Analgesic Effect Comparison and Pharmacokinetic Study of Ropivacaine
with Different Concentrations in Continuous Serratus Anterior Plane
Block in Patients Undergoing Video-Assisted Thoracoscopic Surgery
Abstract
Aims: The serratus anterior plane block (SAPB) has commonly been
utilized as a regional anesthesia technique for pain management in
various upper chest surgical procedures. The purpose of this study was
to investigate the analgesic effect and pharmacokinetics of ropivacaine
in continuous SAPB undergoing VATS. Methods: This prospective randomized
study included patients scheduled for elective VATS. Patients first
received a bolus of 20 ml of 0.2% (Group L) or 0.375% (Group H)
ropivacaine that was administered beneath the serratus anterior muscle.
The pump was connected to the catheter for continuous administration
within 48 hours postoperatively, in which a background infusion at a
rate of 7 ml·h−1 of low-dose at 0.2% (Group L) or high-dose at 0.375%
(Group H) of ropivacaine was administered. The main results were to
compare the analgesic effects and analyze the pharmacokinetics of
different concentrations of ropivacaine. Results: Eighty-eight patients
agreed to participate in the trial and were recruited. The VAS scores in
Group H at 12, 24, and 48 hours postoperatively at rest and on coughing
were significantly lower than those in Group L. The peak values of total
ropivacaine plasma concentrations were observed at 48 hours (2.01
μg·mL−1 for Group L and 2.93 μg·mL−1 for Group H), which were far below
the theoretical toxicity threshold. Postoperative rescue analgesia,
complications, and other outcomes did not differ significantly.
Conclusions: In VATS patients, the analgesic effect of 0.2% ropivacaine
for continuous SAPB was not inferior to that of 0.375% ropivacaine, and
the blood concentration of 0.2% ropivacaine was