Predictive value of the RIFLE urine output criteria on contrast-induced nephropathy in critically ill patients.

BACKGROUND: To investigate the predictive value of decreased urine output based on the Risk of renal dysfunction, Injury to the kidney, Failure of kidney function, Loss of kidney function and End-stage renal disease (RIFLE) classification on contrast- induced acute kidney injury (CA-AKI) in intensive care (ICU) patients. METHODS: All patients who received contrast media (CM) injection for CT scan or coronary angiography during a 3-year period in a 24 bed medico-surgical ICU were reviewed. RESULTS: Daily serum creatinine concentrations and diuresis were measured for 3 days after CM injection. We identified 23 cases of CA-AKI in the 149 patients included (15.4 %). Patients who developed CA-AKI were more likely to require renal replacement therapy and had higher ICU mortality rates. At least one RIFLE urine output criteria was observed in 45 patients (30.2 %) and 14 of these 45 patients (31.1 %) developed CA-AKI based on creatinine concentrations. In 30 % of these cases, urine output decreased or didn't change after the increase in creatinine concentrations. The RIFLE urine output criteria had low sensitivity (39.1 %) and specificity (67.9 %) for prediction of CA-AKI, a low positive predictive value of 50 % and a negative predictive value of 87.2 %. The maximal dose of vasopressors before CM was the only independent predictive factor for CA-AKI. CONCLUSIONS: CA-AKI is a frequent pathology observed in ICU patients and is associated with increased need for renal replacement therapy and increased mortality. The predictive value of RIFLE urine output criteria for the development of CA-AKI based on creatinine concentrations was low, which limits its use for assessing the effects of therapeutic interventions on the development and progression of AKI.

Treatment of the syndrome of inappropriate secretion of antidiuretic hormone with urea in critically ill patients.

BACKGROUND: Hyponatremia occurring as a result of the syndrome of inappropriate antidiuretic hormone secretion (SIADH) is a common and potentially lethal complication in critically ill patients. Urea, by inducing renal water excretion and promoting sodium (Na) retention, has been well described as a treatment for chronic SIADH. However, there are limited data on its use for the treatment of SIADH as encountered in patients admitted to the intensive care unit (ICU). We assessed the effects of urea administration for treatment of SIADH in ICU patients. METHODS: Data from ICU patients treated with urea for SIADH between January 2000 and August 2010 were reviewed. The time courses of Na and urea concentrations were analyzed by variance analysis (ANOVA). RESULTS: Records from 24 patients were analyzed. The most common etiology of SIADH was neurological (18 patients). Before urea administration, the mean serum Na concentration was 124.8 ± 5.9 mEq/l. There was a significant increase in serum Na from the second day of treatment (131.4 ± 3.5 mEq/l, p < 0.001) and a normalization of mean serum Na by the fourth day (136.2 ± 4.1 mEq/l, p < 0.001). The mean serum urea concentration also increased (from 29.8 ± 11.1 mg/dl before urea to 57.6 ± 24.0 mg/dl on the first day of treatment, p < 0.001). CONCLUSIONS: Urea administration appears useful for the treatment of SIADH-associated hyponatremia in critically ill patients. Prospective randomized controlled studies are needed to confirm these results.

Comparison of dopamine and norepinephrine in the treatment of shock.

