Serum potassium concentration in hyperglycemia of chronic dialysis.

We analyzed abnormalities in serum potassium ([K]) in 40 episodes of diabetic ketoacidosis (DKA)--6 episodes in peritoneal dialysis (PD) and 34 episodes in hemodialysis (HD)--and in 245 episodes of nonketotic hyperglycemia (NKH)--70 episodes in PD and 175 episodes in HD. Serum glucose ([Glu]) was 25 mmol/L or higher in all episodes. We compared the PD and HD hyperglycemic episodes separately for DKA and NKH. For DKA, [Glu] was 55.5 + 4.8 mmol/L in PD and 51.9 +/- 12.2 mmol/L in HD [p = nonsignificant (NS)], and [K] was 6.4 +/- 1.5 mmol/L in PD and 6.3 +/- 1.1 mmol/L in HD (p=NS). Also for DKA, [K] was 5.5 mmol/L or higher in 4 episodes (66.7%) in PD and in 26 episodes (76.5%) in HD (p=NS), and 6.0 mmol/L or higher in 3 episodes (50.0%) in PD and in 22 (episodes 64.7%) in HD (p=NS). For NKH, [Glu] was 39.4 +/- 14.7 mmol/L in PD and 37.8 +/- 12.4 mmol/L in HD (p=NS), and [K] was 4.3 +/- 0.9 mmol/L in PD and 5.1 +/- 0.8 mmol/L in HD (p < 0.001). Also for NKH, [K] was 5.5 mmol/L or higher in 7 episodes (10.0%) in PD and in 55 episodes (31.4%) in HD (p < 0.001), and 6.0 mmol/L or higher in 4 episodes (5.7%) in PD and in 31 episodes (17.7%) in HD (p = 0.023). Serum sodium, tonicity, urea, osmolality, creatinine, chloride and anion gap, and arterial blood pH and partial pressure of carbon dioxide did not differ between PD and HDfor either DKA or NKH episodes, but serum total carbon dioxide content was lower in PD than in HD DKA episodes (6.5 + 3.8 mmol/L vs. 9.5 + 2.8 mmol/L, p = 0.038), and higher in PD than in HD NKH episodes (22.5 + 6.0 mmol/L vs. 20.9 + 4.4 mmol/L, p = 0.004). Although PD and HD DKA episodes appear not to differ in [K], the mean [K] and the frequency of hyperkalemia are both lower in PD than in HD NKH episodes. Differences between PD and HD in acid-base balance and, probably, in other factors affecting [K] (such as mineralocorticoid metabolism and blood levels) may account for the differences in [K] between PD and HD NKH episodes.