Renal and pulmonary effects of angiotensin converting enzyme inhibition in chronic hypoxic lung disease

The effects of 28 days' treatment with captopril or with placebo on renal and pulmonary function were evaluated in nine patients with stable pulmonary heart disease. Captopril (25 mg twice daily) caused a 17% rise in effective renal plasma flow but no change in glomerular filtration rate, resulting in a fall in filtration fraction likely to favour natriuresis. Captopril did not alter FEV1, lung volumes, or arterial oxygen or carbon dioxide tension.

Some observations on the role of the abdomen in breathing in patients on peritoneal dialysis

We studied a total of 29 patients on continuous ambulatory peritoneal dialysis (CAPD), who had no present or past respiratory impairment, before and after drainage of dialysate (2.324 +/- SE 0.033 litres). We measured spirometry, lung volumes and carbon monoxide transfer sitting and supine in 20 patients. The only statistically significant changes on drainage were a small increase in supine functional residual capacity (+214 +/- SE 61 ml, P less than 0.01) and a small fall in supine peak expiratory flow rate (-26.6 +/- SE 12.1 litres/min, P less than 0.05). Measurement of maximal mouth and transdiaphragmatic pressures in ten patients made under the same circumstances showed no statistically significant changes on drainage. A model of the abdomen demonstrates that fluid distension is likely to be better tolerated than gaseous distension, and review of previous studies suggests that a wide range of changes in intraabdominal fluid volume can be tolerated without respiratory embarrassment. These results suggest that fluid volumes used for CAPD do not interfere with breathing in patients with previously normal lungs. The nature of the mechanisms compensating for the fluid suggests that patients with chest disease should be able to tolerate this form of dialysis.

Analysis of an optical mapping technique for lung function studies

An optical technique for lung function measurement studies is described and analysed. Procedures which permit the reconstruction of three dimensional data concerning the thoraco-abdominal wall are developed and methods for calculating volumes, surface areas and cross-sections are outlined.

Optical mapping of the thoracoabdominal wall

An optical technique has been developed for mapping the size and shape of the thoracoabdominal wall and the change in its shape with breathing. A fixed pattern composed of stripes of light is projected on to both sides of the trunk. These stripes become distorted when viewed from in front and behind, forming contours over the trunk surface. The contours are photographed and then encoded digitally. The digital information can be used to compute automatically the volume of the trunk, the position of any point on its surface, and its cross sectional shape at any level. The technique has been tested on rigid objects (a globe, a cone, and two dummy torsos) that can be measured precisely. With this optical technique linear dimensions can be calculated to within 0.5 mm, cross sectional area to within 5%, and volume to within 1.6-3.7%. These results suggest that this non-invasive technique measures the shape and volume of complex three dimensional surfaces with sufficient accuracy to be tried in clinical practice.

Arteritis of the arms

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