Lactated Ringer in the line

LR is a roughly isotonic solution with potassium, calcium, lactate, and reduced amounts of sodium and chloride compared with normal saline.

The calcium can bind with drugs such as amphotericin and ampicillin and thus may reduce drug effectiveness.

  

" Calcium may also bind citrated anticoagulant in blood products causing clot formation in the donor "
This statement is a MYTH..Many papers came out challenge this..
It is safe to mix LR with PRBCs..it is proven.(1)

In healthy subjects, a liter of LR over one hour does not raise serum lactate levels. In critically ill patients, lactate clearance may be impaired but it is generally thought that LR has minimal impact on serum lactate levels. One reason is that only a quarter of the volume of crystalloid remains in the vasculature.

As a precaution, lactate measurements for patients receiving intravenous LR should be interpreted with attention to the site of the blood draw; the sample should be obtained from sites other than the infusion site.

(1)Ringer's lactate is compatible with the rapid infusion of AS-3 preserved packed red blood cells.Can J Anaesth. 2009 May;56(5):352-6. Epub 2009 Apr 2.