Heparin gtt with compatible IV fluid

[gnv26]

Hello all! I have a question about drips/compatibility.  I had a patient on a heparin drip.  The patient was a very hard stick, only one PIV.  Prior to initiating the heparin drip, he was only receiving MIVF (NS).  Since NS and heparin are compatible (per pharmacy/resource), is it okay to y-site the heparin into the NS? (two separate pumps, of COURSE). There is no protocol stating that heparin needs to be run completely alone. It seems that this would be okay, but y-siteing the NS into the heparin would NOT be okay since that could result in bolusing the patient with the heparin between the y-site and the patient when first hooking up the NS.  Am I thinking about this correctly? Different nurses had different perspectives on this, so I would love to get some clarity!