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Biomedical subjects

B Allaouchiche

Publications and source records attributed to B Allaouchiche.

69 records · Page 4Linked to original sources
PubMed1997

Pharmacokinetics of cefepime during continuous venovenous hemodiafiltration.

The objective of this study was to analyze the pharmacokinetics of cefepime, in six patients with acute renal failure related to septic shock, during continuous venovenous hemodiafiltration (CVVHD) (Hemospal AN 69S hemofilter; Hospal, Lyon, France). Six patients, mean age 65 +/- 4 years (range, 61 to 69), were included and each received 2 g of cefepime by intravenous infusion over a 30-min period every 12 h. Prefilter serum, dialysate outlet (DO), and ultrafiltrate samples were collected 0.47, 0.50, 0.57, 1, 3, 5, 7, and 12 h after the beginning of infusion. The time design of samples was optimized in accordance with the theory of D optimality. The cefepime concentrations were measured by high-performance liquid chromatography. The pharmacokinetics computation was carried out using P-PHARM software. Mean serum concentration peaks were 53 +/- 21.9 mg/liter (range, 13.0 to 68.9) one-half hour after the infusion. The mean elimination half-life was 8.11 +/- 2.22 h (range, 4.76 to 10.84). DO clearance was 66.57 +/- 30.14 ml/min (range, 38.66 to 119.87). The mean volume of distribution was 0.71 +/- 0.37 liters/kg of body weight. CVVHD was effective for cefepime elimination. In these subjects, the elimination half-life and DO clearance were almost constant. The results of this study suggested that a 2-g twice-daily infusion (usual dosage) was required for an effective concentration in this group of patients.

Acute Kidney Injury↗
PubMed1996

Rapid identification of Staphylococcus aureus in bronchoalveolar lavage fluid using a DNA probe (Accuprobe).

OBJECTIVE: Staphylococcus aureus is one of the prominent causative agents of ventilator-associated pneumonia (VAP). Gram staining of bronchoalveolar lavage (BAL) fluid is not always reliable. A nonisotopid probe (Accuprobe) has been developed by Gen-Probe for the specific identification of S. aureus isolated from cultures. This study was undertaken to assess the reliability of this probe for the early diagnosis of S. aureus VAP. DESIGN: A prospective study in 120 consecutive patients. SETTING: Department of intensive care medicine at a university hospital. PATIENTS: 120 ventilated patients (70 males and 50 females; mean age 52 +/- 12 years; mean simplified acute physiologic score = 13 +/- 4) were studied. INTERVENTIONS: 164 bronchoalveolar lavages were performed (none of the patients received prior antibiotic therapy). MEASUREMENTS AND RESULTS: S. aureus was identified 29 times at significant concentrations (> or = 10(4) cfu/ml) and 7 times at < 10(4) cfu/ml. The sensitivity and specificity of the Accuprobe system were 100 and 96%, respectively. We found agreement between quantitative cultures and probes in 96.3% of cases. CONCLUSIONS: We conclude that this probe provides a rapid (< or = 7 h) and accurate diagnosis of S. aureus pulmonary infection.

Aged↗
PubMed1996

Early diagnosis of ventilator-associated pneumonia. Is it possible to define a cutoff value of infected cells in BAL fluid?

STUDY OBJECTIVE: To assess the usefulness of quantification of infected cells (ICs) in BAL fluid for the diagnosis of ventilator-associated pneumonia (VAP). DESIGN: A prospective study. SETTING: A medico-surgical ICU in a tertiary health-care institution. PATIENTS: One hundred thirty-two patients (mean age, 52 +/- 19 years). The suspicion of nosocomial pneumonia was strong in these patients: all had fever (> or = 38.5 degrees C), purulent tracheal aspirates, leukocytosis (> or = 10,000 cells per cubic millimeter), and new or persistent radiographic lung infiltrates. INTERVENTIONS: One hundred sixty-three samples (BAL and protected specimen brushes [PSB]) were obtained. RESULTS: VAP was present in 56 cases. The diagnosis was excluded in the remaining 107 cases. The IC count was performed on 100 cells in BAL fluid. The percentage of IC was significantly higher (12.6 +/- 12.4 vs 1.14 +/- 3.39; p < 0.0001) in patients with pneumonia: the area under the receiver operating characteristic (ROC) curve was 0.888 and a threshold of 2% of IC corresponded to a sensitivity of 84%, a specificity of 80%, a positive predictive value of 69%, and a negative predictive value of 90%. CONCLUSIONS: It is possible to define a threshold of IC in BAL fluid with a good reliability by using an ROC curve. This technique is useful for the early diagnosis (< 2 h) of nosocomial bacterial pneumonia in mechanically ventilated patients and allows a rapid and appropriate treatment of most of the patients with suspected VAP.

Bronchoalveolar Lavage Fluid↗
PubMed1995

[Clostridium perfringens septicemia associated with foodborne toxic infection and abortion].

