Effect of External Oblique Intercostal Block on Postoperative Analgesia and Early Recovery in Patients Undergoing Open Liver Resection for Hepatocellular Carcinoma or Intrahepatic Bile Duct Stones: A Randomized Controlled Clinical Trial.

Purpose: External oblique intercostal (EOI) block has recently emerged as a promising analgesic method for the upper abdominal surgery. This study aimed to assess the effect of EOI block on postoperative analgesia and early recovery following open liver resection (OLR). Patients and Methods: In this prospective, randomized, controlled trial, 64 patients scheduled for OLR were randomly allocated into EOI group and control group. EOI group received 30 mL of 0.25% ropivacaine bilaterally 30 min before induction of general anesthesia, whereas control group did not receive any block. The primary outcomes were sufentanil consumption 24 h after surgery. The secondary outcomes mainly included: the visual analogue scale (VAS) pain scores at rest and on coughing at 2, 12, 24, 48 h postoperatively; number of analgesia pump compression 24 h postoperatively; quality of recovery-15 (QoR-15) scale score 48 h after surgery; Pittsburgh sleep quality index (PSQI) score the first night postoperatively; and plasma levels of norepinephrine (NE), cortisol (Cor), high mobility group box protein 1 (HMGB1), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) 1h before surgery and 6 h postoperatively. Results: A total of 60 patients had completed the study (n = 30 per group). Sufentanil consumption 24 h postoperatively in EOI group was less than that in control group (mean difference: 4.45 μg, 95% CI, 1.6-7.2, P=0.003). The VAS scores at 2, 12, 24 h postoperatively; number of analgesia pump compression; and PSQI scores were significantly lower in EOI group than in control group. QoR-15 scale scores were higher in EOI group. The plasma levels of NE, Cor, HMGB1, TNF-α and IL-6 at 6 h postoperatively in EOI group were significantly lower than in control group. Conclusion: EOI block given to patients undergoing OLR could provide effective postoperative analgesia, enhance the quality of postoperative recovery, and attenuate postoperative stress and inflammation.