Continuous transcutaneous gas monitoring in adults on regular dialysis treatment.

We tested a transcutaneous (tc) oxygen (O2) and carbon dioxide (CO2) sensor in 15 normal adults and in 20 patients on regular dialysis treatment (RDT). We compared the tc gas values (ptcO2, PtcCO2) with the gas tension values in arterial blood samples (PaO2, PaCO2), in normal adults and in RDT-patients at the end of a 30-min test and six times during RDT. During the test, PtcO2 correlated with PaO2 both in normal adults (r 0.72 p less than 0.01) and in RDT patients (r 0.41 p less than 0.05). PtcCO2 correlated with PaCO2 (r 0.59 in normal adults and r 0.76 in RDT). During 14 acetate dialyses the changes were expressed as % delta from time 0. % delta PaO2 was -12.7 at 60 min, + 4.8 at 240 min; % delta PtcO2 -6.0 at 60 min, + 9.7 at 240 min; % delta PaO2 -17.7 at 240 min, -1.8 1 h later; % delta PtcCO2 was -15.8 at 240 min, -3.2 1 h later. Both in normal adults and in RDT, patients there was a good relationship between PtcCO2 and PaCO2 values. In normal adults the absolute PtcO2 values were always lower than PaO2 (-14.4 +/- 10 mmHg); in RDT-patients this difference was more pronounced (-27.6 +/- 15.1) and is probably attributable to the lower Hb levels (6.7 +/- 1.1 vs 12.4 +/- 1.2). During RDT the pattern was the same between tc and gas tension values.(ABSTRACT TRUNCATED AT 250 WORDS)

Acid-base balance during biofiltration.

Five patients were shifted from acetate dialysis (AD) to biofiltration (BF); their pre-dialytic acid-base balance (ABB) was re-examined for six months before the start of BF. Samples for ABB were drawn at 0', 30', 60', 120' and 180' during three AD and 1, 2 and 3 hours after them (period A). The same procedure was then repeated two months (period B) and 12 months (period C) after the start of BF. From analysis of the data it is concluded that the correction of AD-acidosis is very rapid during the early two months of BF, but the post-BF ABB may be too alkalotic, with risks if respiratory alkalosis is superimposed. After one year of BF, there were fewer pCO2 falls and pH variations; no more post-BF alkalotic rebounds were observed.