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Biomedical subjects

J Carlet

Publications and source records attributed to J Carlet.

At least 91 records · Page 5Linked to original sources

Is protected specimen brush a reproducible method to diagnose ICU-acquired pneumonia?

UNLABELLED: Protected specimen brush (PSB) is considered to be one of the standard methods for the diagnosis of ventilator-associated pneumonia, but to our knowledge, intraindividual variability in results has not been reported previously. PURPOSE: To compare the results of two PSB performed in the same subsegment on patients with suspected ICU-acquired pneumonia (IAP). STUDY DESIGN: Between October 1991 and April 1992, each mechanically ventilated patient with suspected IAP underwent bronchoscopy with two successive PSB in the lung segment identified as abnormal on radiographs. Results of the two PSB cultures were compared using 10(3) cfu/ml cutoff for a positive result. Four definite diagnoses were established during the follow up: definite pneumonia, probable pneumonia, excluded pneumonia, and uncertain pneumonia. POPULATION: Forty-two episodes in 26 patients were studied; 60 percent of patients received prior antibiotic therapy. Thirty-two microorganisms were isolated from 24 pairs of PSB. Definite diagnosis was definite pneumonia in 7, probable pneumonia in 8, excluded pneumonia in 17, and uncertain pneumonia in 10 cases. RESULTS: The PSB recovered the same microorganisms and argued for a good qualitative reproducibility. The distinction of positive and negative results on the basis of the 10(3) cfu/ml classic threshold was less reproducible. For 24 percent of the microorganisms recovered and in 16.7 percent of episodes of suspected IAP, the two consecutive samples gave results spread out on each side of the 10(3) cfu/ml cutoff. Discordance was higher when definite diagnosis was certain or probable than when diagnosis was excluded (p = 0.015). There was no statistical effect of the order of samples between the two specimens for bacterial index and microorganism concentrations. CONCLUSION: These findings argue for the poor repeatability of PSB in suspected IAP and question the yield of the 10(3) cfu/ml threshold. In attempting to diagnose IAP, the results of PSB must be interpreted with caution considering the intraindividual variability.

Bacteriological Techniques↗

Acute colorectal ischemia after aortic surgery: pathophysiology and prognostic criteria.

Acute colorectal ischemia is a rare though potentially lethal complication of aortic surgery. We reviewed our recent experience with 16 cases in order to analyze its causative and prognostic factors. The incidence was 2.8%, and the inferior mesenteric artery was occluded in all cases. All patients also had severe occlusive disease of at least two of the hypogastric or deep femoral arteries. Hypoperfusion due to arterial ligation, prosthetic occlusion or embolism was responsible in half the cases. Ischemia and perfusion due to aortic cross-clamping or perioperative hemorrhage were involved in the rest of the cases. Postoperative mortality was 31%. The mortality was lower for partial, nontransmural necrosis, and for elective operations. Recurrent intestinal ischemia, transmural necrosis, surgery for ruptured aneurysm, intestinal hemorrhage and pulmonary edema were associated with a higher mortality rate. All patients with anuria or extrarenal epuration and hepatic cytolysis died. Although reconstruction of the inferior mesenteric artery might lessen the incidence of postoperative colonic ischemia due to hypoperfusion, the role of oxygen free radicals should be investigated in humans, in order to afford colonic protection against the consequences of ischemia-reperfusion.

Acute Disease↗

Single- versus triple-lumen central catheter-related sepsis: a prospective randomized study in a critically ill population.

PURPOSE: A prospective randomized study was conducted over a 23-month period in an adult medical-surgical intensive care unit to determine whether triple-lumen catheters reduce the need for peripheral vascular access and whether they are associated with a higher rate of infection than single-lumen catheters. PATIENTS AND METHODS: After the insertion route, internal jugular or subclavian, was selected by the physician, patients were randomized either to single-lumen or triple-lumen catheter groups. Complementary peripheral vascular access was allowed in both groups. Catheters were removed according to preestablished defined reasons: suspicion of catheter-related sepsis, uselessness of central venous access, duration of catheterization of more than 21 days, discharge from the intensive care unit, or death. RESULTS: Data on 129 central venous catheters were collected from 91 consecutive patients. Twenty-five of 68 patients from the single-lumen group and 1 of 61 patients from the triple-lumen group needed peripheral vascular access (p less than 0.001). Catheter-related sepsis rates, defined either by clinical signs and positive qualitative tip cultures (8.9% versus 11.5%) or by quantitative tip cultures (16.2% versus 11.5%), were identical in the single-lumen and triple-lumen groups (type II error: 8%). CONCLUSION: In intensive care units, the use of triple-lumen catheters is associated with a dramatic decrease in the need for peripheral vascular access. The incidence of central venous catheter-related sepsis appears identical for single- and triple-lumen catheters.

