Careful conversions

Nurse Practitioner, Apr 2000 by Cohen, Hedy, Cohen, Michael R

An order was written for an intensive care unit patient to receive fentanyl, 12.5 to 25 micrograms, LV q 4 to 6 hours as needed for pain. The unit had 5 ml ampuls of fentanyl 0.05 mg/ml (a total of 0.25 mg or 250 micrograms) available. When preparing the dose, a nurse mentally confused the volume of drug needed when she converted from milligram to microgram. She gave all 5 ml of the ampul for a 25 microgram dose instead of 0.5 ml. The patient had a respiratory arrest but was successfully resuscitated.

This potent narcotic invites preparation errors of decimal point misplacement when converting between milligram amounts on the label and microgram amounts used in dosing. Morphine LV, which does not have this characteristic, can usually provide adequate pain relief in an intensive care unit setting and should be considered the preferred opiate for intermittent dosing. If fentanyl must be used, staff can easily design dosing charts to reduce conversion confusion. Otherwise, for nonanesthesia use, protocols should guide the use of fentanyl, such as with patient-controlled analgesia. Nonanesthesia doses are best prepared in the pharmacy and not on patient-care units.