The impact of the Fundamental Critical Course on knowledge acquisition in Rwanda.

Background: Emerging critical care systems have gained little attention in low- and middle-income countries. In sub-Saharan Africa, only 4% of the healthcare workforce is trained in critical care, and mortality rates are unacceptably high in this patient population. Objectives: We sought to retrospectively describe the knowledge acquisition and confidence improvement of practitioners who attend the Fundamental Critical Care Support (FCCS) course in Rwanda. Methods: We conducted a retrospective study in which we assessed survey data and multiple-choice question data that were collected before and after course delivery. The purpose of these assessments at the time of delivery was to evaluate participants' perception and acquisition of critical care knowledge. Results: Thirty-six interprofessional clinicians completed the training. Performance on the multiple-choice questions improved overall after the course (mean score pre-course of 56.5% to mean score post-course of 65.8%, p-value <0.001) and improved in all content areas with the exception of diagnosis and management of acute coronary syndrome and acute respiratory failure/mechanical ventilation. Both physicians and nurses improved their scores significantly (68.9% to 75.6%, p-value = 0.031 and 52.0% to 63.5%, p-value <0.001, respectively). Self-reported confidence in level of knowledge also increased in all areas. Survey respondents indicated on open-answer questions that they would like the course offerings at least annually, and that further dissemination of the course in Rwanda was warranted. Conclusion: Deploying the established FCCS course improved Rwandan healthcare provider knowledge and confidence across most critical care content areas. Therefore, this course represents a good first step in bridging the gaps noted in emerging critical care systems. Contributions of the study: Critical care education in sub-Saharan Africa is limited and few staff have formal training. The aim of the study was to determine whether a focused course delivered in Rwanda on critical care management improved knowledge in key areas. Our retrospective study on results from a multiple choice question test and survey indicate that short courses may improve knowledge of critical care management.

A feasibility study on the use of digital tomosynthesis with individually-acquired megavoltage portal images for target localization.

PURPOSE: To determine the feasibility of using megavoltage (MV) images and digital tomosynthesis to determine the three dimensional (3D) localization of different objects. MATERIALS AND METHODS: Different phantom geometries were imaged using an electronic portal imaging device and digital tomosynthesis was used to reconstruct tomograms. These were compared with corresponding computed tomography (CT) images. RESULTS: While in-plane resolution of the tomograms was comparable as that of the CT images, definite out-of-plane (depth) localization was restricted to 5 mm. CONCLUSION: The results confirm that it is possible to perform 3D localization of objects by using digital tomosynthesis for volumetric reconstructions from individually-acquired MV-quality portal images.

Modeling the target dose fall-off in IMRT and VMAT planning techniques for cervical SBRT.

There has been growing interest in the use of stereotactic body radiotherapy (SBRT) technique for the treatment of cervical cancer. The purpose of this study was to characterize dose distributions as well as model the target dose fall-off for intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) delivery techniques using 6 and 10 MV photon beam energies. Fifteen (n = 15) patients with non-bulky cervical tumors were planned in Pinnacle3 with a Varian Novalis Tx (HD120 MLC) using 6 and 10 MV photons with the following techniques: (1) IMRT with 10 non-coplanar beams (2) dual, coplanar 358° VMAT arcs (4° spacing), and (3) triple, non-coplanar VMAT arcs. Treatment volumes and dose prescriptions were segmented according to University of Texas Southwestern (UTSW) Phase II study. All plans were normalized such that 98% of the planning target volume (PTV) received 28 Gy (4 fractions). For the PTV, the following metrics were evaluated: homogeneity index, conformity index, D2cc, Dmean, Dmax, and dose fall-off parameters. For the organs at risk (OARs), D2cc, D15cc, D0.01cc, V20, V40, V50, V60, and V80 were evaluated for the bladder, bowel, femoral heads, rectum, and sigmoid. Statistical differences were evaluated using a Friedman test with a significance level of 0.05. To model dose fall-off, expanding 2-mm-thick concentric rings were created around the PTV, and doses were recorded. Statistically significant differences (p < 0.05) were noted in the dose fall-off when using 10 MV and VMAT3-arc, as compared with IMRT. VMAT3-arc improved the bladder V40, V50, and V60, and the bowel V20 and V50. All fitted regressions had an R2 ≥ 0.98. For cervical SBRT plans, a VMAT3-arc approach offers a steeper dose fall-off outside of the target volume. Faster dose fall-off was observed in smaller targets as opposed to medium and large targets, denoting that OAR sparing is dependent on target size. These improvements are further pronounced with the use of 10-MV photons.

