Preoperative versus postoperative ultrasound-guided rectus sheath block for improving pain, sleep quality and cytokine levels in patients with open midline incisions undergoing transabdominal gynecological surgery: a randomized-controlled trial

Abstract

Background: Nerve block is usually performed before surgery because it inhibits reflection of the skin incision and reduces the amount of intraoperative anesthetic used. We hypothesized that performing rectus sheath block (RSB) after surgery would result in a longer duration of the analgesic effects and have a subtle influence on sleep time after surgery but that it would not decrease the perioperative cytokine levels of patients undergoing gynecological surgery.

Methods: A randomized, double-blinded, controlled trial was conducted from October 2015 to June 2016. Seventy-seven patients undergoing elective transabdominal gynecological surgery were randomly assigned to the following two groups: a general anesthesia group who received 0.5% ropivacaine hydrochloride RSB preoperatively and saline RSB postoperatively, and another group who received the opposite sequence. The objective of the trial was to evaluate the postoperative pain, sleep and changes in cytokine levels of patients during the postoperative 48 h.

Results: A total of 61 female patients (mean age: 50 years; range: 24-65 years) were included in the final study sample. There was no significant difference in the pain, consumption of oxycodone, or time to first administration of patient-controlled intravenous analgesia between the two groups. The postoperative sleep stages N2 and N3 were increased by 52.9 and 29.1 min per patient, respectively, in the preoperative RSB group compared with those in the postoperative group. The preoperative IL-6 concentration in the preoperative RSB group was lower than that in the same group at the end of surgery and 24 h postoperatively.

Conclusions: We concluded that preoperative RSB might preserve postoperative sleep by inhibiting the increase of IL-6 without shortening the analgesia time compared with postoperative RSB in female patients undergoing elective midline incision transabdominal gynecological surgery.

Trial registration: ClinicalTrials.gov , NCT02477098 , registered on 15 June 2015.

Keywords: Interleukin-6; Rectus sheath block; Sleep.

Conflict of interest statement

Ethics approval and consent to participate

This trial was approved by the Ethics Committee of the First Hospital of China Medical University (protocol number 2015110901, Chairman Prof. Xing-hua Gao, January 14, 2015 (Trial registration: NCT02477098, Principal investigator’s name: Wen-fei Tan, Date of registration: 2015–06-15 https://ichgcp.net/clinical-trials-registry/NCT02477098?term=NCT02477098&rank=1). All participants provided written informed consent in accordance with the Declaration of Helsinki.

Consent for publication

Not applicable.

Competing interests

The authors declare that they have no competing interests.

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Figures

Fig. 1

Patient flowchart showing the patients included in enrollment, group allocation, follow-up, and analysis phases of the study

Fig. 2

Kaplan-Meier survival plot representing time to first PCIA trigger (a), examples of BIS data on the first postoperative night in the two groups (b), and a picture of one incision (c). a The log-rank test suggested no detectable difference between the two groups (P = 0.736). c The white arrow shows fluid in the rectus sheath

Fig. 3

Comparison of the plasma concentrations of IL-1β (a), IL-6 (b), IFN-γ(c), and TNF-α (d) between the two groups. aPgroup = 0.048, Ptime = 0.285, and Pgroup-time interaction = 0.865. bPgroup, Ptime, and Pgroup-time interaction <  0.001. #P <  0.001 vs. baseline. cPgroup <  0.001, Ptime = 0.949, and Pgroup-time interaction = 0.120. dPgroup = 0.003, Ptime = 0.325, and Pgroup-time interaction = 0.298