Abstract and Introduction
Abstract
Background: Many therapies used in critical care cause potassium depletion. Current practice relies on potassium replacement protocols after a patient becomes hypokalemic. Potassium bolus therapy creates risk for patients, is costly, and increases nurses' workload.
Objectives: To determine if administering potassium preemptively in maintenance intravenous fluid would prevent episodes of hypokalemia and reduce the need for potassium boluses.
Methods: Medical records of 267 patients with normal potassium and creatinine levels at admission who did not receive total parenteral nutrition were reviewed. The 156 patients who met the study criteria were categorized by group: those who received potassium via maintenance intravenous fluid (treatment; n = 76) and those who did not (control; n = 80). The treatment group had potassium chloride or acetate added to intravenous fluid delivered at 36 to 72 mmol/d.
Results: The 2 groups did not differ significantly in age, race, sex, or admitting diagnosis. Type of diagnosis, length of stay, and potassium and creatinine levels at admission did not affect the number of potassium boluses for either group. The patients given maintenance potassium preemptively received significantly fewer (P< .001) potassium boluses (0.8) than did the control group (2.73), for a mean savings of $231 per patient for the treatment group.
Conclusions: Patients with normal potassium and creatinine levels at admission benefitted from a maintenance intravenous dose of potassium of 72 to 144 mmol/L per day. Compared with control patients, patients receiving this dose avoided detrimental hypokalemic events, had fewer invasive procedures and lower costs, and required less nursing care. (American Journal of Critical Care.2014;23:145–149)
Introduction
Potassium is a major intracellular cation critical for many body functions, including maintenance of acid-base balance, osmotic stability of cells, growth, energy production, glucose metabolism, conduction of nerve impulses, and the function of skeletal and smooth muscle. Patients with acute or chronic critical illness are particularly susceptible to potassium loss. Conditions that promote potassium loss in critically ill patients include the response to stress, treatment with mechanical ventilation, hypertension, diarrhea, alcohol withdrawal, and gastric draining or gavage.
Many medications used in critical care promote potassium loss, such as antibiotics with high anion content, antifungal agents, insulin, corticosteroids, diuretics, ®2-agonists, and epinephrine. Hypo - kalemia is often associated with hypomagnesemia, which is also common in critically ill patients.
Normally serum potassium levels fluctuate between 3.5 and 5 mmol/L. Persons with insufficient serum levels of this electrolyte may be asymptomatic but are still prone to less than optimal metabolic function. Signs and symptoms of hypokalemia usually appear as the serum potassium level decreases to less than 3 mmol/L. These indications include nausea, vomiting, weakness, constipation, respiratory compromise, and arrhythmia. In instances of marked potassium loss, paralysis, rhabdomyolysis, myocardial infarction, and sudden death can occur. Hypokalemia has also been associated with difficulty in weaning from mechanical ventilation and subsequently can cause an increase in length of stay in the intensive care unit (ICU) and the hospital.