Korean Journal of Nephrology 2000;19(1):106-111.

원저 : 혈액투석 환자에 있어 투석 간격시간 및 투석중 칼륨 제거량이 혈중 칼륨 농도에 미치는 영향 (Effects of Interdialytic Interval and Potassium(K) Removal via Dialvsis on the Plasma Potassium Concentration in Maintenance Hemodialysis)

김호중(Ho Jung Kim),노광호(Kwang Ho Roh),이경원(Kyung Won Lee),김진영(Jin Yeong Kim),유준호(Joon Ho Ryu),문중돈(Joong Don Moon),박일규(Il Gyu Park)

Abstract

To evaluate potassium(K) homeostasis during in-terdialytic and dialytic phases in chronic hemodialysis patients, we analyzed pre- and post- dialysis plasma K concentration(n=28) over n week with an interdialytic interval of 7Zhrs, 48hrs(l), and 48hrs(II), respectively, and the quantity of total dialytic K removal via dialysate. The predialysis plasma K at 72h interval(prePK72h: 4.89±0.17mEq/L) was significantly higher than those at 48h interval(prePK48h-I: 4.57±0.15mEq/L, and prePK48h-II: 4.40±15mEq/L) (p=0.000, p=0.000). 10.7% in prePK72h were categorized into severe hyperkalemia more than 6.0mEq/L, but none in prePK48h-I, II(p=0.000, p=0.000). In contrast no difference between 72-h and 42-h intervals was found in the postdialysis plasma K(postPK72h: 3.59±0.07 vs postPK48h-I : 3.530±08mEq/L, p>0.05) and in the quantity of total dialytic K removal via dialysate(ΔKtota172h : 74±2.6 vs ΔKtota148h-I:71±2.2mEq, p>0.05). On approach to this with two-compartment model, there was significant difference in dialytic K removal from ECF(ΔKecf72h:22.2±1.6 vs ΔKecf48h-I:17.7±1.6mEq, p<0.01), but not in that from ICF(ΔKicf72h:51.6±3.1 vs ΔKicf48h-I: 53.5±2.7mEq, p>0.05). In all 28 patients, age, sex and body weight were not correlated with either pre- and post- plasma K levels or total K removal per kg body weight. In conclusion, the majority of dialytic K removal is from the replenishment of the ICF potassium and it has rather constant feature in that there was no autoregulatory increment even with the higher predialysis plasma K concentration. So the plasma K concentration on chronic maintenace hemodialysis is more dependent on the potassium gain during interdialytic phase than the potassium removal during dialytic phase. Also it is reasonable to restrict dietary K intake and apply K-exalate orientating to the interdialytic phase of 72hrs because severe hyperkalemia is rare in that of 48hrs.