An optimization based on simulation approach to the patient admission scheduling problem using a linear programing algorithm.

BACKGROUND: As patient's length of stay in waiting lists increases, governments are looking for strategies to control the problem. Agreements were created with private providers to diminish the workload in the public sector. However, the growth of the private sector is not following the demand for care. Given this context, new management strategies have to be considered in order to minimize patient length of stay in waiting lists while reducing the costs and increasing (or at least maintaining) the quality of care. METHOD: Appointment scheduling systems are today known to be proficient in the optimization of health care services. Their utilization is focused on increasing the usage of human resources, medical equipment and reducing the patient waiting times. In this paper, a simulation-based optimization approach to the Patient Admission Scheduling Problem is presented. Modeling tools and simulation techniques are used in the optimization of a diagnostic imaging department. RESULTS: The proposed techniques have demonstrated to be effective in the evaluation of diagnostic imaging workflows. A simulated annealing algorithm was used to optimize the patient admission sequence towards minimizing the total completion and total waiting of patients. The obtained results showed average reductions of 5% on the total completion and 38% on the patients' total waiting time.

Sepsis patients do not differ in health-related quality of life compared with other ICU patients.

INTRODUCTION: The aim of the present multicentre study is to assess health-related quality of life in patients with community-acquired sepsis, severe sepsis, or septic shock (CAS) 6 months after discharge from the intensive care unit (ICU) and to compare the health-related quality of life of the ICU survivors with CAS with ICU survivors with other ICU diagnoses. METHODS: Prospective, multicentre study in nine combined medical and surgical ICUs in Portugal. Health-related quality of life was assessed 6 months after ICU stay, using EuroQol-5D (EQ-5D) mailed to patients. ICU-related factors were obtained from the local ICU database and the local database for the SACiUCI follow-up study. RESULTS: A total of 313 (52%) surviving patients answered the questionnaire, and of these 91 (29%) were admitted for CAS. There were no significant differences in health-related quality of life between the two study groups. CONCLUSION: Patients admitted to ICU for CAS did not perceived different health-related quality of life compared with ICU patients admitted for other diagnoses.

Outcome of ICU survivors: a comprehensive review. The role of patient-reported outcome studies.

Problems survivors face after intensive care unit (ICU) discharge begin while they are still in the ward, where many of their specific problems may run unrecognized, but they assume a heavy weight when they arrive at their homes and face several kind of limitations, from being unable to climb stairs because of weight loss, asthenia, dyspnea or joint stiffness to anxiety, depression or post-traumatic stress disorder. Follow-up consultations have given us a better understanding of these specific problems, and the information gained has been used to improve intensive care itself and promote a quality service for patients and relatives. The aim of this article is to provide an overview on adult ICU outcome studies and discuss how they have influenced and improved the delivery of intensive care. We will explain how we went from real patients to outcome studies and what we have learned concerning the consequences of critical illness and critical care. Development of outcome studies, what we have learned through them and our own experience will be outlined focusing mainly in four topics: mortality, physical disability, neuropsychological disability and health-related quality of life. Interventions to improve outcome on these main topics will be presented, and we will explain how we went from outcome studies to clinical interventions, focusing on the most recent proposals of intervention to improve outcome.

Phospholipase C-gamma 1 association with CD3 structure in T cells.

Recently, we and others have reported tyrosine phosphorylation of phospholipase C-gamma 1 (PLC gamma 1) enzyme after CD3 activation of T cells, and have proposed that PLC gamma 1 mediates signal transduction through the T cell receptor (TCR/CD3). Here, using immunoblotting and immune complex PLC assays, we show that CD3 stimulation of Jurkat cells induces the association of PLC gamma 1 enzyme with CD3 complex. PLC activity is also found to co-precipitate with the CD3 zeta chain from activated cells. In addition, in vitro PLC assays show that CD3 activation leads to about 10-fold stimulation of PLC gamma 1 activity. These results, along with the observation that Jurkat cells preferentially express PLC gamma 1, indicate that PLC gamma 1 participates in CD3 signaling.

Understanding international differences in terminology for delirium and other types of acute brain dysfunction in critically ill patients.

