Influence of Body Posture on Internal Organ Dosimetry: Radiocesium Exposure Modeling Using Novel Posture-dependent Mesh Computational Phantoms.

ABSTRACT: Current practice in reference internal dosimetry assumes a fixed upright standing posture is maintained throughout the dose-integration period. Recently, the mesh-type ICRP adult reference computational phantoms were transformed into different body postures (e.g., sitting, squatting) for use in occupational dose reconstruction applications. Here, for the first time, we apply this phantom series to the study of organ dose estimates following radionuclide intake. We consider the specific cases of 137 Cs and 134 Cs ingestion (accidental/occupational intake) with attention to variability in absorbed dose as a function of posture. The ICRP Publication 137 systemic biokinetic model for soluble cesium ingestion was used to compute organ-level time-integrated activity coefficients for reference adults, over a 50-y dose-integration period, for 134 Cs and 137 Cs (and its radioactive progeny 137m Ba). Mean posture time-allocations (h d -1 for standing, sitting, and lying) were taken from published survey data. In accord with modern dosimetry formalisms (e.g., MIRD, ICRP), a posture weighting factor was introduced that accounts for the fraction of time spent within each independent posture. Absorbed dose coefficients were computed using PHITS Monte Carlo simulations. ICRP 103 tissue weighting factors were applied along with the posture weighting factors to obtain committed effective dose per unit intake (Sv Bq -1 ). For 137 Cs ingestion, most organ absorbed dose coefficients were negligibly to marginally higher (< ~3%) for sitting or crouched (lying fetal/semi-fetal) postures maintained over the dose commitment period, relative to the upright standing posture. The committed effective dose coefficients were 1.3 × 10 -8 Sv Bq -1 137 Cs for standing, sitting, or crouched postures; thus, the posture-weighted committed effective dose was not significantly different than the committed effective dose for a maintained upright standing posture. For 134 Cs ingestion, most organ absorbed dose coefficients for the sitting and crouched postures were significantly larger than the standing posture, but the differences were still considered minor (< ~8% for most organs). The committed effective dose coefficients were 1.2 × 10 -8 Sv Bq -1 134 Cs for the standing posture and 1.3 × 10 -8 Sv Bq -1 134 Cs for the sitting or crouched posture. The posture-weighted committed effective dose was 1.3 × 10 -8 Sv Bq -1 134 Cs. Body posture has minor influence on organ-level absorbed dose coefficients and committed effective dose for ingestion of soluble 137 Cs or 134 Cs.

Reconstructed lung doses for the million person study cohort of 26,650 Tennessee Eastman corporation workers employed between 1942 and 1947.

Tennessee Eastman Corporation workers were exposed to uranium dust resulting in high-linear energy transfer (LET) irradiation to lung tissue. In this work, radiation lung doses were reconstructed for 26 650 men and women working at the plant between 1942 and 1947. Site air monitoring data of uranium concentrations and payroll records were used to determine the daily inhaled activities and annualized lung doses. Variations in the activity median aerodynamic diameter of the uranium dust, the solubility of particulate matter in the lungs and the sex-specific breathing rate were investigated as part of a sensitivity analysis. Male and female mean lung doses of 18.9 and 32.7 mGy, respectively, from high-LET alpha irradiation, and there was general agreement with evaluations from previously published epidemiological studies. Annual lung dose estimates and sensitivity analysis for the 26 650 workers in the TEC cohort have been archived on the United States Department of Energy Comprehensive Epidemiologic Data Resource.

Mortality among Tennessee Eastman Corporation (TEC) uranium processing workers, 1943-2019.

