Ultrasound-Guided Deep Parasternal Intercostal Plane Block in Off-Pump Cardiac Arterial Bypass Surgery: A Retrospective Cohort Single Center Study

<b>Background/Objectives</b>: Sternal pain after cardiac surgery results in considerable discomfort and may contribute to the development of chronic postoperative sternal pain syndrome. Parasternal intercostal plane blocks have been shown to improve postoperative sternal pain and can be an essential part of enhanced recovery after cardiac surgery (ERACS). This cohort study evaluated the postoperative impact of a single-shot deep parasternal intercostal plane block (PIPB) on the requirement of analgesic medication and pain sensation up to 48 h. <b>Methods</b>: This retrospective single-center analysis evaluates the postoperative acute pain in 157 patients undergoing off-pump coronary artery bypass (OPCAB) with median sternotomy. The additive analgesic effects of deep PIPB (38 patients) were compared to a group with standard therapy but without PIPB (119 patients). To strengthen the findings, a propensity score matching analysis was performed. Outcomes included the consumption of emergency pain agents (piritramide), the requirement of the total morphine equivalent (ME), time to extubation, and ICU length of stay. Furthermore, we examined pain sensation with evaluation by using the behavioral pain score (BPS) and numeric rating score (NRS) up to 48 h after extubation. <b>Results</b>: The deep PIPB reduced the piritramide administration 24 h and 48 h after OPCAB surgery. Moreover, the requirement of ME was 24 h and 48 h after bypass surgery also significantly decreased. The one-to-one propensity score matching confirmed our primary findings and showed a decreased requirement for intravenous agents. Additionally, we observed a reduced time for extubation and a decreased NRS rating. However, no significant changes were observed in ICU length of stay, incidence of nausea, and vomiting. <b>Conclusions</b>: Our data suggests that an ultrasound-guided single-shot deep PIPB can be a valuable tool for a multimodal analgesic protocol on patients undergoing OPCAB surgery.