Tissular oxygenation and erythrocyte deformability in haemodialyzed patients using different dialytic membranes

We studied the effect of some dialytic membrane on tissular oxygenation (TO ) and erythrocyte deformability (ED). Sixteen patients (10 M and 6 E aged 5 9 +/- 12 years) have been submitted to bicarbonate dialysis (BD) and subdiv ided into four groups (GR) of 4 patients each: GR 1 (hemophan membrane, 35 ED), GR 2 (polyacrylonitrile, PAN AN 69, 42 ED), GR 3 (polysulphone, 38 ED) and GR 4 (polycarbonate, 37 ED). The TO has been detected with the transcu taneous oxygen pressure (Tc pO(2)) using a transcutaneous oxymeter and the ED has been evaluated with the EMI (Erythrocyte Morphometric Index), which results from the ratio between deformable erythrocytes (bowl shape) and rig id erythrocytes (discocyte shape), for every 100 red cells fixed in vitro w ith 0.3% glutaraldehyde. The ED was also evaluated using a laser instrument : Laser Optical Rotational Cell Analyser. During ED was observed a signific ant decrease of Tc pO(2) in the ist hour only in the ist and 2nd GR and, in contrast with results obtained in the 3rd and 4th GR, in the same GRs the EMI showed a significant reduction of ED at the end of ED. Finally the LORC A results, showing a significant decrease of ED only in the Ist and 2nd GR, confirmed the data obtained with EMI. In conclusion, our study has suggest ed that hemophan and PAN AN 69 are less biocompatible than polysulphone and polycarbonate membranes according to effects on ED and TO.