We are trying to restructure our procedure to utilize Rh positive blood in emergent situations, or situations where there is no confirmation type performed. In so doing, there comes into play the whole anti-D prophylaxis issue. What would be the time frame to determine the amount of Anti-D to administer. Immediately after receiving the dosage of positive blood, 24 hours post when the blood had equilibrated, two hours after, any help would be useful. With the blood supply being at an all time low and the negative units of all blood types being effected, we were trying to establish guidelines for our generalist to utilize, Thanks.