Unlocking the Chest Wall: Revisiting the Intercostal Nerve Block in Regional Anesthesia
- Valkyrie Blog Team
- 2 days ago
- 2 min read
The intercostal nerve block (ICNB) remains a deceptively simple yet potent tool in the regional anesthesia arsenal. While more complex blocks like paravertebral, serratus plane, or erector spinae blocks garner attention, —especially in acuto trauma, post-thoracotomy pain, or minimally invasive procedures. But like all tools, its success lies in understanding not just when to use it—but why.
Procedure Details: Performing the Intercostal Nerve Block
Patient Positioning: The patient is typically placed in a lateral decubitus or prone position, depending on the target intercostal space and imaging modality. The arm on the side of the block is elevated to widen the intercostal spaces.
Anatomical Target: The intercostal nerves run along the inferior border of each rib, nestled between the internal intercostal and innermost intercostal muscles, accompanied by the intercostal artery and vein. The needle is directed toward the posterior axillary line, approximately 6–8 cm lateral to the spinous processes.
Technique Overview:
Identify the rib level using surface landmarks or ultrasound.
Insert a 25–22G needle just inferior to the rib, angling slightly cephalad to avoid pleural puncture.
Advance until contact with the rib is made, then “walk off” the inferior edge.
After negative aspiration, inject 3–5 mL of local anesthetic per level.
Repeat at multiple levels (typically 2 above and 2 below the target dermatome) for adequate coverage.
Ultrasound Guidance (Optional):Ultrasound can enhance safety by visualizing the pleura, intercostal vessels, and needle trajectory. A high-frequency linear probe is placed in a transverse orientation over the rib space.
Precautions:
Avoid in patients with coagulopathy or single-lung physiology on the ipsilateral side.
Monitor for signs of pneumothorax, especially in landmark-based techniques.
Recent Evidence: Refining the Use Case
ICNB for Rib Fracture Management in Trauma Patients
A 2024 randomized trial in the Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine evaluated ICNBs in adult trauma patients with multiple rib fractures. Compared to systemic opioids alone, ICNBs reduced pain scores, improved oxygenation, and shortened hospital stays.
Ultrasound-Guided ICNB vs. PVB for Thoracoscopy
A meta-analysis published in Regional Anesthesia & Pain Medicine compared ICNB and PVB in thoracoscopic procedures. While PVB showed slightly longer duration of analgesia, ICNB was faster to perform, safer in coagulopathic patients, and adequate for short-stay procedures.
ICNB in Breast Surgery: A Limited Role
A smaller prospective study out of India assessed multilevel ICNBs for patients undergoing modified radical mastectomies. While the block provided moderate anterior chest wall analgesia, it failed to cover the axillary and pectoral nerves adequately, reinforcing that ICNB is insufficient as a sole anesthetic for breast surgery.
Where ICNB Excels: Focused, Accessible, Repeatable
When performed with ultrasound guidance, ICNBs are:
Efficient—taking less than 3 minutes per level
Visualized clearly—with rib shadows and pleura as landmarks
Repeatable—allowing serial injections in trauma and chronic pain clinics
They also shine in the emergency department or pre-hospital settings where complex blocks may not be feasible.
As with all regional techniques, the ICNB benefits from tactile training and anatomical simulation—especially to reduce pleural puncture risk and ensure accurate intercostal space identification.
The Valkyrie Intercostal Block Simulator offers detailed external landmarks and internal anatomy for hands-on learning of the ICNB technique. Experience it in action here.