Use of Routine Environmental Monitoring Data to Establish a Dose-based Compliance System for a Low-level Radioactive Waste Disposal Site.

A dose-based compliance methodology was developed for Waste Control Specialists, LLC, low-level radioactive waste facility in Andrews, Texas, that allows routine environmental measurement data to be evaluated not only at the end of a year to determine regulatory compliance, but also throughout the year as new data become available, providing a continuous assessment of the facility. The first step in the methodology is a screening step to determine the potential presence of site emissions in the environment, and screening levels are established for each environmental media sampled. The screening accounts for spatial variations observed in background for soil and temporal fluctuations observed in background for air. For groundwater, the natural activity concentrations in groundwater wells at the facility are highly variable, and therefore the methodology uses ratios for screening levels. The methodology compares the ratio of gross alpha to U + U to identify potentially abnormal alpha activity and the ratio of U to U to identify the potential presence of depleted uranium. Compliance evaluation is conducted for any samples that fail the screening step. Compliance evaluation uses the radionuclide-specific measurements to first determine (1) if the dose exceeds the background dose and if so, (2) the dose consequences, so that the appropriate investigation or action occurs. The compliance evaluation is applied to all environmental samples throughout the year and on an annual basis to determine regulatory compliance. The methodology is implemented in a cloud-based software application that is also made accessible to the regulator. The benefits of the methodology over the existing system are presented.

Risk Factors Associated With Postoperative Delirium in Patients Undergoing Head and Neck Free Flap Reconstruction.

IMPORTANCE: Postoperative delirium (POD) is associated with an increased rate of adverse events, higher health care costs, and longer hospital stays. At present, limited data are available regarding the risk factors for developing POD in patients undergoing head and neck free flap reconstruction. Identification of patients at high risk of developing POD will allow implementation of risk-mitigation strategies. OBJECTIVE: To determine the frequency of and risk factors associated with POD in patients undergoing free flap reconstruction secondary to head and neck disease. DESIGN, SETTING, AND PARTICIPANTS: This retrospective cohort study included 515 patients undergoing free flap reconstruction from January 1, 2006, through December 31, 2012, at the James Cancer Hospital and Solove Research Institute, The Ohio State University Comprehensive Care Center, a tertiary care cancer hospital. Preoperative, intraoperative, and postoperative data were collected retrospectively. Data from January 1, 2006, through December 31, 2012, were analyzed, and the final date of data analysis was January 8, 2018. INTERVENTIONS: Head and neck free flap reconstruction. MAIN OUTCOMES AND MEASURES: The primary outcome was the development of POD as defined by the Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition). Univariable and multivariable logistic regression were used to identify risk factors associated with POD. RESULTS: Five hundred fifteen patients underwent free flap reconstruction during the study period (66.2% male; mean [SD] age, 60.1 [12.8] years). Of these, 56 patients (10.9%) developed POD. On multivariable analysis, risk factors associated with POD included increased age (odds ratio [OR], 1.06; 95% CI, 1.02-1.11), male sex (OR, 5.02; 95% CI, 1.47-17.20), increased operative time (OR for each 1-minute increase, 1.004 [95% CI, 1.001-1.006]; OR for each 1-hour increase, 1.26 [95% CI, 1.08-1.46]), advanced nodal disease (OR, 3.00; 95% CI, 1.39-6.46), and tobacco use (OR, 7.23; 95% CI, 1.43-36.60). Preoperative abstinence from alcohol was identified as a protective factor (OR, 0.24; 95% CI, 0.12-0.51). CONCLUSIONS AND RELEVANCE: This study identified variables associated with a higher risk of developing POD. Although many of these risk factors are nonmodifiable, they provide a target population for quality improvement initiatives. Furthermore, preoperative alcohol abstinence may be useful in preventing POD.