Comparison of peripheral nerve block techniques for cesarean delivery. Dermatomes covered, skin incision type addressed, volume of local anesthetics required, and other considerations are presented and compared between techniques
| Technique | Dermatomes | Skin incision type | Anatomic alterations in obstetric patient | Injectate volume requirements | Somatic analgesia | Visceral analgesia | Adjacent vascularity | Major risks | Notes | References |
| Paravertebral (PVB) | Variable; can address thoraco-lumbar dermatomes | Pfannenstiel Vertical midline | No changes likely | 5–10 mL per side Multiple injections of small volumes (3–4 mL) at contiguous levels preferred over single large-volume injection | Yes | Yes | Yes (thoracic segmental arteries, abdominal branches of lumbar arteries) | Pneumothorax; epidural or intrathecal injections | Few high-quality studies for cesarean analgesia; superiority to neuraxial morphine unknown; parasagittal in-plane approach can minimize risk for epidural spread, but requires skill to maintain needle visualization | 15 80 81 |
| TAP (TAP) | T10-L1* | Pfannenstiel Vertical midline | Postdelivery changes in tissue planes may occur | 20–30 mL per side | Yes | Not reliable; parietal peritoneum only | Yes (abdominal branches of lumbar arteries) | Local anesthetic toxicity; organ injury; hematoma | Not superior to neuraxial morphine; may have benefit in breakthrough pain despite multimodal analgesia or inability to receive neuraxial morphine | 82 83 |
| QL (QL) QL1 (lateral) | T7-L1 | Postdelivery changes in tissue planes may occur | 20–30 mL per side | Yes | Not reliable; depends on posterior spread into paravertebral space (QL2 provides more reliable spread into paravertebral space) | Yes (abdominal branches of lumbar arteries) | Local anesthetic toxicity; organ injury; hematoma | Compared with TAP, QL1 and QL2 are deep nerve blocks; risks include infection, hematoma, organ injury | 36 84 | |
| QL2 (posterior) | T7-L1 | Pfannenstiel Vertical midline | Postdelivery changes in tissue planes may occur | 20–30 mL per side | Yes | |||||
| QLT (transmuscular) | T10-L4 | Postdelivery changes in tissue planes may occur | 20–30 mL per side | Yes | Superiority to neuraxial morphine unknown | |||||
| QLI (intramuscular) | T7-T12 | No changes likely | 20–30 mL per side | Yes | ||||||
| II-IH (II-IIH) | L1 | Pfannenstiel | Postdelivery changes in tissue planes may occur | 10 mL per side | Yes | No | Yes (smaller branches of lumbar arteries) | Intra-arterial injection; partial block if improper injection | Not superior to neuraxial morphine; possible benefit in breakthrough pain despite multimodal analgesia or in absence of neuraxial morphine | 85 86 |
| CWI (CWI) | Variable | Pfannenstiel Vertical midline | No changes likely | 10 mL bolus 2–5 mL/hour infusion rate; maximum infusion rates 14 mL/hour | Yes | No | No | Local anesthetic toxicity; variable analgesia; high infusion rates can lead to leakage around the wound | Not superior to neuraxial morphine; may have benefit in breakthrough pain despite multimodal analgesia or inability to receive neuraxial morphine | 50 56 |
| Erector Spinae Plane (ESP) | Variable | Pfannenstiel | No changes likely | 20–25 mL per side | Yes | No | No | Local anesthetic toxicity; variable analgesia; possible motor block | Only case reports currently available | 59 60 |
*Anterior TAP performed medial to the anterior superior iliac spine.
QL, quadratus lumborum; TAP, transversus abdominis plane.