A 32-year-old pregnant woman with poor life and hygiene conditions presented with premature labour, fever and diarrhoea. After admission she gave birth to a stillborn child. The examination revealed a septicaemia with massive haemolysis and renal failure. Six blood cultures obtained on admission yielded Clostridium perfringens. The outcome was favourable after an adapted antibiomicrobial therapy. This case illustrates the potential severity of Clostridium perfringens foodborne toxi-infection which can lead to abortion and septicaemia with massive haemolysis.

Abortion, Septic↗
PubMed1995

[Post-traumatic dissection of the aortic isthmus with favorable outcome without surgical treatment. Value of transesophageal echocardiography].

We report a case of intimal rupture of aortic isthmus in a severe polytrauma patient diagnosed with transoesophageal echocardiography (TEE). TEE findings were as follows: localized intimal tear without increased aortic diameter or pseudoaneurysm, absence of mediastinal haematoma or false lumen. CT scan and MRI confirmed the diagnosis. Because of the associated injuries, surgery was delayed. Conservative management was successful and the patient was discharged without aortic surgery. A follow up TEE, 3 and 6 months later showed a thrombosis of the intimal tear without false aneurysm. This case underlines the value of TEE in patients with thoracic trauma, for surgical or nonsurgical management of aortic rupture and for the follow up of the patients.

Aortic Rupture↗
PubMed1994

[Value of the cytology of bronchoalveolar lavage in the early diagnosis of nosocomial lung infections in patients with thoracic injuries].

Mechanically ventilated patients, especially those with thorax trauma, suffer commonly from nosocomial pneumonia. In these patients, conventional diagnostic criteria for bacterial pneumonia may not be completely reliable, as an accurate interpretation of the chest radiograph is too difficult. The invasive means for the diagnosis of pneumonia (protected specimen brush, bronchoalveolar lavage), require 24-48 hours to obtain the results of cultures. Therefore no information is available to guide the initial choice of antimicrobial therapy. For some authors, the quantification of intracellular bacteria, present in cytocentrifuged preparations made from lavage fluid, may provide rapid identification of patients with pneumonia. We evaluated the benefit of this type of analysis in thorax trauma patients. In 36 patients, 48 samples were taken. With a threshold value of 10% of cells containing intracellular organisms, microscopic examination had a sensitivity and a specificity of 83%. We conclude that this technique may be useful for the early diagnosis of nosocomial pneumonia in ventilated thorax trauma patients.

Bronchoalveolar Lavage Fluid↗
PubMed1994

[Nosocomial pneumonia in intensive care. Value of different diagnostic tools].

The authors analyzed in published studies providing histologic data the value of diagnostic means of nosocomial bronchopneumonia (NBP) in critically ill patients. At least 10% of patients whose trachea is intubated and the lungs mechanically ventilated suffer an histologically-confirmed NBP. Histology of NBP consists of non systematized foci of infection, localised in 90% of cases in the posterior segments of the lower pulmonary lobes. In fact, small foci are disseminated in both lungs, usually within large areas of non infectious pulmonary lesions and are often multimicrobial. This may explain why the clinical and radiological diagnosis is inaccurate in more than 40% of cases. On chest X-ray, aeric bronchogram and alveolar infiltrates are suggestive but non-specific for NBP, as are also fever, leukocytosis and purulent sputum. Therefore, to confirm the diagnosis of infection and to isolate the microorganisms responsible for NBP, additional investigations are required whose interpretation is uneasy. In a simplified manner, bacteriological inoculum takes a course parallel to the histological bronchopulmonary lesions: no bacteria in the absence of infection, high bacterial inoculum in case of confluent NBP, intermediary in case of bronchitis, however with exceptions when antibiotherapy has recently been modified. In fact, neither bronchial protected brushing nor broncho-alveolar lavage techniques have a perfect sensitivity and specificity. As an example, a diagnostic procedure in assessed in calculating the probability of an accurate diagnosis of NBP. It is concluded that diagnosis of ventilator-associated pneumonia remains still unreliable with the means available today.

Bronchoalveolar Lavage Fluid↗
PubMed1992

[Chemotherapy for human immunodeficiency virus infection. Current status and perspectives].

The role of drugs inhibiting viral replication in patients infected with HIV has been confirmed. Until now only dideoxynucleosides, which are reverse transcriptase inhibitors, have demonstrated antiviral activity in humans. A number of compounds acting on other steps of the viral cycle are currently being evaluated and clinical trials are being performed. Some investigators are attempting to inhibit the binding of viral particles to target cells and their penetration into these by acting on the interaction between HIV ant the CD4 molecule. Another approach consists in the characterization of enzymatic activities which are specific of HIV, other than reverse transcriptase, such as ribonuclease H, integrase or protease, in order to prepare specific inhibitors. Attempts are made to inhibit retroviral gene expression and production of viral particles in infected cells. The development of new nucleoside analogues and drugs with mechanisms of action and toxicities different from those of zidovudine should allow in the near future combination chemotherapy of HIV infection.

Dideoxynucleosides↗
PubMed1991

Severe falciparum malaria (21 cases).