Economic evaluation of a clinical protocol for diagnosing emergency patients with suspected pulmonary embolism.

BACKGROUND: The objective of this paper is to estimate the amount of cost-savings to the Australian health care system from implementing an evidence-based clinical protocol for diagnosing emergency patients with suspected pulmonary embolism (PE) at the Emergency department of a Victorian public hospital with 50,000 presentations in 2001-2002. METHODS: A cost-minimisation study used the data collected in a controlled clinical trial of a clinical protocol for diagnosing patients with suspected PE. The number and type of diagnostic tests in a historic cohort of 185 randomly selected patients, who presented to the emergency department with suspected PE during an eight month period prior to the clinical trial (January 2002-August 2002) were compared with the number and type of diagnostic tests in 745 patients, who presented to the emergency department with suspected PE from November 2002 to August 2003. Current Medicare fees per test were used as unit costs to calculate the mean aggregated cost of diagnostic investigation per patient in both study groups. A t-test was used to estimate the statistical significance of the difference in the cost of resources used for diagnosing PE in the control and in the intervention group. RESULTS: The trial demonstrated that diagnosing PE using an evidence-based clinical protocol was as effective as the existing clinical practice. The clinical protocol offers the advantage of reducing the use of diagnostic imaging, resulting in an average cost savings of at least $59.30 per patient. CONCLUSION: Extrapolating the observed cost-savings of $59.30 per patient to the whole of Australia could potentially result in annual savings between $3.1 million to $3.7 million.

Rectal and bladder dose reduction with the addition of intravaginal balloons to vaginal packing in intracavitary brachytherapy for cervical cancer.

PURPOSE: The use of intravaginal Foley balloons in addition to conventional packing during high-dose-rate (HDR) tandem and ovoids intracavitary brachytherapy (ICBT) is a means to improve displacement of organs at risk, thus reducing dose-dependent complications. The goal of this project was to determine the reduction in dose achieved to the bladder and rectum with intravaginal Foley balloons with CT-based planning and to share our packing technique. METHODS AND MATERIALS: One hundred and six HDR-ICBT procedures performed for 38 patients were analyzed for this report. An uninflated Foley balloon was inserted into the vagina above and below the tandem flange separately and secured in place with vaginal packing. CT images were then obtained with both inflated and deflated Foley balloons. Plan optimization occurred and dose volume histogram data were generated for the bladder and rectum. Maximum dose to 0.1, 1.0, and 2.0 cm(3) volumes for the rectum and bladder were analyzed and compared between inflated and deflated balloons using parametric statistical analysis. RESULTS: Inflation of intravaginal balloons allowed significant reduction of dose to the bladder and rectum. Amount of reduction was dependent on the anatomy of the patient and the placement of the balloons. Displacement of the organs at risk by the balloons allowed an average of 7.2% reduction in dose to the bladder (D0.1 cm(3)) and 9.3% to the rectum (D0.1 cm(3)) with a maximum reduction of 41% and 43%, respectively. CONCLUSIONS: For patients undergoing HDR-ICBT, a significant dose reduction to the bladder and rectum could be achieved with further displacement of these structures using intravaginal Foley balloons in addition to conventional vaginal packing.

Dosimetric effect of photon beam energy on volumetric modulated arc therapy treatment plan quality due to body habitus in advanced prostate cancer.

