Subcutaneous Nitroglycerin to Prevent Radial Artery Occlusion in Pediatric Patients: A Randomized Clinical Trial.

Importance: Pediatric patients are at an increased risk of postprocedural radial artery occlusion (RAO) owing to their small vessels and high tendency for vasospasm after catheterization. Although subcutaneous nitroglycerin increases the success rate of radial artery catheterization by vasodilation and preventing vasospasm, its effect on RAO prevention after catheter removal remains unknown. Objective: To evaluate the efficacy and safety of subcutaneous nitroglycerin for RAO prevention. Design, Setting, and Participants: This double-blind randomized clinical trial was conducted at a single tertiary center and included pediatric patients younger than 3 years who required radial artery catheterization during general anesthesia. Study data were analyzed from April to July 2025. Interventions: Patients were randomized to receive either subcutaneous nitroglycerin (5 μg/kg/0.5 mL) or normal saline (0.5 mL) above the chosen radial artery before radial arterial catheterization and catheter removal under ultrasound guidance. Main Outcomes and Measures: The primary outcome was the RAO incidence after catheter removal, assessed using the reverse Barbeau test with pulse oximetry on the ipsilateral index finger. Results: A total of 200 pediatric patients were initially enrolled, but 68 were excluded for protocol violations. In the per-protocol analysis with 132 participants (median [IQR] age, 5.5 [2.0-16.6] months; 73 female [55.3%]), RAO incidence was lower in the nitroglycerin group than in the control group (25.4% [17 of 67] vs 73.8% [48 of 65]; P < .001; odds ratio [OR], 0.12; 95% CI, 0.06-0.26; absolute risk reduction, 48.5%; 95% CI, 33.6%-63.4%). After catheter removal, the nitroglycerin group showed higher peak blood flow velocity (mean [SD], 13.0 [11.0] cm/s vs 7.4 [9.2] cm/s; 95% CI for mean difference, 2.1-9.1 cm/s; P = .002) and perfusion index (mean [SD], 1.37 [1.09] vs 0.65 [0.49]; 95% CI for mean difference, 0.43-1.01; P < .001) of the radial artery than did the control group. There was no significant intergroup difference in RAO duration. There was no hypotension or localized adverse effects. Conclusions and Relevance: Subcutaneous nitroglycerin injection before radial artery catheterization and catheter removal significantly reduced the incidence of RAO after catheter removal and may promote safe recovery in pediatric patients younger than 3 years. Trial Registration: ClinicalTrials.gov Identifier: NCT05443061.