Biomedical subjects

J-L Vincent

Publications and source records attributed to J-L Vincent.

10 recordsLinked to original sources

PubMed2006

Assessment of erythrocyte shape by flow cytometry techniques.

BACKGROUND: Red blood cell (RBC) rheology is altered in different diseases, including acute conditions such as patients in intensive care units (ICU) with sepsis or with an inflammatory reaction due to postoperative states or intracerebral haemorrhage, or chronic conditions such as diabetes mellitus or terminal renal failure. Several techniques are available to assess alterations in RBC rheology, especially deformability, but they are too cumbersome to be used on a large number of cells. OBJECTIVE: To develop a new, rapid flow cytometry technique for easy assessment of RBC shape in patients. METHODS: In flow cytometry, healthy human RBC shape shows a bimodal distribution related to the biconcave form. On this histogram, the second Pearson coefficient of dissymmetry (PCD) representing the asymmetry of this histogram and the spherical index (M2:M1) were calculated, both representing the spherical shape. This technique was used in healthy volunteers (n=17) and in diseases characterised by abnormalities in RBC rheology, including terminal renal failure requiring haemodialysis (n=28), diabetes mellitus (n=18), sepsis (n=19) and acute inflammatory states (postoperative, intracerebral haemorrhage, chronic obstructive pulmonary disease, epilepsy or severe drug intoxication; n=21). Multivariate analysis was performed to determine the factors influencing RBC shape. RESULTS: Measurement of RBC shape was highly reproducible. A good correlation was observed between the PCD and the spherical index, except in the critically ill patients without sepsis. RBCs were more spherical in patients with terminal renal failure (PCD -0.56 (0.14), p<0.05), diabetes mellitus (PCD -0.59 (0.23), p<0.05), sepsis (PCD -0.58 (0.22), p<0.05) or an acute inflammatory state (PCD -0.65 (0.29), p<0.05) than in healthy volunteers (PCD -0.89 (0.12)). The spherical index was also increased in all populations compared with healthy volunteers (terminal renal failure 2.30 (0.20); diabetes mellitus 2.27 (0.38); sepsis 2.28 (0.37); acute inflammatory state 2.35 (0.42) vs healthy volunteers 2.72 (0.47); all p<0.05). Multivariate analysis demonstrated that the underlying pathology (sepsis, acute inflammatory state, diabetes mellitus, terminal renal failure) was the principal cause of these RBC shape abnormalities. CONCLUSION: RBCs are characterised by an increased spherical shape in many disease states. The measure of the second PCD in flow cytometry is a new, easy method to investigate RBC shape in various diseases. This technique could facilitate the investigation of abnormalities of RBC rheology.

Acute Disease↗

PubMed2006

Successful treatment of septic shock due to pan-resistant Acinetobacter baumannii using combined antimicrobial therapy including tigecycline.

Reported here is the case of a patient with septic shock due to multidrug-resistant Acinetobacter baumannii, which developed after complicated acute pancreatitis with intra-abdominal abscess. Treatment with colistin methanesulphonate and high doses of meropenem were initiated, but since shock persisted, tigecycline was added to the regimen, resulting in successful resolution of the infection.

Acinetobacter Infections↗

PubMed2006

Critical oxygen delivery during cardiopulmonary bypass in dogs: pulsatile vs. non-pulsatile blood flow.

BACKGROUND AND OBJECTIVE: To determine the minimal oxygen delivery and pump flow that can maintain systemic oxygen uptake during normothermic (37 degrees C) pulsatile and non-pulsatile cardiopulmonary bypass in dogs. METHODS: Eighteen anaesthetized dogs were randomly assigned to receive either non-pulsatile (Group C; n = 9) or pulsatile bypass flow (Group P; n = 9). Oxygen delivery was reduced by a progressive decrease in pump flow, while arterial oxygen content was maintained constant. In each animal, critical oxygen delivery was determined from plots of oxygen uptake vs. oxygen delivery and from plots of blood lactate vs. oxygen delivery using a least sum of squares technique. Critical pump flow was determined from plots of lactate vs. pump flow. RESULTS: At the critical point, oxygen delivery obtained from oxygen uptake was 7.7 +/- 1.1 mL min(-1) kg(-1) in Group C and 6.8 +/- 1.8 mL min(-1) kg(-1) in Group P (n.s.). These values were similar to those obtained from lactate measurements (Group C: 7.8 +/- 1.6 mL min(-1) kg(-1); Group P: 7.6 +/- 2.0 mL min(-1) kg(-1)). Critical pump flows determined from lactate measurements were 55.6 +/- 13.8 mL min(-1) kg(-1) in Group C and 60.8 +/- 13.9 mL min(-1) kg(-1) in Group P (n.s.). CONCLUSIONS: Oxygen delivery values greater than 7-8 mL min(-1) kg(-1) were required to maintain oxygen uptake during normothermic cardiopulmonary bypass with either pulsatile or non-pulsatile blood flow. Elevation of blood lactate levels during bypass helps to identify inadequate tissue oxygen delivery related to insufficient pump flow.

