Why does the NRP state the dosage of epinephrine as mL/kg instead of mg/kg?
Dosing epinephrine in the newborn presents unique patient safety risks. Epinephrine is very infrequently used during neonatal resuscitation and many health providers have little experience preparing or administering epinephrine in an emergency. Epinephrine is used only in acute situations that are often not predicted or fully anticipated. Effectively mitigating these potential safety risks remains a high priority for the NRP. The safest method for describing how to correctly prepare and administer epinephrine was discussed at length by the Neonatal Resuscitation Program Steering Committee, its consultants, liaisons, and the textbook editorial team as the 7th edition materials were drafted.
After extensive discussion, the NRP Steering Committee felt that volumetric dosing with a single specified epinephrine concentration would result in the lowest risk of a dosing error. Indeed, volumetric dosing is a very familiar method for neonatal and pediatric health providers and has been used in all previous editions of the NRP textbook. If the dose of epinephrine is ordered as milligrams/kg, the provider would be required to convert the requested dose to a volume for preparation and administration because syringes are marked in milliliters rather than milligrams. To limit the number of calculations and conversions, the dose is described primarily as mL/kg so that providers do not have to convert milligrams to milliliters during an emergency and risk making a decimal point error. While it may be ideal if all hospitals had resuscitation software that would automatically perform any needed calculations, this is uncommon at the present time.
In the textbook, it is clearly and repeatedly stated that only the 0.1 mg/mL concentration of epinephrine (formerly known as 1:10,000 epinephrine) should be used for neonatal resuscitation. For clarity, we felt that it was important to describe the correct concentration of epinephrine using both the older ratio designation (1:10,000) and the current metric designation (0.1 mg/mL) in the 7th edition of the textbook because many units still have vials of epinephrine with the previous ratio labeling, and this nomenclature is well known by the overwhelming majority of providers. We anticipate that the next edition of the textbook will include only the metric description of the drug concentration.
As we plan future editions of the NRP educational materials, we will continue to consider alternate methods of describing the dosage of medications and will evaluate any available patient safety evidence relevant to this important area.