Background: Pediatric radial artery cannulation is challenging because of the small vessel size. Nitroglycerin is a potent vasodilator and facilitates radial artery cannulation by increasing the internal diameter and preventing the vasospasm in adult patients. The authors hypothesize that subcutaneous nitroglycerin injection will improve the success rate of pediatric radial artery cannulation.
Methods: This double-blind, randomized, controlled, single-center study enrolled pediatric patients (n = 113, age less than 2 yr) requiring radial artery cannulation during general anesthesia. The participants were randomized into the nitroglycerin group (n = 57) or control group (n = 56). After inducing general anesthesia, nitroglycerin solution (5 μg/kg in 0.5 ml), or normal saline (0.5 ml) was subcutaneously injected above the chosen radial artery over 10 s with ultrasound guidance. Three minutes later, the ultrasound-guided radial artery cannulation was performed. Radial artery diameter was measured before and after the subcutaneous injection and after cannulation. The primary outcome was the first-attempt successful cannulation rate. The secondary outcomes included the diameter of the radial artery and the overall complication rate including hematoma and vasospasm.
Results: A total of 113 children were included in the analysis. The nitroglycerin group had a higher first-attempt success rate than the control group (91.2% [52 of 57] vs. 66.1% [37 of 56]; P = 0.002; odds ratio, 5.3; 95% CI, 1.83 to 15.6; absolute risk reduction, -25.2%; 95% CI, -39.6 to -10.7%). Subcutaneous nitroglycerin injection increased the diameter of the radial artery greater than normal saline (25.0 ± 19.5% vs. 1.9 ± 13.1%; 95% CI of mean difference, 16.9 to 29.3%; P < 0.001). Overall complication rate was lower in the nitroglycerin group than in the control group (3.5% [2 of 57] vs. 31.2% [18 of 56]; P = 0.001; odds ratio, 0.077; 95% CI, 0.017 to 0.350; absolute risk reduction, 28.6%; 95% CI, 15.5 to 41.8%).
Conclusions: Subcutaneous nitroglycerin injection before radial artery cannulation improved the first-attempt success rate and reduced the overall complication rates in pediatric patients.