Effect of linearly polarized light irradiation near stellate ganglion on postoperative sleep disorders in patients undergoing modified radical mastectomy of breast cancer.

BACKGROUND: Stellate ganglion block (SGB) improves postoperative sleep quality but is associated with a variety of complications. Linearly polarized light irradiation near the stellate ganglion region (LI-SG) is a non-invasive alternative. We investigated the effect of LI-SG on postoperative sleep disorders in patients undergoing modified radical mastectomy of breast cancer. METHODS: This prospective, randomized, controlled trial was conducted between June 2024 to December 2024, enrolling 114 patients undergoing modified radical mastectomy. Participants were randomly assigned to the control or the LI-SG group. The primary outcome was subjective sleep quality assessed using the Pittsburgh Sleep Quality Index (PSQI). Objective sleep measures (sleep efficiency, total sleep time and awaking times), visual analog scale (VAS) score, total number of patient-controlled anesthesia (PCA) compressions, serum indicators, and adverse events were recorded as the secondary outcomes. RESULTS: Compared to the control group, the PSQI and sleep efficiency, total sleep time and awakening times showed significant improvement at the second (all P < 0.001) and the 5th postoperative day (all P < 0.001) in the LI-SG group. The VAS score (3.51 ± 0.77 vs 2.51 ± 0.47, P < 0.001) and total number of PCA compressions (15.39 ± 2.11 vs 5.62 ± 1.53, P < 0.001) in the LI-SG group were significantly decreased. The serum melatonin was significantly increased, while TNF-α and IL-6 levels were decreased in the LI-SG groups at the second (all P < 0.001) and the 5th postoperative day (all P < 0.001). Furthermore, compared to the control group, the incidence of postoperative nausea and vomiting (16.07% vs 5.17%, P < 0.001) was lower and the patient satisfaction (4 vs 6, P < 0.001) was higher in the LI-SG group. CONCLUSION: LI-SG improved the postoperative sleep quality and analgesic effect of patients, while improving patient satisfaction.