- Patients who are on peritoneal dialysis (PD) can be enrolled if their SK level is ≥5.5 and ≤ 6.5 mmol/L in two consecutive i-STAT potassium evaluation at least 24 hours apart before Day 1 (in each evaluation, two i-STAT potassium measurements at least 1 hour apart are required). i-STAT potassium measurement should be performed in the morning before breakfast and in the evening before dinner in PD patients on continuous ambulatory peritoneal dialysis (CAPD) and automated peritoneal dialysis (APD), respectively.