RESUMO
INTRODUCTION: Brazil is a country with great climatic, socioeconomic, and cultural differences that does not yet have a reference value for the 6-min walk test (6MWT) in healthy children. To avoid misinterpretation, the use of equations to predict the maximum walk distance should be established in each country. OBJECTIVES: We sought to establish reference values and to develop an equation to predict the 6-min walk distance for healthy children in Brazil. METHODS: This is a cross-sectional multi-center study that included 1,496 healthy children, aged 7 to 12 y, assessed across 11 research sites in all regions of Brazil, and recruited from public and private schools in their respective regions. Each child was assessed for weight and height. Walk distance was our main outcome. An open-source software environment for statistical computing was used for statistical analysis. RESULTS: We observed a higher average distance walked by boys (531.1 m) than by girls (506.2 m), with a difference of 24.9 m (P < .001). We established 6MWT reference values for boys with the following equation: Distance = (16.86 × age) + (1.89 × Δ heart rate) - (0.80 × weight) + (336.91 × R1) + (360.91 × R2). For girls the equation is as follows: Distance = (13.54 × age) + (1.62 × Δ heart rate) - (1.28 × weight) + (352.33 × R1) + (394.81 × R2). CONCLUSION: Reference values were established for the 6MWT in healthy children aged 7-12 y in Brazil.
Assuntos
Voluntários Saudáveis , Teste de Caminhada , Peso Corporal , Brasil , Criança , Estudos Transversais , Feminino , Frequência Cardíaca , Humanos , Masculino , Conceitos Matemáticos , Valores de Referência , Fatores SexuaisRESUMO
BACKGROUND: Flutter VRP1, Shaker, and Acapella are devices that combine positive expiratory pressure (PEP) and oscillations. OBJECTIVES: To compare the mechanical performance of the Flutter VRP1, Shaker, and Acapella devices. METHODS: An experimental platform and a ventilator, used a flow generator at 5, 10, 15, 20, 26, and 32 L/min, were employed at angles of -30°, 0°, and +30° to evaluate Flutter VRP1 and Shaker, whereas Acapella was adjusted at intermediate, higher, and lower levels of resistance, including positive expiratory pressures (PEP) along with air outflow rates and oscillation frequencies. RESULTS: When the relationships between pressure amplitudes of all air flows were analyzed for the 3 devices at low and intermediate pressures levels, no statistically significant differences were observed in mean pressure amplitudes between Flutter VRP1 and Shaker devices. However, both devices had different values from Acapella, with their pressure amplitude values being higher than that of Acapella (P = .04). There were no statistically significant differences in PEP for the 3 angles or marks regarding all air flows. The expected relationships between variables were observed, with increases in PEP, compared to those of air flows and resistance. Nevertheless, there was a statistically significant difference in frequency of oscillation between these devices and Acapella, whose value was higher than those of Flutter VRP1 and Shaker devices (P = .002). At intermediate pressure levels, the patterns were the same, in comparison to low pressures, although the Acapella device showed frequencies of oscillation values lower than those of Flutter VRP1 and Shaker (P < .001). At high pressures, there were no statistically significant differences among the 3 devices for frequency of oscillations. CONCLUSIONS: The Flutter VRP1 and Shaker devices had a similar performance to that of Acapella in many aspects, except for PEP.
Assuntos
Ventilação de Alta Frequência/instrumentação , Fenômenos Mecânicos , Respiração com Pressão Positiva , Humanos , Muco , PressãoRESUMO
During the anhepatic phase of conventional liver transplantation (LT), the inferior vena cava (IVC) is cross-clamped and venovenous bypass (VVB) is usually indicated for diversion of IVC and portal blood flow. VVB can theoretically lead to pulmonary complications due to the contact of the blood with the surfaces of the circuit. In the piggyback method, preservation of the IVC avoids VVB. The aim of this study is to compare pulmonary alterations after conventional with VVB versus piggyback LT. Sixty-seven patients were randomized for conventional VVB (n = 34) or piggyback (n = 33) LT. Pulmonary static compliance (C(st)) and Pa(O2)/F(IO2) ratio were measured pre- and post-LT. Chest X-rays were obtained daily from the 1st to the 5th postoperative day. Pre- and post-LT C(st) were 73.4 +/- 36.0 mL/cm H(2)O and 59.7 +/- 22.0 mL/cm H(2)O in the conventional group and 69.1 +/- 20.0 mL/cm H(2)O and 58.7 +/- 27.1 mL/cmH(2)O in the piggyback group. The difference between the two groups was not significant (P =.702). C(st) significantly decreased after LT (P =.008). The pre- and post-LT Pa(O2)/F(IO2) were 455.6 +/- 126.6 mm Hg and 463.1 +/- 105.9 mm Hg in the conventional group and 468.9 +/- 114.1 mm Hg and 483.3 +/- 119.8 mm Hg in the piggyback group. The difference among the two groups was not significant (P = 0.331). There was no significant difference after LT (P =.382). Upon the radiological evaluation, piggyback group presented a higher frequency of pulmonary infiltrates (80.6% vs. 50.0%; P =.025). In conclusion, piggyback LT recipients have a higher rate of pulmonary infiltrates when compared to those operated upon using the conventional VVB method.