Assessment of catheter position using chest CT in adults undergoing erector spinae plane analgesia for rib fractures: a retrospective cohort study

Background Continuous erector spinae plane (ESP) analgesia is a common adjuvant for patients with traumatic rib fracture pain and success relies on the ESP catheter remaining within the correct fascial plane for the duration of its placement. However, knowledge on postplacement position of indwelling ESP catheters is largely absent. We hypothesized that migration of over-the-needle ESP catheters was common and detectable with coincidental postprocedure CT. Methods In this single-center retrospective cohort study, adults admitted to the surgical intensive care unit for traumatic rib fractures between January 2020 and July 2022 were screened. Those receiving continuous ESP analgesia via indwelling catheter and undergoing subsequent chest CT were included. The primary outcome was the proportion of catheters that migrated outside the ESP. The secondary outcome was the distance between the catheter tip and the nearest transverse process (TP) or fascial plane. Results 160 medical records were screened for eligibility and 15 patients (18 catheters) met the inclusion criteria. 16 of 18 catheters reviewed were found outside the ESP. Furthermore, catheter position was reported as intramuscular in 14 catheters and subcutaneous in 4 catheters. The median distance between catheter tip and the nearest TP (or the ESP) was 23.20 mm sagittally and 25.05 mm axially. Conclusions Most ESP catheters were found superficial to the fascial plane in the days following their placement. The median distance between the catheter and the ESP is between 23 and 25 mm. Prospective studies should address catheter migration concerns and propose solutions to this common issue.