BACKGROUND: There are few occupational studies of women exposed to ionizing radiation. During World War II, the Tennessee Eastman Corporation (TEC) operated an electromagnetic field separation facility of 1152 calutrons to obtain enriched uranium (235U) used for the Hiroshima atomic bomb. Thousands of women were involved in these operations. MATERIALS AND METHODS: A new study was conducted of 13,951 women and 12,699 men employed at TEC between 1943 and 1947 for at least 90 days. Comprehensive dose reconstruction techniques were used to estimate lung doses from the inhalation of uranium dust based on airborne measurements. Vital status through 2018/2019 was obtained from the National Death Index, Social Security Death Index, Tennessee death records and online public record databases. Analyses included standardized mortality ratios (SMRs) and Cox proportional hazards models. RESULTS: Most workers were hourly (77.7%), white (95.6%), born before 1920 (58.3%), worked in dusty environments (57.0%), and had died (94.9%). Vital status was confirmed for 97.4% of the workers. Women were younger than men when first employed: mean ages 25.0 years and 33.0 years, respectively. The estimated mean absorbed dose to the lung was 32.7 mGy (max 1048 mGy) for women and 18.9 mGy (max 501 mGy) for men. The mean dose to thoracic lymph nodes (TLNs) was 127 mGy. Statistically significant SMRs were observed for lung cancer (SMR 1.25; 95% CI 1.19, 1.31; n = 1654), nonmalignant respiratory diseases (NMRDs) (1.23; 95% CI 1.19, 1.28; n = 2585), and cerebrovascular disease (CeVD) (1.13; 95% CI 1.08, 1.18; n = 1945). For lung cancer, the excess relative rate (ERR) at 100 mGy (95% CI) was 0.01 (-0.10, 0.12; n = 652) among women, and -0.15 (-0.38, 0.07; n = 1002) among men based on a preferred model for men with lung doses <300 mGy. NMRD and non-Hodgkin lymphoma were not associated with estimated absorbed dose to the lung or TLN. CONCLUSIONS: There was little evidence that radiation increased the risk of lung cancer, suggesting that inhalation of uranium dust and the associated high-LET alpha particle exposure to lung tissue experienced over a few years is less effective in causing lung cancer than other types of exposures. There was no statistically significant difference in the lung cancer risk estimates between men and women. The elevation of certain causes of death such as CeVD is unexplained and will require additional scrutiny of workplace or lifestyle factors given that radiation is an unlikely contributor since only the lung and lymph nodes received appreciable dose.

SUBSTANTIAL EXTERNAL DOSE RATE VARIABILITY OBSERVED IN A COHORT OF LU-177 PATIENTS INDEPENDENT OF BMI AND SEX.

External dose rates were measured 1 m away from 230 Lu-177 patients to characterise the variability in normalised dose rates as a function of administered activity, body mass index (BMI) and sex. The largest dose rate observed was 0.07 mSv/h associated with an administered activity of 7.2 GBq. Substantial variability was found in the distribution of the normalised dose rate associated that had an average of 0.0037 mSv/h per GBq and a 95% confidence interval of 0.0024-0.0058 mSv/h per GBq. Based on this study, estimating the patient dose rate based on the Lu-177 gamma exposure factor overestimates the dose rate by a factor of 2. A statistically significant inverse relationship was found between the patient dose rate and patient BMI and an empirically derived equation relating these two quantities was reported. On average, male patient dose rates were 3.5% lower than female dose rates, which may be attributed to the larger average BMI of the male patient group.

Efficient Route for the Preparation of Composite Resin Incorporating Silver Nanoparticles with Enhanced Antibacterial Properties.

An efficient and facile route for the immobilization of silver (Ag) nanoparticles (NPs) in anion exchange resin beads with different silver loading is proposed. In this method, BH4- ions were first introduced into chloride-form resin through an ion exchange process with Cl- ions, followed by in-situ chemical reduction of Ag+ ions at the surface of the resin to form metallic Ag nanoparticles. Morphology and structure of the resulting Ag-resin nanocomposites were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), Fourier transform infra-red (FTIR), inductively coupled plasma-optical emission spectrometry (ICP-OES), and thermogravimetry analysis (TGA). The results confirmed the presence of smaller diameter Ag NPs incorporated into the resin beads having an average diameter on the order of 10 nm with a few Ag NP clusters of 20-100 nm. The nanoparticles were homogeneously distributed throughout the resin. There were no dramatic increases in average particle sizes even at very high Ag loadings. The resin retained its structure and stability, allowing higher stability of immobilized AgNPs than the colloidal ones. The Ag-loaded resins made with 50 mM AgNO3 were tested for antibacterial activity in vitro against Escherichia coli (E. coli) as a model microbial contaminant in water. Results showed greater than 99% bacterial inhibition within 3 h of exposure. The resin form offers greater ease of handling, long-term storage at room temperature, reusability in repeated reactions, and reduces the risk of environmental contamination.

MPS dose reconstruction for internal emitters: some site-specific issues and approaches.

