The reliability of a new measure of inspiratory muscle function in patients with COPD

Rationale: Maximal inspiratory pressure (MIP) is an accepted effort-dependent measure of global inspiratory muscle strength. Prolonged MIP (PMIP) area is a new measure of inspiratory muscle function calculated as the area under the curve produced by sampling maximal inspiratory pressure at 16 Hz during a sustained inspiratory manoeuvre. The reliability of this measure has previously been established in normal subjects, but no published data are available for COPD patients.Methods: Forty-three COPD patients attended for data collection on two occasions, 48 hours apart. Anthropometric data were collected on the first visit, pulmonary function, inspiratory muscle and peripheral muscle function (hand grip) data were collected during both visits. Calculated reliability estimates included the intraclass correlation coefficient (ICC), coefficient of variation (CV) and Bland & Altman 95% limits of agreement.Results: Within-day reliability was consistently higher than between-day reliability. Between-day results generated an ICC of 0.92, a CV of 10% and 95% limits of agreement of - 58 to + 71 pressure time units. Hand grip data generated an ICC of 0.92 and a CV of 8%.Conclusion: In this study group PMIP area was found to be a reproducible measure of inspiratory muscle function, generating comparable levels of reliability to those found in other effort-dependent tests of skeletal muscle function

Sustained maximal inspiratory manoeuvres can be used to predict extubation outcome after prolonged periods of mechanical ventilation

Rationale: Maximal inspiratory pressure (MIP) is an accepted effort-dependent measure of global inspiratory muscle strength. Although numerous studies have examined its ability to predict weaning /extubation outcome after mechanical ventilation, MIP has generally been found to have lower specificity than is clinically acceptable. The Respiratory Trainer (RT2) is a new device originally conceived as a methodology for training the inspiratory muscles. It generates three measures of inspiratory muscle function including a new measure called prolonged MIP (PMIP) area. This is calculated as the area under the curve produced by sampling maximal inspiratory pressure at 16 Hz during a sustained inspiratory manoeuvre.Methods: Twenty-seven intubated adults who had required prolonged mechanical ventilation (48 hours plus) and were deemed ready for extubation were measured using the RT2 prior to extubation. Differences in PMIP area measures between extubation success and failure outcome groups were then sought using independent samples t tests. Sensitivity and specificity of different levels of PMIP area to predict outcome were also calculated using ROC curves.Results: Significant differences in PMIP area were found between the extubation success and failure groups (t = 7.371, p <0.001). A PMIP area cut-off point of 57.5 pressure-time units gave a sensitivity and specificity of 1.0 for extubation outcome prediction.Conclusion: PMIP area measures were significantly different in the extubation success and failure outcome groups. This work suggests that PMIP area may have a role in predicting extubation outcome after prolonged periods of mechanical ventilation

Redução de perdas pós-colheita em tomate de mesa acondicionado em três tipos de caixas Reduction of tomato post-harvest losses stored in three different types of boxes

Atualmente, no Brasil, a embalagem mais usada para tomate continua sendo a caixa de madeira que era usada para transportar querosene na segunda guerra mundial, há meio século, conhecida como caixa "K". Esta embalagem possui características que favorecem as injúrias mecânicas e comprometem a durabilidade e qualidade das hortaliças, como o fato de apresentar superfície áspera, alojar patógenos, profundidade excessiva, possuir aberturas laterais cortantes. Considerando os problemas da caixa K e a necessidade de proteção do tomate, a Embrapa Hortaliças iniciou, em janeiro de 1997, pesquisa para geração de uma embalagem adequada para acondicionamento e transporte de tomate. A embalagem definitiva foi testada em relação à caixa 'K' e caixa de plástico existente no mercado. Nos frutos de tomate foram avaliados a variação de matéria fresca, vida útil, cor, danos mecânicos, variação da firmeza, teor relativo de água e deterioração. A nova embalagem foi nomeada caixa Embrapa e apresenta menores percentagens de danos mecânicos, provavelmente a característica mais importante avaliada, reduzindo perdas pós-colheita em tomate de mesa.<br>The most common box used for harvested vegetables in Brazil is the wood one which was used for kerosene transporting during second world war, in 1945. This box causes mechanical damage and reduces vegetables shelf-life and quality, due to its rough surface allowing pathogen colonization, due to the excessive number of fruit layers, and due to the lateral cut openings. Considering the problems of the K box and the necessity of protecting tomato fruits, Embrapa Hortaliças began in January 1997 a research to develop an adequate box to protect tomato fruits. The definitive box, named "Embrapa box", was compared with the K box and the most common plastic boxes from the market. The weight, shelf-life, color, mechanical damage, firmness, relative water content and deterioration were evaluated. The damage was significantly different and lower in the Embrapa box, reducing post-harvest losses in tomato fruits