Fresh fill consists of how much saline through arterial line and how much through venous line?

• A. 50 mL arterial and 250 mL venous
• B. 100 mL arterial and 200 mL venous
• C. 10 mL arterial and 290 mL venous
• D. 200 mL arterial and 50 mL venous

Answer: (A)

Fresh fill primes the dialysis circuit with saline to expel air and fill the lines before starting therapy. The arterial line is primed with a smaller amount and the venous line with most of the saline, so the entire circuit becomes air-free and ready for blood flow. The standard distribution is 50 mL through the arterial line and 250 mL through the venous line, totaling 300 mL to ensure complete filling of the circuit. This minimizes the risk of air entering the patient and helps ensure smooth initiation of dialysis. The other options either under- or over-prime one limb and do not provide the typical, safe balance used for fresh fill.