23 CONCLUSIO N Through a study comparing the efficacy of a mixture of ropivacaine 0.1% - fentanyl 1 mcg / ml with a mixture of bupivacaine 0.1% - fentanyl 1 mcg / ml in PCEA pain relief in 104 patients after hip surgery in the patient From October 2015 to October 2019, at Military Central Institute 108, we draw the following conclusion: 1.