Hypokalemia and hyperkalemia in patients on peritoneal dialysis: incidence and associated factors.

BACKGROUND: Hypokalemia is a well-described electrolyte disturbance in patients on peritoneal dialysis (PD). Hyperkalemia, however, is still overlooked, although it also represents a risk factor for mortality. Angiotensin-converting enzyme inhibitors and/or angiotensin receptor blockers (ACE/ARB), diuretics, and proton pump inhibitor (PPI) can interfere with potassium levels in these patients. METHODS: This is a retrospective study that evaluated monthly serum potassium in a 5-year period. Serum potassium disturbances were evaluated as time-average and number of hypo- and hyperkalemia episodes per patient. Prescribed medication such as ACE/ARB, diuretics, and omeprazole were recorded. RESULTS: We evaluated 2025 potassium measurements obtained from 146 patients on PD. Serum potassium ranged from 2.5 to 8.3 mEq/L with an average of 4.72 ± 0.74 mEq/L. Hypokalemia was found in 59 measurements (2.9%) obtained from 35 patients (23.9%) whereas hyperkalemia was demonstrated in 269 (13.3%) measurements obtained from 74 patients (50.7%). Hypokalemia was associated with low albumin (p = 0.022), and omeprazole use (p = 0.024). Black race was a protector factor (p = 0.031). Omeprazole-associated hypokalemia was seen only in non-anuric patients and remained an independent risk factor even after adjustments. Patients who had hyperkalemia were more likely to be anuric (p = 0.001) and in use of furosemide (p = 0.0001). CONCLUSION: Hyperkalemia and hypokalemia are very frequent in patients on PD and should be closely monitored. Interventional studies should address the impact of discontinuing omeprazole in the levels of potassium.

Long-term outcome and prognostic indicators in the hemolytic-uremic syndrome.

We examined 61 patients an average of 9.6 years (range 5 to 18 years) after an episode of childhood hemolytic-uremic syndrome. Twenty-four (39%) had one or more abnormalities. Seven (11%) had proteinuria and six (10%) had low creatinine clearance as solitary abnormalities. Eight (13%) had both proteinuria and reduced creatinine clearance; three (5%) had a combination of hypertension, proteinuria, and low creatinine clearance. Abnormalities sometimes appeared after an interval of apparent recovery. Logistic regression analysis showed that duration of anuria was the best predictor of disease at follow-up. No patients who had anuria lasting longer than 8 days or oliguria exceeding 15 days escaped chronic disease. However, 45% of those with disease had no anuria, and a third had no oliguria. Physicians should therefore be cautious in assuming recovery from HUS on the basis of a single evaluation and should periodically evaluate patients for an extended period.

Paradoxical behavior of serum digoxin concentrations in an anuric neonate.

Serum digoxin values were determined in a newborn infant with severe heart failure and renal failure. The half-life of digoxin in the serum appeared to change, possibly the result of prolonged distribution and/or absorption owing to circulatory insufficiency, or to the accumulation of cross-reacting metabolites of digoxin in the serum. No clinical toxicity was apparent, and no cardiac arrhythmia was observed. The need for monitoring serum digoxin concentration and clinical effect in newborn infants is emphasized.