Single-injection or continuous femoral nerve block for total knee arthroplasty?

BACKGROUND: The ideal local anesthetic regime for femoral nerve block that balances analgesia with mobility after total knee arthroplasty (TKA) remains undefined. QUESTIONS/PURPOSES: We compared two volumes and concentrations of a fixed dose of ropivacaine for continuous femoral nerve block after TKA to a single injection femoral nerve block with ropivacaine to determine (1) time to discharge readiness; (2) early pain scores and analgesic consumption; and (3) functional outcomes, including range of motion and WOMAC scores at the time of recovery. METHODS: Ninety-nine patients were allocated to one of three continuous femoral nerve block groups for this randomized, placebo-controlled, double-blind trial: a high concentration group (ropivacaine 0.2% infusion), a low concentration group (ropivacaine 0.1% infusion), or a placebo infusion group (saline 0.9% infusion). Infusions were discontinued on postoperative Day (POD) 2. The primary outcome was time to discharge readiness. Secondary outcomes included opioid consumption, pain, and functional outcomes. Ninety-three patients completed the study protocol; the study was halted early because of unanticipated changes to pain protocols at the host institution, by which time only 61% of the required number of patients had been enrolled. RESULTS: With the numbers available, the mean time to discharge readiness was not different between groups (high concentration group, 62 hours [95% confidence interval [CI], 51-72 hours]; low concentration group, 73 hours [95% CI, 63-83 hours]; placebo infusion group 65 hours [95% CI, 56-75 hours]; p = 0.27). Patients in the low concentration group consumed significantly less morphine during the period of infusion (POD 1, high concentration group, 56 mg [95% CI, 42-70 mg]; low concentration group, 35 mg [95% CI, 27-43 mg]; placebo infusion group, 48 mg [95% CI, 38-59 mg], p = 0.02; POD 2, high concentration group, 50 mg [95% CI, 41-60 mg]; low concentration group, 33 mg [95% CI, 24-42 mg]; placebo infusion group, 39 mg [95% CI, 30-48 mg], p = 0.04); however, there were no important differences in pain scores or opioid-related side effects with the numbers available. Likewise, there were no important differences in functional outcomes between groups. CONCLUSIONS: Based on this study, which was terminated prematurely before the desired sample size could be achieved, we were unable to demonstrate that varying the concentration and volume of a fixed-dose ropivacaine infusion for continuous femoral nerve block influences time to discharge readiness when compared with a conventional single-injection femoral nerve block after TKA. A low concentration of ropivacaine infusion can reduce postoperative opioid consumption but without any important differences in pain scores, side effects, or functional outcomes. These pilot data may be used to inform the statistical power of future randomized trials. LEVEL OF EVIDENCE: Level II, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Human endometrial carcinomas serially transplanted in nude mice and established in continuous cell lines.

Three out of five human endometrial carcinomas were successfully grafted into nude mice (BALB/c/nu/nu). Two of these tumors could be maintained by serial transplantation. The morphological characteristics displayed by the grafted tumors were comparable to those of the original carcinomas. Permanent cell lines were established from these two tumors. Reinjection of cells grown in vitro into nude mice produced nodules of identical histology as compared to original solid transplants. The influence of medroxyprogesterone acetate on tumor growth in vivo and cell proliferation in vitro was studied. This hormonal treatment did not produce any significant effect on tumor cells, either in vitro or in vivo, for the two endometrial carcinomas. After medroxyprogesterone administration, a slight but non-significant growth inhibition of the tumor cells in vitro was observed and the tumor transplants in vivo did not appear to be influenced. The experiments illustrate the possible use of this model for testing potential anti-cancer agents.

A continuous strain-space model of viral evolution within a host

Viruses rapidly evolve, and HIV in particular is known to be one of the fastest evolving human viruses. It is now commonly accepted that viral evolution is the cause of the intriguing dynamics exhibited during HIV infections and the ultimate success of the virus in its struggle with the immune system. To study viral evolution, we use a simple mathematical model of the within-host dynamics of HIV which incorporates random mutations. In this model, we assume a continuous distribution of viral strains in a one-dimensional phenotype space where random mutations are modelled by di ffusion. Numerical simulations show that random mutations combined with competition result in evolution towards higher Darwinian fitness: a stable traveling wave of evolution, moving towards higher levels of fi tness, is formed in the phenoty space.

Contribution of physical education to overall physical activity.

