The effects of perineural versus intravenous dexamethasone on sciatic nerve
blockade outcomes: a randomized, double-blind, placebo-controlled study.
Author(s): Rahangdale R(1), Kendall MC, McCarthy RJ, Tureanu L, Doty R Jr, Weingart A, De
Oliveira GS Jr.
Affiliation(s): Author information:
(1)From the Department of Anesthesiology, Northwestern University, Chicago,
Illinois.
Publication date & source: 2014, Anesth Analg. , 118(5):1113-9
BACKGROUND: Perineural dexamethasone has been investigated as an adjuvant for
brachial plexus nerve blocks, but it is not known whether the beneficial effect
of perineural dexamethasone on analgesia duration leads to a better quality of
surgical recovery. We hypothesized that patients receiving dexamethasone would
have a better quality of recovery than patients not receiving dexamethasone. We
also sought to compare the effect of perineural with that of IV dexamethasone on
block characteristics.
METHODS: Patients undergoing elective ankle and foot surgery were recruited over
a 9-month period. Patients received ultrasound-guided sciatic nerve blocks by
using 0.5% bupivacaine with epinephrine 1:300,000 (0.45 mL/kg) and were
randomized into 3 groups: group 1 = perineural dexamethasone 8 mg/2 mL with 50 mL
IV normal saline, group 2 = perineural saline/2 mL with IV 8 mg dexamethasone in
50 mL normal saline, and group 3 = perineural saline/2 mL with 50 mL normal
saline. The primary outcome was the global score in the quality of recovery
(QoR-40). The secondary outcomes included analgesia duration, opioid consumption,
patient satisfaction, numeric pain rating scores, and postoperative neurologic
symptoms.
RESULTS: Eighty patients were randomized, and 78 patients completed the study
protocol. There was no improvement in the global QoR-40 score at 24 hours between
the perineural dexamethasone and saline, median (97.5% CI) difference of -3 (-7
to 3); IV dexamethasone and saline, median difference of -1 (-8 to 5); or
perineural dexamethasone and IV dexamethasone median difference of -2 (-6 to 5).
Analgesia duration (P < 0.001) and time to first toe movement (P < 0.001) were
prolonged by perineural dexamethasone compared with saline. IV dexamethasone
prolonged time to first toe movement compared with saline (P = 0.008) but not
analgesia duration (P = 0.18). There was no significant difference in the time to
first toe movement or analgesia duration between the perineural and IV
dexamethasone groups. Postoperative opioid consumption was not different among
study groups. Self-reported neurologic symptoms at 24 hours were not different
among perineural dexamethasone (17, 63%), IV dexamethasone (10, 42%), or normal
saline (8, 30%) (P = 0.31). All postoperative neurologic sequelae were resolved
by 8 weeks.
CONCLUSIONS: Preoperative administration of IV and perineural dexamethasone
compared with saline did not improve overall QoR-40 or decrease opioid
consumption but did prolong analgesic duration in patients undergoing elective
foot and ankle surgery and receiving sciatic nerve block. Given the lack of
clinical benefit and the concern of dexamethasone neurotoxicity as demonstrated
in animal studies, the practice of perineural dexamethasone administration needs
to be further evaluated.
|