BACKGROUND: As part of the Million Person Study (MPS), dose reconstructions for internal emitters have been performed for several U.S. facilities where large quantities of radionuclides were handled. The main challenges and dominant sources of potential error in retrospective dose estimates for internally exposed workers have been found to vary from site to site. This article discusses some important issues encountered in dose reconstructions performed for selected MPS sites and the approaches used to address those issues. The focus is on some foundational components of retrospective dose assessments that have received little attention in the literature. METHODS: The discussion is built around illustrative exposure data and dose reconstructions for workers at selected facilities addressed in the MPS. Related findings at some non-MPS sites are also discussed. RESULTS: Each of the following items has been found to be a major source of potential error in reconstructed tissue doses for some MPS sites: identification of all dosimetrically important internal emitters; the time pattern of intake; the mode(s) of intake; reliability of bioassay measurements; application of surrogate (coworker) information in lieu of, or in conjunction with, worker-specific monitoring data; the chemical and physical forms of inhaled radionuclides; and the relation of air monitoring data to actual intake. CONCLUSIONS: (1) Much of the dose reconstruction effort for internal emitters should be devoted to development of best feasible exposure scenarios. (2) Coworker data should be used to assign exposure scenarios or dose estimates to workers with missing exposure data only if there is compelling evidence of similar coworker exposure. (3) Bioassay data for some radionuclides and periods of operation at MPS sites are of questionable reliability due to sizable uncertainties associated with contamination, recovery, or background issues. (4) Dose estimates derived solely from air monitoring data should be treated as highly uncertain values in the absence of site-specific information demonstrating that the data are reasonably predictive of intake. (5) For intakes known or assumed to be via inhalation, the uncertainty in lung dose typically is much greater than the uncertainty in dose to systemic tissues, when dose estimates are based on urinary excretion data. (6) The lung dose estimate often can be improved through development of site-specific respiratory absorption parameter values. (7) There is generally insufficient site-specific information to justify development of site-specific systemic models.

Cohort profile - MSK radiation workers: a feasibility study to establish a deceased worker sub-cohort as part of a multicenter medical radiation worker component in the million person study of low-dose radiation health effects.

BACKGROUND: The National Council on Radiation Protection and Measurements (NCRP) is coordinating an expansive epidemiologic effort entitled the Million Person Study of Low-Dose Radiation Health Effects (MPS). Medical workers constitute the largest occupational radiation-exposed group whose doses are typically received gradually over time. METHODS: A unique opportunity exists to establish an Institutional Review Board/Privacy Board (IRB/PB) approved, retrospective feasibility sub-cohort of diseased Memorial Sloan Kettering Cancer Center (MSK) medical radiation workers to reconstruct occupational/work history, estimate organ-specific radiation absorbed doses, and review existing publicly available records for mortality from cancer (including leukemia) and other diseases. Special emphasis will be placed on dose reconstruction approaches as a means to provide valid organ dose estimates that are as accurate and precise as possible based on the available data, and to allow proper evaluation of accompanying uncertainties. Such a study that includes validated dose measurements and information on radiation exposure conditions would significantly reduce dose uncertainties and provided greatly improved information on chronic low-dose risks. RESULTS: The feasibility sub-cohort will include deceased radiation workers from MSK who worked during the nearly seventy-year timeframe from 1946 through 2010 and were provided individual personal radiation dosimetry monitors. A feasibility assessment focused on obtaining records for about 25-30,000 workers, with over 124,000 annual doses, including personnel/work histories, specific dosimetry data, and appropriate information for epidemiologic mortality tracing will be conducted. MSK radiation dosimetry measurements have followed stringent protocols complying with strict worker protection standards in order to provide accurate dose information for radiation workers that include detailed records of work practices (including specific task exposure conditions, radiation type, energy, geometry, personal protective equipment usage, badge position, and missed doses), as well as recorded measurements. These dose measurements have been ascertained through a variety of techniques that have evolved over the years, from film badges to thermoluminescent dosimetry technology to optically stimulated luminescent methodologies. It is expected that individual total doses for the sub-cohort will have a broad range from <10 mSv to > =1000 mSv. CONCLUSIONS: MSK has pioneered the use of novel radiation diagnostic and therapeutic approaches over time (including initial work with x-rays, radium, and radon), with workplace safety in mind, resulting in a variety of radiation worker exposure scenarios. The results of this feasibility sub-cohort of deceased radiation workers, and associated lessons learned may potentially be applied to an expanded multicenter study of about 170,000 medical radiation worker component of the MPS.

