Surgical Duration Estimation via Data Mining and Predictive Modeling: A Case Study.

Operating rooms (ORs) are one of the most expensive and profitable resources within a hospital system. OR managers strive to utilize these resources in the best possible manner. Traditionally, surgery durations are estimated using a moving average adjusted by the scheduler (adjusted system prediction or ASP). Other methods based on distributions, regression and data mining have also been proposed. To overcome difficulties with numerous procedure types and lack of sufficient sample size, and avoid distributional assumptions, the main objective is to develop a hybrid method of duration prediction and demonstrate using a case study.

Preclinical assessment of a new magnetic resonance-based technique for determining bone quality by characterization of trabecular microarchitecture.

The utility of HR-CT to study longitudinal changes in bone microarchitecture is limited by subject radiation exposure. Although MR is not subject to this limitation, it is limited both by patient movement that occurs during prolonged scanning at distal sites, and by the signal-to-noise ratio that is achievable for high-resolution images in a reasonable scan time at proximal sites. Recently, a novel MR-based technique, fine structure analysis (FSA) (Chase et al. Localised one-dimensional magnetic resonance spatial frequency spectroscopy. PCT/US2012/068284 2012, James and Chase Magnetic field gradient structure characteristic assessment using one-dimensional (1D) spatial frequency distribution analysis. 7932720 B2, 2011) has been developed which provides both high-resolution and fast scan times, but which generates at a designated set of spatial positions (voxels) a one-dimensional signal of spatial frequencies. Appendix 1 provides a brief introduction to FSA. This article describes an initial exploration of FSA for the rapid, non-invasive characterization of trabecular microarchitecture in a preclinical setting. For L4 vertebrae of sham and ovariectomized (OVX) rats, we compared FSA-generated metrics with those from CT datasets and from CT-derived histomorphometry parameters, trabecular number (Tb.N), bone volume density (BV/TV), trabecular thickness (Tb.Th) and trabecular separation (Tb.Sp). OVX caused a reduction of the higher frequency structures that correspond to a denser trabecular lattice, while increasing the preponderance of lower frequency structures, which correspond to a more open lattice. As one example measure, the centroid of the FSA spectrum (which we refer to as fSAcB) showed strong correlation in the same region with CT-derived histomorphometry values: Tb.Sp: r -0.63, p < 0.001; Tb.N: r 0.71, p < 0.001; BV/TV: r 0.64, p < 0.001, Tb.Th: r 0.44, p < 0.05. Furthermore, we found a 17.5% reduction in fSAcB in OVX rats (p < 0.0001). In a longitudinal study, FSA showed that the age-related increase in higher frequency structures was abolished in OVX rats, being replaced with a 78-194% increase in lower frequency structures (2.4-2.8 objects/mm range), indicating a more sparse trabecular lattice (p < 0.05). The MR-based fine structure analysis enables high-resolution, radiation-free, rapid quantification of bone structures in one dimension (the specific point and direction being chosen by the clinician) of the spine.

[Multiple trauma - treatment of skeletal injuries with damage control orthopaedics]. / Polytrauma - osetrení skeletálních poranení metodou damage control orthopaedics.

New methods of treating seriously injured patients have been introduced in the field of trauma surgery since 1993. These consist mostly of differentiated and rapid procedures of treatment of the injured skeleton, with the aim of preventing the development of severe haemorrhagic shock and exsanguination of the patient. The precondition for introducing these techniques is the study of the organisms inflammatory response to trauma. Since 2000, this approach has been called damage control orthopaedics. The authors deal with the history of this method, the physiology of severe trauma, selection of patients eligible for this method and the appropriate timing of definitive treatment.

Obsolete pesticide storage sites and their POP release into the environment--an Armenian case study.

Organochlorinated pesticides were widely applied in Armenia until the 1980s, like in all former Soviet Union republics. Subsequently, the problem of areas contaminated by organochlorinated pesticides emerged. Environmental, waste and food samples at one pesticide burial site (Nubarashen) and three former pesticide storage sites (Jrarat, Echmiadzin and Masis) were taken and analysed on the content of organochlorinated pesticides, polychlorinated dibenzo-p-dioxins and furans and dioxin-like polychlorinated biphenyls. Gradient sampling and diffusivity-based calculations provided information on the contamination release from the hot spots on a local scale. A risk analysis based on samples of locally produced food items characterised the impact of storage sites on the health of nearby residents. All four sites were found to be seriously contaminated. High pesticide levels and soil and air contamination gradients of several orders of magnitude were confirmed outside the fence of the Nubarashen burial site, confirming pesticide release. A storage in Jrarat, which was completely demolished in 1996 and contained numerous damaged bags with pure pesticides until 2011, was found to have polluted surrounding soils by wind dispersion of pesticide powders and air by significant evaporation of lindane and ß-endosulfan during this period. Dichlorodiphenyltrichloroethane-contaminated eggs, sampled from hens roaming freely in the immediate surroundings of the Echmiadzin storage site, revealed a significant health risk for egg consumers above 1E-5. Although small in size and previously almost unknown to the public, storage sites like Echmiadzin, Masis and Jrarat were found to stock considerable amounts of obsolete pesticides and have a significant negative influence on the environment and human health. Multi-stakeholder cooperation proved to be successful in identifying such sites suspected to be significant sources of persistent organic pollutants.

