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Biomedical subjects

J L Vincent

Publications and source records attributed to J L Vincent.

At least 55 records · Page 3Linked to original sources
PubMed2001

[Peripartum cardiomyopathy].

Peripartum cardiomyopathy is a rare, potentially life-threatening cardiomyopathy of unknown cause. Diagnosis includes clinical (development of cardiac failure in the last month of pregnancy or within 5 months after delivery, absence of an identifiable cause of cardiac failure and absence of recognizable heart disease prior to the last month of pregnancy) and echographic (left ventricular systolic dysfunction) criteria. Therapy is standard, except for angiotensin converting enzyme inhibitors, which should be avoided at the end of pregnancy, and heart transplantation if medical treatment fails. We report the case of a 24 year-old woman who required left ventricular assistance as a bridge before cardiac transplantation.

Adult↗
PubMed2001

Tube and column agglutination technology for autocontrol testing.

The incidence of positive autocontrol test results with column agglutination technology is a concern. This study investigates the incidence and significance of positive autocontrols in the ID Micro Typing System (gel) and the Gamma ReACT (ReACT). The study encompassed a total of 1021 randomly selected samples from patients and 95 samples from donors collected during 1 month. The autocontrol testing was carried out according to the manufacturer's instructions for the column agglutination tests. The tube method was carried out using low-ionic-strength solution (LISS). The direct antiglobulin test (DAT) was performed using the tube method, and further investigated with elution studies if warranted. Seventy-nine patient's samples (7.74%) had a positive autocontrol: the gel test, 72 (91.13%); ReACT, 21 (26.58%); and the tube method, 27 (34.18%). Of the 79 positive autocontrols, 44 samples had a negative DAT. Of the samples with positive DAT results, only one possessed a clinically significant antibody, anti-D. Moreover, the same sample also tested positive in all three methods. Column agglutination techniques have increased sensitivity for a positive autocontrol beyond the conventional tube method. However, ReACT and gel tests differ significantly in their frequency of positives. Investigation of the significance of a positive autocontrol in column agglutination technology when the conventional tube method is also positive is suggested.

Journal Article↗
PubMed2000

Issues in contemporary fluid management.

Fluid management strategies need to be guided by an understanding of the pathophysiologic mechanisms underlying fluid imbalance. In the hypovolaemic patient, reduced circulating blood volume and venous return and, in severe cases, altered tissue perfusion may initiate a cascade of pathophysiologic processes culminating in multiple organ failure. The objectives of fluid management are to maintain adequate blood pressure, tissue oxygenation and intravascular fluid volume. Both crystalloids and colloids can be useful for these purposes. In the hypovolaemic patient with normal pulmonary function, the use of colloids to maintain colloid osmotic pressure can limit the development of peripheral as well as pulmonary oedema. However, choice of fluid is less important in states of increased lung capillary permeability. Further evidence is needed to broaden understanding of the optimal roles for particular fluid management strategies. Experimental models can make an important contribution in gathering such evidence. Rigorous pharmacoeconomic studies are also needed to define the benefits and costs of differing fluid regimens.

Critical Care↗
PubMed2000

Fluid management: the pharmacoeconomic dimension.

Cost is a key concern in fluid management. Relatively few data are available that address the comparative total costs of care between different fluid management regimens in particular clinical indications. Relevant costs of fluid-associated morbidity and mortality, including those incurred after intensive care unit or hospital discharge, also need to be considered in evaluating the cost-benefit ratios of administered fluids. Rigorously designed pharmacoeconomic studies are needed to delineate the costs and benefits of various approaches to fluid management.

Cost-Benefit Analysis↗
PubMed2000

Microbial resistance: lessons from the EPIC study. European Prevalence of Infection.

