Paradoxical glucose-induced hyperkalemia. Combined aldosterone-insulin deficiency

Abnormalities of serum potassium concentration in dialysis-associated hyperglycemia and their correction with insulin: review of published reports

The main difference between dialysis-associated hyperglycemia (DH) and diabetic ketoacidosis (DKA) or nonketotic hyperglycemia (NKH) occurring in patients with preserved renal function is the absence of osmotic diuresis in DH, which eliminates the need for large fluid and solute (including potassium) replacement. We analyzed published reports of serum potassium (K(+)) abnormalities and their treatment in DH. Hyperkalemia was often present at presentation of DH with higher frequency and severity than in hyperglycemic syndromes in patients with preserved renal function. The frequency and severity of hyperkalemia were higher in DH episodes with DKA than those with NKH in both hemodialysis and peritoneal dialysis. For DKA, the frequency and severity of hyperkalemia were similar in hemodialysis and peritoneal dialysis. For NKH, hyperkalemia was more severe and frequent in hemodialysis than in peritoneal dialysis. Insulin infusion corrected the hyperkalemia of DH in most cases. Additional measures for the management of hyperkalemia or modest potassium infusions for hypokalemia were needed in a few DH episodes. The predictors of the decrease in serum K(+) during treatment of DH with insulin included the starting serum K(+) level, the decreases in serum values of glucose concentration and tonicity, and the increase in serum total carbon dioxide level. DH represents a risk factor for hyperkalemia. Insulin infusion is the only treatment for hyperkalemia usually required.

Abnormalities of serum potassium concentration in dialysis-associated hyperglycemia and their correction with insulin: review of published reports

The main difference between dialysis-associated hyperglycemia (DH) and diabetic ketoacidosis (DKA) or nonketotic hyperglycemia (NKH) occurring in patients with preserved renal function is the absence of osmotic diuresis in DH, which eliminates the need for large fluid and solute (including potassium) replacement. We analyzed published reports of serum potassium (K(+)) abnormalities and their treatment in DH. Hyperkalemia was often present at presentation of DH with higher frequency and severity than in hyperglycemic syndromes in patients with preserved renal function. The frequency and severity of hyperkalemia were higher in DH episodes with DKA than those with NKH in both hemodialysis and peritoneal dialysis. For DKA, the frequency and severity of hyperkalemia were similar in hemodialysis and peritoneal dialysis. For NKH, hyperkalemia was more severe and frequent in hemodialysis than in peritoneal dialysis. Insulin infusion corrected the hyperkalemia of DH in most cases. Additional measures for the management of hyperkalemia or modest potassium infusions for hypokalemia were needed in a few DH episodes. The predictors of the decrease in serum K(+) during treatment of DH with insulin included the starting serum K(+) level, the decreases in serum values of glucose concentration and tonicity, and the increase in serum total carbon dioxide level. DH represents a risk factor for hyperkalemia. Insulin infusion is the only treatment for hyperkalemia usually required.

Effect of dialysate sodium concentration on interdialytic increase of potassium

To evaluate the role of plasma tonicity in the postdialysis increment of plasma potassium (p[K(+)]), the outcome of two hemodiafiltration treatments that differed only in the Na(+) level in dialysate (Na(D))-143 mmol/L (high dialysate sodium concentration [H-Na(D)]) and 138 mmol/L (low dialysate sodium concentration [L-Na(D)])-were compared in the same group of uremic patients from the end of treatment (T0) to the subsequent 30 to 120 min and up to 68 h. Kt/V and intradialytic K(+) removal were comparable. At T0, plasma [Na(+)] was 145+/-1 and 137+/-1 mmol/L after H-Na(D) and L-Na(D), respectively (P<0.001). The difference in plasma tonicity persisted from T0 to T68 h. At T120, p[K(+)] was increased from the T0 value of 3.7+/-0.2 to 4.7+/-0.2 mmol/L (P<0.05) after H-Na(D), whereas it was unchanged after L-Na(D). The change of p[K(+)] was still different after 68 h (+76+/-10% and +50+/-7% in H-Na(D) and L-Na(D), respectively; P<0.05). Of note, in the first 2 h after the end of treatment, bioimpedance analysis revealed only in H-Na(D) a significant 11+/-3% decrement of phase angle that is compatible with a decrease of intracellular fluid volume at the expense of the extracellular volume. Similarly, within the same time frame, in H-Na(D), a significant reduction of mean corpuscular volume of red cells, associated with a 2 +/-1% decrease of the intracellular [K(+)], was observed. In contrast, mean corpuscular volume of red cells did not change and erythrocyte [K(+)] increased by 6+/-1% after L-Na(D) (P<0.005 versus H-Na(D)). Thus, hypertonicity significantly contributes to the increase of p[K(+)] throughout the whole interdialytic period by determining intracellular fluid volume/extracellular volume redistribution of water and K(+).

