Premium
Patient‐controlled bolus femoral nerve block after knee arthroplasty: quadriceps recovery, analgesia, local anesthetic consumption
Author(s) -
Sakai N.,
Nakatsuka M.,
Tomita T.
Publication year - 2016
Publication title -
acta anaesthesiologica scandinavica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.738
H-Index - 107
eISSN - 1399-6576
pISSN - 0001-5172
DOI - 10.1111/aas.12778
Subject(s) - medicine , femoral nerve , femoral nerve block , anesthesia , arthroplasty , nerve block , bolus (digestion) , local anesthetic , adductor canal , total knee arthroplasty , anesthetic , surgery
Background Continuous femoral nerve block ( cFNB ) induces quadriceps muscle weakness, but patient‐controlled femoral nerve block ( PCFNB ) can provide analgesia with lower consumption of local anesthetics compared to cFNB . We hypothesized that cFNB followed by PCFNB leads to accelerated recovery of quadriceps weakness after total knee arthroplasty compared to cFNB alone. Secondary outcomes were local anesthetic consumption, pain, and mobilization. Methods Fifty‐six subjects received post‐operative cFNB for 24 h and then randomized to receive either cFNB (basal infusion of 6 ml/h using a dummy bolus button; n = 27) or PCFNB (bolus infusion of 3 ml with a lockout time of 30 min and no basal infusion; n = 29) using 0.08% levobupivacaine for the subsequent 24 h in a double‐blind manner (registration: UMIN 000010105). Quadriceps strength was assessed using a hand‐held dynamometer. The percentage change from baseline was compared between groups. Results Quadriceps strength at 48 h was 47.3 ± 18.3% in the cFNB group and 49.7 ± 15.7% in the PCFNB group (95% confidence interval −7.0–11.9%, P = 0.61). Local anesthetic consumption during the post‐operative period was significantly lower in the PCFNB group compared to the cFNB group (102 ± 10.8 ml vs.146 ± 4.6 ml; P < 0.001). No significant differences were found in any of the other outcomes, including pain scores at rest and during knee rehabilitation. Conclusion Continuous femoral nerve block followed by PCFNB does not improve quadriceps strength recovery time compared to cFNB alone after total knee arthroplasty, but similar analgesic effects were demonstrated with reduced levobupivacaine consumption.