TEAM C SURVIVAL GUIDE: Answer to Question #6

6.       Baby girl Smith is a 7 day old with a K of 2.6 and weighs 3kg.  She is getting TPN w/ D15 P3 @ 10cc/h and F3 @ 2cc/h w/20meq/L of KCL.  Her urine output has been roughly 4 cc/kg/h with a recent Cr of 0.4.  How many meq/kg/day of KCl is she currently getting? Double the KCl in her TPN.  What will be the new meq/kg/day with the new regimen?  How much KCl in meq/l should you order if you want to give 5meq/kg/day?  

Potassium (K) is in the TPN bag containing dextrose and protein. This bag is running at 10cc/h = 240cc/d. The K is standard at 20meq/L. 
If we increase the K to 40meq/L

40meq     =         x  
  1000cc            240cc

Solving for x, x = 9.6 meq/d of K

Divide by wt of 3kg gives 3.2meq/kg/d

If we want to give 5meq/kg/d of KCl, 

5 meq/kg/d x 3kg = 15meq/d

15meq      =          x  
       240cc              1000cc

x = ~60meq/L

You’d better call the NICU attending to get this approved before 1pm!