Deep Parasternal Intercostal Plane Block for Postoperative Analgesia After Sternotomy for Cardiac Surgery-A Retrospective Cohort Study.

Objective: To examine the analgesic efficacy of postoperative deep parasternal intercostal plane (DPIP) blocks for patients having cardiac surgery via median sternotomy.

Design: This single-center retrospective study compared patients receiving bilateral DPIP blocks with a matched cohort of patients not receiving DPIP blocks.

Setting: Large quaternary referral center.

Participants: Adult patients admitted to the authors' institution from January 1, 2016, to August 14, 2020, for elective cardiac surgery via median sternotomy.

Interventions: Patients received ultrasound-guided bilateral DPIP blocks.

Measurements And Main Results: A total of 113 patients received a DPIP block; 3,461 patients did not. The estimated multiplicative change in cumulative opioid consumption through 24 hours was 0.42 (95% CI 0.32-0.56; p < 0.001), indicating that patients receiving DPIP blocks required 60% fewer opioids than patients who did not. Proportional odds ratios for the average pain score on postoperative day (POD) 0 was 0.46 (95% CI 0.32-0.65; p < 0.001), and POD 1 was 0.67 (95% CI 0.47-0.94; p = 0.021), indicating lower pain scores for patients receiving blocks. The exploratory analysis identified an inverse correlation between DPIP blocks and atrial fibrillation incidence (2% v 15%; inverse probability of treatment weighting odds ratio 0.088, 95% CI 0.02-0.41; p = 0.002).

Conclusions: The use of DPIP blocks in patients undergoing cardiac surgery via median sternotomy was associated with less opioid use and improved pain scores in the early postoperative period compared with patients not receiving blocks. Prospective randomized controlled studies should further elucidate the efficacy and risks of DPIP blocks in cardiac surgery.