The failure rate of peripheral intravenous catheterization is higher in older adults than in younger adults. Safe peripheral intravenous catheterization requires the veins to be fully dilated to improve palpation. Heat application has been empirically recognized as an effective venous dilation technique. However, evidence is lacking regarding the venous dilation effect of heat application in older adults with degenerated venous walls and impaired endothelial function due to aging. This study aimed to verify the venous dilation effect of heat application before tourniquet use in comparison with tourniquet application in hospitalized older adults (n = 88; mean age: 79.3 ± 8.1 years). Participants underwent 2 conditions on the same day in sequence: the control condition (using a tourniquet) and the heat application condition (applying a hot pack at 40 ± 2 °C for 7 minutes followed by tourniquet use). Measurements pre- and post-intervention included venous diameter, depth, and assessment scores (palpability and visibility). Heat application significantly increased venous diameter, reduced depth, and improved palpability and visibility compared to the control. Additionally, venous palpability improved with heat application in half of the patients whose veins were not palpable after tourniquet application alone. Therefore, heat application is recommended to assess the suitable veins for catheterization in older adults.

Yasuda K, Shishido I, Matsuno C, Yano R. Heat Application to Improve Venous Dilation for Peripheral Intravenous Catheterization in Older Adults: A Quasi-Experimental Study. J Infus Nurs. 2025 May-Jun 01;48(3):181-190. doi: 10.1097/NAN.0000000000000585. Epub 2025 Apr 29. PMID: 40327875.