PURPOSE: The purpose of this study was to dosimetrically compare 6- and 10-MV photon beam energies in high-risk prostate cancer patients of various body habitus using a volumetric modulated arc therapy (VMAT) radiation delivery technique. The objectives of the study were to evaluate whether dosimetric differences exist and to investigate whether differences are dependent on patient body habitus. METHODS AND MATERIALS: Forty patients with various body habitus who had previously received treatment to the prostate and pelvic lymph nodes with VMAT techniques were chosen. Patients were planned in the Pinnacle(3) treatment planning system with double or triple SmartArc plans with 6- and 10-MV photon energies. All patients were optimized with the same planning objectives and normalized such that 95% of the planning target volume (PTV) received the prescription dose. Patients were evaluated for PTV and organ at risk (OAR) parameters for the bladder, rectum, small bowel, penile bulb, and sigmoid colon. Metrics used for comparison were D2%, D98%, homogeneity, conformity, and dose falloff for the PTV and D(2%), D(mean), V(80%), V(60%), and V(40%) for OARs. Statistical differences were evaluated with a paired-sample Wilcoxon signed rank test with a significance level of .05. RESULTS: For the PTV, there were no statistically significant differences in D(mean), D(2cc), conformation number, and homogeneity index values, but the dose falloff parameters, R50 and R25, showed a median improvement of 6.7% (P<.01) and 6.2% (P<.01), respectively, with 10 MV. A correlation between patient anterior-posterior distance (d(AP)) and percentage reduction in R50 of 0.436% per centimeter (P<.01) was determined. For OARs, statistically significant reductions in dose metrics were found in the small bowel and bladder, but increases in the D(2cc) of 3.5% in the penile bulb (P<.01) and 0.2% in the rectum (P=.02) were shown with 10 MV. The use of 10 MV also demonstrated a statistically significant reduction in the total number of monitor units of 15.9% (P<.01) compared with 6 MV. CONCLUSIONS: The study showed that 10 MV provides a faster dose falloff than 6 MV for patients whose prostate and pelvic lymph nodes are treated using a VMAT technique irrespective of body habitus; however, the improvement in dose falloff is dependent on body habitus and increases as the patient body habitus increases.

HIV risk behavior among Peace Corps Volunteers.

OBJECTIVE: To describe HIV risk behaviors among Peace Corps Volunteers (PCV) and to examine correlates of sexual risk behaviors. METHOD: Cross-sectional data were collected from 1242 randomly selected PCV serving in 28 countries in 1991. PCV reported the frequency of specific risk behaviors in self-administered questionnaires, which were completed anonymously and returned to the Centers for Disease Control and Prevention. RESULTS: Non-sexual HIV risk behaviors were rarely reported by PCV. Sixty-one per cent of the 1080 PCV who answered questions about sexual behavior during their Peace Corps service reported having at least one sex partner. Sixty per cent of PCV had another PCV partner, 39% had a host-country national partner, and 29% had a non-PCV expatriate partner. Overall, less than one-third (32%) of unmarried PCV used condoms during every episode of sexual intercourse; more frequent use was reported in relationships with non-steady and (for male PCV) host-country national partners. Among male PCV, condom use was positively related to lower alcohol use and the belief that HIV was a problem in the host country. Female PCV reporting more condom use with male partners were younger and had fewer partners than those reporting less use. CONCLUSION: These data indicate that PCV are at risk for acquiring HIV through unprotected vaginal intercourse. All persons who become sexually active with new partners while travelling or living abroad should be encouraged to use condoms consistently.

PIP: At least 10 former Peace Corps volunteers are believed to have acquired human immunodeficiency virus (HIV) during their time of service. To assess HIV risk behavior among current Peace Corps volunteers, cross-sectional data were collected from 1242 randomly selected volunteers in 28 countries in 1991. 474 (38%) were stationed in sub-Saharan Africa. Non-sexual HIV-related risk activities included injection from local health facilities (209) and ears or body parts pierced (59). Of the 1018 volunteers who were unmarried or not living with a spouse, 61% of men and 60% of women indicated they had at least one sexual partner during their time of service; 30% and 20%, respectively, had three or more partners. Only 17 men and 12 women reported having a same-sex partner. 52% of sexually active Peace Corps volunteers stationed in Eastern Europe, 43% of those in Central or South America, 36% in sub-Saharan Africa, and 32% in Asia and the Pacific had a sexual partner from the host country. 32% of these volunteers used condoms on every occasion with partners from the host country, 49% used condoms some of the time, and 19% never used them. For male volunteers, consistent condom use was negatively associated with alcohol use and positively related to the perception that HIV was a problem in the host country; for female volunteers, younger age and fewer partners were the significant correlates of condom use. The inconsistent use of condoms in countries where HIV is widespread suggests a need for Peace Corps leaders to educate volunteers about local seroprevalence rates, cultural differences in sexual negotiation, and the importance of condom use.

