Objective. To evaluate the effectiveness and harms of peripheral nerve blocks (PNB) for pain management in cardiothoracic surgeries, including opioid consumption. This review aims to provide clinicians and researchers with evidence summaries to inform clinical decision-making, guideline development, and ultimately optimize pain management strategies in this surgical population.
Data sources. MEDLINE®, Embase®, Cochrane Register of Controlled Trials from January 2013 to September 2023, supplemented by citation searching of relevant reviews and original research, and a Federal Register notice.
Review methods. Following AHRQ Methods Guide for Effectiveness and Comparative Effectiveness Reviews and using dual review, we included randomized controlled trials of adults undergoing intrathoracic surgeries who received a PNB alone or as part of multimodal analgesia for postoperative pain management. We evaluated risk of bias (RoB) using the ROB2 tool and overall strength of evidence (SOE) for prespecified outcomes (PROSPERO registration CRD42024549561).
Results. We identified 84 unique studies meeting our inclusion criteria: 17 studies for cardiac surgery (12 open cardiac and 5 minimally invasive cardiac surgery), 52 for minimally invasive thoracic surgery, and 15 for open thoracic surgery. We found limited evidence for various outcomes in this review, however, we did determine that in open cardiac surgery chest wall blocks (CWB) compared to sham decrease pain and opioid consumption at 24 hours postoperative (low strength of evidence). In minimally invasive thoracic surgery, erector spinae plane blocks (ESPB) likely decrease pain scores at 24 hours postoperative when compared to no block (low strength of evidence). When ESPB is compared to neuraxial blocks (NAB) in minimally invasive thoracic surgery, there is likely no difference in postoperative opioid consumption (low strength of evidence). The CWB appears beneficial in minimally invasive thoracic surgery; for CWB versus no block opioid consumption is decreased, and there appears to be a small benefit in pain scores but not meeting minimal clinically important difference (MCID) (low strength of evidence). Across all studies, adverse events were sparse and not appropriately defined or reported for all comparisons.
Conclusions. Overall, low strength evidence supports that PNBs may provide at least some level of pain relief and opioid reduction relative to sham block or no block in cardiothoracic surgery, and there is likely no difference in pain or opioid reduction with PNBs versus NAB. Adverse events were poorly reported but were not significantly higher in this population secondary to PNB relative to any comparator. Evidence is also insufficient to address patient satisfaction and quality of recovery. Evidence supporting the benefit of PNBs in cardiothoracic surgery is limited and mostly of insufficient or low strength largely due to many high risk of bias RCTs in the literature.