Background: Local anesthetic (LA) concentration and nerve block duration is sparsely described in a heterogenic study mass. Aim: To investigate the effect of LA concentration on peripheral nerve block duration in healthy volunteers. Methods: Randomization of 60 healthy volunteers who will receive 1 of 5 different volumes of LA (ropivacaine) using a constant dose. Primary endpoint: Sensory nerve block defined by insensitivity towards cold.
Inclusion criteria 1. Male or female from and above 18 years of age 2. ASA classification ≤ II Exclusion criteria 1. BMI below 18 kg/m2 2. Former surgery to the lower extremity in which intervention is planned and surgery which may have caused neural damage to the common peroneal nerve/affected the sensory distribution area of the common peroneal nerve 3. Peripheral nerve disease 4. Allergy to LA 5. Pregnancy or breastfeeding 6. Enrolment in other investigational drug studies or recent clinical trials that may interfere with this study 7. Habitual use of any kind of analgesic treatment 8. Anatomic abnormalities preventing successful US-guided peripheral nerve catheter insertion