Evaluation of the safety and efficacy of topical nitroglycerin ointment to facilitate venous cannulation.

The purpose of this study was to determine the safety and efficacy of 2% nitroglycerin ointment to facilitate venous cannulation. In a double-blind experimental design, 80 adult subjects were randomly assigned to receive a 2% nitroglycerin ointment or a placebo ointment prior to cannulation. Variables measured before and after ointment application included heart rate, electrocardiogram, vein size, and presence of headache. No statistically significant differences were found in vein size or adverse effects following nitroglycerin ointment application.