Potassium added to maintenance intravenous
fluid is ordered by physicians as they determine the
need. For patients who received potassium in maintenance
intravenous fluid, the concentration was
40 mmol/L. Intravenous rates of 75 to 150 mL/h
would supply 72 to 144 mmol of potassium in 24
hours. The maintenance fluid for these patients was
either physiological saline or 5% dextrose in physiological
saline. Hypokalemic events were identified
by the data on administration of potassium boluses
as entered on the medication administration record.
A total of 267 records were reviewed, and 156
patients met the study criteria. Of these 76 received
potassium in their maintenance intravenous fluid
and 80 did not. A power analysis indicated that a
sample size of at least 35 patients per group was
needed to achieve a power of at least 80% for
detecting a difference in the number of potassium
replacement events at a = .05.