Serratus plane block impact in pain and opioid uptake in oncological breast surgery.

Author(s): Casasempere Sanus A., Mazzinari G., Ortega Monzó J.M., Rovira Soriano L., Belaouchi M.,Esparza Miñana J.M.

Institute(s): Hospital de Manises, Dept of Anaesthesiology, Manises, Spain

Background and Goal of Study: 
Regional anaesthesia is related with less incidence of cancer recurrence and less chronic pain developement. The paravertebral block is the most common regional technique in breast surgery, but it is difficult to perform and is not free from complications.
Alternatively, ultrasound guided serratus plane block achieves complete analgesia of the axilomammary area by reaching the nerves between the pectoral and the serratus muscles (pectoral nerves, supraclavicular and long thoracic nerve) with a high security profile. The goal of this study is to evaluate the effect of the serratus plane block on opioids requirements during surgery and the immediate postoperative period as well as on the level of postoperative pain in oncological breast surgery.

Materials and methods: We present a randomized intervention study (NCT02905149). Patients recruited undergoing oncological breast surgery are assigned to Control (intravenous opioid) or Serratus group. Every patient receives general anaesthesia with opioid analgesia according to the current hospital protocol. The block is performed with 20 ml 0'5% Levobupivacaine immediately after induction. In the postoperative period every patient is given a morphine PCA infusion pump which allows boluses of 1 mg every 15 min but no continuous infusion. Patients are followed­up during 24 h, asked for opioid consumption and pain estimated by VAS. We analyzed differences in opioid
uptake in 24 h and pain VAS scores at set intervals (1,3,6,12,24 h).

Results and discussion: We offer preliminary results from the data analysis of the first 11 recruited patients. The serratus plane block was effective in all cases. The cumulative opioids consumption over 24 h was higher in control group (35.2 mg, SD 5.96, 95% CI 21.92,48.48) than in Serratus group (21.5 mg, SD 3.41, 95% CI 13.89, 29.11). VAS scores for 24 h cumulative pain at rest and movement were higher in control than in Serratus group (AUCRcontrol 54.3, AUCRserratus 7.08, AUCMcontrol 75.9, AUCMserratus 13.3). Serratus group pain VAS scores were 2 or more points lower than the control group scores, both at rest and at movement.

Conclusion(s): Serratus plane block provides adequate intraoperative and postoperative analgesia for oncological breast surgery. It is a simple, reproducible and safe technique, and may be an alternative to opioid analgesia or paravertebral block.