Hyperkalaemia in diabetes: prevalence and associations

Hyperkalaemia is associated with diabetes, but there are no recent reports of its prevalence and associations. Serum potassium concentrations were measured in all 1764 patients attending a diabetic clinic over a 12-month period and found to be > 5.0 mmol/l in 270 (15%), and > 5.4 mmol/l in 67 (4%). There was no other evident cause of hyperkalaemia in 41 of these 67 patients. These data serve to highlight the risk of dangerous hyperkalaemia in diabetic patients, particularly with concurrent administration of angiotensin-converting-enzyme inhibitors and potassium-sparing diuretics.

Severe hyperkalemia in two patients with diabetes after cosyntropin administration

Some patients with diabetes mellitus are at increased risk for the development of hyperkalemia. Included in this group are patients with glucose-induced hyperkalemia who may have renal insufficiency, hyporeninemic hypoaldosteronism, or other impediments to the release or action of aldosterone. In an unusual demonstration of this abnormality, two patients with diabetes, who form the basis of our report, became markedly hyperglycemic and hyperkalemic after cosyntropin administration. To our knowledge, this complication of adrenocorticotropic hormone (ACTH) stimulation testing has not been previously reported. It should therefore be emphasized that the use of cosyntropin as a diagnostic agent can provoke severe hyperglycemia and hyperkalemia in a susceptible subgroup of patients with diabetes mellitus.

Emergency department evaluation and management of dialysis patient complications

The number of dialysis patients in the United States has markedly increased in recent years to more than 100,000. An emergency physician is increasingly likely to be presented with the challenge of handling the emergent problems of the dialysis patient. This article is a review of the complications seen in the population of hemodialysis and peritoneal dialysis patients, with recommendations for emergency department evaluation and management.

A patient with hyperkalemia and metabolic acidosis

Uptake of potassium by extrarenal tissues, primarily muscle and liver, represents a major defense mechanism in the maintenance of normokalemia following an acute elevation in the serum potassium concentration. Insulin, epinephrine, and aldosterone all play major roles in maintaining the normal distribution of potassium between the intracellular and extracellular environment. In addition to hormonal regulation, changes in blood pH and tonicity also exert a strong influence on extrarenal potassium metabolism. Last, the serum potassium concentration per se directly influences its own cellular uptake and this transport mechanism appears to be inhibited by uremia.

Potassium homeostasis and hypokalemia

Potassium, largely an intracellular cation, contributes to the regulation of cellular volume, to tissue growth and metabolic synthesis of proteins and nucleic acids, and to the integrity of electrical properties of excitable tissues as well as nonexcitable, transporting epithelia. Potassium balance is closely regulated by a variety of nonrenal and renal mechanisms. When potassium losses are sufficient to induce hypokalemia, either through nonrenal or renal causes, profound adverse effects on neuromuscular, cardiac, vascular, and renal tissues may ensue. The diagnostic approach is straightforward, and therapy must be directed to replenish losses without inducing a rapid, excessive, and potentially fatal increase in the potassium concentration of the serum.

Dynamic changes in serum phosphorus levels in diabetic ketoacidosis

The dynamic changes in serum phosphorus levels in 69 episodes of ketoacidosis in 48 diabetic patients were retrospectively evaluated. The mean age was 41 +/- 2 years (mean +/- SEM), and the duration of diabetes mellitus was 7 +/- 1 years. The serum phosphorus levels determined within the first six hours of admission were analyzed. Before initiation of therapy, the incidence of hyperphosphatemia was 94.7 percent. At the end of 12 hours, the mean serum phosphorus level fell from 9.2 +/- 0.6 to 2.8 +/- 0.3 mg/dl. Before therapy, the serum phosphorus level correlated positively with the serum glucose level, the effective plasma osmolality, and anion gaps, and correlated negatively with the serum chloride level. It is concluded that hyperphosphatemia is common in diabetic ketoacidosis before therapy. The increase in serum phosphorus is likely to be due to a transcellular shift. Potential factors responsible for the shift are serum glucose, through its osmotic effect, and the organic anions.

