.

Few adverse effects have been reported with adjunctive dexamethasone treatment in pneumococcal meningitis. Nevertheless, we report a case of cerebral vasculitis. A 49-year-old man was admitted for fever and altered mental status. Lumbar puncture revealed a high inflammatory response and Streptococcus pneumoniae was identified by culture. Antibacterial therapy and adjunctive dexamethasone treatment were initiated as recommended. The immediate outcome was favorable but due to the onset of focal cerebral abnormalities, a CT scan was performed on the ninth day showing cerebral vasculitis. The patient died on the thirteenth day despite antibacterial therapy and resuscitation. In our case, a secondary neurological worsening appeared when adjunctive dexamethasone treatment was stopped suggesting a rebound effect. Observation of similar cases may lead to modifying adjunctive dexamethasone treatment protocol in bacterial meningitis.

[Microparticles during sepsis and trauma. A link between inflammation and thrombotic processes]. / Microparticules circulantes au cours des traumatismes graves et des sepsis: un élément du couplage inflammation-thrombose.

Sepsis and trauma lead to a sustained activation of monocytes and endothelium. In the vascular compartment, stimulated cells release microparticles. Circulating MP provide an additional procoagulant phospholipid surface enabling the assembly of the clotting enzymes complexes and thrombin generation. Their procoagulant properties rely on the exposition of phosphatidylserine, made accessible after cell stimulation and on the possible presence of tissue factor, the main cellular initiator of blood coagulation. Microparticles constitute the main reservoir of blood-borne tissue factor activity. At sites of endothelium injury, enhanced release or recruitment of procoagulant MP through P-selectin-PSGL-1 pathway could concentrate TF activity above a threshold allowing blood coagulation to be triggered. Converging evidences from experimental or clinical data highlight a role for MP harboring tissue factor in the initiation of disseminated intravascular coagulopathy. In these settings, the pharmacological modulation of MP levels or biological functions through activated protein C or factor VIIa allows challenging issues.

Oxacillin susceptibility testing of staphylococci directly from Bactec Plus blood cultures by the BBL Crystal MRSA ID system.

The BBL Crystal MRSA ID test (Becton Dickinson) was applied directly to blood culture vials containing clusters of gram-positive cocci. The sensitivity and specificity of the test were 84 and 100% and 54 and 100% for vials containing Staphylococcus aureus and coagulase-negative staphylococci, respectively. This test is a reliable method for direct detection of methicillin resistance in positive blood culture vials when S. aureus is identified in parallel by rapid identification procedures.

Frequency of isolation of Staphylococcus intermedius from humans.

We collected 3,397 consecutive isolates of coagulase-positive staphylococci from various specimens of hospitalized patients. All were retrospectively classified as Staphylococcus aureus, except two which were identified as S. intermedius: one isolated from the nasal flora of a healthy carrier and the other isolated from pleural fluid, probably as a sample contaminant.