External respiration in patients with chronic renal failure in a predialysis state

The purpose of this study was to make functional assessment of the external respiration in patients with chronic renal failure (CRF) in a predialysis state and to find some early indicators for uremic lung impairment. Twenty two patients (13 men, 9 women, aged 30 to 65) with different renal diseases were investigated. According to the stage of progression of CRF we allocated the patients to two groups-14 patients with stage I CRF (serum creatinine up to 353.6 mumol/I), and 8 patients with stage II CRF (serum creatinine from 353.6 to 707.2 mumol/I). The comprehensive functional study included slow spirometry, forced expiration, bodyplethysmography, and investigation of the diffusion, blood-gas and acid-base parameters. The respiratory muscle strength was measured by means of a modified device first used by Black LE and Hyatt RE. Ventilatory parameters in stage I CRF patients were found to be either normal or slightly changed while the parameters of the respiratory muscle strength worsened earlier than the ventilatory parameters. In the patients with stage II CRF the pronounced ventilatory and diffusion disorders was found to occur much more frequently.