Objective: To document the incidence of medication errors related to medications administered by continuous infusion.
Design: Observational study.
Setting: Sixteen-bed surgical intensive care unit.
Measurements and main results: All continuous infusions in the surgical intensive care unit were evaluated at least once daily for correct flow-sheet charting, concentration, infusion rate, and dose administered, as well as patients' heights and weights (actual, ideal, and "dry"). Collected information was examined to determine the error rate, types of errors occurring, and weight used for dose calculation. Variations inpatient weight measures were compared. Seventy-one patients with 202 total infusions were observed. Errors involving continuously infused medications in our surgical intensive care unit occurred at a rate of 105.9 per 1,000 patient days. For nonweight-based infusions, 94% of doses were delivered correctly. Slightly >10% of the doses administered for weight-based infusions (dose based on dry body weight) were incorrect. Significant differences were found between the weight measurements recorded, but this did not translate into statistically significant differences in the apparent calculated doses delivered.
Conclusions: Medications delivered by continuous infusion, particularly those that are weight based, can contribute to medication errors in the intensive care unit. A large proportion (87.6%) of doses for weight-based infusions was calculated based on estimated or unreliable admission weights. There were no severe consequences resulting from the errors observed in this 1 month investigation; however, depending on the pharmacokinetic characteristics of the drug being administered, there is a potential to deliver artificially low or high doses resulting in subtherapeutic or adverse effects.