Algorithms↗

PubMed2004

[Laparoscopy under local anaesthesia and hypnoanaesthesia about 35 cholecystectomies and 15 inguinal hernia repair].

OBJECTIVE: To present hypnosedation and the feasibility of this technique performed for laparoscopic procedure. STUDY DESIGN: Retrospective and descriptive study of feasibility. PATIENTS AND METHODS: Hypnosis can significantly reduce intraoperative requirements of intravenous sedation for surgery under local anaesthesia. Modifications of surgical procedure: laparoscopic surgery under local anaesthesia and hypnosis is performed using a subcutaneous lifting of anterior abdominal wall. Insufflation is only use to push out smoke. If patient or surgical uncomfort happens, moral contract with patient includes convert to general anaesthesia. RESULTS: We performed 35 cholecystectomies; 13 needed convert to general anaesthesia, mainly for peritoneal pain induced by CO(2) insufflation; 22 procedures were completed with patients' satisfaction. Upon 15-hernia repairs, only one patient needed convert to general anaesthesia, for dissection difficulty. CONCLUSION: Probably hypnosis can't be extent to intraperitoneal laparoscopic procedures. On the other hand interest of hypnosis performed for extraperitoneal laparoscopic hernia repair must be explore.

Adult↗

PubMed2004

Ventilator-associated pneumonia.

Ventilator-associated pneumonia is the most common nosocomial infection. Mortality rates, morbidity, and costs are all increased in the patient with VAP, and every measure should thus be taken to prevent its development. There are several clearly defined risk factors for VAP, and awareness of these can facilitate early diagnosis and hence treatment. In this article, we discuss the risk factors, strategies for prevention, approaches to diagnosis and management plan for the patient with VAP.

Algorithms↗

PubMed2004

Effects of low-dose dopamine on ventilation in patients with chronic obstructive pulmonary disease.

BACKGROUND: Dopamine plays an important role in the regulation of respiration and low-dose dopamine infusion is associated with a decreased respiratory drive response to hypoxia in animals and humans. The effects of dopamine on ventilation in patients with chronic obstructive pulmonary disease (COPD) is unknown. We tested the hypothesis that dopamine inhibits ventilation in patients with COPD. MATERIALS AND METHODS: In a double-blinded, cross-over, placebo-controlled, randomized study we studied nine patients with decompensated COPD, ventilated in the pressure support mode in the intensive care unit (ICU) and five ambulatory patients with stable COPD. All patients received 5 micro g kg(-1) min(-1) of dopamine or an equivalent volume of 5% glucose solution. RESULTS: In the mechanically ventilated COPD patients, there was no difference in the effects of dopamine compared with placebo on blood pressure, heart rate, minute ventilation (-0.5 +/- 1.1 vs. -0.2 +/- 0.9 L min(-1), P = 0.46, respectively), respiratory rate (-0.4 +/- 2.7 vs. -0.3 +/- 2.1 min(-1), P = 0.96), PaO(2) (-5 +/- 4 vs. -5 +/- 10 mmHg, P = 0.90, respectively), or PaCO(2) (-0.7 +/- 1.4 vs. -1.0 +/- 3.4 mmHg, P = 0.83, respectively). In spontaneously breathing stable patients, dopamine increased systolic blood pressure (P = 0.02) but did not influence other haemodynamic and respiratory variables. CONCLUSION: Although low-dose dopamine has been shown to depress ventilation in a variety of conditions, it does not compromise ventilation in COPD patients either breathing spontaneously or when weaned using pressure support ventilation.

Aged↗

PubMed2004

Potential risk factors for infection with Candida spp. in critically ill patients.

The incidence, risk factors and prognostic factors for candidal infection were determined in a prospective study of 280 infected patients. Thirty-one (11%) patients were infected with Candida spp., sub-divided into 18 (58%) with C. albicans, and 13 (42%) with non-albicans spp. (six C. glabrata, three C. parapsilosis, and one each of C. krusei, C. tropicalis, C. guilliermondii and C. lusitaniae). Infection with Candida spp. was always associated with concurrent bacterial infection. By univariate logistic regression analysis, the degree of morbidity and the duration of mechanical ventilation were independent predictive factors for death, but infection with Candida spp., was not. Factors associated with Candida spp. infection were the degree of morbidity, intensive care unit length of stay, alterations of immune response, and the number of medical devices involved. By multivariate logistic regression analysis, the only independent risk factor for candidal infection was intensive care unit length of stay.

