Abstract
Introduction: Spine surgeries often result in significant postoperative pain, which can hinder rehabilitation efforts. The Erector Spinae Plane Block (ESPB), traditionally performed by anesthesiologists with ultrasound guidance, has proven to be effective in improving postoperative outcomes. Recently, spine surgeons have begun administering ESPB using a freehand technique, which may offer advantages such as time efficiency and cost-effectiveness. However, there is limited research on how the method of ESPB administration affects patient outcomes. Therefore, this study aims to compare the impact of freehand versus ultrasound-guided delivery modes of ESPB in improving postoperative patient outcomes.
Methods: This retrospective cohort study included patients aged 18 and older who underwent primary spine surgery via a posterior approach involving at least the lumbar spine at a single institution between May 2022 and May 2024. Patients were divided into two groups based on the spine block delivery method: the freehand group (FHG) and the ultrasound-guided group (USG). The main outcome measured consisted in the Numerical Rating Scale (NRS) pain scores, both at rest and during activity at different time points within the first 48 postoperative hours. The secondary outcomes assessed included postoperative opioid consumption, length of stay, and physical therapy outcomes.
Results: A total of 283 patients were included, of whom 237 received a freehand administered ESPB and 46 the ultrasound-guided ESPB. The median age of the study population was 62.9 years old and 50.2% were female. When comparing the success or failure of ESPB in pain management using a cutoff of NRS score of 4, significantly more patients in the FHG had a successful pain management at rest between 18-36 hours post-surgery as compared to the USG (p = 0.01). A significantly greater number of patients walked on post-surgery day 0 in the FHG as compared to the patients in the USG (p=0.046). Nevertheless, no statistically significant differences were observed for other outcome measures.
Discussion: In our single-center population, the freehand and ultrasound-guided ESP blocks demonstrated comparable postoperative outcomes. Although a statistically significant difference in pain scores was observed, it did not translate into clinically meaningful benefits for pain management. Additionally, the difference in time to ambulation between the two groups may be attributed to greater adherence to a recently introduced perioperative resource distribution protocol, the spine pathway, that was established around the start of the study period. These findings contribute to the limited evidence on the effectiveness of freehand ESPB; however, future studies with larger sample sizes and more rigorous designs, such as randomized controlled trials, are necessary.
Keywords: Erector Spinae Plane Block; Freehand; Lumbar Spine; Postoperative Pain; Regional Anesthesia; Ultrasound-Guided