[A study on the mechanism of enhanced diuresis following direct hemoperfusion with polymyxin B-immobilized fiber].

In the present study, we applied direct hemoperfusion with polymyxin B-immobilized fiber(PMX-DHP) to patients who developed endotoxin shock after laparotomy, and examined the influence of PMX-DHP on the kidney function. Seven patients were enrolled in this study, whose conditions were matched to the following criteria: 1) endotoxin shock was highly suspected, 2) blood pressure became stable before PMX-DHP was indicated, 3) renal function(demonstrated with creatinine clearance(CCr) and fractional excretion of sodium (FENa)) was proven before the surgery. All patients underwent emergency surgery in Fuji City General Hospital because of perforative peritonitis. A 2-hour session of PMX-DHP was performed on the day of the laparotomy and the second 2-hour treatment was performed the following day. Urine was collected at 2 hours before starting PMX, during the treatment, and 2 hours after PMX-DHP, and urine volume(U-Vol), sodium and creatinine levels of urine were monitored. Sodium and creatinine levels in the serum were measured at the start and end of the PMX-DHP session. Average atrial natriuretic polypeptide (ANP) was obtained using a total of 8 samples from the 14 treatment sessions. Parameters of hemodynamics such as pulmonary capillary wedge pressure(PCWP) were monitored at the start and end of PMX-DHP session. Urine volume increased significantly during and after PMX-DHP. The change in urine volume correlated significantly with the change in CCr during PMX-DHP, and with the change in FENa after PMX-DHP. The change in FENa was significantly correlated with the changes in hemodynamic factors such as PCWP and with the change in serum ANP, but no significant correlation was observed between the change of CCr and the other parameters. In conclusion, the early increase in urine volume with PMX-DHP treatment might be attributable to the increase in glomerular filtration independently of systemic hemodynamic factors.