Mortality among workers at the Los Alamos National Laboratory, 1943-2017.

BACKGROUND: During World War II (WWII), the Manhattan Engineering District established a secret laboratory in the mountains of northern New Mexico. The mission was to design, construct and test the first atomic weapon, nicknamed 'The Gadget' that was detonated at the TRINITY site in Alamogordo, NM. After WWII, nuclear weapons research continued, and the laboratory became the Los Alamos National Laboratory (LANL). MATERIALS AND METHODS: The mortality experience of 26,328 workers first employed between 1943 and 1980 at LANL was determined through 2017. Included were 6157 contract workers employed by the ZIA Company. Organ dose estimates for each worker considered all sources of exposure, notably photons, neutrons, tritium, 238Pu and 239Pu. Vital status determination included searches within the National Death Index, Social Security Administration and New Mexico State Mortality Files. Standardized Mortality Ratios (SMR) and Cox regression models were used in the analyses. RESULTS: Most workers (55%) were hired before 1960, 38% had a college degree, 25% were female, 81% white, 13% Hispanic and 60% had died. Vital status was complete, with only 0.1% lost to follow-up. The mean dose to the lung for the 17,053 workers monitored for radiation was 28.6 weighted-mGy (maximum 16.8 weighted-Gy) assuming a Dose Weighting Factor of 20 for alpha particle dose to lung. The Excess Relative Risk (ERR) at 100 weighted-mGy was 0.01 (95%CI -0.02, 0.03; n = 839) for lung cancer. The ERR at 100 mGy was -0.43 (95%CI -1.11, 0.24; n = 160) for leukemia other than chronic lymphocytic leukemia (CLL), -0.06 (95%CI -0.16, 0.04; n = 3043) for ischemic heart disease (IHD), and 0.29 (95%CI 0.02, 0.55; n = 106) for esophageal cancer. Among the 6499 workers with measurable intakes of plutonium, an increase in bone cancer (SMR 2.44; 95%CI 0.98, 5.03; n = 7) was related to dose. The SMR for berylliosis was significantly high, based on 4 deaths. SMRs for Hispanic workers were significantly high for cancers of the stomach and liver, cirrhosis of the liver, nonmalignant kidney disease and diabetes, but the excesses were not related to radiation dose. CONCLUSIONS: There was little evidence that radiation increased the risk of lung cancer or leukemia. Esophageal cancer was associated with radiation, and plutonium intakes were linked to an increase of bone cancer. IHD was not associated with radiation dose. More precise evaluations will await the pooled analysis of workers with similar exposures such as at Rocky Flats, Savannah River and Hanford.

COVID-19 and its impact on the cardiovascular system.

OBJECTIVES: The clinical impact of SARS-CoV-2 has varied across countries with varying cardiovascular manifestations. We review the cardiac presentations, in-hospital outcomes and development of cardiovascular complications in the initial cohort of SARS-CoV-2 positive patients at Imperial College Healthcare National Health Service Trust, UK. METHODS: We retrospectively analysed 498 COVID-19 positive adult admissions to our institute from 7 March to 7 April 2020. Patient data were collected for baseline demographics, comorbidities and in-hospital outcomes, especially relating to cardiovascular intervention. RESULTS: Mean age was 67.4±16.1 years and 62.2% (n=310) were male. 64.1% (n=319) of our cohort had underlying cardiovascular disease (CVD) with 53.4% (n=266) having hypertension. 43.2%(n=215) developed acute myocardial injury. Mortality was significantly increased in those patients with myocardial injury (47.4% vs 18.4%, p<0.001). Only four COVID-19 patients had invasive coronary angiography, two underwent percutaneous coronary intervention and one required a permanent pacemaker implantation. 7.0% (n=35) of patients had an inpatient echocardiogram. Acute myocardial injury (OR 2.39, 95% CI 1.31 to 4.40, p=0.005) and history of hypertension (OR 1.88, 95% CI 1.01 to 3.55, p=0.049) approximately doubled the odds of in-hospital mortality in patients admitted with COVID-19 after other variables had been controlled for. CONCLUSION: Hypertension, pre-existing CVD and acute myocardial injury were associated with increased in-hospital mortality in our cohort of COVID-19 patients. However, only a low number of patients required invasive cardiac intervention.

Adapting the role of handheld echocardiography during the COVID-19 pandemic: A practical guide.

