Overview
Pain after median sternotomy is often underestimated relative to its actual severity — it arises from bone disruption (sternum), costal cartilage, intercostal nerve injury from retraction, internal mammary artery harvest (for CABG), and chest drains. Inadequately treated pain impairs deep breathing and coughing, increasing risk of atelectasis and pulmonary complications, while also delaying mobilisation in an already physiologically vulnerable population.
PROSPECT 2023 summary (319 studies screened, 209 RCTs + 3 systematic reviews included, search to Nov 2020): Paracetamol + NSAIDs as basic analgesia. IV magnesium and IV dexmedetomidine recommended as adjuncts, particularly when basic analgesics cannot be given. Parasternal block/surgical site infiltration recommended. COX-2 inhibitors are explicitly not recommended — a notable departure from most other procedure guidelines, reflecting cardiac-specific safety concerns. Opioids reserved for rescue.
Analgesic Pathway
- Paracetamol 1g PO (if able to take orally pre-op)
- Patient education re: deep breathing, coughing technique
- Paracetamol 1g IV
- Parasternal block/infiltration (superficial or deep) — by surgeon or anaesthetist
- Magnesium infusion — consider, esp. if basic analgesics limited
- Dexmedetomidine infusion — consider, esp. if basic analgesics limited
- COX-2 inhibitors — not recommended
- Paracetamol 1g QDS regular (IV→PO as tolerated)
- NSAID if not contraindicated (renal function, bleeding risk, post-CABG considerations)
- Opioid PRN/PCA rescue
- Early mobilisation, chest physiotherapy, incentive spirometry
- Non-pharmacological adjuncts — music/massage therapy (PROSPECT-noted, low-grade evidence)
✓ Recommended | ◎ Optional/conditional | ✗ Not recommended. Based on PROSPECT 2023.
Systemic Analgesia
Paracetamol + NSAIDs (where not contraindicated) administered intraoperatively and continued postoperatively form the foundation. Note the NSAID caveat below regarding cardiac-specific concerns.
| Agent | Dose | Route | Frequency | Notes |
|---|---|---|---|---|
| Paracetamol | 1 g | IV/PO | QDS | Regular throughout; foundation of regimen |
| Ibuprofen / Diclofenac | Standard doses | PO/IV | Per agent | Non-selective NSAID; consider bleeding risk, renal function, post-CABG graft patency concerns — discuss with surgical team |
| Morphine/Fentanyl | Titrated | IV PCA/PRN | PRN | Rescue analgesia mainstay; fast-track protocols aim to minimise total dose |
NSAID caution post-cardiac surgery: While PROSPECT recommends NSAIDs as basic analgesia "unless contraindicated," cardiac surgical patients frequently have relative contraindications — renal impairment (common post-bypass), bleeding risk, and (controversially) theoretical concerns about graft patency after CABG. Many cardiac centres restrict or avoid NSAID use; decisions should be individualised in conjunction with the cardiac surgical team.
COX-2 inhibitors — Not Recommended. Unlike most other surgical procedures on this site, PROSPECT explicitly advises against COX-2-selective inhibitors for cardiac surgery via sternotomy, citing insufficient/inconsistent evidence and cardiovascular safety concerns specific to this population (COX-2 inhibitors carry an independent cardiovascular risk signal that is particularly relevant in patients with established cardiac disease).
Parasternal Block
Parasternal block (also called pectointercostal fascial block or parasternal intercostal plane block) targets the anterior cutaneous branches of the intercostal nerves (T2–T6) as they pierce the pectoralis major/intercostal muscles near the sternal border — precisely the territory most affected by sternotomy and internal mammary artery harvest.
Superficial Parasternal (S-PIP)
Simpler, saferLA deposited between pectoralis major and external intercostal muscle, anterior to the sternum. Simple, safe, lower theoretical risk of pleural/cardiac injury given its superficial plane.
Deep Parasternal (DPIP / TTP)
Denser blockAlso called transversus thoracis plane (TTP) block — LA deposited between internal intercostal and transversus thoracis muscles, closer to the internal mammary vessels. Studies suggest superior opioid-sparing vs superficial approach, but requires more precision given proximity to pleura/vessels.
Technique — Ultrasound-Guided (Bilateral)
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Position & probe placement
Patient supine (pre-induction) or block performed by surgeon intraoperatively under direct vision before sternal closure. For percutaneous US approach: place linear probe parasagittally, 2–3 cm lateral to the sternal edge, at the level of the 3rd–4th costal cartilage.
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Identify the layers
From superficial to deep: skin, pectoralis major, external intercostal muscle, internal intercostal muscle, transversus thoracis muscle, pleura. Superficial block targets the plane beneath pectoralis major; deep block targets the plane beneath internal intercostal muscle (transversus thoracis plane).
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In-plane needle insertion
Advance in-plane to the target fascial plane. For the deep block, particular care is needed given proximity to the internal mammary artery and pleura — real-time visualisation is essential.
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Injection — bilateral
Inject 15–20 mL per side after negative aspiration. Repeat on the contralateral side. Total bilateral dose must be calculated together.
Dosing
| Agent | Concentration | Volume (per side) | Duration |
|---|---|---|---|
| Ropivacaine | 0.25–0.5% | 15–20 mL | 10–18 h |
| Bupivacaine | 0.25% | 15–20 mL | 12–18 h |
Bilateral injection — calculate total LA dose for both sides combined before performing the block.
Magnesium & Dexmedetomidine
Both IV magnesium and IV dexmedetomidine infusions reduced postoperative pain in the PROSPECT review. PROSPECT notes it is unclear whether combining both provides additional benefit over either alone — they should be considered individually rather than assumed additive.
| Agent | Dose | Route | Timing | Notes |
|---|---|---|---|---|
| Magnesium sulfate | 30–50 mg/kg loading, then 8–15 mg/kg/h infusion | IV | Intraop, continue postop | Monitor for hypotension, hyporeflexia at high doses; caution in renal impairment |
| Dexmedetomidine | 0.2–0.7 mcg/kg/h infusion (± loading 0.5–1 mcg/kg slow) | IV | Intraop, continue into ICU | Bradycardia/hypotension risk; particularly useful in fast-track protocols given sedative + analgesic-sparing effect |
Not Recommended
Insufficient/inconsistent evidence and cardiovascular safety concerns specific to this surgical population. This is a notable exception to the general PROSPECT pattern of favouring COX-2 inhibitors over non-selective NSAIDs in most other procedures.
Practical Analgesic Protocol
Suggested protocol for elective CABG via median sternotomy, fast-track pathway:
References
- PROSPECT Working Group. Pain management after cardiac surgery via median sternotomy: a systematic review with PROSPECT recommendations. Eur J Anaesthesiol. 2023. EJA 2023 ↗
- Maia ADS, Lindo RDS. Median sternotomy pain after cardiac surgery: to block, or not? A systematic review and meta-analysis. J Card Surg. 2022;37(12). PMID 36098374 ↗
- Deep Parasternal Intercostal Plane Block for Postoperative Analgesia After Sternotomy: A Retrospective Cohort Study. PMID 37968198 ↗
- Superficial Parasternal Intercostal Plane Block for Analgesia After Cardiac Surgery: Updated Meta-analysis. J Cardiothorac Vasc Anesth. 2026.
- ESRA. New PROSPECT recommendations about postoperative pain management — median sternotomy and elective craniotomy. esraeurope.org ↗