The law of unintended consequences in action: increase in incidence of hypokalemia with improved adequacy of dialysis.Adv Perit Dial. 2000; 16:134-7.AP
In 1996, we raised our peritoneal dialysis (PD) dose to meet new DOQI adequacy targets. Concurrently, we noted an increase in the frequency of K+ levels below 3.5 mEq/L. A continuous quality improvement (CQI) project was initiated to quantify the impact of increasing dialysis dose on the prevalence of hypokalemia in our unit. Measurements of serum K+, blood urea nitrogen (BUN), creatinine, residual renal function, and the number and type of clinical interventions required to maintain eukalemia were abstracted from the charts of 62 patients enrolled in our program for more than 6 months and having more than two adequacy data points. In the seven consecutive 6-month periods from January 1996 to June 1999, dialysis dose progressively increased while median serum K+ decreased, and the percentage of patients requiring either diet counselling or K+ supplementation rose from 9% to 42%. We conclude that the increased clearance of K+ that occurs with increasing dialysis dose may lead to significant hypokalemia in a large proportion of PD patients dialyzed to DOQI adequacy targets. Maintenance of eukalemia in this population often requires increased K+ intake and or oral supplementation. Further studies are needed to ascertain whether the prevalence of hypokalemia is sufficient to warrant routine addition of K+ to PD dialysis solutions.