The Changes of Serum Potassium and Acid-Base Balance in Diabetic Ketoacidosis(DKA)

Kim, Jin Bae; Lee, Chang Beom; Kim, Ho Jung

Abstract

OBJECTIVE
The biochemical data of 10 patients admitted with diabetic ketoacidosis(DKA) during the last 2 years were analyzed for the disturbances of serum potassium(K) and acid-base balance with a special interest to look for the underlying causes of potassium(K) disorder, retrospectively.
METHODS
Arterial blood gas analysis was done and electrolytes, serum glucose, serum osmolality, BUN, creatinine were checked on admission and recovery in 10 patients with diabetic ketoacidosis.
RESULTS
The mean(+/-SE) serum K at diagnosis and on recovery was 4.9+/-0.9mEq/L(range, 3.2-6.5 mEq/L) and 3.8+/-0.2mEq/L(range, 3.0-4.3mEq/L), respectively. Hyperkalemia(>5.0mEq/L) in 30%(3/10) and hypokalemia(<3.5mEq/L) in 10%(1/10) was noted on admission, whereas, on recovery, hyperkalemia in none and hypokalemia in 40%(4/10). Initial K levels showed a negative correlation with pH(gamma= -0.62, P=0.05) but no significant correlation was found between the initial K levels with anion gap (AG), with serum glucose value and with blood osmolality. Only 40%(4/10) had a simple metabolic acidosis while 60%(6/10) had a mixed acid-base disorder DKA with respiratory alkalosis, mostly(5/6). The ratio of delta AG over delta HCO3 was not significantly different between patients with a simple metabolic acidosis(0.95) and with a mixed acid-base disorder(0.92).
CONCLUSION
The degree of acidosis must be one of the predominant factors in the pathogenesis of the initial hyperkalemia rather than hyperglycemia resulting from insulinopenia itself. Also, we observed that patients with DKA commonly develop mixed acid- base disorders, and delta AG/delta HCO3 ratio would not be an useful tool to look for a mixed acid-base disorder.