The effect of humic acids on the reverse osmosis treatment of hazardous landfill leachate.

This study deals with the treatment of hazardous waste landfill leachate with the help of reverse osmosis. The landfill is located in an abandoned brown coal pit in northern Bohemia. The leachate contained 7.2 g/L of dissolved inorganic salts. Among other contaminants were heavy metals, arsenic, ammonia nitrogen and associated organic pollutants, especially chlorinated compounds. A mobile membrane unit (LAB M30) equipped with a spiral wound element (FILMTEC SW30-4040), with a membrane area equaling 7.4 m2 was used for the pilot plant experiments. All experiments were carried out in batch mode. 94% conversion of the input stream into the permeate was achieved by use of a two-stage arrangement. Removal efficiencies of the monitored contaminants in the feed ranged from 94% for ammonia nitrogen to 99% for the two-valent ions. Removal efficiency for total dissolved solids was 99.3% on average. Due to varying levels of humic acids in the leachate throughout the year, fouling experiments were performed to investigate the separation process under different conditions than those used in the pilot plant. Leachates containing different concentrations of added humic acids were separated using a thin film composite on a propylene membrane. The added humic acids were obtained from samples of contaminated oxihumolite.

[Right ventricular perforation by a rib fragment following blunt thoracic trauma]. / Perforace pravé komory srdecní ulomkem zebra po tupém urazu hrudníku.

Blunt chest trauma produces a variety of injuries. Penetrating cardiac injuries from rib fractures are extremely rare. We report the unusual case of a patient with multiple rib fractures and penetrating cardiac injury from dislocated segment of fractured VIII left rib. We did find eight patients reported in the literature having penetrating cardiac injuries from rib fractures. The clinical finding and the diagnosis of this injuries are discussed.

[Our first experiences with autologous transplantation of bone marrow stem cells to treat pseudarthrosis, delayed fracture healing and long bone defects fracture]. / Nase první zkusenosti s transplantatí autologních kmenových bunek kostní drene v lécbe pakloubu, opozdeného hojení zlomenin a defektních zlomenin dlouhých kostí.

Traumatology and orthopaedics have undergone substantial progress in the use of new, sophisticated techniques, implants and navigation methods. Nevertheless, these new methods continue to fail in some instances. Regenerative medicine using the growth potential of stem cells that posses the ability to regenerate damaged tissues represent one of the possible ways forward. There is a potential for more comprehensive utilization of bone marrow stem cells that had for many years been used in transplant medicine. Traumatology and orthopaedics could utilise stem cells in the treatment of bone defects, i.e. in the treatment of pseudarthrosis, delayed fracture healing, defect fractures and aseptic bone necroses. Bone formation and growth is a complex, predominantly anabolic, process with a range of feedbacks. Nevertheless, it is the bone marrow where the necessary progenitors of bone growth are located. These are mesenchymal stem cells (MSCs), haematopoietic stem cells (HSCs) as well as thrombocytes containing a range of necessary growth factors. A number of studies showed positive results for stem cells treatment of pseudarthrosis, with only a fraction, however, being statistically significant in human medicine. This method was used in 11 patients of the Traumatology Centre of the Faculty Hospital in Ostrava, Czech Republic in 2008. The researched patients were treated for pseudarthrosis of long bones, delayed multifragmentary fracture haling and defect fractures of long bones. Autologous concentrate of bone marrow stem cells was applied in one session into the area of bone defect in a patient lightly anaesthetised with propofol. The results from this small sample of patients are not yet available. However, we are sharing our first experiences with this treatment option.

[The present level of control of hypertension in the South Moravian Region]. / Soucasná úroven kontroly hypertenze v Jihomoravském kraji.

The authors present the results of a cross sectional and prospective investigation of hypertension in the South Moravian region. The inadequate control of high blood pressure is according to the authors due to inadequate screening, unsuitable dosage and selection of antihypertensive drugs, lack of confidence in medicamentous treatment, inadequate cooperation of doctors and patients, and frequently lack of perception of the disease. The authors mention also the importance of the unbalanced supplies in previous years. They refute objections that screening and treatment of hypertension is time consuming and expensive and consider prevention the prerequisite of all efforts to reduce the morbidity and mortality from cardiovascular diseases.