In 1992, a one day point prevalence study (EPIC) was conducted in European intensive care units (ICUs) to determine the prevalence of nosocomial infection among ICU patients. Of the 10,038 patients included, 45% were infected and 21% had a nosocomial ICU-acquired infection. Many of the organisms responsible for these infections were resistant to commonly used antibiotics. For example, 60% of the Staphylococcus aureus isolated were resistant to methicillin and 46% of Pseudomonas aeruginosa were resistant to gentamicin. The incidence of nosocomial infection varied between countries as did the incidence of antibiotic resistance. Mortality rates were higher in countries with higher rates of nosocomial infection and higher again in those countries with higher rates of resistant organisms. Antibiotic resistance is rising and clearly efforts to contain its development and spread are vital. Basic infection control procedures such as hand-washing must be developed and implemented, and antibiotic prescribing needs to be rationalized. The international variations in resistance rates, even within Europe, highlight the importance of being familiar with local resistance patterns when prescribing. The assistance of an infectious diseases specialist can be invaluable in providing a global overview of the local microbial milieu and of antibiotic resistance patterns. Epidemiological studies of this sort can provide useful information which can be used to stimulate debate on the reasons behind regional differences in infection and help in the development of strategies to combat the rising tide of microbial antibiotic resistance.

Adolescent↗
PubMed2000

Report from the meeting: Gastrointestinal Tonometry: State of the Art. 22nd-23rd May 1998, London, UK.

Gastrointestinal (GI) tonometry, the only clinically available method for the accurate diagnosis of compromised GI blood flow, has been shown to be a sensitive predictor of increased morbidity, mortality and prolonged hospitalization. The recent introduction of the Tonocap, as a means of performing automated air tonometry, has simplified the application of GI tonometry in the clinical setting. Despite this the utility of GI tonometry remains controversial. The GI Tonometry: State of the Art meeting brought together a group of clinicians with a proven track record of research, clinical interest and expertise in this field. The aim of the meeting was to come to a consensus regarding certain issues such as the past and future roles of GI tonometry and standards for its correct usage and interpretation. Finally suggestions as to further research and clinical evaluation were made within a broader discussion regarding the complexities of applying the principles of evidence-based medicine to the introduction of a new piece of medical technology.

Carbon Dioxide↗
PubMed2000

Acute renal failure in the ICU: risk factors and outcome evaluated by the SOFA score.

OBJECTIVES: To describe risk factors for the development of acute renal failure (ARF) in a population of intensive care unit (ICU) patients, and the association of ARF with multiple organ failure (MOF) and outcome using the sequential organ failure assessment (SOFA) score. DESIGN: Prospective, multicenter, observational cohort analysis. SETTING: Forty ICUs in 16 countries. PATIENTS: All patients admitted to one of the participating ICUs in May 1995, except those who stayed in the ICU for less than 48 h after uncomplicated surgery, were included. After the exclusion of 38 patients with a history of chronic renal failure requiring renal replacement therapy, a total of 1411 patients were studied. MEASUREMENTS AND RESULTS: Of the patients, 348 (24.7%) developed ARF, as diagnosed by a serum creatinine of 300 micromol/l (3.5 mg/dl) or more and/or a urine output of less than 500 ml/day. The most important risk factors for the development of ARF present on admission were acute circulatory or respiratory failure; age more than 65 years, presence of infection, past history of chronic heart failure (CHF), lymphoma or leukemia, or cirrhosis. ARF patients developed MOF earlier than non-ARF patients (median 24 vs 48 h after ICU admission, p < 0.05). ARF patients older than 65 years with a past history of CHF or with any organ failure on admission were most likely to develop MOF. ICU mortality was 3 times higher in ARF than in other patients (42.8% vs 14.0%, p < 0.01). Oliguric ARF was an independent risk factor for overall mortality as determined by a multivariate regression analysis (OR = 1.59 [CI 95%: 1.23-2.06], p < 0.01). Infection increased the risk of death associated with all factors. Factors that increased the ICU mortality of ARF patients were a past history of hematologic malignancy, age more than 65 years, the number of failing organs on admission and the presence of acute cardiovascular failure. CONCLUSION: In ICU patients, the most important risk factors for ARF or mortality from ARF are often present on admission. During the ICU stay, other organ failures (especially cardiovascular) are important risk factors. Oliguric ARF was an independent risk factor for ICU mortality, and infection increased the contribution to mortality by other factors. The severity of circulatory shock was the most important factor influencing outcome in ARF patients.

