Fatal air embolism in an extremely low birth weight infant: can it be caused by intravenous injections during resuscitation?

Objective: A preterm infant with a birth weight of 384 g who succumbed to vigorous resuscitation for sudden respiratory failure on the third day of life is presented. Postmortem examination revealed, apart from extensive pulmonary hemorrhage, a fatal amount of air mainly in the right ventricle. We believe that this air had been introduced via peripheral venous cannulas due to inadvertent and unavoidable air admixture to each injection volume administered with a syringe, and we develop an experimental model to confirm that fatal amounts of air can indeed accumulate with frequent change over of syringes within a short period of time. Design: An empty 50-ml syringe was connected to a 15-cm-long connection line via a three-way tap. With a I ml syringe 100 doses of 0.5 ml aqua were injected into the connection line. The amount of air which had collected in the 50 ml syringe after the 100 injection cycles was measured. This process was repeated three times each by three of the authors and the average air volume introduced with 100 injections calculated for each investigator. Results: The average amounts of air which had entered the closed system after 100 acts of syringe assembly and aqua administration were 1.84, 1.95, and 2.0 ml. This corresponds to an average volume of almost 0.02 ml per injection.