Peripheral Nerve Blocks for Postoperative Pain Management in Cardiothoracic Surgery: A Systematic Review

Objective. To evaluate the effectiveness and harms of peripheral nerve blocks (PNB) for pain management, including minimizing opioid consumption in cardiothoracic surgeries to inform clinical decision-making and guideline development for postoperative pain management in adults. Data sources. MEDLINE®, Embase®, and Cochrane Register of Controlled Trials, January 2013 to December 2024; reference lists of relevant systematic reviews, and a Federal Register notice. Review methods. We included randomized controlled trials (RCTs) of adults who underwent intrathoracic surgery and received a PNB alone or as part of multimodal analgesia for postoperative pain management. We evaluated risk of bias (ROB) with Cochrane ROB2 and overall strength of evidence (SOE) using Agency for Healthcare Research and Quality Evidence-based Practice Center Program methods for prespecified outcomes (PROSPERO registration CRD42024549561). Results. We identified 104 eligible RCTs: 25 cardiac surgery (16 open, 9 minimally invasive surgery [MIS]), 62 thoracic MIS, and 17 open thoracic. Most trials reported short-term, inpatient outcomes for pain and opioid use up to 48 hours; longer-term outcomes were uncommon. For open cardiac surgery, chest wall blocks (CWB) reduced 24-hour pain (≥ 1.5 points), and opioid consumption compared with sham (low strength of evidence [SOE]). For cardiac MIS, continuous erector spinae plane blocks (ESPB) did not improve outcomes (low SOE). In thoracic MIS, ESPB may modestly decrease pain at 24 hours compared to no block (low SOE) and improve patient-reported quality of recovery scores at 48 hours postoperative (low SOE). There was no difference in 24-hour opioid consumption or in-hospital length of stay with ESPB versus neuraxial blocks (NAB, low and moderate SOE, respectively). In thoracic MIS, CWBs may decrease opioid consumption with small benefit in pain scores (low SOE); CWB plus NAB versus NAB alone may not improve outcomes in open or MIS thoracic surgery (low SOE). Overall, PNB-related adverse events were rare, not consistently defined, or not reported. Very few RCTs reported patient satisfaction or quality of life scores. Conclusions. Overall, low strength evidence supports that some PNBs provide short-term, modest pain relief and opioid reduction relative to sham or no block in cardiothoracic surgery. PNBs may be as effective as NAB for controlling pain in this patient population. Block-related adverse events are rare but need consistent definitions and longer-term reporting. Evidence is insufficient to address patient satisfaction and quality of recovery. Evidence for using PNBs in cardiothoracic surgery is limited and mostly of insufficient or low strength largely due to high risk of bias. Standardized outcomes reporting would advance the field.