Ratios of Eye Lens and Hand Equivalent Doses with Whole-Body Effective Doses for Operators Performing Interventional Radiological Procedures.

ABSTRACT: Estimating radiation doses for operators performing interventional radiological procedures is crucial in the occupational radiation protection of medical staff. In this study, Monte Carlo simulations coupled with an anthropomorphic phantom were used to model various exposure scenarios during the procedures. Conversion coefficients of the dose-area product of x rays for the eye lens equivalent dose, hand equivalent dose, and whole-body effective dose of the operator were calculated. Accordingly, the relationships between these dose quantities in typical interventional configurations were established, considering various source locations, tube voltages, and use of protective equipment or not. The results are presented in a systematic way for easy comparison and use. Tables and figures of the data can be helpful to provide estimates of eye lens and hand equivalent doses when records of specific dosimeters are absent, such as in the retrospective assessment of operators' eye lens and hand equivalent doses in past practices.

Comparison of different methods for the shielding analysis of an AB-BNCT facility based on the Be(p,xn) reaction with 30-MeV protons.

Five shielding calculation methods were employed to estimate the dose rate distribution around an accelerator-based boron neutron capture therapy facility. Their performances were compared in terms of accuracy and efficiency. The results indicate that the hybrid deterministic/Monte Carlo method is the most efficient in the context of accurate modeling and simulation, whereas the analytical approximation with pre-generated source terms and attenuation lengths is preferable in the design phase because of its simplicity and ease of verification while retaining a reasonable accuracy.

Standardization of 109Cd by two methods.

109Cd is quite a useful nuclide for the calibration of X-ray spectroscopy, gamma-ray spectroscopy or as an excitation source in X-ray fluorescence. In this work, 4π(PC)e-X coincidence counting and 4π(LS)ce counting were used to determine the activity of the 109Cd solution. The two methods showed good agreement in their counting results. On the other hand, the mean value came from the results of the two methods was used to calibrate the well type ionization chambers to maintain the radioactivity measurement standard of 109Cd at INER.

Validation of Test Performance and Clinical Time Zero for an Electronic Health Record Embedded Severe Sepsis Alert.

BACHGROUND: Increasing use of EHRs has generated interest in the potential of computerized clinical decision support to improve treatment of sepsis. Electronic sepsis alerts have had mixed results due to poor test characteristics, the inability to detect sepsis in a timely fashion and the use of outside software limiting widespread adoption. We describe the development, evaluation and validation of an accurate and timely severe sepsis alert with the potential to impact sepsis management. OBJECTIVE: To develop, evaluate, and validate an accurate and timely severe sepsis alert embedded in a commercial EHR. METHODS: The sepsis alert was developed by identifying the most common severe sepsis criteria among a cohort of patients with ICD 9 codes indicating a diagnosis of sepsis. This alert requires criteria in three categories: indicators of a systemic inflammatory response, evidence of suspected infection from physician orders, and markers of organ dysfunction. Chart review was used to evaluate test performance and the ability to detect clinical time zero, the point in time when a patient develops severe sepsis. RESULTS: Two physicians reviewed 100 positive cases and 75 negative cases. Based on this review, sensitivity was 74.5%, specificity was 86.0%, the positive predictive value was 50.3%, and the negative predictive value was 94.7%. The most common source of end-organ dysfunction was MAP less than 70 mm/Hg (59%). The alert was triggered at clinical time zero in 41% of cases and within three hours in 53.6% of cases. 96% of alerts triggered before a manual nurse screen. CONCLUSION: We are the first to report the time between a sepsis alert and physician chart-review clinical time zero. Incorporating physician orders in the alert criteria improves specificity while maintaining sensitivity, which is important to reduce alert fatigue. By leveraging standard EHR functionality, this alert could be implemented by other healthcare systems.

Comparison exercise on activity determination of radioactive waste drums in Taiwan.