The COVID-19 pandemic has altered our approach to inpatient echocardiography delivery. There is now a greater focus to address key clinical questions likely to make an immediate impact in management, particularly during the period of widespread infection. Handheld echocardiography (HHE) can be used as a first-line assessment tool, limiting scanning time and exposure to high viral load. This article describes a potential role for HHE during a pandemic. We propose a protocol with a reporting template for a focused core dataset necessary in delivering an acute echocardiography service in the setting of a highly contagious disease, minimising risk to the operator. We cover the scenarios typically encountered in the acute cardiology setting and how an expert trained echocardiography team can identify such pathologies using a limited imaging format and include cardiac presentations encountered in those patients acutely unwell with COVID-19.

Management of Acute Coronary Syndromes During the Coronavirus Disease 2019 Pandemic: Deviations from Guidelines and Pragmatic Considerations for Patients and Healthcare Workers.

Coronavirus disease 2019 (COVID-19) is forcing cardiology departments to rapidly adapt existing clinical guidelines to a new reality and this is especially the case for acute coronary syndrome pathways. In this focused review, the authors discuss how COVID-19 is affecting acute cardiology care and propose pragmatic guideline modifications for the diagnosis and management of acute coronary syndrome patients, particularly around the appropriateness of invasive strategies as well as length of hospital stay. The authors also discuss the use of personal protective equipment for healthcare workers in cardiology. Based on shared global experiences and growing peer-reviewed literature, it is possible to put in place modified acute coronary syndrome treatment pathways to offer safe pragmatic decisions to patients and staff.

A Descriptive Analysis of Causalities Undergoing CASEVAC from the Point-of-Injury in the Department of Defense Trauma Registry.

INTRODUCTION: The recent conflicts in Iraq and Afghanistan entail an asymmetric battlefield without clearly defined forward lines of troops as seen in previous wars. Accordingly, the United States military medical services have increasingly adopted casualty evacuation (CASEVAC) platforms. We describe CASEVAC events reported within the Department of Defense Trauma Registry (DODTR). MATERIALS AND METHODS: This is a secondary analysis of previously published data from two datasets spanning from 2007 through 2017. We isolated casualties within our dataset that had a documented evacuation method from the point-of-injury other than dedicated medical evacuation platforms (e.g., MEDEVAC, etc.). RESULTS: During OPERATION IRAQI FREEDOM, three casualties underwent CASEVAC. The median age was 30 and all were male. Most sustained injuries from explosives (67%) and the median composite injury scores were low (10). The most frequent seriously injured body region was the thorax (67%). All survived to hospital discharge. During operations in Afghanistan (OPERATION ENDURING FREEDOM, OPERATION FREEDOMS SENTINEL, OPERATION NEW DAWN), 248 casualties underwent CASEVAC. The median age was 28 and most (96%) were male. Most sustained injuries from explosives (58%) and the median injury score was low (9). The most frequent seriously injured body region was the extremities (24%). Most (97%) survived to hospital discharge. During OPERATION INHERENT RESOLVE, 247 casualties underwent CASEVAC. The median age was 21 and most (96%) were male. The majority sustained injuries from explosives (61%) and the median injury score was low (9). The most frequent seriously injury body region was the extremities (27%). Most survived to hospital discharge (94%). CONCLUSIONS: In our dataset, CASEVAC events most frequently involved US military personnel service members with most surviving to hospital discharge. Developing new terminology that distinguishes different types of CASEVAC would allow for more accurate future analyses of casualty evacuation and outcomes - such as those transports that are truly in a non-medical versus the various medical platforms that do not fall with into the confines of the MEDEVAC platforms.

Aortic Stenosis in Dialysis Patients.

Aortic valve stenosis occurs 10-20 years earlier in patients on dialysis compared with the general population. This is likely related to the exposure of the valve to a milieu that predisposes to calcification as well as increased shear stress across the valve. Objective assessment of stenosis severity is largely made using echocardiography though accurate interpretation requires an understanding of the potential pitfalls of the technique and the influence of cardiac output upon the gradient measured across the valve. Timing of valve replacement in severe aortic stenosis is predominantly guided by exercise-induced symptoms (breathlessness, chest pain and [pre] syncope), which are often difficult to assess in the dialysis population who may have limited exercise capacity and symptoms due to renal failure and other comorbidities. Finally, treatment of aortic stenosis remains a constantly evolving area with advances in both conventional surgery and percutaneous techniques.

