Continuous erector spinae plane block versus intercostal nerve block in patients undergoing video-assisted thoracoscopic surgery: a pilot randomized controlled trial

BACKGROUND: The optimal analgesia method in video-assisted thoracoscopic surgery (VATS) remains controversial. Intercostal nerve blockade (ICNB) is limited by its duration of action. The erector spinae plane (ESP) block has the potential to provide satisfactory analgesia for VATS; however, the effectiveness of continuous ESP versus surgeon-performed ICNB has not been investigated. The objectives of this study were to establish feasibility of patient recruitment and follow-up before undertaking a fully powered randomized controlled trial (RCT); and, secondarily, to compare opioid usage, pain control, and sensory blockade. METHODS: This feasibility RCT was undertaken at St Joseph’s Hospital, Hamilton, Ontario, Canada, and included 24 patients (>18 years) having elective VATS with at least one overnight stay. Exclusion criteria were patient refusal, body mass index >40 kg/m(2), contraindications to neuraxial analgesia techniques as per the American Society of Regional Anesthesia and Pain guidelines, known allergy to local anesthetics, language or comprehension barriers, procedures with a higher chance of open surgery, and regular opioid use for ≥3 months preoperatively. Patients underwent either continuous ESP (n=12) or surgeon-performed ICNB (n=12). All patients received routine intraoperative anesthesia care and multimodal analgesia. Feasibility criteria were recruitment rate of two patients/week and full follow-up in all patients in-hospital. We compared opioid consumption, postoperative pain scores (0–10 numerical rating scale), adverse events, patient satisfaction, and distribution of sensory blockade as clinical outcomes (secondary). RESULTS: Feasibility of primary outcomes was successfully demonstrated. Five patients had an epidural in anticipation of open surgery. Mean opioid consumption as equivalent morphine units was less in the ESP group over the first 24 h (mean difference, 1.63 [95% CI –1.20 to 4.45]) and 48 h (mean difference, 2.34 [95% CI –1.93 to 6.61]). There were no differences in adverse effects. CONCLUSIONS: A fully powered RCT is feasible with modifications. Our results also suggest that continuous ESP is safe and can decrease opioid needs. However, it is important to consider procedures to improve compliance to protocol and adherence to assigned interventions. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT03176667. Registered June 5, 2017. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40814-021-00801-7.