In the hours after the 9/11 attacks, New York City hospitals and blood banks filled with willing donors hoping to be of use on a helpless day. Primum Non Nocere, director James Reynolds's starchy but persuasive argument doc about the dubious merits of blood transfusions, suggests that impulse is a measure of the blood industry's success. A working history of the transfusion--beginning with its emergency inception on the battlefields of World War I--gives way to a poorly organized critique of the culture of authority that gathers around "breakthrough" medical practices and the dearth of scientific research into the repercussions of a now-entrenched protocol. An international assortment of nay-saying doctors testify to camera; amid the wonky talk about hematocrits and hemoglobin one sentiment makes itself most plain: "Laypeople think we know exactly what we're doing." Reynolds's point is that they don't, especially when it comes to infusing one human being with another's blood. Scattered construction--an unceasing onslaught of information is broken up by random B-roll footage; discontinuous anecdotes compete with alarmist cable-news packaging--reflects rather than clarifies the issue's complications. Clearly designed to wake up the whole red-blooded world, Primum Non Nocere plays like an underground video for radical med students.