For many children, physical activity (PA) during physical education (PE) lessons provides an important opportunity for being physically active. Although PA during PE has been shown to be low, little is known about the contribution of PA during PE to overall PA. The aim was therefore to assess children's PA during PE and to determine the contribution of PE to overall PA with special focus on overweight children. Accelerometer measurements were done in 676 children (9.3 ± 2.1 years) over 4-7 days in 59 randomly selected classes. Moderate-and-vigorous PA (MVPA; ≥ 2000 counts/min) during PE (MVPA(PE) ), overall MVPA per day (MVPA(DAY) ), and a comparison of days with and without PE were calculated by a regression model with gender, grade, and weight status (normal vs overweight) as fixed factors and class as a random factor. Children spent 32.8 ± 15.1% of PE time in MVPA. Weight status was not associated to MVPA(PE) . MVPA(PE) accounted for 16.8 ± 8.5% of MVPA(DAY) , and 17.5 ± 8.2% in overweight children. All children were more active on days with PE than on days without PE (differences: 16.1 ± 29.0 min of MVPA(DAY) ; P ≤ 0.001; 13.7 ± 28.0 min for overweight children). Although MVPA(PE) was low, PE played a considerable role in providing PA and was not compensated by reducing extracurricular MVPA.

A general continuous auction model with insiders

We analyse in a unified way how the presence of a trader with privilege information makes the market to be efficient when the release time is known. We establish a general relation between the problem of finding an equilibrium and the problem of enlargement of filtrations. We also consider the case where the time of announcement is random. In such a case the market is not fully efficient and there exists equilibrium if the sensitivity of prices with respect to the global demand is time decreasing according with the distribution of the random time.

An electronic portfolio for quantitative assessment of surgical skills in undergraduate medical education.

BACKGROUND We evaluated a newly designed electronic portfolio (e-Portfolio) that provided quantitative evaluation of surgical skills. Medical students at the University of Seville used the e-Portfolio on a voluntary basis for evaluation of their performance in undergraduate surgical subjects. METHODS Our new web-based e-Portfolio was designed to evaluate surgical practical knowledge and skills targets. Students recorded each activity on a form, attached evidence, and added their reflections. Students self-assessed their practical knowledge using qualitative criteria (yes/no), and graded their skills according to complexity (basic/advanced) and participation (observer/assistant/independent). A numerical value was assigned to each activity, and the values of all activities were summated to obtain the total score. The application automatically displayed quantitative feedback. We performed qualitative evaluation of the perceived usefulness of the e-Portfolio and quantitative evaluation of the targets achieved. RESULTS Thirty-seven of 112 students (33%) used the e-Portfolio, of which 87% reported that they understood the methodology of the portfolio. All students reported an improved understanding of their learning objectives resulting from the numerical visualization of progress, all students reported that the quantitative feedback encouraged their learning, and 79% of students felt that their teachers were more available because they were using the e-Portfolio. Only 51.3% of students reported that the reflective aspects of learning were useful. Individual students achieved a maximum of 65% of the total targets and 87% of the skills targets. The mean total score was 345 ± 38 points. For basic skills, 92% of students achieved the maximum score for participation as an independent operator, and all achieved the maximum scores for participation as an observer and assistant. For complex skills, 62% of students achieved the maximum score for participation as an independent operator, and 98% achieved the maximum scores for participation as an observer or assistant. CONCLUSIONS Medical students reported that use of an electronic portfolio that provided quantitative feedback on their progress was useful when the number and complexity of targets were appropriate, but not when the portfolio offered only formative evaluations based on reflection. Students felt that use of the e-Portfolio guided their learning process by indicating knowledge gaps to themselves and teachers.

Presència, traducció i recepció de la literatura del Quebec a Catalunya

Les literatures francòfones, relegades durant molts anys a una quasi total indiferència per part de la literatura francesa, han pres en els últims quinze anys una importància considerable. L'esforç per part de molts professors d'incloure aquestes literatures en els programes d'ensenyament està donant els seus fruits. L'interès suscitat per l'estudi de la literatura quebequesa i l'apogeu que està prenent a Catalunya –a més de les bones relacions Catalunya-Quebec– van ser el motor d’una recerca sobre la presència, la traducció i la recepció de la literatura de Quebec a Catalunya. Per tal de conèixer l’estat de la qüestió, es va procedir, en un primer temps, a un seguiment de tot el que s’havia publicat a Catalunya referent a la literatura del Quebec. Igualment, es va sondejar els treballs sobre aquesta matèria que no havien estat objecte de publicació i es va recopilar la diversa informació sobre les manifestacions culturals relacionades amb aquesta matèria. En un segon temps, es va procedir a l’estudi dels materials obtinguts i a la seva avaluació. Malgrat la presència recent de la literatura del Quebec a Catalunya i la manca de planificació institucional per dur a terme una traducció sistemàtica que permeti mostrar l’estat actual d’aquesta literatura, es troba, cada vegada més, una voluntat manifesta de donar a conèixer aquesta cultura provinent de Quebec ja sigui per afinitats o voluntats individuals o per respondre a les tendències de mercat.

