Faster onset time of supraclavicular brachial plexus block using local anesthetic diluted with dextrose / Tempo mais rápido de início do bloqueio do plexo braquial supraclavicular usando anestésico local diluído com dextrose

Abstract Background and objectives: A high sodium concentration is known to antagonize local anesthetics when infiltrated around neural tissue. Thus, we hypothesized that the onset time for sensory and motor blockade, in supraclavicular brachial plexus block using ropivacaine diluted with dextrose would be shorter than with saline. Methods: Patients scheduled for upper limb surgery were randomized to receive ultrasound guided supraclavicular brachial plexus block with 0.5% ropivacaine. Evaluation of sensory and motor blockade was performed every 5 min for 60 min. Patients were followed-up on postoperative day 1, and between days 7 and 10 for the presence of any complications. Twenty-five patients in each group were analyzed. Results: Mean time for onset of analgesia for the dextrose group was 37.6 ± 12.9 min while the mean time for the saline group was 45.2 ± 13.9 min with a p-value of 0.05. The effect size was 0.567, which was moderate to large. No major complications were observed. Conclusion: We conclude that there was a decrease in onset time of analgesia when dextrose was used as a diluent instead of saline for ultrasound guided supraclavicular block.

Resumo Justificativa e objetivos: A alta concentração de sódio é conhecida por antagonizar anestésicos locais quando infiltrado em torno de tecido neural. Portanto, a nossa hipótese foi a de que o tempo de início para os bloqueios sensorial e motor, em bloqueio do plexo braquial supraclavicular com ropivacaína diluída com dextrose, seria menor do que com solução salina. Métodos: Os pacientes agendados para cirurgia em membro superior foram randomizados para receber bloqueio do plexo braquial supraclavicular com ropivacaína a 0,5%g guiado por ultrassom. A avaliação dos bloqueios sensorial e motor foi feita a cada cinco minutos durante 60 minutos. Os pacientes foram acompanhados no pós-operatório no primeiro dia e entre os dias 7-10 para presença de qualquer complicação. Foram analisados 25 pacientes em cada grupo. Resultados: A média do tempo para o início da analgesia no grupo dextrose foi de 37,6 ± 12,9 minutos, enquanto que no grupo solução salina foi de 45,2 ± 13,9 minutos, com um valor-p de 0,05. O tamanho do efeito foi 0,567, o que foi de moderado a grande. Complicações maiores não foram observadas. Conclusão: Concluímos que houve uma redução do tempo de início da analgesia quando dextrose em vez de solução salina foi usada como diluente para bloqueio supraclavicular guiado por ultrassom.

Glutamine treatment attenuates hyperglycemia-induced mitochondrial stress and apoptosis in umbilical vein endothelial cells

OBJECTIVE: The aim of this study was to determine the in vitro effect of glutamine and insulin on apoptosis, mitochondrial membrane potential, cell permeability, and inflammatory cytokines in hyperglycemic umbilical vein endothelial cells. MATERIALS AND METHODS: Human umbilical vein endothelial cells were grown and subjected to glutamine and insulin to examine the effects of these agents on the hyperglycemic state. Mitochondrial function and the production of inflammatory cytokines were assessed using fluorescence analysis and multiple cytotoxicity assays. Apoptosis was analyzed by the terminal deoxynucleotidyl transferase dUTP nick end-labeling assay. RESULTS: Glutamine maintains the integrity of the mitochondria by reducing the cell permeability and cytochrome c levels and increasing the mitochondrial membrane potential. The cytochrome c level was significantly (p<0.005) reduced when the cells were treated with glutamine. An apoptosis assay revealed significantly reduced apoptosis (p<0.005) in the glutamine-treated cells. Moreover, glutamine alone or in combination with insulin modulated inflammatory cytokine levels. Interleukin-10, interleukin-6, and vascular endothelial growth factor were up-regulated while tumor necrosis factor-α was down-regulated after treatment with glutamine. CONCLUSION: Glutamine, either alone or in combination with insulin, can positively modulate the mitochondrial stress and cell permeability in umbilical vein endothelial cells. Glutamine regulates the expression of inflammatory cytokines and maintains the balance of the mitochondria in a cytoprotective manner. .