Which is safer for a patient on anticoagulation (blood thinner) therapy, a paravertebral block or an erector spinae block, for analgesia (pain management) during surgery?

Erector Spinae Plane Block is Safer for Anticoagulated Patients

For patients on anticoagulation therapy, the erector spinae plane (ESP) block is the safer choice compared to paravertebral block (PVB) due to its superficial plane of injection away from critical vascular structures, making it a compressible site with significantly lower risk of clinically significant hematoma. 1

Safety Profile in Anticoagulation

The fundamental safety advantage of ESP block stems from its anatomical location:

• ESP block is performed in a superficial fascial plane between the erector spinae muscle and the transverse process, which is readily compressible and allows direct visualization of bleeding if it occurs 2, 3

• The incidence of hematoma is significantly lower with ESP block compared to other regional blocks including paravertebral block (odds ratio 0.19,95% CI 0.05-0.73), representing an 81% reduction in hematoma risk 1

• ESP block has been successfully used with documented safety in a patient with post-operative coagulopathy following hepatectomy, with uncomplicated catheter removal despite anticoagulation 4

Why Paravertebral Block Carries Higher Risk

Paravertebral block poses substantially greater hemorrhagic risk in anticoagulated patients:

• PVB involves injection near the paravertebral space where major intercostal vessels and the spinal canal are located, creating risk for non-compressible bleeding 5

• Hematoma in the paravertebral space can lead to spinal cord compression or epidural hematoma, which are catastrophic complications in anticoagulated patients 1

• The paravertebral space is not readily compressible, making hemorrhage control difficult if bleeding occurs 4

Analgesic Efficacy Comparison

While safety is paramount in anticoagulated patients, ESP block also provides adequate analgesia:

• For thoracic surgery, ESP block demonstrates non-inferiority to PVB with comparable efficacy in reducing pain scores and opioid consumption during the first 48 hours postoperatively 2, 3

• ESP block provides effective analgesia with reduced pain scores and opioid consumption during the first 24 hours after video-assisted thoracoscopic surgery 2, 3

• One meta-analysis showed PVB provided marginally better pain control for thoracic surgery at certain time points (0-1 hours, 4-6 hours, 24 hours at rest), but these differences may not be clinically significant given the substantial safety advantage of ESP block 6

• For breast surgery, PVB and ESP block show similar analgesic effects with no significant differences in pain scores or opioid consumption 6

Clinical Decision Algorithm

In anticoagulated patients requiring regional analgesia:

1. Choose ESP block as first-line for thoracic, breast, or abdominal surgery requiring regional analgesia 2, 4, 1

2. ESP block is specifically indicated when the parietal pleural leaflet is damaged, which would preclude PVB efficacy 2

3. Use ultrasound guidance to identify the erector spinae muscle and transverse process at the target level 2

4. Administer 20 ml of bupivacaine 5 mg/ml (0.5%) for single-shot ESP block 2, 3

5. Always combine with multimodal analgesia including paracetamol and NSAIDs (if not contraindicated by anticoagulation indication) 2, 3

Critical Caveats

• The analgesic effect of single-shot ESP block diminishes after 6-8 hours, requiring supplemental analgesia or consideration of continuous catheter techniques 2, 3

• Adding dexmedetomidine to ropivacaine results in reduced pain scores and lower rescue analgesia requirements if prolonged analgesia is needed 2, 3

• ESP block must be part of comprehensive multimodal analgesia, not used as sole analgesic technique 2, 3

• Even with ESP block's superior safety profile, assess the patient's specific coagulation status and timing of anticoagulation dosing before proceeding 4