血液透析時の生化学的研究,ことにDialysis Disequilibriumについて

Abstract

Seven patients with chronic renal failure were treated by repeated hemodialysis with the Kolff twin coil artificial kidney. Biochemical studies were made on the blood serum, red blood cells and cerebrospinal fluid before and after hemodialysis; and the dialysis disequilibrium was investigated in this line. 1) Fortunately enough, no serious neurological complications due to the dialysis disequilibrium were experienced in any case. 2) A delayed dialysis of the cerebrospinal fluid NPN, compared with the serum NPN, resulted in the great concentration gradient of NPN between the two compartments after hemodialysis. This is the dialysis disequilibrium between the serum and cerebrospinal fluid. 3) Between NPN of the red blood cells and that of the serum, a delayed dialysis of the former was observed; thus the presence of dialysis disequilibrium between the intracellular and extracellular fluid was interestingly suggested. 4) As to sodium, potassium and chloride, no dialysis disequilibrium was particularly observed. Both sodium and chloride level of the serum and cerebrospinal fluid were reversed after hemodialysis, but without noticeable influence on the osmotic pressure of them. 5) The osmotic pressure of the serum and that of cerebrospinal fluid were reversed after hemodialysis; therefore, the osmotic gradient between the fluid compartments, the derangement of water balance and the elevated cerebrospinal fluid pressure ensued. The difference of glucose concentration of the dialyzing fluid did not affect on the osmotic pressure. 6) As to the spinal fluid pressure, the higher the glucose concentration of dialysate, the less elevation of it after hemodialysis was observed. 7) From our studies and the previous reports by the investigators, etiology of dialysis disequilibrium might be summarized as follows. ( i) Change in the mode of presence of the waste nitrogen substances, particulary urea, in the intracellular and extracellular fluid due to hemodialysis. (ii) Influence of the change in urea nitrogen concentration due to hemodialysis on the osmotic pressure. (iii) Elevated cerebrospinal fluid pressure due to the osmotic gradient between the serum and the fluid. 8) The following measures are to be considered to prevent dialysis disequilibrium. ( i) Rapid dialysis of the short duration should be avoided. BUN should be kept not too low. (ii) Hemodialysis should be started before BUN reaches the high level. (iii) Hemodialysis should be repeated frequently. (iv) Whenever dialysis disequilibrium is anticipated, mannitol should be started during the last half of hemodialysis. (v) Low protein diet. (vi) Spinal tap to lower the cerebrospinal fluid pressure. (vii) Keep the proper glucose concentration of the dialyzing fluid. In azotemia, approximately 500 mg % (311.2 mOsm/kg•H2O) might be adequate considering the elevated serum osmotic pressure.