Femoral Nerve Block Using 0.25% or 0.5% Bupivacaine for Analgesia after Arthroscopic Anterior Cruciate Ligament Reconstruction
Arissara Iamaroon MD*, Suwimon Tangwiwat MD*, Busara Sirivanasandha MD*, Pathom Halilamien MD*, Yada Lertpenmetha MD*, Saroj Sirimaneewattana MD*, Sudkanoung Surachetpong BSc*, Supranee Puangchan BSc*
Affiliation : * Department of Anesthesiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
Background : Femoral nerve block (FNB) with varying concentrations of bupivacaine is often used for postoperative
analgesia after anterior cruciate ligament (ACL) reconstruction.
Objective : To determine whether FNB using 0.25% or 0.5% bupivacaine provided better analgesia with less effect on
quadriceps strengths after ACL reconstruction.
Material and Method: One hundred patients were randomized to receive FNB with 20 mL of 0.25% or 0.5% bupivacaine.
Data regarding demographic, effectiveness of FNB, time to first pain, time to first analgesic, pain scores, morphine use,
and recovery of sensory and motor function were recorded.
Results : Median time to first morphine requirement was 12 hours in 0.5% bupivacaine group and 10 hours in 0.25%
bupivacaine group (p = 0.048). Pain score at 18 hours was lower in 0.5% bupivacaine group compared with 0.25%
bupivacaine group (p = 0.001). When specify to the patellar tendon graft subgroup, the patients requiring morphine were
70% in 0.5% bupivacaine group and 90% in 0.25% bupivacaine group (p = 0.03). No differences were found in demographic
data, effectiveness of FNB, time to first pain, morphine consumption, and recovery of sensorimotor function.
Conclusion : FNB with 0.5% bupivacaine provided longer time to first analgesic and lower narcotic requirements after
patellar tendon graft ACL reconstruction when compared to 0.25% bupivacaine. Both concentrations showed similar effect
on quadriceps strengths.
Keywords : Femoral nerve block, 0.5% bupivacaine, 0.25% bupivacaine, Arthroscopic anterior cruciate ligament (ACL) reconstruction
