Low Serum Parathyroid Hormone Is a Predictor of Early Death after Hip Arthroplasty in Hemodialysis Patients

Background and Purpose:  Colloid osmotic pressure (COP) in plasma rises by ultrafiltration during hemodialysis, and it consequently causes plasma refilling in which water moves from interstitial tissue to capillary space. Although hemodynamic stability is one of the important factors for good dialysis outcome, no informative and convenient indicators are available other than monitoring of blood pressure. Thus, we measured COP during hemodialysis whether COP can be used as an indicator for the hemodynamic status in comparison with hematocrit (Ht). Plasma osmolality, ultrafiltration volume, and the alteration of blood pressure were also measured to examine whether COP is associated with them.
Method:  Sixteen patients hospitalized in this hospital were examined. Amongst them, 10 patients underwent both dialysis and ultrafiltration, while 4 patients received only dialysis and 2 patients were with ultrafiltration only by extracorporeal ultrafiltration method. Ultrafiltration was performed with constant speed to the dry weight for 4 h. The measurements of COP, plasma osmolality, Ht levels, and blood pressure were performed at 30 min (12.5% of the total water removal), 1 h (25%), 2 h (50%), and 3 h (75%) after the start of hemodialysis and also at the end of dialysis (100%).
Result:  COP markedly rose by 26.0% (±13.3%) in the patients who received both dialysis and ultrafiltration, whereas Ht rose by only 13.6% (±5.21%). And the curve for COP increase was sigmoid shape, whereas that for Ht showed linear change. On the other hand, in the patients whose Ht levels showed low values, the curves for both COP and Ht showed similar pattern.
Conclusion:  These results suggest that COP is a more sensitive indicator to be monitored for the hemodynamic status than Ht during hemodialysis.