According to a Kleihauer-Betke stain indicating a fetomaternal hemorrhage of 35 mL, how many vials of Rh immune globulin are required?

To determine the number of vials of Rh immune globulin required after a fetomaternal hemorrhage of 35 mL, it's essential to understand the standard dosing guidelines for Rh immune globulin (RhIg).

Rh immune globulin is typically administered to Rh-negative individuals who have been sensitized to Rh-positive blood, often due to fetomaternal hemorrhage. The standard dose of RhIg provides coverage for up to 30 mL of Rh-positive red blood cells.

In the case of a hemorrhage of 35 mL, the calculation involves dividing the total volume of fetal blood by the amount that one vial can cover. Since one vial covers 30 mL, a fetomaternal hemorrhage of 35 mL would require the equivalent of at least one full vial for the first 30 mL. The additional 5 mL requires a portion of an additional vial. In practice, since doses are administered in whole vials, clinicians would round up when determining how many vials to provide.

Therefore, for a hemorrhage involving 35 mL, 2 vials of Rh immune globulin would adequately cover the amount required to counteract the potential sensitization due to the excess fetal blood volume.