CORRECTION to "Arterial lines for shock: harms exceed benefits (EVERDAC trial)"
Tartrate, schmartrate
The post below overstated (doubled) the norepinephrine threshold dose at which patients were permitted to cross over and receive arterial catheters for continuous blood pressure monitoring.
It stated that patients could cross over when their dose exceeded 2.5 mcg/kg/min of norepinephrine tartrate or epinephrine. This is technically correct, but in the U.S., norepinephrine doses are expressed as the base equivalents (half the tartrate dose).
Arterial lines for shock: harms exceed benefits (EVERDAC trial)
Continuous measurement of blood pressure by arterial catheters has been a cornerstone of shock management since the birth of critical care. Directed by clinical guidelines and generations of tradition, clinicians insert arterial lines into millions of patients each year in ICUs around the world.
To clarify:
In EVERDAC, patients could cross over to receive arterial lines when they received >1.25 mcg/kg/min of norepinephrine base (2.5 mcg/kg/min of the tartrate form).
By U.S. dosing conventions, this corresponds to 87.5 mcg/min for a 70 kg person or 125 mcg/min for a 100 kg person.
In the U.S., norepinephrine is produced and packaged as the tartrate (salt), but the dose is expressed as base equivalents, which are half the tartrate dose.
In France, norepinephrine doses are commonly expressed as the tartrate dose (twice the weight as the base), and the French authors used this convention in the protocol and paper.
The post has been corrected. Hat tip to Steve Rappaport for flagging this.
Great catch! Never knew this.