Need for standardizing critical care drug infusions has never been greater

Problem: Several errors occurred with a norepinephrine infusion that was administered to a COVID-19 patient via a smart infusion pump positioned outside the patient’s room. The smart pump was set up with a standard administration set plus three attached extension sets, with tubing running from the pump, under the door, and to the patient. Before the event, a pharmacist responded to the patient’s intubation and assisted with medications from outside the patient’s room. The patient was hypotensive, so the   pharmacist prepared the standard norepinephrine infusion containing 4 mg/250 mL (16 mcg/mL) and applied a handwritten label to the bag.

The first two mistakes occurred when programming the initial norepinephrine infusion. The smart infusion pump asked the nurse to indicate whether the norepinephrine dosing was weight-based or not since both mcg/kg/minute and mcg/minute dosing were available for the medication. The nurse chose the weight-based dosing option and, thus, programmed the pump to deliver the infusion as mcg/kg/minute instead of the verbally prescribed infusion rate of mcg/minute. The nurse also mistakenly selected the maximum concentration in the library of 32 mg/250 mL (128 mcg/mL) instead of the prepared concentration of 4 mg/250 mL (16 mcg/mL). However, since the vasopressor was being titrated to effect for hypotension, neither programming error adversely affected the patient.

Soon afterwards, the patient’s physician entered the order for the norepinephrine infusion, selecting the more concentrated norepinephrine infusion (32 mg/250 mL) due to significant fluid restrictions in place for the patient. The pump was already erroneously programmed for that concentration, so the nurse continued it. Barcode scanning could not be used for the medication because the bag infusing had a handwritten label without a barcode. The pharmacy prepared a new bag containing 32 mg/250 mL, which was not hung at this time.

When the nurse for the next shift inspected the original infusion bag while switching to interoperability, the error was caught. The nurse consulted a pharmacist to see what the dose was in mcg/min, hung the new bag, corrected the pump, and changed the tubing.

Over the course of the patient’s stay, the patient was switched between the standard and more concentrated norepinephrine infusions several times. Multiple tubing changes occurred during the changes in concentrations, worsening the shortage of extension sets. The nurses suspected that they might have inadvertently administered some bolus doses to the patient, who experienced unexpected blood pressure changes. Also, with the low rate of infusion for the concentrated norepinephrine, nurses were not confident that the medication was reaching the patient given the volume left in the extension sets.   

Safe Practice Recommendations: The pharmacist who reported this event stated that programming errors with norepinephrine have happened previously (before the COVID-19 pandemic) since both mcg/kg/minute and mcg/minute are options for prescribing, as well as choices in the facility’s pump library. The organization is exploring standardizing to either weight-based (mcg/kg/minute) or non-weight-based (mcg/minute) dosing for norepinephrine to reduce the opportunities for error. The American Society of Health-System Pharmacists (ASHP) Standardize 4 Safety initiative recommends using mcg/kg/minute dosing units for norepinephrine.  

Also, instead of using new extension sets with each change in concentration, a better option during a shortage might have been to disconnect the existing extension tubing from the patient, flush it with the new concentration, and reattach it to the patient. However, the trade-off is an increased risk of infection with each disconnection and reconnection; thus, aseptic technique is paramount.