Extraction of Nitroglycerin by a Membrane Oxygenator

This study examined the extraction efficiency of a membrane oxygenator for nitroglycerin (NTG). An In-Vitro cardiopulmonary bypass circuit was constructed to mimic clinical conditions. A NTG solution (150 ng/ml) was placed into the circuit via a glass cardiotomy reservoir and circulated at 5 Ll min for 60 min. Analysis of NTG samples obtained during the study showed that the oxygenator initially extracted 70% of drug entering the device. A small increase in drug concentration was observed for the first 10 min, followed by a continual decrease. By 60 min only 20% of the original drug concentration remained. We conclude that the membrane oxygenator used during cardiopulmonary bypass is capable of substantially extracting NTG.