Adult↗

Influence of surgery on in-vitro cytokine production by human monocytes.

Surgery leads to significant modulation of the immune system, in which cytokines play a major role. Circulating interleukin 6 (IL-6) and IL-1 have been reported following surgery whereas tumor necrosis factor alpha (TNF-alpha) is only found in gut ischemia-associated surgery. We have investigated the consequences of surgery on in-vitro cytokine production by human monocytes stimulated by lipopolysaccharide (LPS) and staphylococcal toxic shock syndrome toxin-1 (TSST-1). Comparisons were made between the responsiveness of cells obtained the day before (D-1), during (D0) and after (D1, D2, D3) surgery. Patients undergoing abdominal aortic surgery (N = 9), carotid surgery (N = 4) and spinal surgery (N = 4) have been studied. A significant decrease of TNF-alpha, IL-1 beta and IL-1 alpha production by monocytes prepared from blood samples taken during the surgery was noticed, whereas IL-6 production was not significantly modified. On D2 a significant increase of monocyte responsiveness was observed and levels of cytokine productions rose back to initial values by the end of the follow up. The diminished in-vitro cytokine production observed during surgery might be the consequence of the effects of anaesthetic drugs, whereas the enhancement observed on D2 might reflect the surgical stress, leading to in-vivo priming of circulating monocytes.

Aged↗

Single-dose amoxycillin-clavulanic acid vs. cefotetan for prophylaxis in elective colorectal surgery: a multicentre, prospective, randomized study. The PRODIGE Group.

A prospective, multicentre, randomized trial was carried out in 19 hospitals in order to compare the efficacy of amoxycillin-clavulanic acid with cefotetan as antibiotic prophylaxis in patients undergoing elective colorectal surgery. Since the main purpose of the study was to demonstrate equivalence between the two regimens, the protocol planned the inclusion of 200 patients. Eligible patients were randomly assigned to receive either amoxycillin-clavulanic acid (2.2 g) or cefotetan (2 g) in a single infusion on the induction of anaesthesia. Failure of prophylaxis was defined as occurrence of infection of intestinal origin, either minor (wound cellulitis) or major (abscess, peritonitis, septicaemia) within the 30-day postoperative period. Among 221 randomized patients, 208 (105 amoxycillin-clavulanic acid, 103 cefotetan) aged 66 +/- 12 years (mean +/- SD) were evaluated while 13 were withdrawn. Colorectal cancer was the indication for surgery in 73% of cases. Eleven (10 +/- 6%, 95% confidence interval) and 13 (13 +/- 7%) failures were observed in the amoxycillin-clavulanic acid and cefotetan groups (P = 0.63 chi-square test) respectively. Most infections occurred before the 10th postoperative day (8% failures at this time, estimated by the Kaplan-Meier method). The results of the trial demonstrate that amoxycillin-clavulanic acid and cefotetan have similar efficacy when used for prophylaxis of infection after elective colorectal surgery.

Adult↗

[Erythroderma induced by teicoplanin].

We report the case of a 38-year old man who developed erythroderma during treatment with teicoplanin for staphylococcal septicaemia. The clinical symptoms, which included high fever, shock and erythroderma, were suggestive of staphylococcal toxic shock. After teicoplanin was withdrawn and replaced by vancomycin the disease followed a favourable course. The reintroduction test was positive. This case illustrates the problems associated with the diagnosis of erythroderma in intensive care patients and confirms that it is possible to prescribe vancomycin in cases with allergic reaction to teicoplanin.

