Hypokalemia in a pediatric intensive care unit

Abstract

Objective: To examine the frequency, severity, risk factors and mortality of hypokalemia, and efficacy of therapy used for its correction.

Design: Descriptive, retrospective analysis.

Sample: 290 patient records admitted consecutively to a Pediatric Intensive Care Unit (PICU) over a period of one year.

Results: Forty three (14.8%) patients had 54 episodes of hypokalemia. Predisposing factors included the nature of primary disease (renal disease 19%, septicemia 19%, acute diarrhea 14%, heart disease with congestive failure, and meningoencephalitis 12% each), malnutrition (weight for age less than 80% in 72%) and therapy with drugs (diuretics, corticosteroids and antiasthma drugs). For correction of hpokalemia all the patients received 4-6 mEq potassium per 100 ml of intravenous fluids (slow correction). Seven patients (9 episodes), with ECG changes of hpokalemia, also received infusion of 0.3 mEq potassium/kg/hour till ECG became normal (rapid correction). Normal potassium level was achieved in all nine episodes where rapid correction was given, and in 40 of 45 episodes which received slow correction. The overall mortality among patients with hypokalemia (25.6%, 11/43) was significantly higher than that among the remaining PICU patients (10.9%, 27/247; odd's ratio 2.34; 95% confidence interval 1.3-4.2) (p < 0.05). All the patients receiving rapid correction survived.

Conclusions: Hypokalemia is a common problem among PICU patients. Early detection through regular monitoring and rapid correction may help in improving the outcome.

PIP: Data were analyzed on 290 children admitted consecutively to the pediatric intensive care unit (PICU) of the Postgraduate Institute of Medical Education and Research in Chandigarh, India, in 1993 to examine the frequency, severity, risk factors, and mortality of hypokalemia (3.5 mEq/l serum potassium) and the efficacy of treatment. 43 (14.8%) children had 54 episodes of hypokalemia. Most (68.6%) episodes were moderate. Predisposing factors were the nature of primary disease (renal disease 19%, septicemia 19%, acute diarrhea 14%, and heart disease with congestive failure and meningoencephalitis 12% each), malnutrition (weight for age 80% in 72%), and treatment with drugs (diuretics 20%, beta-agonists 13%, and corticosteroids 11%). Diagnoses most common in hypokalemia cases were acute renal failure (25%), septicemia (22.8%), and acute severe bronchial asthma (20%). The most important predisposing factor for hypokalemia prior to hospitalization was poor oral intake (i.e., inability to replace adequate potassium) (27%). All 43 children received 4-6 mEq potassium/100 ml of intravenous fluids. Clinicians administered an infusion of 0.3 mEq potassium/kg/hour to 7 children (9 episodes) who had ECG changes of hypokalemia until the ECG became normal. Potassium levels returned to normal in all 9 episodes requiring rapid correction and in 40 of 45 episodes requiring slow correction. PICU patients with hypokalemia were more likely to die than PICU patients with no hypokalemia (25.6% vs. 10.9%; p 0.05; odds ratio = 2.34). Hypokalemia patients who received slow correction therapy were more likely to die than those who received rapid correction therapy (31% vs 0; p 0.05). Mortality was lower in PICU patients whose hypokalemia was corrected than in PICU patients whose hypokalemia was not corrected (13.5% vs. 100%; p 0.05). Based on these findings, regular monitoring and rapid correction are recommended to improve the outcome of hypokalemia.