Clinical response to intravenous nitroglycerin infused through polyethylene or polyvinyl chloride tubing

The effects of polyethylene and polyvinyl chloride (PVC) administration sets on the clinical response to i.v. nitroglycerin were studied. Patients with ischemic heart disease were randomly assigned to receive nitroglycerin solution through either a polyethylene administration set or a PVC set. The rate of the infusion was 5-10 micrograms/min initially and was adjusted upward by 5-10 micrograms/min every 5-10 minutes until anginal symptoms were relieved or an adverse effect limited further increases. The data collected included patient demographics, the indication for nitroglycerin, nitroglycerin dosages, the initial dosage-adjustment time (the time necessary to reach the initial effective dosage), the number of dosage adjustments and the indications for them, the duration of the infusion, the time of tubing changes, the total dose of nitroglycerin, the amounts of sublingual nitroglycerin and i.v. morphine used, and the occurrence of various clinical events. There were 78 courses of therapy in the PVC group and 62 in the polyethylene group. The two groups were comparable in all respects except gender. There were no significant differences between the two groups in any of the primary study variables. Patients who received i.v. nitroglycerin through a PVC administration set had the same clinical response as patients given the drug through a polyethylene set.