Background: A transversus abdominis plane block provides reliable abdominal wall analgesia,
but which adjuvants best sustain its effect remains debated. By facilitating diffusion of local
anesthetics, hyaluronidase may improve block quality.
Objectives: This study evaluated the safety and efficacy of 2 hyaluronidase doses added to
bupivacaine for bilateral transversus abdominis plane blocks in patients having a cesarean delivery.
Study Design: A prospective, randomized, double-blind, controlled clinical trial.
Setting: Benha University Hospital, Arab Republic of Egypt, from May 2023 through February
2024.
Methods: A double-blind, controlled randomized trial was performed with 114 patients having
elective cesarean delivery. The patients were allocated equally into 3 arms: Group I (bupivacaine
alone), Group II (bupivacaine plus 750 IU hyaluronidase), and Group III (bupivacaine plus 1500
IU hyaluronidase). The time to first rescue analgesia served as the primary outcome. Secondary
outcomes encompassed 24-hour morphine requirements, Visual Analog Scale pain score at rest
and on coughing, patient satisfaction, hemodynamics, and adverse events. Analyses employed the
appropriate statistical tests (parametric or nonparametric), with subsequent post hoc comparisons
for significant findings.
Results: Both hyaluronidase groups had significant prolonged analgesia (median 8.1 hours and
9.6 hours) compared to the control group (5.8 hours) (P < 0.001). Morphine requirements over
the first postprocedure 24 hours diminished significantly (P < 0.001); Groups II and III had lower
pain scores at rest and on coughing between postprocedure hours 2 and 12 (all P < 0.05). Patient
satisfaction increased with hyaluronidase (P = 0.0039). No group differences were observed for
adverse events, including postoperative nausea and vomiting or local anesthetic toxicity.
Limitations: This single-center trial with 24-hour follow-up may restrict generalizability and
long-term safety assessment; also only 2 hyaluronidase doses were examined.
Conclusions: Adding hyaluronidase to bupivacaine for transversus abdominis plane block
enhances analgesic duration and quality without compromising safety in patients having cesarean
delivery. Both high and low doses appear equally effective, suggesting that even lower doses are
sufficient for optimal effect.
Key words: Hyaluronidase, peripheral nerve block, postoperative pain, analgesia, bupivacaine,
adjuvant, opioid-sparing, cesarean delivery, patient satisfaction, regional anesthesia, fascial plane |