BACKGROUND: Both dopamine and norepinephrine are recommended as first-line vasopressor agents in the treatment of shock. There is a continuing controversy about whether one agent is superior to the other. METHODS: In this multicenter, randomized trial, we assigned patients with shock to receive either dopamine or norepinephrine as first-line vasopressor therapy to restore and maintain blood pressure. When blood pressure could not be maintained with a dose of 20 microg per kilogram of body weight per minute for dopamine or a dose of 0.19 microg per kilogram per minute for norepinephrine, open-label norepinephrine, epinephrine, or vasopressin could be added. The primary outcome was the rate of death at 28 days after randomization; secondary end points included the number of days without need for organ support and the occurrence of adverse events. RESULTS: The trial included 1679 patients, of whom 858 were assigned to dopamine and 821 to norepinephrine. The baseline characteristics of the groups were similar. There was no significant between-group difference in the rate of death at 28 days (52.5% in the dopamine group and 48.5% in the norepinephrine group; odds ratio with dopamine, 1.17; 95% confidence interval, 0.97 to 1.42; P=0.10). However, there were more arrhythmic events among the patients treated with dopamine than among those treated with norepinephrine (207 events [24.1%] vs. 102 events [12.4%], P<0.001). A subgroup analysis showed that dopamine, as compared with norepinephrine, was associated with an increased rate of death at 28 days among the 280 patients with cardiogenic shock but not among the 1044 patients with septic shock or the 263 with hypovolemic shock (P=0.03 for cardiogenic shock, P=0.19 for septic shock, and P=0.84 for hypovolemic shock, in Kaplan-Meier analyses). CONCLUSIONS: Although there was no significant difference in the rate of death between patients with shock who were treated with dopamine as the first-line vasopressor agent and those who were treated with norepinephrine, the use of dopamine was associated with a greater number of adverse events. (ClinicalTrials.gov number, NCT00314704.)

Guillain-Barré syndrome following hepatitis E.

Guillain-Barré syndrome (GBS) is often triggered by a preceding bacterial or viral infection. Occasionally, it has been observed in association with acute hepatitis A, B and C, and three cases have been previously described in India in which GBS was associated with acute hepatitis E. A molecular mimicry mechanism is supposed to be involved in the pathogenesis of GBS triggered by infectious agents, although the nature of the shared epitopes has not been characterized in most instances, including that in the case of hepatotropic viruses. We report a case of GBS following acute hepatitis E in a European individual. The presence of antiganglioside GM2 antibodies in this patient suggested molecular mimicry involving ganglioside GM2 in the pathogenesis of GBS associated with hepatitis E.

Spectral filtering of visible light by the cuticle of metallic woodboring beetles and microfabrication of a matching bioinspired material.

Samples of the cuticle taken from the body of Buprestidae Chrysochroa vittata have been studied by scanning electron microscopy and optical reflectance measurements, related to numerical simulations. The cause of the metallic coloration of the body of these insects is determined to be the structure of the hard carapace constructed as a stack of thin chitin layers separated by very thin irregular air gaps. In particular the change of color as a function of the observation angle is elucidated in terms of an infinite photonic-crystal model, confirmed by finite multilayer calculations. These mechanisms are used to develop an artificial bioinspired multilayer system which reproduces the visual effects provided by the insect surface.

3.5% urea-linked gelatin is as effective as 6% HES 200/0.5 for volume management in cardiac surgery patients.

PURPOSE: To compare the efficacy of volume expansion with 3.5% gelatin and 6% hydroxyethyl starch 200/0.5 in patients undergoing cardiac surgery. The second objective was to compare the two colloids in terms of blood losses and allogeneic blood transfusion exposure rate. METHODS: In this open-label controlled study, patients were randomly allocated to receive either 3.5% urea-linked gelatin (GEL group: n = 55) or 6% hydroxyethyl starch 200/0.5/5.1 (HES group: n = 55) for per- (including priming of the bypass machine) and postoperative volume management with a maximum dosage of 30 +/- 3 mL.kg(-1).day(-1). Volume replacement was guided according to routine per- and postoperative care based on cardiac index, mixed venous oxygen saturation, and diuresis. If additional colloid was required, 4.5% albumin had to be given. The study period comprised per- and postoperative investigations up to 18 hr after surgery. RESULTS: All hemodynamic variables were comparable in both groups. Total study drug was 25.8 +/- 4.8 mL.kg(-1) in the GEL group and 24.5 +/- 6.0 mL.kg(-1) in the HES group. There was no difference in the number of patients receiving albumin solution or in the amount of albumin administered. Total blood loss was higher in the HES than in the GEL group (11.0 +/- 7.8 mL.kg(-1) vs 8.7 +/- 4.0 mL.kg(-1); P < 0.05) resulting in a higher need for allogeneic blood transfusion (HES: nine patients received 12 units, GEL two patients received 3 units; P = 0.026). CONCLUSION: In the conditions of the present study, HES was not associated with a better plasma expansion effect than GEL. HES could result in a higher need for allogeneic blood transfusion.