The purpose of this paper is to point out the potential danger of an air embolus to the donor when a vacuum type bottle is used for blood collection purposes and, further, to present two simple methods by which this hazard may be avoided.
Examination of the literature discloses several reported instances of fatal and nonfatal air embolisms which have occurred during the collection of blood. Some of these instances were in cases in which positive pressure was produced in the collecting bottle by means of a faulty pump,1 a reverse syringe,2 blocked escape vents3 or the like. In most of the cases cited a positive pressure was created in the collecting bottle, and on the release of the tourniquet varying quantities of air were injected into the vein of the donor. Fortunately the quantity of air necessary to produce death in man is usually considerable, frequently