Newswise — Although it may not relieve pain to the same degree as intrathecal morphine (ITM), ultrasound-guided bilateral rectus sheath block (RSB) is associated with earlier return of intestinal function and similar patient satisfaction scores which may hold promise for fast-track surgery protocols according to the results of a study from the All India Institute of Medical Sciences (AIIMS) in New Delhi, India.

Alkananda Behera, Vimi Rewari, Rashmi Ramachandran, Anjan Trikha, and Sunesh Kumar received a Best of Meeting Award for their abstract of the study, “A Non-inferiority Trial of Ultrasound-Guided Bilateral Rectus Sheath Block With Multimodal Analgesia Versus Intrathecal Morphine in Gynaecological Oncology Surgery,” which will be presented on Thursday, April 11, 2019, during the 44th Annual Regional Anesthesiology and Acute Pain Medicine Meeting in Las Vegas, NV.

Use of opioids for postoperative analgesia increases the risk of sedation, nausea, vomiting, constipation, pruritus, and paralytic ileus, all of which impair early recovery and prolong hospital stay and introduce the potential for addiction. Intrathecal opioids, delivered into the spinal space, have been a breakthrough in pain management; however, they are also associated with undesirable adverse effects, particularly nausea, vomiting, and pruritus, which reduce overall patient satisfaction. Truncal blocks (transversus abdominis plane and RSB in particular) have emerged as an alternative pain management modality that provide effective analgesia without the side effects of opioids.

To evaluate whether RSB in combination with multimodal analgesia (i.e, non-opioid drugs like paracetamol, dexamethasone, and diclofenac) provided similar analgesia compared with the standard pain management technique of intrathecal morphine (ITM), researchers conducted a study in 90 women undergoing gynecologic cancer surgeries with a midline incision. In the prospective, randomized, concealed allocation, non-blinded, non-inferiority trial, patients were randomized to an ITM or RSB group and were monitored for the overall use of patient-controlled analgesia (PCA) morphine and side effects thereof.

More patients in the RSB group used PCA morphine than in the ITM group (p = 0.001). Postoperative pain scores at rest and on movement were higher in the RSB group at 6, 12, and 24 hours and at 2, 4, 6, 12, and 24 hours, respectively (p < 0.05). Postoperative nausea and vomiting and pruritus scores were statistically lower in the RSB group at 30 minutes, 1 hour, and 2 hours postoperatively, but patients in the ITM group were significantly more sedated at 24 hours. The mean time to the return of gastro-intestinal function as determined by the passage of flatus was also significantly higher in the ITM group. Patients were, however, equally satisfied with either analgesic regime (p = 0.32).

The study failed to prove that RSB alleviates pain to the same degree as ITM. However, it reduced the problematic side-effect of postoperative ileus and contributed to equivalent patient satisfaction scores as in the ITM group. The researchers concluded that ITM is superior to RSB for postoperative pain relief in gynecologic cancer surgeries. But a limitation of the study was the non-usage of continuous infusion of local anesthetics via catheters in the RSB group which might have prolonged the duration of analgesia in this group. They added that, however, further studies are needed to establish the role of this pain-block technique in terms of its supposed advantage of opioid-sparing effect and better side-effect profile as the study was not adequately powered to address these outcomes.

The 44th Annual Regional Anesthesiology and Acute Pain Medicine Meeting will be held April 11–13, 2019, in Las Vegas, NV. The conference brings together worldwide experts in acute pain medicine to discuss standard and novel techniques, new pain targets, and strategies to address the opioid epidemic.