The incidence of severe falciparum malaria is increasing in the developed countries and mortality remains high despite progress in intensive care management and schizonticide treatment. Many authors emphasize the importance of exchange transfusion (EXT) in the most severe cases. We studied 21 cases (34 +/- 12 years, 6 females; SAPS: 8.4 +/- 3.7) of severe malaria (according to WHO criteria) consecutively admitted to ICU between 1985 and 1990: 3 patients underwent EXT. Twenty were febrile above 39 degrees C, 10 had cerebral malaria, 14 hepatic impairment, 8 acute renal failure, 5 pulmonary oedema. Nine patients required mechanical ventilation, 1 haemodialysis, 1 intracranial pressure monitoring. Mean parasitemia was 13%, 16 patients had thrombocytopenia less than 50 x 10(9)/l, 3 anemia less than 7 g/dl and 3 leucopenia less than 2.8 x 10(9)/l. Nineteen received quinine i.v., 1 mefloquine, 1 chloroquine. Sixteen patients received blood products transfusion, 3 were treated by EXT in addition. Twenty were cured and discharged from hospital without sequelae (mean stay: 14 days); 4 had nosocomial infection, 1 a splenic infarction. One patient (17-years-old; SAPS: 17; parasitemia: 7.8%) died 12 h after admission from non-cardiogenic pulmonary oedema with multi-organ failure. The literature and this study lead us to propose EXT in patients with unfavourable evolution after conventional treatment rather than in all the patients with a parasitemia above 10% at admission. A randomized study to compare conventional treatment in ICU with or without EXT is necessary.

Adolescent↗
PubMed1991

Acute renal failure with preserved renal plasma flow induced by cancer immunotherapy.

Adoptive immunotherapy in patients with advanced cancer produces significant regression of metastatic disease in selected patients, but it is complicated by severe side effects. Prevention of these complications is still limited because their precise mechanisms remain unknown. For this reason we have investigated renal function and hemodynamic parameters in 16 patients with renal cell carcinoma before and during treatment with a combination of high doses of both recombinant interleukin-2 (rIL2) and recombinant alpha-interferon. After patients had received three injections of combined immunotherapy, there was a decrease in mean blood pressure (-20%), glomerular filtration rate (-25%), urine output (-50%), and fractional sodium excretion (-0.8%). This was associated with an increase in heart rate (+30%), plasma creatinine level (+30%), fractional potassium excretion (+14%) and microalbuminuria (+130%). However, renal plasma flow remained constant. The increment in microalbuminuria may reflect an alteration of glomerular capillary permeability. The reduction in GFR may be accounted either for a decrease in efferent to afferent arteriolar resistance ratio, leading to a decrease in glomerular capillary pressure, or for a decrease in ultrafiltration coefficient, or both. Nonsteroidal antiinflammatory drugs, such as ketoprofen, used to minimize side effects, could considerably worsen renal function and should be avoided in patients treated by rIL2. Our results bring new insights into the pathogenesis of functional acute renal failure and provide a rational basis for the use of vasopressors in the treatment of cytokine-induced acute renal failure.

Acute Kidney Injury↗
PubMedDate not supplied

[Diffusion in bone tissue of antibiotics].

DIFFICULT ASSESSMENT: Bone and joint infections are difficult to treat. Therapeutic success depends greatly on the diffusion of antibiotics into bone tissue. Few studies have been devoted to this subject and the variable nature of those reported hinders interpretation. Bone biopsies are generally obtained during orthopedic procedures. Antibiotic administration routes vary although intravenous infusion predominates. Agar gel diffusion is generally used for antibiotic assays but methodology varies depending of the study. The most recent reports use high-performance liquid chromatography. DIFFUSION STUDIES: The different studies examining antibiotic diffusion in bone tissue describe three classes: good diffusion (greater than 30%), moderate diffusion (between 15% and 30%), and low diffusion (less than 15%). Antibiotics in the good diffusion class include fluoroquinolones, teicoplanin, macrolides, rifampicin and trimethoprime. Antibiotics with moderate bone diffusion are ureidopenicillins, second and third generation cephalosporins, aminoglycosides, clindamycin, fosfomycin and vancomycin. Those with low bone diffusion are aminopenicillins, penicillin M and first generation cephalosporins. No data is available on the bone diffusion of pristinamycin. DATA INTERPRETATION: The clinical impact of these classifications must be interpreted with precaution when considering bone and joint infections as they were established on the basis of pharmacokinetic studies and not clinical trials. They would however appear to be useful in guiding antibiotic prophylaxis for orthopedic surgery in protocols with administration conditions and concentration goals similar to the experimental conditions. PRACTICAL ATTITUDES: These laboratory results could be used in clinical practice by comparing the MIC50 of the germs regularly encountered in bone infections (staphylococci, streptococci including enterococci, Gram negative bacilli including P. aeruginosa and H. influenzae) with concentrations obtained in the different studies, i.e. by calculating the inhibitor coefficient (IQ) of each antibiotic for each susceptible germ. This gives a classification by efficacy (excellent IQ > 10, good 1 < IQ < 10, poor IQ < 1) useful for guiding antibiotic choice in the difficult situation of bone and joint infection.

Anti-Bacterial Agents↗