BACKGROUND: Delirium (acute brain dysfunction) is a potentially life threatening disturbance in brain function that frequently occurs in critically ill patients. While this area of brain dysfunction in critical care is rapidly advancing, striking limitations in use of terminology related to delirium internationally are hindering cross-talk and collaborative research. In the English literature, synonyms of delirium such as the Intensive Care Unit syndrome, acute brain dysfunction, acute brain failure, psychosis, confusion, and encephalopathy are widely used. This often leads to scientific "confusion" regarding published data and methodology within studies, which is further exacerbated by organizational, cultural and language barriers. OBJECTIVE: We undertook this multinational effort to identify conflicts in terminology and phenomenology of delirium to facilitate communication across medical disciplines and languages. METHODS: The evaluation of the terminology used for acute brain dysfunction was determined conducting communications with 24 authors from academic communities throughout countries/regions that speak the 13 variants of the Romanic languages included into this manuscript. RESULTS: In the 13 languages utilizing Romanic characters, included in this report, we identified the following terms used to define major types of acute brain dysfunction: coma, delirium, delirio, delirium tremens, délire, confusion mentale, delir, delier, Durchgangs-Syndrom, acute verwardheid, intensiv-psykose, IVA-psykos, IVA-syndrom, akutt konfusion/forvirring. Interestingly two terms are very consistent: 100 % of the selected languages use the term coma or koma to describe patients unresponsive to verbal and/or physical stimuli, and 100% use delirium tremens to define delirium due to alcohol withdrawal. Conversely, only 54% use the term delirium to indicate the disorder as defined by the DSM-IV as an acute change in mental status, inattention, disorganized thinking and altered level of consciousness. CONCLUSIONS: Attempts towards standardization in terminology, or at least awareness of differences across languages and specialties, will help cross-talk among clinicians and researchers.

High resolution imaging of 2D distribution of lithium in thin samples measured with multipixel detectors in sandwich geometry.

A method that enables visualization of lateral distribution of Li in thin films is described. The method is based on the simultaneous detection of the reaction products of the 6Li(n,α)t nuclear reaction with thermal neutrons measured with two multipixel detectors in a sandwich geometry with a sample. Here, the principle and basic methodological parameters of the method, including tests with thin polymers with known Li microstructure, are discussed.

A comparative study of LaBr3(Ce(3+)) and CeBr3 based gamma-ray spectrometers for planetary remote sensing applications.

The recent availability of large volume cerium bromide crystals raises the possibility of substantially improving gamma-ray spectrometer limiting flux sensitivities over current systems based on the lanthanum tri-halides, e.g., lanthanum bromide and lanthanum chloride, especially for remote sensing, low-level counting applications or any type of measurement characterized by poor signal to noise ratios. The Russian Space Research Institute has developed and manufactured a highly sensitive gamma-ray spectrometer for remote sensing observations of the planet Mercury from the Mercury Polar Orbiter (MPO), which forms part of ESA's BepiColombo mission. The Flight Model (FM) gamma-ray spectrometer is based on a 3-in. single crystal of LaBr3(Ce(3+)) produced in a separate crystal development programme specifically for this mission. During the spectrometers development, manufacturing, and qualification phases, large crystals of CeBr3 became available in a subsequent phase of the same crystal development programme. Consequently, the Flight Spare Model (FSM) gamma-ray spectrometer was retrofitted with a 3-in. CeBr3 crystal and qualified for space. Except for the crystals, the two systems are essentially identical. In this paper, we report on a comparative assessment of the two systems, in terms of their respective spectral properties, as well as their suitability for use in planetary mission with respect to radiation tolerance and their propensity for activation. We also contrast their performance with a Ge detector representative of that flown on MESSENGER and show that: (a) both LaBr3(Ce(3+)) and CeBr3 provide superior detection systems over HPGe in the context of minimally resourced spacecraft and (b) CeBr3 is a more attractive system than LaBr3(Ce(3+)) in terms of sensitivities at lower gamma fluxes. Based on the tests, the FM has now been replaced by the FSM on the BepiColombo spacecraft. Thus, CeBr3 now forms the central gamma-ray detection element on the MPO spacecraft.

Effect of ionizing radiation on the human brain: white matter and gray matter T1 in pediatric brain tumor patients treated with conformal radiation therapy.