Acute Kidney Injury↗
PubMed2000

A profile of European intensive care unit physiotherapists. European Society of Intensive Care Medicine.

OBJECTIVE: To determine the profile and role of the physiotherapist in European intensive care units (ICUs). DESIGN: Postal questionnaire. SETTING: 460 ICUs in 17 western European countries. PARTICIPANTS: Heads of intensive care physiotherapy. RESULTS: One hundred and two completed questionnaires were analyzed, representing 22% of the questionnaires sent: 48% were from university hospitals, 45% of the hospitals had more than 700 beds, and 50% had more than 24 ICU beds. 38% of the hospitals had more than 30 physiotherapists working in the hospital, but 25% had no exclusive ICU physiotherapist. 34% had a physiotherapist available during the night, and 85% during the weekend. In almost 100% of ICUs the physiotherapist performed respiratory therapy, mobilization, and positioning. The physiotherapist played an active role in the adjustment of mechanical ventilation in 12% of the respondent's units, in weaning from mechanical ventilation in 22% of units, in extubation in 25%, and in the implementation of non-invasive mechanical ventilation (NIV) in 46%. Among the physiotherapists, there were equivalent numbers of university and non-university graduates. Differences in the role of the physiotherapist were apparent between countries. For example, 80% of respondents from the United Kingdom stated that physiotherapists were available during the night, while in Germany and Sweden physiotherapists were available at night in none of the respondent's units. CONCLUSIONS: Even though the response rate was limited, variations in the role and profile of the ICU physiotherapist are apparent across Europe. The involvement of physiotherapists in more specialized techniques is also a function of the number of physiotherapists working exclusively in an ICU.

Data Collection↗
PubMed2000

Hemodynamic responses to successful weaning from mechanical ventilation after cardiovascular surgery.

Weaning from mechanical ventilation is usually associated with an increase in oxygen consumption (VO2), which may stress the cardiovascular system. We studied relative changes in the cardiac index and oxygen extraction ratio (EO2) during successful weaning in patients after cardiac surgery (n = 52), cardiac transplantation (n = 17), or abdominal aortic surgery (n = 11). Cardiac index was determined by the thermodilution technique and arterial and mixed venous blood gases were obtained before and 30 min after the start of weaning through a T-piece. The cardiovascular changes were evaluated in 42 patients in whom VO2 (calculated by Fick's equation) increased by more than 10%. Cardiac index increased more after abdominal aortic surgery (from 3.27 +/- 0.77 to 4.44 +/- 0.581 min(-1) m(-2), p < 0.01) than after cardiac surgery (from 2.53 +/- 0.59 to 2.87 +/- 0.46 1 min(-1) m(-2), p < 0.01) or cardiac transplantation (from 2.99 +/- 0.64 to 3.33 +/- 0.741 min(-1) m(-2), p < 0.05). EO2 remained stable in patients after aortic surgery (from 25.9 +/- 7.1 to 25.2 +/- 5.6 %, NS) but increased slightly after cardiac surgery (from 33.3 +/- 6.1 to 37.3 +/- 6.4%, NS) and significantly after cardiac transplantation (from 25.8 +/- 4.1 to 28.2 +/- 4.0%, p < 0.05). Hence the cardiovascular response to weaning from mechanical ventilation may vary according to the type of surgery.

Analysis of Variance↗
PubMed2000

Scoring systems for assessing organ dysfunction and survival.

