The effect of abdominal distension on lung functions in continuous ambulatory peritoneal dialysis

The effect of abdominal distension on lung functions and gas exchange were examined in 13 continuous ambulatory peritoneal dialysis patients suffering from end stage renal failure. Forced residual capacity reduced significantly when the abdomen was filled with 2 L of dialysate (p < 0.01), whereas diffusing capacity and oxygen saturation by pulse oximetry were significantly high on full abdomen (p < 0.0004; p < 0.05 respectively). Other parameters did not differ significantly between empty and full abdomen. Intra-abdominal pressure on full and empty abdomen did not correlate with either functional residual capacity (FRC) or forced vital capacity (FVC) values. The observed changes in FRC was probably related to slight mechanical changes due to installation of 2 L of dialysate. The increases in oxygen saturation and diffusion capacity were likely to be due to an increase of blood flow to the lungs and a decrease in pulmonary water.