OBJECTIVE: To test a hypothesis that fractionated radiation therapy (RT) to less than 60 Gy is associated with a dose-related change in the spin-lattice relaxation time (T1) of normal brain tissue, and that such changes are detectable by quantitative MRI (qMRI). METHODS: Each of 21 patients received a qMRI examination before treatment, and at several time points during and after RT. A map of brain T1 was calculated and segmented into white matter and gray matter at each time point. The RT isodose contours were then superimposed upon the T1 map, and changes in brain tissue T1 were analyzed as a function of radiation dose and time following treatment. We used a mixed-model analysis to analyze the longitudinal trend in brain T1 from the start of RT to 1 year later. Predictive factors evaluated included patient age and clinical variables, such as RT dose, time since treatment, and the use of an imaging contrast agent. RESULTS: In white matter (WM), a dose level of greater than 20 Gy was associated with a dose-dependent decrease in T1 over time, which became significant about 3 months following treatment. In gray matter (GM), there was no significant change in T1 over time, as a function of RT doses < 60 Gy. However, GM in close proximity to the tumor had an inherently lower T1 before therapy. Neither use of a contrast agent nor a combination of chemotherapy plus steroids had a significant effect on brain T1. CONCLUSION: Results suggest that T1 mapping may be sensitive to radiation-related changes in human brain tissue T1. WM T1 appears to be unaffected by RT at doses less than approximately 20 Gy; GM T1 does not change at doses less than 60 Gy. However, tumor appears to have an effect upon adjacent GM, even before treatment. Conformal RT may offer a substantial benefit to the patient, by minimizing the volume of normal brain exposed to greater than 20 Gy.

Attitudes towards do-not-resuscitate decisions: differences among health professionals in a Portuguese hospital.

OBJECTIVES: Implementation of an in-hospital cardiopulmonary resuscitation (CPR) program stresses the need to discuss do-not-resuscitate (DNR) orders, as CPR may not be desirable in some terminally ill patients. Ethical, social, educational, and professional issues may influence these decisions. This study was designed to evaluate attitudes among four categories of healthcare professionals. DESIGN AND SETTING: Survey in a tertiary hospital in Portugal. METHODS: An anonymous self-completed questionnaire was distributed to 825 staff members, 527 of whom responded (20% physicians, 44% nurses, 20% health technicians, 16% healthcare domestic staff). Responses were compared between the various health professional groups. RESULTS: The level of medical/health training was positively related to the frequency of DNR decisions (physicians and nurses could foresee more circumstances warranting DNR decisions than technical/administrator or domestic staff) and negatively related to the willingness to include the patient's family in the DNR decision (physicians and nurses saw less need for the family's participation than technical/administrator or domestic staff). Significant differences were also found between professional groups regarding the physician's responsibility and the nurses' participation in DNR decisions. There was no difference between the professional groups regarding the need to note the DNR decision in clinical charts. CONCLUSION: Health professionals differ in their attitudes concerning DNR decisions. In particular, the level of medical/health training and/or degree of involvement with the patient's daily care may play an important role in DNR decisions.

Outcome of cardiac arrests in a Portuguese hospital--evaluation of a hospital cardiopulmonar resuscitation program at one year.

OBJECTIVE: Evaluation of a hospital-wide resuscitation program at one year. METHODS: All records of cardiac arrest calls were collected, logged in a database by the same operator, and analyzed. The cardiac arrest teams consist of a physician and a nurse with ALS (Advanced Life Support) training. Each team has a radio that is activated by a single emergency number. Only cardiac arrest calls were analyzed. RESULTS: Between March 1999 and March 2000 there were 173 emergency team calls. Of these, 120 were cardiac arrest calls (90 in-hospital and 30 from the emergency room--out-of-hospital cardiac arrests). Of the 90 in-hospital cardiac arrests, 61% were male, and median age was 73 years. In 90% of the calls, basic life support (BLS) was started before the arrival of the cardiac arrest team. The immediate cause was cardiac in 39% of the patients. Initial rhythm was ventricular fibrillation in 8%, asystole in 60% and other rhythms in 24% of the patients. Thirty percent presented return of spontaneous circulation (ROSC). There were no differences between those in whom BLS was started before the arrival of the cardiac arrest team and those in whom BLS had not been started. Ten patients (11%) were discharged from hospital. Of the 30 out-of-hospital cardiac arrests, 70% were male, and median age was 69 years. In 97% BLS was started before the arrival of the cardiac arrest team. The immediate cause was cardiac in 30% of patients. Initial rhythm was ventricular fibrillation in 10%, asystole in 73% and other rhythms in 17% of the patients. ROSC was achieved in 27% of the patients. Three patients (10%) were discharged from hospital. There were no differences either in ROSC or in survival to hospital discharge between in-hospital and out-of-hospital cardiac arrests. The state of health previous to cardiac arrest was significantly different between in- and out-of-hospital cardiac arrests: 3% versus 32% healthy, with no functional limitation. The authors conclude that: first, the current records do not enable all the desired goals of the "Utstein style" to be achieved and need to be reviewed; second, 90 to 97% of BLS previous to the arrival of the cardiac arrest team is a good indication of the efficiency of the hospital-wide program, which included training in BLS for all the hospital staff; third, the survival rate, although in accordance with much of the literature, could be improved.