Accompagnement thérapeutique : le chemin du suivi à long terme [Patient education: the way for long-term follow up]

L'éducation thérapeutique du patient est maintenant parfaitement intégrée dans les soins. Son champ d'application se situe essentiellement dans le domaine des maladies chroniques pour l'acquisition de compétences dans la gestion du traitement, en coopération avec les professionnels. En médecine ambulatoire, patients et soignants se heurtent actuellement aux difficultés du suivi avec sa part d'incertitude, lassitude et de pression économique. La médecine fondée sur les preuves (EBM) et les différents modèles en psychologie de la santé ne nous éclairent que partiellement le chemin. Un nouveau type de démarche réflexive est en train d'émerger. Cette réflexion devrait placer en son centre la notion de relation thérapeutique : entre science et existence. Nous résumons ici ce processus réflexif en cours d'une équipe interdisciplinaire regroupant sciences humaines, art et médecine. Therapeutic education is now perfectly integrated in caring and medicine. Its field of application is primarily in chronic diseases for the acquisition of competences in the management of treatments, in co-operation with health professionals. In ambulatory medicine, patients and health professionals are currently running up against the difficulties of the long-term follow-up with its part of uncertainty, lassitude and economic pressure. EBM and the various models of health psychology light us only partially the way. A new type of reflexive step is emerging. This way of thinking should place in its center the concept of therapeutic relation: between science and being. We summarize here our reflexive process in the course of an interdisciplinary team gathering social sciences, art and medicine

Surveillance, health promotion and control of Chagas disease in the Amazon Region - Medical attention in the Brazilian Amazon Region: a proposal

We refer to Oswaldo Cruz’s reports dating from 1913 about the necessities of a healthcare system for the Brazilian Amazon Region and about the journey of Carlos Chagas to 27 locations in this region and the measures that would need to be adopted. We discuss the risks of endemicity of Chagas disease in the Amazon Region. We recommend that epidemiological surveillance of Chagas disease in the Brazilian Amazon Region and Pan-Amazon region should be implemented through continuous monitoring of the human population that lives in the area, their housing, the environment and the presence of triatomines. The monitoring should be performed with periodic seroepidemiological surveys, semi-annual visits to homes by health agents and the training of malaria microscopists and healthcare technicians to identify Trypanosoma cruzi from patients’ samples and T. cruzi infection rates among the triatomines caught. We recommend health promotion and control of Chagas disease through public health policies, especially through sanitary education regarding the risk factors for Chagas disease. Finally, we propose a healthcare system through base hospitals, intermediate-level units in the areas of the Brazilian Amazon Region and air transportation, considering the distances to be covered for medical care.

Nasal trauma due to continuous positive airway pressure in neonates.

PATIENTS: All neonates admitted between January 2002 and December 2007 treated by nCPAP were eligible. METHODS: Patients' noses were monitored during nCPAP. Nasal trauma was reported into three stages: (I) persistent erythema; (II) superficial ulceration; and (III) necrosis. RESULTS: 989 neonates were enrolled. Mean gestational age was 34 weeks (SD 4), mean birth weight 2142 g (SD 840). Nasal trauma was reported in 420 (42.5%) patients and it was of stage I, II and III in 371 (88.3%), 46 (11%) and 3 (0.7%) patients, respectively. Incidence and severity of trauma were inversely correlated with gestational age and birth weight. The risk of nasal trauma was greater in neonates <32 weeks of gestational age (OR 2.48, 95% CI 1.59 to 3.86), weighing <1500 g at birth (OR 2.28, 95% CI 1.43 to 3.64), treated >5 days by nCPAP (OR 5.36, 95% CI 3.82 to 7.52), or staying >14 days in the NICU (OR 1.67, 95% CI 1.22 to 2.28). Most cases of nasal trauma (90%) appeared during the first 6 days of nCPAP. Persistent visible scars were present in two cases. CONCLUSIONS: Nasal trauma is a frequent complication of nCPAP, especially in preterm neonates, but long-term cosmetic sequelae are very rare. This study provides a description of nasal trauma and proposes a simple staging system. This could serve as a basis to develop strategies of prevention and treatment of this iatrogenic event.