 Important factors for a safe and successful nerve block include volume, dose and concentration of local anesthetic LA. Knowing the duration of peripheral nerve blocks is important to prevent pain breakthrough. With the advancements in ultrasound US-guided nerve block techniques it has been possible to substantially reduce the amount of LA required to perform a successful nerve block. This has reduced the risk of systemic toxicity. However, lowering LA volume may reduce nerve block duration, but the extent of this is sparsely described in a heterogenic study mass. 