[Control of the endotracheal cuff balloon pressure as a method of preventing laryngotracheal lesions in critically ill intubated patients]. / Control de la presión del balón de neumotaponamiento como método de prevención de lesiones laringotraqueales en pacientes críticos intubados.

OBJECTIVES: To study the development of tracheal stenosis after endotracheal intubation, percutaneous tracheotomy or both; to assess risk factors for tracheal stenosis and the relation of risk to endotracheal cuff pressure. PATIENTS AND METHODS: A prospective study enrolling patients sustaining endotracheal intubation longer than 8 hours and/or undergoing percutaneous tracheotomy. Cuff pressure was recorded at the moment of intubation and every 8 hours thereafter; a ceiling of 25 mm Hg was targeted. The patients were examined 6 months after discharge. RESULTS: Sixteen percutaneous tracheotomies were performed in the 95 patients enrolled (58 men, 37 women). The mean age was 54.1 +/- 19.7 years. The mean APACHE II score for all patients was 16.3 +/- 7.7 and the mean intubation time was 7.3 +/- 11 days, whereas the respective means for patients undergoing percutaneous tracheotomy were 18.4 +/- 7.6 and 20.5 +/- 19 days. Six months after discharge, 55 patients were examined for laryngotracheal lesions by fiberoptic endoscopy. Twenty-three of the remaining patients had died, 7 were lost to follow-up and 10 were only interviewed by telephone. Fiberoptic laryngotracheal endoscopy revealed minimal scarring and reduction of the endotracheal lumen. Reduction of the lumen was observed only in patients who had undergone percutaneous tracheotomy. CONCLUSIONS: Monitoring cuff pressure three times per day seems to contribute to preventing ischemic lesions and tracheal stenosis.

[Implantation of an intra-hospital resuscitation program]. / Instalação de um programa de ressuscitação intra-hospitalar.

The authors present their own experience on the installation of an in-hospital resuscitation programme, in a new tertiary hospital with 400 beds, an ICU with 8 beds and an emergency room 24 hours per day. The most important features presented are: the support by the Board of the Hospital, the engagement of all the health professionals, the distribution standardization and maintenance of the resuscitation equipment, the training in basic life-support techniques the doctors and nurses in the hospital, the performance of the cardiac arrest teams, all of which are fundamental to the maintenance of the chain of survival of cardiopulmonary resuscitation.

Non-invasive monitoring of therapeutic carbon ion beams in a homogeneous phantom by tracking of secondary ions.