Validation of PIMAL 3.0-Phantom with Moving Arms and Legs.

When it comes to determining radiation protection measurements, complex geometries often require the use of computational modeling to solve the problems; the human body is no exception. However, both old and new phantom models have almost always been rigidly created in the vertical upright position. Oak Ridge National Laboratory solved this issue in 2007 by developing a piece of software named 'Phantom with Moving Arms and Legs (PIMAL)',  which creates a flexible phantom model for computer simulations. Though the initial hermaphrodite phantom is validated, new gender-specific models need validation against generally accepted values. Thus, the purpose of this study was to compare the dose coefficients from PIMAL against known values in Federal Guidance Report 12 for water submersion. Of 21 organ-tissue doses, all but 2 matched to within 15% for photon energies above 1 MeV. For plots with notable discrepancies at multiple energies, including bone surface and effective dose, explanations are given to justify differences.

Resolving the paradox of randomised controlled trials and observational studies comparing multi-vessel angioplasty and culprit only angioplasty at the time of STEMI.

BACKGROUND: Patients presenting with ST-elevation myocardial infarction commonly have multi-vessel coronary artery disease. After the culprit artery is treated, the optimal treatment strategy for the residual disease is not yet defined. Large observational studies suggest that treatment of residual disease should be deferred but smaller randomised controlled trials (RCTs) suggest multi-vessel primary percutaneous coronary intervention (MV-PPCI) at the time of STEMI is safe. We examine if allocation bias of high-risk patients could explain the conflicting results between observational studies and RCTs and aim to resolve the paradox between the two. METHODS: A meta-analysis of registries comparing culprit-only PPCI to MV-PPCI was performed. We then determined if high-risk patients were more likely to be allocated to MV-PPCI. A meta-regression was performed to determine if any allocation bias of high-risk patients could explain the difference in outcomes between therapies. RESULTS: 47,717 patients (19 studies) were eligible. MV-PPCI had higher mortality than culprit-only PPCI (OR 1.59, 95% CI 1.12 to 2.24, p=0.03). However, higher risk patients were more likely to be allocated to MV-PPCI (OR 1.45, 95% CI 1.18 to 1.78, p=0.0005). When this was accounted for, there was no difference in mortality between culprit-only PPCI and MV-PPCI (OR 0.99, 95% CI 0.69 to 1.41, p=0.94). DISCUSSION: Clinicians preferentially allocate higher-risk patients to MV-PPCI at the time of STEMI, resulting in observational studies reporting higher mortality with this strategy. When this is accounted for, these large observational studies in 'real world' patients support the conclusion of the smaller RCTs in the field: MV-PPCI has equivalent mortality to a culprit-only approach.

Assessment of the Point-Source Method for Estimating Dose Rates to Members of the Public from Exposure to Patients with 131I Thyroid Treatment.

The U.S. Nuclear Regulatory Commission (USNRC) initiated a contract with Oak Ridge National Laboratory (ORNL) to calculate radiation dose rates to members of the public that may result from exposure to patients recently administered iodine-131 (131I) as part of medical therapy. The main purpose was to compare dose rate estimates based on a point source and target with values derived from more realistic simulations of a human source and target. The latter simulations considered the time-dependent distribution of 131I in the patient and attenuation of emitted photons by the patient's tissues. The external dose rate estimates were derived using Monte Carlo methods and two representations of the Phantom with Movable Arms and Legs (PIMAL), previously developed by ORNL and the USNRC, to model the patient and a nearby member of the public. Dose rates to tissues and effective dose rates were calculated for distances ranging from 10 cm to 300 cm between the phantoms. Dose rates estimated from these simulations are compared to estimates based on the point-source method, as well as to results of previous studies that estimated exposure from 131I patients. The point-source method overestimates dose rates to members of the public in very close proximity to an 131I patient but is a broadly accurate method of dose rate estimation at separation distances of 300 cm or more at times closer to administration.

A new method of applying randomised control study data to the individual patient: A novel quantitative patient-centred approach to interpreting composite end points.

