Why sodium hydrochloride rather than LRS?

[allie and newkitty]

I just noticed the bag the vet gave me for Newkitty's CRF treatment says Sodium Hydrochloride, rather Lactated Ringer's Solution. We have gotten LRS before (admittedly, not for kidney issues) What is the difference?

 

[Lisa and Merlyn (GA)]

some fluid info from Tanyas site
http://www.felinecrf.org/fluid_therapy.htm