CVC's and # of Lumens

I work on a very busy unit where nearly all of our patients' meds are IV and literally everyone has a central line.

I've seen CVC's with 2-5 lumens.

It's not uncommon for this to be a typical med list for a shift:

TPN
PCA pump
Insulin drip
IV cellcept and prograf (over 2 hrs each)
maintenance fluids
IV vanco
IV zosyn
IV anidulafungin
IV acyclovir
IV protonix
IV zofran
IV reglan
IV ganciclovir
IV lopressor/hydralazine/dopamine/something for their BP be it high or low
Plus multiple blood/platlet transfusions throughout the shift...

It makes me think there's a special place in hell reserved for docs who give out patients double lumen CVCs- especially if they have pre-existing conditions coming into the transplant. It sometimes has me deciding if I should transfuse them for their 7.0 hgb or give their immunosuppresans on time. They usually end up getting a double lumen PICC later on in the game (when they're generally less stable and we're realizing we don't have nearly enough access) when they only have a double lumen CVC.

So here's my question. I can't find anything suggesting benefits of double lumen over triple lumen. Why would they even think of just doing a double lumen? Are triple lumens riskier?