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Published on: May 26, 2023
Injection Volume and Anesthetic Effect in Serratus Plane Block
Tatsuya Kunigo1, Takeshi Murouchi, Shuji Yamamoto
1From the *Department of Anesthesia, Kushiro City General Hospital, Kushiro; †Department of Anesthesia, Kitami Red Cross Hospital, Kitami; ‡Department of Anesthesia, Hokkaido P.W.F.A.C. Obihiro-Kosei General Hospital, Obihiro; and §Department of Anesthesiology, Sapporo Medical University School of Medicine, Sapporo, Japan.
This study found that a larger volume of ropivacaine (40 mL) in serratus plane blocks resulted in greater dermatomal spread for anterior chest wall analgesia. However, increased volume did not extend the time to first postoperative pain medication.
Area of Science:
- Regional Anesthesia
- Pain Management
- Thoracic Surgery
Background:
- Serratus plane block is used for anterior chest wall analgesia.
- Optimal volume for serratus plane block is not established.
- This study investigates volume-dependent spread and efficacy.
Purpose of the Study:
- To assess the dermatomal spread of serratus plane block.
- To evaluate the analgesic effects of different ropivacaine volumes.
- To determine the appropriate volume for serratus plane block.
Main Methods:
- Prospective randomized controlled study.
- Ultrasound-guided serratus plane block with 20 mL or 40 mL of 0.375% ropivacaine.
- Dermatomal spread assessed by cold and pinprick tests; primary endpoint.
Main Results:
- 40 mL of ropivacaine resulted in significantly wider dermatomal spread compared to 20 mL (P = 0.002 for cold test, P = 0.009 for pinprick test).
- Mean spread: 6 dermatomes (cold test) and 4 dermatomes (pinprick test) with 40 mL.
- No significant difference in time to first postoperative analgesic rescue between groups.
Conclusions:
- Increased volume of 0.375% ropivacaine in serratus plane block enhances craniocaudal spread.
- Larger volumes do not prolong the duration of postoperative analgesia.
- Further research needed to optimize serratus plane block volume for clinical practice.
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