Diagnostic performance of fractional excretion of urea in the evaluation of critically ill patients with acute kidney injury: a multicenter cohort study

International audienceINTRODUCTION: Several factors, including diuretic use and sepsis, interfere with the fractional excretion of sodium, which is used to distinguish transient from persistent acute kidney injury (AKI). These factors do not affect the fractional excretion of urea (FeUrea). However, there are conflicting data on the diagnostic accuracy of FeUrea. METHODS: We conducted an observational, prospective, multicenter study at three ICUs in university hospitals. Unselected patients, except those with obstructive AKI, were admitted to the participating ICUs during a six-month period. Transient AKI was defined as AKI caused by renal hypoperfusion and reversal within three days. The results are reported as medians (interquartile ranges). RESULTS: A total of 203 patients were included. According to our definitions, 67 had no AKI, 54 had transient AKI and 82 had persistent AKI. FeUrea was 39% (28 to 40) in the no-AKI group, 41% (29 to 54) in the transient AKI group and 32% (22 to 51) in the persistent AKI group (P = 0.12). FeUrea was of little help in distinguishing transient AKI from persistent AKI, with the area under the receiver operating characteristic curve being 0.59 (95% confidence interval, 0.49 to 0.70; P = 0.06). Sensitivity was 63% and specificity was 54% with a cutoff of 35%. In the subgroup of patients receiving diuretics, the results were similar. CONCLUSIONS: FeUrea may be of little help in distinguishing transient AKI from persistent AKI in critically ill patients, including those receiving diuretic therapy. Additional studies are needed to evaluate alternative markers or strategies to differentiate transient from persistent AKI

Continuous infusion of ceftazidime in critically ill patients undergoing continuous venovenous haemodiafiltration: pharmacokinetic evaluation and dose recommendation

INTRODUCTION: In seriously infected patients with acute renal failure and who require continuous renal replacement therapy, data on continuous infusion of ceftazidime are lacking. Here we analyzed the pharmacokinetics of ceftazidime administered by continuous infusion in critically ill patients during continuous venovenous haemodiafiltration (CVVHDF) in order to identify the optimal dosage in this setting. METHOD: Seven critically ill patients were prospectively enrolled in the study. CVVHDF was performed using a 0.6 m(2 )AN69 high-flux membrane and with blood, dialysate and ultrafiltration flow rates of 150 ml/min, 1 l/hour and 1.5 l/hour, respectively. Based on a predicted haemodiafiltration clearance of 32.5 ml/min, all patients received a 2 g loading dose of ceftazidime, followed by a 3 g/day continuous infusion for 72 hours. Serum samples were collected at 0, 3, 15 and 30 minutes and at 1, 2, 4, 6, 8, 12, 24, 36, 48 and 72 hours; dialysate/ultrafiltrate samples were taken at 2, 8, 12, 24, 36 and 48 hours. Ceftazidime concentrations in serum and dialysate/ultrafiltrate were measured using high-performance liquid chromatography. RESULTS: The mean (± standard deviation) elimination half-life, volume of distribution, area under the concentration-time curve from time 0 to 72 hours, and total clearance of ceftazidime were 4 ± 1 hours, 19 ± 6 l, 2514 ± 212 mg/h per l, and 62 ± 5 ml/min, respectively. The mean serum ceftazidime steady-state concentration was 33.5 mg/l (range 28.8–36.3 mg/l). CVVHDF effectively removed continuously infused ceftazidime, with a sieving coefficient and haemodiafiltration clearance of 0.81 ± 0.11 and 33.6 ± 4 mg/l, respectively. CONCLUSION: We conclude that a dosing regimen of 3 g/day ceftazidime, by continuous infusion, following a 2 g loading dose, results in serum concentrations more than four times the minimum inhibitory concentration for all susceptible pathogens, and we recommend this regimen in critically ill patients undergoing CVVHDF

METHEMOGLOBINEMIE ACQUISE AU COURS D'UNE INTOXICATION VOLONTAIRE PAR RILUZOLE (RILUTEK*)

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When vitamin deficiency mimics thrombotic thrombocytopenic purpura.

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Méningites bactériennes ou virales à examen direct négatif : pouvoir discriminant des différents marqueurs cyto-chimiques

L'objectif de cette étude est de déterminer le pouvoir discriminant, entre le caractère bactérien ou viral des méningites, des différents paramètres habituellement utilisés pour le diagnostic des méningites aigües de l'adulte avec un examen direct négatif du liquide céphalo-rachidien (ED-). Il s'agit d'une étude prospective (conduite depuis 1998), incluant tous les patients admis au service d'urgence, présentant une méningite aigüe avec un ED-. Les prélèvements sériques et du LCR ont été réalisés dès l'admission. Les patients ont été répartis en deux groupes : méningites bactériennes (MB) et virales (MV). Les paramètres suivants ont été étudiés : pour le LCR (cytologie, protéine, glucose, lactate), pour le sérum (leucocyte, neutrophile, protéine C-récative, procalcitonine) ainsi que les rapports glucose LCR/sérum et lactates LCR/sérum. Les résultats ont été exprimés par la moyenne +/- ds. Les tests suivants ont été utilisés : comparaison des moyennes par les tests de Mann-Whitney et Kruskal-Wallis (p<0,05), méthode des courbes ROC afin d'étudier le pouvoir discriminant des différents paramètres étudiés et seuil de décision déterminé au maximum de l'indice de Youden, comparaison des courbes ROC par la méthode de Hanley. Parmi 253 patients présentant une méningites à ED-, 35 étaient des MB et 218 des MV. Toutes les méningites bactériennes ont eu une documentation microbiologique. Les paramètres les plus discriminants pour le diagnostic de MB se sont révélés être le taux de lactates LCR avec une sensibilité de 94% et une spécificité de 97% au seuil de 3,8 mmol/L et la procalcitonine sérique avec une sensibilité de 97 % une spécificité de 100% au seuil de 0,28ng/mL. Cette étude confirme que la procalcitonine sérique et le lactate du LCR apparaissent être les paramètres les plus déterminants dans la distinction entre méningites bactériennes et virales.ST ETIENNE-BU Médecine (422182102) / SudocSudocFranceF