Sepsis is an ongoing disease process carrying a high risk of organ failure and death. Scoring systems to determine disease severity and risk of mortality may be useful in patient management and clinical trial enrollment, although the role of either type of score in the determination of admission or discharge criteria or in decisions relating to the continuation or withholding of treatment remains controversial. General scoring systems have been developed to quantify the severity of illness and the risk of mortality in ICU patients. Ideally, these should be customized before use in patients with septic shock, but in general noncustomized models are used, and this potential limitation should be acknowledged. Prognostic scores are remarkably reliable at predicting outcome in groups of patients and give an indication of severity of disease on admission, but they are unable to provide detail on how a patient is responding to treatment or on the disease progression. Organ function scores, however, can be assessed repeatedly and used to define a patient's progress. This approach can thus be used to evaluate individual patient care, to identify patients for enrollment in clinical trials or epidemiologic analyses, and to assess morbidity measures in clinical trials of new interventions. Organ dysfunction scores are just that, descriptors of organ dysfunction, and although high values correlate well with mortality, prognostication is not their prime aim; organ dysfunction scores and outcome prediction scores should rather be viewed as complementary systems in the description of ICU populations.

APACHE↗
PubMed2000

Comparison of cellulose diacetate and polysulfone membranes in the outcome of acute renal failure. A prospective randomized study.

BACKGROUND: Whether the nature of haemodialysis (HD) membranes can influence the outcome of acute renal failure (ARF) remains debatable. Recent studies have suggested that dialysis with bioincompatible unsubstituted cellulosic membranes is associated with a less favourable patient outcome than dialysis with biocompatible synthetic membranes. Since we generally use a modified cellulosic membrane with substantially lower complement- and leukocyte-activating potential than cuprophane, for dialysis of patients with ARF, and because there are no data in the literature regarding the influence of modified cellulosic membranes on the outcome of patients with ARF, we compared the outcome of ARF patients dialysed either with cellulose diacetate or with a synthetic polysulfone membrane. We also investigated the potential role of permeability by comparing membranes with high-flux versus low-flux characteristics. METHODS: This prospective, randomized, single centre study included 159 patients with ARF requiring HD. Patients were stratified according to age, gender, and APACHE II score and then randomized in chronological order to one of three dialysis membranes: low-flux polysulfone, high-flux polysulfone and meltspun cellulose diacetate. RESULTS: Aetiologies of ARF and the prevalence of oliguria were similarly distributed among the three groups. There was no significant difference between the three groups for survival (multivariate Cox's proportional hazards model, P=0.57), time necessary to recover renal function (P=0.82), and number of dialysis sessions required before recovery (P=0.86). Multivariate analysis showed that survival was significantly influenced only by the severity of the disease state (APACHE III score, P<0.0001), but not by the nature of the dialysis membrane (P=0.57) or the presence of oliguria (P=0.24). CONCLUSIONS: Among patients with ARF requiring HD survival and recovery time are not significantly influenced by the use of either meltspun cellulose diacetate or the more biocompatible high-flux or low-flux polysulfone. Dialysis using modified cellulose membranes is just as effective as dialysis using synthetic polysulfone membranes, but at a lower cost. In addition, the flux of the membrane did not influence patient outcome.

Acute Kidney Injury↗
PubMed2000

Nodule-expressed Cyp15a cysteine protease genes map to syntenic genome regions in Pisum and Medicago spp.

PsCyp15a is a gene that encodes a vacuolar cysteine protease expressed in wilt-induced shoots of Pisum sativum (pea) and in root nodules. To further the understanding of nodular PsCyp15a expression, a region 5' to the coding sequence of the gene was cloned. Varying lengths of 5' untranslated sequence were fused with the uidA coding region and introduced from Agrobacterium rhizogenes into "hairy roots" of Vicia hirsuta. In this transgenic root nodulation assay, a promoter sequence of 900 bp was sufficient to give an expression pattern indistinguishable from that obtained in pea nodules by in situ hybridization. An orthologue of PsCyp15a was cloned from nodule mRNA of Medicago sativa and a corresponding gene identified in M. truncatula was also shown to express strongly in nodules. With molecular mapping techniques, it was demonstrated that these genes map to a syntenic genome location in pea and Medicago spp., but the map positions of the Cyp15a genes cannot be correlated with existing nodulation mutants.

Amino Acid Sequence↗