Perceptual reference frames and visual field asymmetry for verbal processing.

Two experiments investigated the role of perceptual reference frames in producing visual field asymmetries for the recognition of consonant-vowel-consonant (CVC) nonsense syllables. In an upright stimulus display condition, both quantitative and qualitative visual field asymmetries replicated those obtained in earlier studies of CVC identification. When the stimulus displays were rotated 90 degrees clockwise or counterclockwise, there were no effects of presenting the CVC in relative LVF vs relative RVF stimulus locations. The contrast between results in the upright and rotated stimulus display conditions indicates that the LVF/RVF differences in the upright displays are attributable to the position of the CVC relative to the fovea, rather than relative to the perceptual reference frame. This finding is consistent with the interpretation that LVF/RVF differences in the upright condition are attributable to hemispheric differences in the processing of linguistic/phonetic information.

Precision radiation therapy for optic nerve sheath meningiomas.

A more precise radiation therapy technique to treat unilateral optic nerve sheath meningioma is presented. It uses an immobilization device to align the ipsilateral optic nerve with a vertical axis and employs three small half-beam blocked fields to deliver radiation to a small conformal volume, thereby reducing the dose to the optic chiasm and the contralateral optic nerve. Three patients were successfully treated with this technique, and a fourth patient with optic nerve glioma was also treated in a similar fashion and was included in this study. The new technique irradiates a much smaller volume of tissue to high dose levels: 58 cm3 is irradiated to the 80% isodose level and only 18 cm3 to the 95% level. In contrast, the opposed lateral technique irradiates 171 and 73 cm3 to these levels, respectively. Thus, a considerable reduction in the volume of normal tissue irradiated was accomplished. Doses to the pituitary and contralateral optic nerve were 4% of the treatment dose for the new technique, whereas these doses were 40% and 100% for opposed laterals and 10% and 3% for wedged pair, respectively. The average setup error for this technique was very small, 50% of the setups measured were less than 1 mm off, and 92.5% were less than 3 mm off. However, for the conventional setups without a mask, only 21% of the setups were less than 1 mm off and 55% less than 3 mm off. We recommend this technique for localized unilateral optic nerve sheath meningioma and other optic nerve lesions that may require radiation therapy.

Individual variation in hemispheric asymmetry: multitask study of effects related to handedness and sex.

Functional hemispheric asymmetries were examined for right- or left-handed men and women. Tasks involved (a) auditory processing of verbal material, (b) processing of emotions shown on faces, (c) processing of visual categorical and coordinate spatial relations, and (d) visual processing of verbal material. Similar performance asymmetries were found for the right-handed and left-handed groups, but the average asymmetries tended to be smaller for the left-handed group. For the most part, measures of performance asymmetry obtained from the different tasks did not correlate with each other, suggesting that individual subjects cannot be simply characterized as strongly or weakly lateralized. However, ear differences obtained in Task 1 did correlate significantly with certain visual field differences obtained in Task 4, suggesting that both tasks are sensitive to hemispheric asymmetry in similar phonetic or language-related processes.

Prevention of sexually transmitted diseases. A model for overcoming barriers between managed care and public health. The IOM Workshop on the Role of Health Plans in STD Prevention.

CONTEXT: The growth of managed care has spurred re-evaluation of the roles and responsibilities of public health agencies and private health plans for providing public health services. Although rates of curable sexually transmitted diseases (STDs) in the United States are the highest in the developed world, many clinicians and managed care organizations are not systematically providing high-quality, comprehensive STD-related services to their patients and the community. OBJECTIVE: To examine issues around managed care and STD prevention as a model for overcoming barriers that impede managed care organizations from providing comprehensive public health services and collaborating with health agencies. SETTING: Two-day invitational workshop. PARTICIPANTS: Representatives from 18 health plans, 10 public health agencies, 6 academic institutions, 1 purchasing coalition, and 5 other health organizations. RESULTS: Major obstacles include: turnover and heterogeneity in the health care system; deficiencies in clinical knowledge and skills; differences in organizational culture and language; low priority of STDs; inadequate public health surveillance data and performance measures; confidentiality concerns; and lack of coverage for sex partners. CONCLUSIONS: Potential approaches for addressing these barriers include: requiring that STD-related services be covered by Medicaid managed care programs; implementing performance measures; requiring collaborative activities; promoting education of and outreach to stakeholders; funding of pilot projects; and researching the cost-benefit and cost-effectiveness of STD-related services for various populations.