Radiotherapy with narrow scanned carbon ion beams enables a highly accurate treatment of tumours while sparing the surrounding healthy tissue. Changes in the patient's geometry can alter the actual ion range in tissue and result in unfavourable changes in the dose distribution. Consequently, it is desired to verify the actual beam delivery within the patient. Real-time and non-invasive measurement methods are preferable. Currently, the only technically feasible method to monitor the delivered dose distribution within the patient is based on tissue activation measurements by means of positron emission tomography (PET). An alternative monitoring method based on tracking of prompt secondary ions leaving a patient irradiated with carbon ion beams has been previously suggested. It is expected to help in overcoming the limitations of the PET-based technique like physiological washout of the beam induced activity, low signal and to allow for real-time measurements. In this paper, measurements of secondary charged particle tracks around a head-sized homogeneous PMMA phantom irradiated with pencil-like carbon ion beams are presented. The investigated energies and beam widths are within the therapeutically used range. The aim of the study is to deduce properties of the primary beam from the distribution of the secondary charged particles. Experiments were performed at the Heidelberg Ion Beam Therapy Center, Germany. The directions of secondary charged particles emerging from the PMMA phantom were measured using an arrangement of two parallel pixelated silicon detectors (Timepix). The distribution of the registered particle tracks was analysed to deduce its dependence on clinically important beam parameters: beam range, width and position. Distinct dependencies of the secondary particle tracks on the properties of the primary carbon ion beam were observed. In the particular experimental set-up used, beam range differences of 1.3 mm were detectable. In addition, variations in the beam width could be measured with a precision of 0.9 mm. Furthermore, shifts of the lateral beam position could be monitored with a sub-millimetre precision. The presented investigations demonstrate experimentally that the non-invasive measurement and analysis of secondary ion distributions around head-sized homogeneous objects provide information on the actual beam delivery. Beam range, width and position could be monitored with a precision attractive for therapeutic situations.

Microtron MT 25 as a source of neutrons.

The objective was to describe Microtron MT25 as a source of neutrons generated by bremsstrahlung induced photonuclear reactions in U and Pb targets. Bremsstrahlung photons were produced by electrons accelerated at energy 21.6 MeV. Spectral fluence of the generated neutrons was calculated with MCNPX code and then experimentally determined at two positions by means of a Bonner spheres spectrometer in which the detector of thermal neutrons was replaced by activation Mn tablets or track detectors CR-39 with a (10)B radiator. The measured neutron spectral fluence and the calculated anisotropy served for the estimation of neutron yield from the targets and for the determination of ambient dose equivalent rate at the place of measurement. Microtron MT25 is intended as one of the sources for testing neutron sensitive devices which will be sent into the space.

SU-D-BRB-02: Investigations of Secondary Ion Distributions in Carbon Ion Therapy Using the Timepix Detector.

PURPOSE: Due to the high conformity of carbon ion therapy, unpredictable changes in the patient's geometry or deviations from the planned beam properties can result in changes of the dose distribution. PET has been used successfully to monitor the actual dose distribution in the patient. However, it suffers from biological washout processes and low detection efficiency. The purpose of this contribution is to investigate the potential of beam monitoring by detection of prompt secondary ions emerging from a homogeneous phantom, simulating a patient's head. METHODS: Measurements were performed at the Heidelberg Ion-Beam Therapy Center (Germany) using a carbon ion pencil beam irradiated on a cylindrical PMMA phantom (16cm diameter). For registration of the secondary ions, the Timepix detector was used. This pixelated silicon detector allows position-resolved measurements of individual ions (256×256 pixels, 55µm pitch). To track the secondary ions we used several parallel detectors (3D voxel detector). RESULTS: For monitoring of the beam in the phantom, we analyzed the directional distribution of the registered ions. This distribution shows a clear dependence on the initial beam energy, width and position. Detectable were range differences of 1.7mm, as well as vertical and horizontal shifts of the beam position by 1mm. To estimate the clinical potential of this method, we measured the yield of secondary ions emerging from the phantom for a beam energy of 226MeV/u. The differential distribution of secondary ions as a function of the angle from the beam axis for angles between 0 and 90° will be presented. In this setup the total yield in the forward hemisphere was found to be in the order of 10-1 secondary ions per primary carbon ion. CONCLUSIONS: The presented measurements show that tracking of secondary ions provides a promising method for non-invasive monitoring of ion beam parameters for clinical relevant carbon ion fluences. Research with the pixel detectors was carried out in frame of the Medipix Collaboration.

MO-A-213AB-11: First Experimental Test of Secondary Ion Tracking for the Assessment of Beam Range in a Patient-Like Phantom.

