Complete the RhoGAM dose calculation for an Rh-negative postpartum client with a quantified exposure of 22 mL Rh-positive red blood cells.
Drop-down Cloze
Choose your responses, then check the answer.
Explanation
At 20 mcg per 1 mL, 22 mL requires 440 mcg. Because 1 syringe contains 300 mcg and the label directs rounding up to a whole syringe, prepare 2 syringes for an authorized total of 600 mcg within 72 hours.
Quick answer Calculate 440 mcg, then round up to 2 whole 300-mcg syringes.
Why this is correct Use the labeled calculation: 22 mL times 20 mcg per 1 mL equals 440 mcg. 1 syringe is insufficient, so 440 divided by 300 is rounded up to 2 syringes.
Easy analogy or mental picture If the calculated load exceeds 1 container, the remaining partial amount still requires 1 whole prepared syringe.
Memory hook mL RBC times 20 mcg; divide by 300 and round up.
NCLEX decision rule Use the measured Rh-positive red-cell volume, preserve units through the calculation, and round only at the final 1-syringe step.
Why the other choices are wrong Rounding down leaves part of the exposure uncovered, and using fetal whole-blood volume instead of the reported red-cell volume changes the calculation.
References
1DailyMed: RhoGAM Ultra-Filtered PLUSTwenty micrograms per mL of Rh-positive red cells and rounding up to whole syringes
Rh immune globulin calculationConfirm maternal and newborn Rh status, quantified red-cell exposure, mcg per 1 mL, syringe strength, rounding rule, route, and timing.