BACKGROUND AND OBJECTIVES: This study evaluated the efficacy of a single injection of 0.25% bupivacaine in the psoas compartment or inguinal paravascular for postoperative analgesia in patients undergoing orthopedic surgeries using a peripheral nerve stimulator. METHODS: One hundred patients who had a lumbar plexus block through the psoas compartment were compared to 100 patients who had an inguinal paravascular block, using a peripheral nerve stimulator, with 40 mL of 0.25% bupivacaine. The analgesia of the ilioinguinal, genitofemoral, lateral femoral cutaneous, femoral, and obturator nerves was assessed 4, 8, 12, 16, 20, and 24 hours after the end of the surgical procedure. Pain severity was also evaluated in the same period. The amount of opioids administered in the postoperative period was recorded. A radiological study with non-ionic contrast was done in five patients in each group to evaluate the dispersion of the anesthetic. RESULTS: The ilioinguinal, genitofemoral, lateral femoral cutaneous, femoral, and obturator nerves were blocked in 92% of the patients with psoas compartment block versus 62% in those with inguinal paravascular block. Lumbar plexus block reduced the need for opioids, and 42% of the patients who underwent psoas compartment block and 36% of the patients who underwent inguinal paravascular block did not need additional analgesics in the postoperative period. Analgesia lasted for approximately 21 hours in the psoas compartment block and 15 hours in the inguinal paravascular block. CONCLUSIONS: Psoas compartment block and inguinal paravascular block are excellent techniques for postoperative analgesia in orthopedic surgeries, decreasing the need for opioids. This study showed that the injection in the psoas compartment was easier and more effective in blocking the five nerves of the lumbar plexus.
BACKGROUND AND OBJECTIVES: This study evaluated the efficacy of a single injection of 0.25% bupivacaine in the psoas compartment or inguinal paravascular for postoperative analgesia in patients undergoing orthopedic surgeries using a peripheral nerve stimulator. METHODS: One hundred patients who had a lumbar plexus block through the psoas compartment were compared to 100 patients who had an inguinal paravascular block, using a peripheral nerve stimulator, with 40 mL of 0.25% bupivacaine. The analgesia of the ilioinguinal, genitofemoral, lateral femoral cutaneous, femoral, and obturator nerves was assessed 4, 8, 12, 16, 20, and 24 hours after the end of the surgical procedure. Pain severity was also evaluated in the same period. The amount of opioids administered in the postoperative period was recorded. A radiological study with non-ionic contrast was done in five patients in each group to evaluate the dispersion of the anesthetic. RESULTS: The ilioinguinal, genitofemoral, lateral femoral cutaneous, femoral, and obturator nerves were blocked in 92% of the patients with psoas compartment block versus 62% in those with inguinal paravascular block. Lumbar plexus block reduced the need for opioids, and 42% of the patients who underwent psoas compartment block and 36% of the patients who underwent inguinal paravascular block did not need additional analgesics in the postoperative period. Analgesia lasted for approximately 21 hours in the psoas compartment block and 15 hours in the inguinal paravascular block. CONCLUSIONS: Psoas compartment block and inguinal paravascular block are excellent techniques for postoperative analgesia in orthopedic surgeries, decreasing the need for opioids. This study showed that the injection in the psoas compartment was easier and more effective in blocking the five nerves of the lumbar plexus.