Loss of nitroglycerin during passage through two different infusion sets

The loss of nitroglycerin (GTN) during passage through a polyvinyl chloride (PVC) or polyethylene (PE) infusion set was investigated. The GTN concentration had no influence on the GTN loss in the PVC set. The study confirmed reports in the literature that the greatest loss of GTN occurs at the slowest rate of infusion. Interestingly, the lowest concentration of GTN is seen when the volume equivalent to the capacity of the infusion set has passed through the set. When we simulated the procedure recommended by the health authorities in Norway and Sweden, we observed a loss of up to 70% during infusion through the PVC set in the first 30 minutes, which decreased to 30% over the next seven hours. The loss from the PE set did not exceed 15% over eight hours.