Health care providers and purchasers and evaluation of interactive health communication applications. Science Panel on Interactive Communication and Health.

Health care providers and purchasers of health services have an opportunity to improve patient care and potentially save costs through the wise purchase of interactive health communication applications for patients and employees. Purchasing decisions based on evaluation and evidence should drive the design and development of new systems. The cycle of evaluation includes a needs assessment before system development, usability testing during development, and studies of use and outcomes in natural settings. This type of evidence is critical to our understanding of how best to provide health information and decision assistance to patients, employees, and others.

Policy issues relevant to evaluation of interactive health communication applications. The Science Panel on Interactive Communication and Health.

This article provides an analysis of policy-related issues associated with the evaluation of interactive health communication (IHC) applications. These include an assessment of the current health and technology policy environment pertinent to public (government, education, public health) and private (medical care providers, purchasers, consumers, IHC developers) IHC stakeholders and discussion of issues likely to merit additional consideration by these stakeholders in the future.

Adjuvant radiation therapy for low stage testicular seminoma: Diagnosis and therapy in evolution.

We performed a retrospective study to evaluate the clinical outcome of patients with early stage testicular seminoma who received adjuvant radiation therapy after orchiectomy over the past 15 years. During the 15 year period, 61 patients were treated with adjuvant radiation therapy for stages I, IIA, and IIB testicular seminoma. Patients received from 2,000 to 4,000 cGy delivered by a Cobalt machine and later by a linear accelerator. Our standard treatment protocol was modified in 13 patients: 7 secondary to abnormal lymphangiography (LAG) parameters and 6 due to abnormal computed tomography findings. We analyzed each patient's outcome for survival, recurrence, and complications. We then compared outcomes, looking for differing trends based on evolving evaluation or treatment techniques. The average follow-up is 75 months, with an overall survival rate of 93%. The cause specific survival is 100%. Four patients died from intercurrent diseases; at time of autopsy, one of these patients was noted to have a small focus of seminoma in a lateral inguinal node. He died from widely disseminated Hodgkin's disease. Three patients, including the aforementioned one, had recurrent disease outside of the radiation field, yielding a recurrence rate of 5%. No significant long term treatment complications were reported, although 24% of patients had one or more complications from LAG. Regardless the various changes in patient evaluation and radiation treatment techniques over the past 15 years, adjuvant radiation therapy remains effective in patients with early stage testicular seminoma.

Interhemispheric interaction when both hemispheres have access to the same stimulus information.

Right-handed Ss identified consonant-vowel-consonant (CVC) nonsense syllables presented tachistoscopically. The CVC on each trial was presented to the left visual field-right hemisphere (LVF-RH), to the right visual field-left hemisphere (RVF-LH), or the same CVC was presented to both visual fields (bilateral presentation). When recognition was incorrect, the pattern of errors was qualitatively different on LVF-RH and RVF-LH trials, suggesting that each cerebral hemisphere has its own preferred mode of processing the CVC stimuli. The qualitative pattern of errors on bilateral trials was identical to that obtained on LVF-RH trials. The bilateral results are described well by a model that assumes the mode of processing characteristic of the RH dominates on bilateral trials but is applied to both the LVF-RH and RVF-LH stimuli.

Hemispheric asymmetry for processing unpronounceable and pronounceable letter trigrams.

In each of two experiments, observers attempted to identify three-letter strings presented briefly to the left visual field/right hemisphere (LVF/RH), to the right visual field/left hemisphere (RVF/LH), or to both visual fields (and hemispheres) simultaneously (redundant BILATERAL trials). Similar visual half-field effects were obtained for both all-consonant (CCC) strings and consonant-vowel-consonant (CVC) nonwords. For both types of strings, there were fewer errors on RVF/LH trials than on LVF/RH trials and the pattern of error types was qualitatively different for the two visual fields. The similarity of visual half-field results for CCC and CVC strings indicates that results that have been reported in earlier studies with CVC strings are not restricted to letter strings that can be coded as a single pronounceable syllable, as some have suggested. Instead, the results are consistent with hypotheses about hemispheric differences in the ability to encode and remember individual letters in a multielement display. In addition, for both CCC and CVC letter strings there were fewer errors on redundant BILATERAL trials than on either type of unilateral trial, suggesting interhemispheric collaboration in both cases. However, the qualitative error patterns obtained on redundant BILATERAL trials suggest that the precise way in which the hemispheres collaborate differs with the type of letter string.