The National Radiation Standard Laboratory of Taiwan organized in 2014 a comparison exercise by distributing 210 L drum-typed samples to seven radioactive waste analysis laboratories in Taiwan. Four drums were filled with uniformly distributed active carbon, water, resin and concrete, respectively and five drums were filled with cracked metals and heterogeneously distributed radioactive sources. Measurement uncertainties of participants results are in the range 3­40% (k=2) and about 96% of the reported results produced En values (ISO, 1997) smaller than one for drums with activity uniformly distributed. The minimum discrepancies, expressed as Bi values (ISO, 1997), of drums with heterogeneously distributed 137Cs and 60Co were 0.34 and 0.17, respectively.

Preoperative angiotensin-converting enzyme inhibitor use is not associated with increased postoperative pain and opioid use.

AIM/OBJECTIVES/BACKGROUND: Angiotensin-converting enzyme inhibitors (ACEIs) increase potent proinflammatory and pain mediators in local tissues. Consistent with these observations, animal and human studies demonstrate that ACEIs have hyperalgesic and proinflammatory properties. However, there is no information in literature whether or not the use of ACEIs is associated with increased postoperative pain. Specifically, we tested the primary hypothesis that use of ACEIs is independently associated with increased opioid requirements and pain scores during the initial 72 hours after surgery. METHODS: Data from 9993 patients undergoing colorectal resection, hysterectomy, nephrectomy, or open prostatectomy were obtained from the Cleveland Clinic Perioperative Health Documentation System. A propensity-matching procedure was used to pair ACEI users to similar nonusers. Corresponding estimates and Bonferroni-adjusted 95% confidence intervals for the effect of ACEIs on each outcome were also estimated. The exact matching procedure, based on type of surgery and propensity score, identified 1038 matched pairs. The final analyzed subsample size was 212. RESULTS AND CONCLUSIONS: The adjusted difference in mean 72-hour postoperative using a time-weighted average pain score was estimated at +0.17 [-0.40, +0.74] units on the verbal response scale. This was not statistically significant (P=0.50). Opioid use was estimated by the percent difference in mean 72-hour total postoperative intravenous morphine equivalent dose at -8.1% [-46%, +56%], which was not statistically significant (P=0.72). In conclusion, after controlling for all available factors, we found no significant difference that postoperative pain-as defined by either pain scores or opioid requirements-differed between patients taking ACEIs and patients not taking ACEIs.

Consequences of succinylcholine administration to patients using statins.

BACKGROUND: Statins cause structural changes in myocytes and provoke myotoxicity, myopathy, and myalgias. Thus, patients taking statins may be especially susceptible to succinylcholine-induced muscle injury. The authors tested the hypothesis that succinylcholine increases plasma concentrations of myoglobin, potassium, and creatine kinase more in patients who take statins than in those who do not and that succinylcholine-induced postoperative muscle pain is aggravated in statin users. METHODS: Patients who took statins for at least 3 months and those who had never used statins were enrolled. General anesthesia was induced and included 1.5 mg/kg succinylcholine for intubation. The incidence and degree of fasciculation after succinylcholine administration were recorded. Blood samples were obtained before induction and 5 and 20 min and 24 h after succinylcholine administration. Patients were interviewed 2 and 24 h after surgery to determine the degree of myalgia. RESULTS: The authors enrolled 38 patients who used statins and 32 who did not. At 20 min, myoglobin was higher in statin users versus nonusers (ratio of medians 1.34 [95% CI: 1.1, 1.7], P = 0.018). Fasciculations in statin users were more intense than in nonusers (P = 0.047). However, plasma potassium and creatine kinase concentrations were similar in statin users and nonusers, as was muscle pain. CONCLUSIONS: The plasma myoglobin concentration at 20 min was significantly greater in statin users than nonusers, although the difference seems unlikely to be clinically important. The study results suggest that the effect of succinylcholine given to patients taking statins is likely to be small and probably of limited clinical consequence.