Mineral pollutants removal through immobilized microalgae-bacterial flocs in a multitrophic microreactor.

Microalgae-bacterial flocs (MaB-flocs) immobilization technique using polyvinyl alcohol (PVA) crosslinked with sodium alginate represent a novel approach for sustainable pollutants removal. The present work was performed to evaluate the performance of a multitrophic batch reactor at microscale for treating two synthetic wastewater solutions prepared with two different initial Chemical Oxygen Demand (COD): 200 mg.L-1 and 450 mg.L-1, respectively. Three MaB-flocs concentrations were entrapped into PVA-alginate beads: C1 (2%, v/v), C2 (5%, v/v) and C3 (10%, v/v), without O2 supply, during three periods 2, 4 and 6 days of batch incubation. PVA-alginate beads containing the highest concentration C3 of MaB-flocs improved the performance of the microreactor to remove significantly NH4+ and PO43- of about 61% and 82%, respectively, from wastewater more than two other concentrations used. This result confirms that C3 of MaB-flocs displays not only a good potential for nutrients removals but also the highest MaB-flocs morphological progression after 6 days of treatment with the highest COD of 450 mg.L-1. The feasibility of the PVA-alginate for cells immobilization, investigated through microscopy analysis, reveals that the evolution of multicellularity in MaB-flocs, for all experiments.

Effects of pleural effusion drainage on oxygenation, respiratory mechanics, and hemodynamics in mechanically ventilated patients.

OBJECTIVES: In mechanically ventilated patients, the effect of draining pleural effusion on oxygenation is controversial. We investigated the effect of large pleural effusion drainage on oxygenation, respiratory function (including lung volumes), and hemodynamics in mechanically ventilated patients after ultrasound-guided drainage. Arterial blood gases, respiratory mechanics (airway, pleural and transpulmonary pressures, end-expiratory lung volume, respiratory system compliance and resistance), and hemodynamics (blood pressure, heart rate, and cardiac output) were recorded before and at 3 and 24 hours (H24) after pleural drainage. The respiratory settings were kept identical during the study period. MEASUREMENTS AND MAIN RESULTS: The mean volume of effusion drained was 1,579 ± 684 ml at H24. Uncomplicated pneumothorax occurred in two patients. Respiratory mechanics significantly improved after drainage, with a decrease in plateau pressure and a large increase in end-expiratory transpulmonary pressure. Respiratory system compliance, end-expiratory lung volume, and PaO2/FiO2 ratio all improved. Hemodynamics were not influenced by drainage. Improvement in the PaO2/FiO2 ratio from baseline to H24 was positively correlated with the increase in end-expiratory lung volume during the same time frame (r = 0.52, P = 0.033), but not with drained volume. A high value of pleural pressure or a highly negative transpulmonary pressure at baseline predicted limited lung expansion following effusion drainage. A lesser improvement in oxygenation occurred in patients with ARDS. CONCLUSIONS: Drainage of large (≥500 ml) pleural effusion in mechanically ventilated patients improves oxygenation and end-expiratory lung volume. Oxygenation improvement correlated with an increase in lung volume and a decrease in transpulmonary pressure, but was less so in patients with ARDS.

Fever control using external cooling in septic shock: a randomized controlled trial.

RATIONALE: Fever control may improve vascular tone and decrease oxygen consumption, but fever may contribute to combat infection. OBJECTIVES: To determine whether fever control by external cooling diminishes vasopressor requirements in septic shock. METHODS: In a multicenter randomized controlled trial, febrile patients with septic shock requiring vasopressors, mechanical ventilation, and sedation were allocated to external cooling (n = 101) to achieve normothermia (36.5-37°C) for 48 hours or no external cooling (n = 99). Vasopressors were tapered to maintain the same blood pressure target in the two groups. The primary endpoint was the number of patients with a 50% decrease in baseline vasopressor dose after 48 hours. MEASUREMENTS AND MAIN RESULTS: Body temperature was significantly lower in the cooling group after 2 hours of treatment (36.8 ± 0.7 vs. 38.4 ± 1.1°C; P < 0.01). A 50% vasopressor dose decrease was significantly more common with external cooling from 12 hours of treatment (54 vs. 20%; absolute difference, 34%; 95% confidence interval [95% CI], -46 to -21; P < 0.001) but not at 48 hours (72 vs. 61%; absolute difference, 11%; 95% CI, -23 to 2). Shock reversal during the intensive care unit stay was significantly more common with cooling (86 vs. 73%; absolute difference, 13%; 95% CI, 2 to 25; P = 0.021). Day-14 mortality was significantly lower in the cooling group (19 vs. 34%; absolute difference, -16%; 95% CI, -28 to -4; P = 0.013). CONCLUSIONS: In this study, fever control using external cooling was safe and decreased vasopressor requirements and early mortality in septic shock.

Compressive pleural effusion after ovarian hyperstimulation syndrome--a case report and review.

OBJECTIVE: To report a case of early onset ovarian hyperstimulation with massive pleural effusion and respiratory failure before IVF. DESIGN: Case report. SETTING: University teaching intensive care unit. PATIENT(S): A 26-year-old healthy woman with an unexplained infertility transferred to the intensive care unit on day 4 after hCG injection for early severe presentation of ovarian hyperstimulation syndrome with massive compressive pleural effusion before she underwent embryo transfer. INTERVENTION(S): Mechanical ventilation, thoracocentesis. MAIN OUTCOME MEASURE(S): Resolution of symptoms/stopping of embryos transfer. RESULT(S): Drainage of 5,300 mL of sterile exudative pleural fluid for a period of 48 hours, which permitted resolution of symptoms and allowed mechanical weaning. The IVF procedure was stopped. CONCLUSION(S): This case described is unusual in that the patient presented with early massive pleural effusion on day 4 after hCG injection and before embryo transfer. This is much earlier than in any case report elsewhere.

Epidemiology and risk factors for colonization and infection by Acinetobacter baumannii in an ICU in Tunisia, where this pathogen is endemic.

Because Acinetobacter baumannii has become an alarming endemic pathogen in our country we decided to conduct this prospective study, from January 2004 to December 2005, in order to determine risk factors and outcomes involved in clinical colonization or infection by A. baumannii in a 16-bed Tunisian intensive care unit (ICU). One hundred and two A. baumannii isolates were obtained from 63 patients, with an infection rate of 45%. The rate of multidrug-resistant (MDR) A. baumannii was 39% during the 2-year study, with an epidemic outbreak in October 2004. This outbreak was followed by closure of all the involved ICU rooms and the selective intestinal decontamination of patients, with polymyxin. During the 12-month post-intervention program (January-December 2005), the infection rate declined. The analysis of risk factors for the spread of A. baumannii showed that only the Simplified Acute Physiological Score (SAPS II) was involved. On the other hand, no risk factor was identified for multidrug resistance in patients either colonized or infected by A. baumannii. There was a statistically significant difference only in crude mortality (67.5% in MDR A. baumannii vs 46.7% in susceptible A. baumannii; P = 0.04).