Expanding on our previously developed method for inserting synthetic objects into clinical computed tomography (CT) data, we model a set of eight clinical tumors that span a range of geometries and locations within the lung. The goal is to create realistic but synthetic tumor data, with known volumes. The set of data we created can be used as ground truth data to compare volumetric methods, par...

It is not readily apparent how pulmonary function could be improved by resecting portions of the lung in patients with emphysema. In emphysema, elevation in residual volume relative to total lung capacity reduces forced expiratory volumes, increases inspiratory effort, and impairs inspiratory muscle mechanics. Lung volume reduction surgery (LVRS) better matches the size of the lungs to the size...

We have examined the effect of varying end-expiratory lung volume on carbon dioxide elimination in 10 mongrel dogs undergoing conventional mechanical ventilation at 12 b.p.m. and forced diffusion ventilation (FDV) at 6 Hz and 50 Hz and continuous flow. End-expiratory volumes were altered by changing the pressure in a plethysmographic box in which the dogs underwent ventilation. The pressures st...

signifi cant and prolonged lung reaeration after intratracheal bolus instillation of porcine-derived surfactant. In this substudy of a larger randomized controlled trial of patients with acute lung injury [2], the investigators elegantly demonstrate increased volumes of gas in poorly and non-aerated lung of patients who were treated with surfactant as compared with patients who received routine...

The morbidly obese are known to have impaired respiratory function. A prospective study of the changes in lung volumes, carbon monoxide transfer, and arterial blood gas tensions was undertaken in 29 morbidly obese patients before and after surgery to induce weight loss. Before surgery the predominant abnormality in respiratory function was a reduction in lung volumes. These increased towards no...

The pressure-volume (P-V) characteristics of the lung microcirculation are important determinants of the pattern of pulmonary perfusion and of red and white cell transit times. Using diffuse light scattering, we measured capillary P-V loops in seven excised perfused dog lobes at four lung volumes, from functional residual capacity (FRC) to total lung capacity (TLC), over a wide range of vascula...

Nineteen survivors of congenital diaphragmatic hernia repair were compared with age and sex matched control children six to 11 years after repair. All subjects were examined clinically and underwent lung function testing. The patients also had individual lung volumes assessed radiographically and had radionuclide (krypton-81 m, technetium-99 m macroaggregates) ventilation-perfusion (V/Q) lung s...

This study was conducted to observe effects of two methods of setting positive end-expiratory pressure (PEEP) based on the pressure-volume (PV) curve. After lung injury was induced by oleic acid in six mongrel adult dogs, the inflation PV curve was traced and the lower inflection point (LIP) was measured. The 'PEEP(INF)' was defined as LIP+2 cmH(2)O. After recruitment maneuver to move the lung ...

Objective: To evaluate spirometric patterns of respiratory disorders and their relationship with functional severity and maximal expiratory flows at low lung volumes in patients with cystic fibrosis (CF). Methods: A retrospective cross-sectional study including adolescents and adults with CF. All of the patients were submitted to spirometry. Patients were classified as having preserved respirat...

UNLABELLED We tested the hypothesis that one-lung ventilation (OLV) with high tidal volumes (VT) and zero positive end-expiratory pressure (PEEP) may lead to ventilator-induced lung injury. In an isolated, perfused rabbit lung model, VT and PEEP were set to avoid lung collapse and overdistension in both lungs, resulting in a straight pressure-time (P-vs-t) curve during constant flow. Animals we...