What is the most significant reason for starting intravenous infusions in the upper extremities of adults?

Starting intravenous infusions in the upper extremities of adults is often preferred because a decreased flow rate in an infusion can potentially lead to complications such as thrombosis in the cannulated vein. When an intravenous line is placed in a location where blood flow is lower or where movement can cause kinking of the catheter, the risk of clot formation increases. The upper extremities, particularly the forearm and hand, typically have better veins that are more superficial and allow for a more stable and straightforward infusion. This helps maintain an adequate flow rate, reducing the chances of thrombosis compared to areas such as the feet or ankles, where blood flow dynamics may not support optimal infusion rates.