On solving 3CNF-satisfiability with an in vivo algorithm.

Several in vitro DNA algorithms have been proposed in the literature for solving various combinatorial search problems. The next logical step is the critical examination of whether or not such computation can be performed within the cellular environment. We consider the possibility of solving 3-conjunctive-normal-form Satisfiability with one possible in vivo algorithm. The exact biological details still remain to be defined and seem beyond the capabilities of current technologies, but perhaps, this will serve as a springboard for further theoretical inquiry into in vivo approaches.

Dose attenuation through a titanium alloy hip prosthesis.

The problem of dose perturbation due to hip prostheses during pelvic irradiation can be significant. Dose attenuation by a commonly used titanium alloy hip prosthesis was measured. Depending on the energy of the radiation beam and the thickness along the prosthesis, the attenuation was between 32% and 64%. This attenuation effect should be considered in treatment planning, especially in a patient with bilateral hip prostheses and when undergoing treatment for prostate cancer where the tumor typically lies between prostheses.

Epidemiologic factors, clinical findings, and vaccination status of rabies in cats and dogs in the United States in 1988. National Study Group on Rabies.

Despite the availability of rabies vaccination through private veterinarians and government-sponsored rabies control programs, rabies was reported in an average of 338 cats and dogs per year from 1980 through 1987 in the United States. Information was collected on 90% of the 183 cats and 97% of the 119 dogs that were reported to have rabies in the continental United States in 1988. The median age of rabid cats and dogs was 1 year, and 81% were from rural areas. Compared with rabid cats, rabid dogs were more likely to have been male (66 vs 42%, odds ratio = 2.6), to have been kept as pets (84 vs 43%, odds ratio = 6.8), and to have had reported contact with wildlife before onset of illness (38 vs 14%, odds ratio = 3.8). Rabid cats accounted for a greater proportion of human rabies postexposure prophylaxis, bites to people, and exposures to other animals than did rabid dogs. Although the clinical signs of rabies varied, rabid cats were more likely than dogs to have had aggressive behavior (55 vs 31%, odds ratio = 2.8). In contrast, rabid dogs were more likely than cats to have had an illness consistent with a paralytic process. The median period between onset of illness and death was 3 days (range, less than 1 to 10) in rabid cats and dogs that were allowed to die of rabies. Vaccine failures were documented in 3 (1%) rabid animals (2 cats and 1 dog). All animals had received only a single dose of vaccine in their lifetime and were vaccinated when they were between 3 and 6 months old.

Published criteria for evaluating health related web sites: review.

OBJECTIVE: To review published criteria for specifically evaluating health related information on the world wide web, and to identify areas of consensus. DESIGN: Search of world wide web sites and peer reviewed medical journals for explicit criteria for evaluating health related information on the web, using Medline and Lexis-Nexis databases, and the following internet search engines: Yahoo!, Excite, Altavista, Webcrawler, HotBot, Infoseek, Magellan Internet Guide, and Lycos. Criteria were extracted and grouped into categories. RESULTS: 29 published rating tools and journal articles were identified that had explicit criteria for assessing health related web sites. Of the 165 criteria extracted from these tools and articles, 132 (80%) were grouped under one of 12 specific categories and 33 (20%) were grouped as miscellaneous because they lacked specificity or were unique. The most frequently cited criteria were those dealing with content, design and aesthetics of site, disclosure of authors, sponsors, or developers, currency of information (includes frequency of update, freshness, maintenance of site), authority of source, ease of use, and accessibility and availability. CONCLUSIONS: Results suggest that many authors agree on key criteria for evaluating health related web sites, and that efforts to develop consensus criteria may be helpful. The next step is to identify and assess a clear, simple set of consensus criteria that the general public can understand and use.