Prehospital locoregional anesthesia: a case series.

Background: Standard prehospital pain management relies on opioids, which involved avoidable risks. Few studies have evaluated pre-hospital locoregional anesthesia (LRA), especially fascia iliaca compartment blocks (FICB) and femoral nerve blocks (FB). We aimed to analyze the safety and opioid sparing potential of LRA in a Swiss alpine Helicopter Emergency Medical Service (HEMS).

Methods: Retrospective analysis over 36 months. Variables recorded included type of block, ultrasound guidance, provider training, injury mechanism, diagnosis, patient data, on site time, pain scores evolution, complementary medication before/after LRA and complications. Descriptive statistics and non-parametric test were used.

Results: Twenty-eight procedures were performed (0.26% of all missions): 25 FICB (89.3%) and 3 FB (10.7%). Ultrasound was used in 21.4% of cases (12% of FICBs, 100% of FBs). Ski accidents accounted for 64,3% and femoral diaphyseal fracture was suspected in 82,1%. Eight missions required hoisting, one terrestrial evacuation. Sixty percent 60.0% of blocs were performed by non-anesthesiologist. Only lidocaine 1% was used. Time on site was similar with or without ultrasound (p = 0.25). Pain score documentation (NRS) was incomplete in 50% but scores significantly decreased after LRA (p < 0.001). The need for complementary analgesic and or sedative was reduced (p = 0.025). Fentanyl use significantly decreased (p = 0.028), midazolam and ketamine did not (p = 0.16 and 0.56). No complications were documented.

Conclusions: LRA appears effective and safe in prehospital (alpine) settings, providing substantial pain relief and reducing fentanyl use. Further studies are needed to investigate whether LRA protocols could reduce opioid-related morbidity and mortality.