In vivo study to assess fat embolism resulting from the Reamer-Irrigator-Aspirator 2 system compared to a novel aspirator-based concept for intramedullary bone graft harvesting.

INTRODUCTION: Fat embolism (FE) following intramedullary (IM) reaming can cause severe pulmonary complications and sudden death. Recently, a new harvesting concept was introduced in which a novel aspirator is used first for bone marrow (BM) aspiration and then for subsequent aspiration of morselized endosteal bone during sequential reaming (A + R + A). In contrast to the established Reamer-Irrigator-Aspirator (RIA) 2 system, the new A + R + A concept allows for the evacuation of fatty BM prior to reaming. In this study, we hypothesized that the risk of FE, associated coagulopathic reactions and pulmonary FE would be comparable between the RIA 2 system and the A + R + A concept. MATERIALS AND METHODS: Intramedullary bone graft was harvested from intact femora of 16 Merino sheep (age: 1-2 years) with either the RIA 2 system (n = 8) or the A + R + A concept (n = 8). Fat intravasation was monitored with the Gurd test, coagulopathic response with D-dimer blood level concentration and pulmonary FE with histological evaluation of the lungs. RESULTS: The total number and average size of intravasated fat particles was similar between groups (p = 0.13 and p = 0.98, respectively). D-dimer concentration did not significantly increase within 4 h after completion of surgery (RIA 2: p = 0.82; A + R + A: p = 0.23), with an interaction effect similar between groups (p = 0.65). The average lung area covered with fat globules was similar between groups (p = 0.17). CONCLUSIONS: The use of the RIA 2 system and the novel A + R + A harvesting concept which consists of BM evacuation followed by sequential IM reaming and aspiration of endosteal bone, resulted in only minor fat intravasation, coagulopathic reactions and pulmonary FE, with no significant differences between the groups. Our results, therefore, suggest that both the RIA 2 system and the new A + R + A concept are comparable technologies in terms of FE-related complications.

Regulatory aspects and evidences of melatonin use for sleep disorders and insomnia: an integrative review / Aspectos regulatórios e evidências do uso de melatonina em distúrbio do sono e insônia: uma revisão integrativa

ABSTRACT Background: Insomnia is a sleep disorder characterized by difficulty of falling asleep or maintaining sleep, which affects different age groups. Currently, melatonin is used as a therapeutic treatment in cases of insomnia in children, adults, and elderly people. Objective: To evaluate the effectiveness of melatonin in sleep disorders, its dosage, potential adverse effects, as well as labeling laws and regulations in Brazil. Methods: This integrative review was carried out using the Cochrane Library, Medline (Pubmed), and Science Direct databases. Twenty-five articles and three documents available on the Brazilian Society of Endocrinology and Metabology (SBEM) and National Health Surveillance Agency (ANVISA) websites published between 2015 and 2020 were selected to be evaluated in full. Results: It was found that in most of the selected articles the use of melatonin reduces sleep latency. The effective melatonin doses varied according to each age group, from 0.5 to 3 mg in children, 3 to 5 mg in adolescents, 1 to 5 mg in adults, and 1 to 6 mg in elderly people. Side effects are mild when taking usual doses. In Brazil, no registered drug and current regulation on the use and marketing of melatonin has been identified. Conclusion: The use of melatonin is an alternative therapy that can be used for sleeping disorders. According to the evidences found, it did not demonstrate toxicity or severe side effects, nor dependence even when administered at high doses, suggesting that it is a safe medication to treat patients of different ages suffering from sleeping disorders.

RESUMO Antecedentes: Insônia é um distúrbio do sono caracterizado por dificuldade de iniciar e manter o sono, afetando diferentes faixas etárias. Atualmente, a melatonina é utilizada no tratamento de insônia em crianças, adultos e idosos. Objetivo: Avaliar a eficácia da melatonina nos distúrbios do sono, posologia e potenciais efeitos adversos, bem como a regulamentação vigente no Brasil. Métodos: Trata-se de uma revisão integrativa, os artigos foram identificados nas bases de dados Cochrane Library, Medline (Pubmed) e Science Direct, totalizando 25 artigos, e foram selecionados três materiais disponíveis no site da Sociedade Brasileira de Endocrinologia e Metabologia e Agência Nacional de Vigilância Sanitária, publicados entre 2015 e 2020. Resultados: Verificou-se na maioria dos artigos selecionados que a melatonina reduz a latência do sono. Quanto as dosagens de melatonina identificou-se variação em cada faixa etária, para crianças de 0,5 a 3mg; adolescentes de 3 a 5mg; adultos de 1 a 5mg e idosos 1 mg a 6 mg demostraram serem eficazes. Em doses habituais os efeitos colaterais são leves. No Brasil, não foi identificado medicamento registrado e regulamentação vigente sobre o uso e comercialização de melatonina. Conclusão: A utilização da melatonina é uma alternativa que pode ser utilizada em distúrbios do sono. De acordo com as evidências encontradas, não demonstrou toxicidade ou efeitos colaterais severos, nem dependência mesmo em doses elevadas, sendo, portanto, segura para tratamento de pacientes desde crianças a idosos que sofrem de distúrbios do sono.

A preclinical large-animal model for the assessment of critical-size load-bearing bone defect reconstruction.

Critical-size bone defects, which require large-volume tissue reconstruction, remain a clinical challenge. Bone engineering has the potential to provide new treatment concepts, yet clinical translation requires anatomically and physiologically relevant preclinical models. The ovine critical-size long-bone defect model has been validated in numerous studies as a preclinical tool for evaluating both conventional and novel bone-engineering concepts. With sufficient training and experience in large-animal studies, it is a technically feasible procedure with a high level of reproducibility when appropriate preoperative and postoperative management protocols are followed. The model can be established by following a procedure that includes the following stages: (i) preoperative planning and preparation, (ii) the surgical approach, (iii) postoperative management, and (iv) postmortem analysis. Using this model, full results for peer-reviewed publication can be attained within 2 years. In this protocol, we comprehensively describe how to establish proficiency using the preclinical model for the evaluation of a range of bone defect reconstruction options.