Multimodal analgesia with multiple intermittent doses of erector spinae plane block through a catheter after total mastectomy: a retrospective observational study

Abstract

Background: Although case reports have suggested that the erector spinae plane block (ESPB) may help analgesia for patients after breast surgery, no study to date has assessed its effectiveness. This retrospective observational study analyzed the analgesic effects of the ESPB after total mastectomy.

Methods: Forty-eight patients were divided into an ESPB group (n = 20) and a control group (n = 28). Twenty patients in the control group were selected by their propensity score matching the twenty patients in the ESPB group. Patients in the ESPB group were injected with 30 mL 0.375% ropivacaine, followed by catheter insertion for further injections of local anesthetics every 12 hours. Primarily, total fentanyl consumption was compared between the two groups during the first 24 hours postoperatively. Secondary outcomes included pain intensity levels (visual analogue scale) and incidence of postoperative nausea and vomiting (PONV).

Results: Median cumulative fentanyl consumption during the first 24 hours was significantly lower in the ESPB (33.0µg; interquartile range [IQR], 27.0-69.5µg) than in the control group (92.8µg; IQR, 40.0-155.0µg) (P = 0.004). Pain level in the early postoperative stage (<3 hr) and incidence of PONV (0% vs. 55%) were also significantly lower in the ESPB group compared to the control (P = 0.001).

Conclusions: Intermittent ESPB after total mastectomy reduces fentanyl consumption and early postoperative pain. ESPB is a good option for multimodal analgesia after breast surgery.

Keywords: Acute Pain; Analgesia; Anesthesia; Breast; Conduction; Mastectomy; Nerve Block; Pain; Postoperative; Ropivacaine; Ultrasonography..

Fig. 1

The erector spinae plane block. (A) The level of the T5 rib and transverse process was located using a counting-down approach from the first rib; this was marked on the skin at the lateral position. (B) After placing a linear probe parallel to the vertebral axis, a needle was inserted toward the transverse process. (C) After confirming proper position of needle tip, we injected the local anesthetic. The catheter was inserted using real-time ultrasound guidance. (D) The catheter was secured by suture to the skin. ESM: erector spinae muscle, RMM: rhomboid major muscle, TM: trapezius muscle, TP: transverse process, SP: spinous process of vertebra. Data from the article of Kwon et al. (J Korean Med Sci. 2018; 33: e291) [32].

Fig. 2

Flow chart of patient selection and propensity score matching. PCA: patient-controlled analgesia, ESPB: erector spinae plane block, IV: intravenous.

Fig. 3

Cumulative fentanyl consumption over time in the erector spinae plane block (ESPB) and control groups. Cumulative fentanyl consumption at all postoperative time points was lower in the ESPB than in the control group. Data are expressed as median (interquartile range). *P < 0.01.

Fig. 4

Pain visual analogue scales over time in the erector spinae plane block (ESPB) and control groups. Pain intensity at an early postoperative stage was significantly lower in the ESPB than in the control group. Data are expressed as median (interquartile range). PACU: post-anesthesia care unit. *P < 0.008.