Friday, February 7, 2014

Norepinephrine(Levophed) usage in ME EMS protocol

From the ME EMS Protocols:

A. Preperation - Mix NOREPINephrine 8 mg in 250 ml NS. 

B. Dosing - Starting Dose is NOREPINephrine 0.03  μg(mcg)/kg/min. Titrate by 0.03 μg(mcg)/kg/min every 3-5 minutes. Usual dose is 0.03-0.25 μg(mcg)/kg/min. Usual max dose is 0.6 μg(mcg)/kg/min. Absolute max dose is 3 μg(mcg)/kg/min

C. Titrate to maintain SBP greater than 90 mm Hg.

For 2013 the Medical Direction and Practice Board decided to move away from Dopamine to Norepinephrine. I am no doctor (yet) but I'm guessing it has to do with some of these studies (2,3). 

 A subgroup analysis showed that dopamine, as compared with norepinephrine, was associated with an increased rate of death at 28 days among the 280 patients with cardiogenic shock but not among the 1044 patients with septic shock or the 263 with hypovolemic shock - Daniel De Backer, M.D., Ph.D., Patrick Biston, M.D., Jacques Devriendt, M.D.... for the SOAP II Investigators
 Medicine is called a practice for a reason. We are constantly learning, discovering, and fine tuning treatments, ideas, and methods. This literature is showing us that Norepinepherine could be a better choice in choosing a what drugs we use in our sickest of patients. So starting December 2013 these updates were released. By March of 2014 all services in Maine have to have IV pumps and provided the proper training and education. While I'm still an Advance I'm not getting that training but I like to harass medics so hopefully I'll know how to work them by then. When we had Dopamine paramedics had to be able to calculate the drip rate using a 60gtts drip set. Good skills to have and more then a few Medics still want to keep that and don't trust machines to do our work (rightfully so!). Being the terrible mathematician I am I had to sit down and work hard to learn the drip rate formula.

After searching the internet I finally found one I liked.

DD = Desired Dose

Wt = Weight
DS = Dolution Set
C = Concentration
T = Time

With Norepinephrine the starting dose is 0.03μg(mcg)/kg/Min. We're going to use my weight of 96kg and a 60gtts drip set. Our drug concentration is 8mg (which is 8000 in μg(mcg)) in 250ml which equals 32μg(mcg) per 1ml

Punching this into our equation we get:
 0.03μg(mcg)/kg x 96kg x 60gtts/ml
32μg(mcg)/ml x min

Did I mention this is a tiny amount? It is.

Cross out common factors:
0.03μg(mcg)/kg x 96kg x 60gtts/ml
32μg(mcg)/ml x min

0.03 x 96 x 60 = 172.8

173/32 =  5.4 ml/hr OR 5gtts/min

DD x Wt x DS
C x T

Easy right?

I'll be interested so see if this choice changes at all in the next couple years. The MDPB chooses everything, including dosages. A quick look shows that no one starts out with that dose of 0.03μg(mcg)/kg/min.

Most others I've seen mentioned in articles and forums say similar things. I have yet to find anything using 0.03. Ether way the MDPB spent time, energy, and brain power deciding on these. I would like to see it in the field. We'll see if it gets any action when it's up and running. Until then!

Does anyone else carry Levophed? Have you used it in the field and what were the results?