Ultrasound‐Guided Continuous Deep Serratus Anterior Plane Block Versus Continuous Thoracic Paravertebral Block for Perioperative Analgesia in Videoscopic‐Assisted Thoracic Surgery

BACKGROUND: The deep serratus anterior plane block (SAPB) is a promising novel regional anaesthesia technique for blockade of the anterolateral chest wall. Evidence for the efficacy of SAPB versus other analgesic techniques in thoracic surgery remains inadequate. AIMS: This study compared ultrasound-guided continuous SAPB with a surgically placed continuous thoracic paravertebral block (SPVB) technique in patients undergoing videoscopic-assisted thoracic surgery (VATS). METHODS: In a single-centre, double-blinded, randomized, non-inferiority study, we allocated 40 patients undergoing VATS to either SAPB or SPVB, with both groups receiving otherwise standardized treatment, including multimodal analgesia. The primary outcome was 48-hr opioid consumption. Secondary outcomes included numerical rating scale (NRS) for postoperative pain, patient-reported worst pain score (WPS) as well as functional measures (including mobilization distance and cough strength). RESULTS: A 48-hr opioid consumption for the SAPB group was non-inferior compared with SPVB. SAPB was associated with improved NRS pain scores at rest, with cough and with movement at 24 hr postoperatively (p = .007, p = .001 and p = .012, respectively). SAPB was also associated with a lower WPS (p = .008). Day 1 walking distance was improved in the SAPB group (p = .012), whereas the difference in cough strength did not reach statistical significance (p = .071). There was no difference in haemodynamics, opioid side effects, length of hospital stay or patient satisfaction between the two groups. CONCLUSIONS: The SAPB, as part of a multimodal analgesia regimen, is non-inferior in terms of 48-hr opioid consumption compared to SPVB and is associated with improved functional measures in thoracic surgical patients. ClinicalTrials.gov Identifier: NCT03768193. SIGNIFICANCE: The SAPB interfascial plane block is an efficacious alternative method of opioid-sparing analgesia in high-risk thoracic surgical patients as part of an enhanced recovery programme.