Adult↗

Circulating cytokines: the tip of the iceberg?

Circulating cytokines, particularly TNF alpha, IL-1, IL-6 and IL-8, can be detected during severe infections consecutively to an exacerbate release by activated cells. The presence or absence of cytokines within biological fluids reflects a rather complex balance between enhancing and inhibitory signals acting on producer cells, between production and catabolism, and between their binding to the target cells and the modulation of their receptors on the cell surface. Furthermore, their presence does not necessarily parallel their activity and a possible interplay between the cytokines and their corresponding inhibitors should be considered. On the contrary, the absence of detectable circulating cytokines does not indicate an absence of production by activated cells. We discuss the concept that circulating cytokines represent the tip of the iceberg.

Animals↗

Dissociation between plasma and monocyte-associated cytokines during sepsis.

We report our investigations of circulating interleukin (IL) 1 beta, IL 6 and tumor necrosis factor (TNF)-alpha, as well as cell-associated IL 1 alpha, IL 1 beta and TNF-alpha in plasma and monocytes of 21 patients with sepsis syndrome and 6 patients with non-septic shock. Longitudinal studies reveal that (a) the most frequent detectable plasma cytokines were TNF-alpha and IL 6, (b) the presence and the kinetics of circulating cytokines were independent of one other, (c) detectable levels of cytokines could be found for a long period of time, and (d) significantly higher levels of IL 6 were found for non-surviving patients. Because of the in vivo half-life of cytokines and of the existence of numerous specific high-affinity receptors, it is quite probable that detectable plasma cytokines represent the excess of produced mediators which have not been trapped by the target cells. TNF-alpha (410 +/- 65 pg/10(6) monocytes) and IL 1 beta (153 +/- 60 pg/10(6) monocytes) were frequently found associated to monocyte lysates (88% and 50%, respectively). Despite the fact that IL 1 alpha is the most abundant cytokine found associated to monocytes following in vitro activation, IL 1 alpha was rarely found in monocytes of intensive care unit patients (29%). No correlation was found to exist between the levels of plasma cytokines and cell-associated cytokines. Some patients had plasma TNF-alpha or IL 1 beta in the absence of the corresponding monocyte-associated cytokine. This observation suggests that cells other than monocytes can participate in the production of circulating cytokines. At the end of the longitudinal study (day 14 +/- 2), only 2/12 surviving patients still had plasma TNF-alpha, whereas 8/12 had monocyte-associated TNF-alpha. These results indicate that activation of monocytes still occurs in patients for whom no plasma cytokines can be detected. Thus, in addition to the measurement of plasma cytokine, measurement of cell-associated cytokine appears useful to assess cytokine production and monocyte activation in vivo.

Bacterial Infections↗

Dysregulation of in vitro cytokine production by monocytes during sepsis.

The production by monocytes of interleukin-1 alpha (IL-1 alpha), interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF alpha) in intensive care unit (ICU) patients with sepsis syndrome (n = 23) or noninfectious shock (n = 6) is reported. Plasma cytokines, cell-associated cytokines within freshly isolated monocytes and LPS-induced in vitro cytokine production were assessed at admission and at regular intervals during ICU stay. TNF alpha and IL-6 were the most frequently detected circulating cytokines. Despite the fact that IL-1 alpha is the main cytokine found within monocytes upon in vitro activation of cells from healthy individuals, it was very rarely detected within freshly isolated monocytes from septic patients, and levels of cell-associated IL-1 beta were lower than those of TNF alpha. Cell-associated IL-1 beta and TNF alpha were not correlated with corresponding levels in plasma. Upon LPS stimulation, we observed a profound decrease of in vitro IL-1 alpha production by monocytes in all patients, and of IL-1 beta, IL-6, and TNF alpha in septic patients. This reduced LPS-induced production of cytokines was most pronounced in patients with gram-negative infections. Finally, monocytes from survival patients, but not from nonsurvival ones recovered their capacity to produce normal amounts of cytokines upon LPS stimulation. In conclusion, our data indicate an in vivo activation of circulating monocytes during sepsis as well as in noninfectious shock and suggest that complex regulatory mechanisms can downregulate the production of cytokines by monocytes during severe infections.

