Prehospital locoregional anesthesia: a case series

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).

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.

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.

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.