Analgesia and spread of erector spinae plane block in breast cancer surgeries: a randomized controlled trial

Abstract

Background: To evaluate the analgesic efficacy and spread of variable volumes of local anesthetics (LA) in Erector spinae plane block (ESPB).

Methods: Sixty patients aged between 18 and 50 years with an ASA I-II and scheduled for breast cancer surgery were randomized to receive either ESPB with 20 ml 0.25% bupivacaine (Standard volume ESPB), or with 40 ml 0.125% bupivacaine (High volume ESPB), or no ESPB (GA only group). The primary outcome was pain intensity evaluated by the visual analogue scale (VAS), 12 hours after surgery. P-values < 0.05 were considered the cutoff point for statistical significance. The secondary outcomes were pain at rest and pain on movement evaluated by the VAS, craniocaudal injectate spread, to paravertebral (PV) and epidural spaces assessed by CT, clinical dermatomal spread, level of sedation or agitation, and patient satisfaction with anesthesia and analgesia.

Results: VAS at rest 12 h after surgery was less in both intervention groups compared to the control (1.75 ± 0.79 vs. 1.6 ± 0.88 vs. 3.4 ± 1.96, p = 0.001). The LA had extended further in the high volume group than the standard volume group (11.20 ± 3.07 vs. 9.15 ± 2.54 vertebral levels, p = 0.027). No difference of the spread to PV or epidural spaces between the 2 intervention groups. More dermatomes were covered in the high volume group (7.20 ± 2.12 vs. 5.75 ± 1.37 dermatomes, p = 0.014). Agitation was higher in the GA only group than both ESPB groups in the first 8 postoperative hours. Patients were more satisfied in both ESPB groups than the GA only group.

Conclusions: Preoperative ESPB is an excellent analgesic modality and it can also attenuate both postoperative agitation and sedation. Doubling the injectate volume enhances the craniocaudal spreading and may be useful for surgeries requiring multiple dermatomes. However, larger volume has no effect on analgesic efficacy or patient satisfaction as there is no further spread to the PV, epidural spaces or spinal nerve rami.

Trial registration: NCT04796363 (12/3/2021).

Keywords: Analgesia; Erector spinae plane block; Spread; Ultrasound guided; and Breast cancer surgery.

Conflict of interest statement

The authors declare that they have no conflict of interest.

© 2022. The Author(s).

Figures

Fig. 1

CONSORT flow diagram of the study participants

Fig. 2

Comparison among the three groups based on VAS during rest

Fig. 3

Comparison among the three groups based on VAS during arm movement

Fig. 4

Comparison among the two intervention groups based on CranioCaudal dye spread

Fig. 5

3 D reconstruction by CT (postero-anterior view) of the craniocaudal spread of LA-dye mixture

Fig. 6

Sagittal CT scan demonstrating paravertebral spread of LA-dye mixture at T4-T5 (Right exit foramen)

Fig. 7

Axial CT scan demonstrating epidural spread of LA-dye mixture at T5 level

Fig. 8

Axial CT scan showing accidental crossing of LA-dye mixture to the contralateral side at T4 level

Fig. 9

Comparison among the two intervention groups based on clinical dermatomal level achieved

Fig. 10

Correlation between craniocaudal dye spread and clinical dermatomal level achieved in the standard volume ESPB group

Fig. 11

Correlation between craniocaudal dye spread and clinical dermatomal level achieved in the high volume ESPB group

Fig. 12

Comparison among the three groups based on Richmond agitation sedation scale