Portal de Periódicos da CAPES

Adverse events associated with treatment of latent tuberculosis in the general population

2011; Canadian Medical Association; Volume: 183; Issue: 3 Linguagem: Inglês

10.1503/cmaj.091824

1488-2329

B. M. Smith, Kevin Schwartzman, Gillian Bartlett, Dick Menzies,

Inhalation and Respiratory Drug Delivery

Techniques for measuring flow, for example through perfused bronchial segments, frequently use a flow head as the sensing device. The sensitivity of these instruments to changes in airway resistance is dependent on the flow head resistance. This study aims to quantify the effect of flow head resistance on sensitivity and flow, allowing optimization of flow head resistance. A mathematical model of the perfused bronchial segment preparation was constructed and used to explore the effect of flow head resistance on sensitivity. The model9s assumptions were experimentally tested using segments of pig bronchus, perfused through the lumen with Krebs solution. The model suggests a complex relationship between flow head resistance and sensitivity that has a distinct maximum when approximately half of the total resistance is present in the flow head. Furthermore, the maximum sensitivity was found to be proportional to the resting flow. Regression between experimentally derived sensitivities and modelled predictions was linear, with a correlation coefficient of 0.93. We have defined the optimum recording conditions for study of flow through isolated bronchial segments.