Adult↗

PubMed2004

Platelet function in sepsis.

BACKGROUND: Coagulation abnormalities and thrombocytopenia are common in severe sepsis, but sepsis-related alterations in platelet function are ill-defined. OBJECTIVES: The purpose of this study was to elucidate the effect of sepsis on platelet aggregation, adhesiveness, and growth factor release. PATIENTS AND METHODS: Agonist-induced platelet aggregation was measured in platelet-rich plasma separated from blood samples collected from 47 critically ill patients with sepsis of recent onset. Expression of platelet adhesion molecules was measured by flow cytometry and the release of vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) was measured by ELISA in the supernatant of platelet aggregation. RESULTS: Septic patients had consistently decreased platelet aggregation compared with controls, regardless of the platelet count, thrombin generation, or overt disseminated intravascular coagulation (DIC) status. The severity of sepsis correlated to the platelet aggregation defect. Adhesion molecules, receptor expression (CD42a, CD42b, CD36, CD29, PAR-1), and alpha-granule secretion detected by P-selectin expression remained unchanged but the release of growth factors was differentially regulated with increased VEGF and unchanged PDGF after agonist activation even in uncomplicated sepsis. CONCLUSIONS: Sepsis decreases circulating platelets' hemostatic function, maintains adhesion molecule expression and secretion capability, and modulates growth factor production. These results suggest that sepsis alters the hemostatic function of the platelets and increases VEGF release in a thrombin-independent manner.

Aged↗

PubMed2003

Red blood cell rheology in sepsis.

Changes in red blood cell (RBC) function can contribute to alterations in microcirculatory blood flow and cellular dysoxia in sepsis. Decreases in RBC and neutrophil deformability impair the passage of these cells through the microcirculation. While the role of leukocytes has been the focus of many studies in sepsis, the role of erythrocyte rheological alterations in this syndrome has only recently been investigated. RBC rheology can be influenced by many factors, including alterations in intracellular calcium and adenosine triphosphate (ATP) concentrations, the effects of nitric oxide, a decrease in some RBC membrane components such as sialic acid, and an increase in others such as 2,3 diphosphoglycerate. Other factors include interactions with white blood cells and their products (reactive oxygen species), or the effects of temperature variations. Understanding the mechanisms of altered RBC rheology in sepsis, and the effects on blood flow and oxygen transport, may lead to improved patient management and reductions in morbidity and mortality.

Belgium↗

PubMed2003

Safety of human albumin--serious adverse events reported worldwide in 1998-2000.

BACKGROUND: Previous pharmacovigilance studies have indicated a low rate of adverse events in patients receiving human albumin. However, the incidence of adverse events is likely to have been underestimated because of under-reporting. A more accurate estimate may be possible during a period such as 1998-2000, when awareness regarding albumin safety was heightened by publication of a meta-analysis. METHODS: All serious adverse event reports received, and total doses of albumin distributed worldwide from the beginning of 1998 to the end of 2000 by 10 major suppliers of therapeutic human albumin were compiled. RESULTS: Distributed albumin doses totalled 1.62 x 10(7). The total numbers of non-fatal and fatal serious adverse events reported were 198 and 13, respectively. The incidence of all reported serious non-fatal and fatal adverse events was 5.28 per 10(6) doses (CI 1.60-17.4 per 10(6) doses). For non-fatal serious adverse events only, the observed incidence was 4.65 per 10(6) doses (CI 1.34-16.2 per 10(6) doses). No patient death was classified as probably related to albumin administration. The observed incidence of fatal serious adverse events possibly related to albumin was 0.185 per 10(6) doses (CI 0.0597-0.574 per 10(6) doses). The observed incidence of all non-fatal and fatal serious adverse events was significantly higher during the 1998-2000 period as compared with 1990-1997 (incidence rate ratio 4.98; CI 3.94-6.29), probably chiefly as a result of reduced under-reporting. CONCLUSIONS: Although the observed incidence of adverse events is likely to be an underestimate, nevertheless both non-fatal and fatal serious adverse events in albumin recipients appear to be rare. These results add further support to the excellent safety record of human albumin.

Adverse Drug Reaction Reporting Systems↗