BACKGROUND: Modern randomised controlled trials typically use composite endpoints. This is only valid if each endpoint is equally important to patients but few trials document patient preference and seek the relative importance of components of combined endpoints. If patients weigh endpoints differentially, our interpretation of trial data needs to be refined. METHODS AND RESULTS: We derive a quantitative, structured tool to determine the relative importance of each endpoint to patients. We then apply this tool to data comparing angioplasty with drug-eluting stents to bypass surgery. The survey was administered to patients undergoing cardiac catheterisation. A meta-analysis comparing coronary artery bypass grafting (CABG) to percutaneous coronary interventuin (PCI) was then performed using (a) standard MACE and (b) patient-centred MACE. Patients considered stroke worse than death (stroke 102.3 ± 19.6%, p < 0.01), and MI and repeat revascularisation less severe than death (61.9 ± 26.8% and 41.9 ± 25.4% respectively p < 0.01 for both). 7 RCTs (5251 patients) were eligible. Meta-analysis demonstrated that standard MACE occurs more frequently with PCI than surgery (OR 1.44; 95% CI 1.10 to 1.87; p = 0.007). Re-analysis using patient-centred MACE found no significant difference between PCI and CABG (OR 1.22, 95% CI 0.97 to 1.53; p = 0.10). CONCLUSIONS: Patients do not consider the constituent endpoints of MACE equal. We derive a novel patient-centred metric that recognises and quantifies the differences attributed to each endpoint. When patient preference data are applied to contemporary trial results, there is no significant difference between PCI and CABG. Responses from individual patients in clinic could be used to give individual patients a recommendation that is truly personalised.

A comparison of the incidence of cricothyrotomy in the deployed setting to the emergency department at a level 1 military trauma center: a descriptive analysis.

Airway management is a critical skill of emergency medicine physicians and prehospital providers. Airway compromise is the cause of 1.8% of battlefield deaths. Cricothyrotomy is a critical, lifesaving procedure. In this study, we conducted a retrospective descriptive analysis comparing the incidence of cricothyrotomies in the deployed setting versus the incidence in a military level 1 trauma center emergency department (ED) setting in San Antonio, Texas. The deployed/in-theater procedures were performed from September 2007 to July 2009. The ED procedures were performed from April 2010 to February 2012. Over these study periods, 28 cricothyrotomies were performed in the deployed setting against a backdrop of 11,492 trauma admissions compared to 4 cricothyrotomies performed during 2,741 trauma admissions in the ED setting. The per admission incidence of deployed cricothyrotomies was 0.24% versus an incidence of 0.15% in the ED (p=0.46). We conclude that this rare, lifesaving procedure is performed more often in the deployed setting than the ED, but this difference was not statistically significant.

Pre-angioplasty instantaneous wave-free ratio pullback provides virtual intervention and predicts hemodynamic outcome for serial lesions and diffuse coronary artery disease.

OBJECTIVES: The aim of this study was to perform hemodynamic mapping of the entire vessel using motorized pullback of a pressure guidewire with continuous instantaneous wave-free ratio (iFR) measurement. BACKGROUND: Serial stenoses or diffuse vessel narrowing hamper pressure wire-guided management of coronary stenoses. Characterization of functional relevance of individual stenoses or narrowed segments constitutes an unmet need in ischemia-driven percutaneous revascularization. METHODS: The study was performed in 32 coronary arteries with tandem and/or diffusely diseased vessels. An automated iFR physiological map, integrating pullback speed and physiological information, was built using dedicated software to calculate physiological stenosis severity, length, and intensity (ΔiFR/mm). This map was used to predict the best-case post-percutaneous coronary intervention (PCI) iFR (iFRexp) according to the stented location, and this was compared with the observed iFR post-PCI (iFRobs). RESULTS: After successful PCI, the mean difference between iFRexp and iFRobs was small (mean difference: 0.016 ± 0.004) with a strong relationship between ΔiFRexp and ΔiFRobs (r = 0.97, p < 0.001). By identifying differing iFR intensities, it was possible to identify functional stenosis length and quantify the contribution of each individual stenosis or narrowed segment to overall vessel stenotic burden. Physiological lesion length was shorter than anatomic length (12.6 ± 1.5 vs. 23.3 ± 1.3, p < 0.001), and targeting regions with the highest iFR intensity predicted significant improvement post-PCI (r = 0.86, p < 0.001). CONCLUSIONS: iFR measurements during continuous resting pressure wire pullback provide a physiological map of the entire coronary vessel. Before a PCI, the iFR pullback can predict the hemodynamic consequences of stenting specific stenoses and thereby may facilitate the intervention and stenting strategy.