A new automated system for the preparation of sclerosant foam: A study of the physical characteristics produced and the device settings required.

OBJECTIVES: To determine the quality of sclerosant foam produced with an automated preparation system with multiple combinations of sclerosing agents, gases, and device settings. METHODS: Single-use mixing capsules filled with air or O2/CO2 and polidocanol (0.25, 1, or 3%) or sodium tetradecyl sulfate (0.2 or 1%) were coupled to a customized magnetic stirrer. Stirring speed and time were adjusted between 1500 and 4000 r/min and 30 and 60 s, respectively, and characteristics of the foam produced were measured: half-life, bubble diameter, and gas-to-liquid ratio. RESULTS: With optimized device settings, the following foam characteristics were obtained: half-life range, 1.4 ± 0.9 to 5.2 ± 0.6 min; bubble diameter, 84 ± 14 to 119 ± 6 µm; and gas-to-liquid ratio, 5:1-7:1. Sodium tetradecyl sulfate foam was quicker to form than polidocanol but faster to degrade. Foams with low sclerosant concentrations and O2/CO2 required higher speed and longer time. CONCLUSIONS: Suitable foam characteristics could be obtained with all combinations of sclerosing agent, concentration, and gas.

Model-based design of a software sensor for real-time diagnosis of the stability conditions in high-rate anaerobic reactors - Full-scale application to Internal Circulation technology.

Internal Circulation (IC) anaerobic systems are especially suitable when plant designs that involve both small footprints and high organic loading rates (>25 kg COD m-3 d-1) are required. However, given that operating anaerobic processes at high organic loads increases their vulnerability to external disturbances, real-time indicators of the stability conditions become particularly pertinent for IC reactors. This paper addresses the design and full-scale validation of a software sensor that uses only feeding flow-rate and biogas flow-rate measurements to classify the operating conditions of the reactor as "strongly", "moderately" or "weakly" stable. A simulation-based procedure was used to design the software sensor and configure its parameters. Then, the performance of the software sensor was tested under real conditions in a full-scale IC reactor of 1679 m3 installed in a recycled paper mill (RPM).

Professional liability claims in vascular surgery practice.

BACKGROUND: Patient safety is a major concern worldwide, but particularly high rates of adverse events are reported in the surgery setting. Angiology and vascular surgery is of special interest due to the complexity of the pathologies involved and the esthetic component of some of its procedures. In this study we identified the most frequent factors that apply to vascular surgery claims to determine areas of special risk in vascular surgery, with an aim to improve patient safety. METHODS: We performed a retrospective and descriptive study of the claims pertaining to vascular surgery from the database of the Service of Professional Liability (SRP) of the Official College of Physicians of Barcelona. The time frame of data collection was from 1986 to 2009. We analyzed both the clinical and legal characteristics of the cases. RESULTS: Of the total of 6952 registered claims during the 23-year period, 91 (1.3%) were related to the practice of vascular surgery. Of these, 53.8% were related to venous pathology and 46.1% to arterial pathology. Neurologic damage was the main motive for claims (15.3%), followed by thromboembolic disease (14.2%), burns as a result of cosmetic treatment (12%), and amputation (10.9%). The neurologic damage in relation to vein pathology registered the greatest proportion of cases with professional liability (30.8%), followed by burns (19.2%), forgotten gauze (11.5%), and amputations (11.5%). CONCLUSIONS: Angiology and vascular surgery does not seem to be a specialty with a high risk for claims, but complications, such as thromboembolic disease and neurologic damage after varicose vein intervention, do occur and deserve special attention so improvements can be made to patient safety.