Deep Serratus Anterior Plane Block for Multimodal Analgesia in Minimally Invasive Mitral Valve Surgery Performed via Right Anterior Mini-Thoracotomy

Objective: This study investigated if the serratus anterior plane block (SAPB) within a multimodal analgesia scheme would reduce acute post-operative pain and intravenous opioid consumption in patients admitted to the intensive care unit after isolated minimally invasive mitral valve surgery. Design: Retrospective study. Setting: Patients were admitted to the intensive care unit (ICU) of the University Hospital of Siena (Italy). Interventions: Patients treated with intravenous opioids (OP-G) as a postoperative analgesic regimen were compared to those managed with an opioid-sparing protocol consisting of a single-shot SAPB with 0.5% ropivacaine plus 4 mg dexamethasone administered 1 hour before the extubation (SAPB-G). The behavioral pain scale (BPS) for intubated (I) or non-intubated patients (NI) and the Richmond Agitation Sedation Scale (RASS) scores were collected at ICU admission and every 8 hours during the initial 24 postoperative hours. Measurements and Main Results: One hundred five patients (50 SAPB-G; 55 OP-G) were enrolled (median age 67 [60-70]; male 67 [64%]). RASS score at 8 hours after ICU admission was higher in the SAPB-G (0 [0, 0] v OP-G –2 [–3, 0], p < 0.001). At 24 hours after ICU admission, the number of patients with a BPS/BPS-NI score >4 was lower in the SAPB-G (4.0% v 18.2% OP-G, p = 0.048). SAPB-G received a lower number of opioid rescue doses during the first 24 hours (20% v 84% OP-G, p < 0.001). Conclusions: The SAPB may be effective in reducing the postoperative use of opioids in patients undergoing minimally invasive mitral valve surgery. Prospective randomized studies are warranted.