Parasternal Intercostal Nerve Blocks in Patients Undergoing Cardiac Surgery: Evidence Update and Technical Considerations.

In the Enhanced Recovery After Surgery era, parasternal intercostal nerve block has been proposed to improve pain control and reduce opioid use in patients undergoing cardiac surgery. However current literature has reported conflicting evidence about the effect of this multimodal pain management, as procedural variations might pose a significant bias on outcomes evaluation. In this setting, the infiltration of the parasternal plane into 2 intercostal spaces, second and fifth, with a local anesthetic spread under or above the costal plane with ultrasound guidance, seem to be standardized in theory, but significant differences might be observed in clinical practice. This narrative review summarizes and defines the optimal techniques for parasternal plane blocks in patients undergoing cardiac surgery with full median sternotomy, considering both pectointercostal fascial block and transversus thoracic plane block. A total of 10 randomized trials have been published, in adjunct to observational studies, which are heterogeneous in terms of techniques, methods, and outcomes. Parasternal block has been shown to reduce perioperative opioid consumption and provide a more favorable analgesic profile, with reduced postoperative opioid-related side effects. A trend toward reduced intensive care unit stay or duration of mechanical ventilation should be confirmed by adequately powered randomized trials or registry studies. Differences in operative technique might impact outcomes and, therefore, standardization of the procedure plays a pivotal role before reporting specific outcomes. Parasternal plane blocks might significantly improve outcomes of cardiac surgery with full median sternotomy, and should be introduced comprehensively in Enhanced Recovery After Surgery protocols.