Introduction of a novel ultrasound-guided extrathoracic sub-paraspinal block for control of perioperative pain in Nuss procedure patients

Background: A safe and effective method of multilevel thoracic pain control remains an elusive goal in patients undergoing the Nuss procedure. The aim of our study was to develop a nonopioid centered approach using a novel regional technique as part of a quality improvement initiative. Methods: The proposed ultrasound-guided technique positionsmulti-perforated soaker catheter deep to the paraspinal muscles from T2 to T11. The project was conducted in two phases. First, a cadaveric dissection was performed to establish the pathway of spread of local anesthetic in vivo. Second, a pilot double blind randomized control projectwas conducted to evaluate effectiveness of the technique in ten patients and to derive parameters necessary for the definitive future study. Outcomes were evaluated based on the narcotic requirement, pain scores and functional measures. Results: Placement of the catheters in two cadavers demonstrated reliable positioning in the subparaspinal tissue plane, and multilevel dye spread along the intercostal nerve path. In addition, a potential route of spread toward the paravertebral space along the canal accommodating dorsal ramus of the thoracic nerve was demonstrated. The pilot trial demonstrated a trend in decreased cumulative hydromorphone requirement in comparison to the control group at both 24 h (0.19 +/- 0.09 mg/kg vs. 0.13 +/- 0.08 mg/kg p = 0.72) and 48 h (0.37 +/- 0.2 mg/kg vs. 0.3 +/- 0.12mg/kg p = 0.37). Functional performance abilitywas higher in the treatment group on both POD# 1 (6.7 +/- 1.8 vs. 4.8 +/- 1 p = 0.0495) and POD# 2 (8.9 +/- 0.8 vs. 6.5 +/- 1.2 p = 0.04). Pain scores were similar among the two groups ( p = 0.96). Conclusions: We describe a new technique to treat multilevel thoracic pain following the Nuss procedure that is reproducible, safe, allows diminished opioid use and enhances functional recovery. (C) 2017 Elsevier Inc. All rights reserved.