PURPOSE: Radiation therapy with ion beams provides highly conformal dose distributions. Therefore, monitoring the dose delivery within the patient in a non- invasive way is desired. The clinically available method based on tissue activation measurements with a PET-camera shows limitations due to the low induced activities and biological washout of the activated nuclei. The prompt production of secondary ions is supposed to be less influenced by biological processes. This contribution investigates the feasibility of beam range monitoring in a patient-like geometry containing realistic tissue inhomogeneities. METHODS: The experiments were performed at the Heidelberg Ion-Beam Therapy Center in Germany using carbon ion beams of 213 and 250MeV/u. Static pencil beams (FWHM of 6mm) were applied to the skull base and brain regions of a head phantom containing real bones. The emerging secondary ions were registered by the silicon detector Timepix. It was developed by the Medipix Collaboration and provides 256×256 pixels with 55um pitch. To determine the direction of the particles, a multi-layered detector (3D voxel detector, J.Jakubek etal. JINST6 C12010) was employed. The contribution of K. Gwosch etal. addresses the performance of this method in a homogeneous phantom. RESULTS: In the 3D distributions of the measured secondary ions clear differences between the application of lower and higher energies were observed. This Result was achieved in both brain (homogeneous) and skull base regions (containing inhomogeneities). Differences between the energies could be observed with the detector positioned on the occipital side as well as on the facial side of the head. CONCLUSIONS: We performed the first experiments towards beam range monitoring in a patient-like geometry exploiting tracking of prompt secondary ions with a small detector prototype. Despite the inherent tissue inhomogeneities, we found sensitivity on the beam range in both brain and skull base. Research carried out in frame of the Medipix Collaboration. Research carried out in frame of the Medipix Collaboration.

Knowledge and behavior among health professionals in relation to cadaveric organ donation and transplantation: a questionnaire-based analysis in Portuguese hospitals.

OBJECTIVE: To assess knowledge and behavior relative to cadaveric organ donation and transplantation among physicians and nurses working at nine Portuguese hospitals. METHODS: This prospective study between May and October 2009 included 495 questionnaires that were returned among 840 that were delivered, a 59% response rate. The transplant questionnaire comprised three main sections: section 1, sociodemographic-professional variables of the participants with nine questions; section 2, generic questions on organ donation and transplantation with 12 questions; and section 3 evaluated knowledge with 20 specific questions on organ donation and transplantation. RESULTS: Sixty-one percent of the participants were females, with 40% of the overall cohort between 31 and 40 years old; 62% married; 63% working in the emergency department; and 78% nurses. Although 78% of the participants stated that they had undergone specific training on organ donation and transplantation, 62% felt that they needed more training. The reasons evoked for the low rate of donation included difficulties in initiating the process of organ donation, in diagnosing cerebral death and in obtaining necessary human resources. There were no significant differences in knowledge between physicians and nurses concerning specific organ donation and transplantation issues. Having had specific training on organ donation and transplantation was significantly associated with correct answers to several questions, including those pertaining to knowledge of the national legislation on organ donation and transplantation. CONCLUSIONS: The present study showed a lack of specific knowledge and training on organ donation and transplantation issue. It also suggested that for hospital staff to successfully act as initiators of the organ procurement process, more information and education are necessary. This effort could significantly increase the rate of organ donation and transplantation in Portugal.

Laparoscopic mesh repair antireflux surgery for treatment of large hiatal hernia.

SUMMARY: One of the most frequently occurring anatomic failures after laparoscopic fundoplication is migration of the wrap into the chest, with or without disruption. This so-called 'slipped' Nissen fundoplication may be the result of inadequate closure of the diaphragmatic crura or rupture of the sutures or disruption of the muscle fibers approached. From January 2000 to December 2002, a total of seven patients (four male) with a mean age of 56 years (range 22-72 years), were considered for laparoscopic antireflux procedure using DACRON mash to reinforce the crural hiatal closure. The patients were operated under general anesthesia; laparoscopy was performed by classical approach with five trocars. The mean operative time was 120 minutes (range 40-240 min). There were no deaths. The average of postoperative hospital stay was 3.5 days (range, 3-5). Patients returned to normal activities usually on postoperative day 10 (range, 7-15). The follow-up time was at least 2 years. There was only one late complication related to the use of DACRON mesh at the hiatus, due to migration of the mesh into the esophageal lumen causing disphagia. In conclusion the mesh repair antireflux surgery is a good alternative for closing the diaphragmatic defect in large hiatal hernias or to correct this problem in case of recurrence or Barrett's esophagus.