Adult↗

[Improvement in the prognosis of severe mediastinitis by the use of muscle flaps].

Between 1984 and 1988, 12 mediastinitis were observed in a series of 1.724 cases of cardiac surgical procedures by sternotomy (0.7%). These 12 patients were retrospectively separated in 2 groups in terms of surgical management. In group I (5 patients in 1984 and 1985) the treatment was mediastinal irrigation and in case of failure, an omental transposition. In group II (7 patients in 1986, 86 and 88) the treatment was mediastinal irrigation and in case of failure, a mobilization of muscle flaps. Four patients died in group I of poly-visceral failure with a persistent severe sepsis. In group II, there was no death and the cicatrization was quickly obtained with an average length of stay in intensive care unit of 62 days. The mediastinal irrigation is the treatment of choice for benign mediastinitis, but the prognosis of severe mediastinitis was in our series greatly improved by muscle flap procedures realized with plastic and reconstructive surgical techniques.

Cardiac Surgical Procedures↗

[Prevention of nosocomial pneumonia. Control of endogenous flora. Technique and evaluation].

Endogenous infection is considered nowadays as the main factor in the pathogenesis of nosocomial infection. Micro aspirations of hyperseptic secretions coming from the stomach or from the oropharynx is probably responsible for most of nosocomial pneumonia. Theoretical possibilities to reduce nosocomial pneumonia are: 1) reduce the adherence of micro organisms to the bronchi. 2) increase hygienic measures. 3) use topical antibiotics in the oropharynx and the gut (selective digestive decontamination). 4) avoid anti-acids and H2 blockers. 5) avoid inappropriate sedation. 6) increase defenses of the patients against infection. 7) use anti-endotoxins and other type of immunotherapy. All those therapy are to be tested very carefully.

Anti-Bacterial Agents↗

[Prospective evaluation of modalities of ceftazidime prescription].

Between November 1987 and October 1988, we have prospectively studied 101 hospital prescriptions of ceftazidime, a third generation cephalosporine, including all the health care departements of St Joseph hospital. A standard questionnaire was used to collect the date: dosage, length, and conditions of prescriptions. We observed that this antibiotic is correctly prescribed concerning dosage, length of prescription, and is adapted to bacteriological findings. The striking results were a high proportion of empirical prescriptions (48%) comparing to less than 10% 6 months before the beninning of this study. 75% of these empirical prescriptions being later on confirmed by bacteriological exams.

Aged↗

[Nosocomial urinary infections: epidemiology, detection, prevention and management].

Urinary tract infection is the most common of nosocomial infections, as demonstrated by numerous prospective surveys, especially the American NNIS. 2.5 p. 100 of hospitalized patients are likely to acquire a nosocomial urinary tract infection, usually directly due to indwelling urinary catheters. The prognosis is very good in most cases, but relapsing of persistent infections are extremely frequent and may raise very difficult therapeutic problems, as with chronic prostatitis. Such infections can be prevented, at least in 30 to 40 p. 100 of the cases, by applying simple and well-defined guidelines. However, infection remains difficult to control in hospitals since a precise management of its incidence and a sustained teaching programme are mandatory.

Cross Infection↗

Dissemination of the novel plasmid-mediated beta-lactamase CTX-1, which confers resistance to broad-spectrum cephalosporins, and its inhibition by beta-lactamase inhibitors.

The novel beta-lactamase CTX-1 (pI 6.3) encoded on a transferable 84-kilobase plasmid was found in six different bacterial species. It was responsible for a significant decrease in susceptibility towards most penicillins and cephalosporins, except imipenem, temocillin, and cephalosporins which have a 7-alpha-methoxy substituent. Synergy between either ampicillin, piperacillin, cefotaxime, ceftazidime, or aztreonam and three beta-lactamase inhibitors (clavulanic acid, sulbactam, and YTR 830) was generally found for different strains harboring CTX-1. This enzyme may be related to or derived from the TEM enzyme, since an intragenic probe of the TEM-1 gene hybridized with a fragment of the plasmid carrying CTX-1.

Cephalosporins↗