Hyperkalaemia in diabetes mellitus--potential hazards of coexisting hyporeninaemic hypoaldosteronism

Two patients with insulin-dependent diabetes mellitus (Type I), developed severe, life-threatening hyperkalaemia, the first following treatment with spironolactone, the second during treatment for staphylococcal septicaemia when glucose-induced hyperkalaemia occurred. Investigations demonstrated co-existing hyporeininaemic hypoaldosteronism. Prompt recognition of this combined hormone-deficiency syndrome led to appropriate treatment and recovery. The biochemical features and clinical importance of hyporeninaemic hypoaldosteronism are discussed.

Evaluation of the effect of pentobarbitone anaesthesia on the plasma potassium concentration in the rabbit and the dog

The purpose of these studies was to determine the reasons for the hypokalaemia observed in rabbits studied in our laboratory. The rabbits consumed standard rabbit chow which is rich in potassium and remained in potassium balance. Hypokalaemia was only observed following anaesthesia. A number of additional investigations were undertaken to clarify the mechanisms involved. The hypokalaemia could not be attributed to technical factors, alkalaemia, hyperinsulinaemia or hyperaldosteronism, but seemed to be a function of anaesthesia. This effect of pentobarbitone anaesthesia was not unique to the rabbit, as similar changes also occurred in the anaesthetized dog. The findings reported in this paper have significant implications with respect to the interpretation of plasma potassium concentrations in anaesthetized subjects or animals.

Effect of insulinopenia and adrenal hormone deficiency on acute potassium tolerance

The ability to dispose of an acute intravenous potassium load was examined in glucocorticoid-replaced adrenalectomized rats and in rats made insulinopenic with somatostatin. Adrenalectomy resulted in a significantly greater rise in plasma potassium concentration compared with controls (1.46 +/- 0.11 vs. 0.92 +/- 0.05 mEq/liter, P less than 0.001) despite the excretion of an identical percentage (47%) of the administered potassium load in 2 hours. Somatostatin-induced insulinopenia (insulin levels decreased from 37 +/- 5 to 20 +/- 3 microU/ml) was also associated with a significantly greater increment in plasma potassium controls, despite the excretion of a similar amount (39%) of the administered potassium load. In animals with combined adrenal and insulin deficiency, the rise in plasma potassium concentration occurred earlier and remained elevated for a more prolonged period of time compared with animals with either adrenalectomy or insulinopenia alone. Conclusion. During acute potassium loading in the rat, insulin and adrenal hormones play an important role in maintaining normal potassium homeostasis, primarily by enhancing potassium uptake by external tissues.

Glucose-induced paradoxical hyperkalemia in patients with suppression of the renin-aldosterone system: prevention by sodium depletion

A paradoxical transitory elevation of serum potassium concentration after intravenous infusion of hypertonic glucose has been found in 6 renal and/or hypertensive patients with suppression of the renin-aldosterone system (RAS) while on high sodium intake. Sodium restriction induced a dramatic increase in plasma renin activity (PRA) and/or plasma aldosterone (PA) in every patient, a substantial fall in the elevated serum potassium levels in 4 out of the 6 patients and a marked increase in fractional potassium excretion. During sodium restriction the glucose-induced paradoxical transitory hyperkalemia was abolished. The study confirmed the important extrarenal influence of aldosterone in the maintenance of normal potassium level in the hyperosmolal extracellular fluid and showed that: i) high sodium intake may predispose to hazardous hyperkalemia after massive glucose loading in certain nondiabetic patients with liability to suppression of aldosterone; ii) sodium restriction abolishes the glucose-induced abnormal serum potassium response.

Control of plasma aldosterone in diabetic patients with hyporeninemic hypoaldosteronism

In three patients with diabetes and hyporeninemic hypoaldosteronism changes in renin activity, plasma aldosterone and cortisol were examined under various conditions: orthostasis and intravenous furosemide, infusion of synthetic beta1-24 ACTH on two consecutive days and diurnal variations in basal hormone fluctuations. Each patient showed unmeasurably low renin activity unresponsive to orthostasis and intravenous furosemide while plasma aldosterone was below normal range. Under ACTH-infusion only marked increases in aldosterone were observed in one patient whereas cortisol responded normally in all diabetics tested. Analysis of diurnal night day fluctuations (20.00-8.00) in plasma aldosterone and cortisol revealed a close and statistically significant relationship between both hormones in each of the three patients (p less then 0.05-less than 0.001). Variations in plasma aldosterone thus were mediated through changes in endogenous pituitary ACTH. Compared with normal controls however, diurnal aldosterone curves were set at a lower level. Our results demonstrate that a reduced sensitivity of the adrenal gland to ACTH is not responsible for the observed subnormal plasma aldosterone levels in these patients. Therefore, the lack of circulating angiotensin II seems to be the causative reason of hypoaldosteronism. The exact mechanism of undetectable renin activity in these patients remains unknown.