Functional performance of different venous limb options in simulated neonatal/pediatric cardiopulmonary bypass circuits

Abstract Objective: Hemodilution is a concern in cardiopulmonary bypass (CPB). Using a smaller dual tubing rather than a single larger inner diameter (ID) tubing in the venous limb to decrease prime volume has been a standard practice. The purpose of this study is to evaluate these tubing options. Methods: Four different CPB circuits primed with blood (hematocrit 30%) were investigated. Two setups were used with two circuits for each one. In Setup I, a neonatal oxygenator was connected to dual 3/16" ID venous limbs (Circuit A) or to a single 1/4" ID venous limb (Circuit B); and in Setup II, a pediatric oxygenator was connected to dual 1/4" ID venous limbs (Circuit C) or a single 3/8" ID venous limb (Circuit D). Trials were conducted at arterial flow rates of 500 ml/min up to 1500 ml/min (Setup I) and up to 3000 ml/min (Setup II), at 36°C and 28°C. Results: Circuit B exhibited a higher venous flow rate than Circuit A, and Circuit D exhibited a higher venous flow rate than Circuit C, at both temperatures. Flow resistance was significantly higher in Circuits A and C than in Circuits B (P<0.001) and D (P<0.001), respectively. Conclusion: A single 1/4" venous limb is better than dual 3/16" venous limbs at all flow rates, up to 1500 ml/min. Moreover, a single 3/8" venous limb is better than dual 1/4" venous limbs, up to 3000 ml/min. Our findings strongly suggest a revision of perfusion practice to include single venous limb circuits for CPB.

Analysis of TMJ vibration sounds before and after use of two types of occlusal splints

Temporomandibular joint (TMJ) sounds are important and common physical signs of temporomandibular disorders (TMD). The aim of this study was to evaluate the influence of the effect of the use of occlusal bite splints (stabilizing and repositioning) on the sounds produced in the TMJ, by means of the electrovibratography (EVG). Thirty-one patients with TMD from the Dental School of Ribeirão Preto, University of São Paulo, Brazil were selected for this study. Group 1 (n=23) wore stabilizing bite splints and Group 2 (n=8) used anterior repositioning splints. Before and after treatment with occlusal splints both groups were analyzed using the SonoPAK Q/S recording system (BioResearch System, Inc.). The treatments with stabilizing bite splints were satisfactory, since they reduced the total amount of the sound energies (p<0.05), but the use of anterior repositioning splints for no more than 4 weeks produced significantly better results (p<0.01). The total amount of vibration energy involved in the vibrating movements of the TMJ showed significant improvement using anterior repositioning splints.

Os ruídos da articulação temporomandibular (ATM) são sinais físicos importantes e comuns da disfunção temporomandibular (DTM). O objetivo do presente estudo foi avaliar o efeito do uso da placa oclusal (estabilizadora e reposicionadora) nos sons produzidos na ATM, por meio da eletrovibratografia (EVG). Um total de 31 pacientes da Faculdade de Odontologia de Ribeirão Preto - USP foram selecionados para este estudo. O grupo 1 (n=23) foi selecionado para usar a placa estabilizadora e o grupo 2 (n=8) para usar a placa reposicionadora. Antes e depois do uso das placas os grupos foram analisados usando o SonoPAK Q/S (BioResearch System). Os tratamentos com placas estabilizadoras foram satisfatórios quando analisados estatisticamente uma vez que reduziram a quantidade total de energia dos sons (p<0,05). O tratamento com placa reposicionadora, por 4 semanas no máximo, produziu melhores resultados estatísticos (p<0,01). A quantidade total de energia de vibração nos movimentos vibratórios da ATM mostrou significante melhora usando a placa reposicionadora.

Fatores de relevância na determinaçäo e registro da relaçäo cêntrica / Relevance factors in the determination and registration of the centric relation

Säo abordados os fatores de relevância na determinaçäo do registro da relaçäo cêntrica, tais como: posiçäo e relaxamento do paciente, técnica de manipulaçäo e material para registro. Seräo demonstradas as associaçöes entre técnicas e materiais que preencham os requisitos para um registro preciso da relaçäo cêntrica