The effects of modified deep serratus anterior plane block on surgical stress and perioperative neurocognitive disorders in elderly patients undergoing thoracic surgery: a randomized clinical study

Abstract Background To evaluate and compare the effects of a modified deep serratus anterior plane block (DSPB) combined with general anesthesia on surgical stress and perioperative neurocognitive disorder (PND) in elderly patients undergoing thoracic surgery, providing a new way to reduce the occurrence of PND in elderly patients undergoing thoracic surgery. Methods Sixty-six patients undergoing thoracic surgery were randomly assigned to receive either single-shot DSPB or local block after tracheal intubation using ropivacaine 0.5% 20 mL. The primary outcomes were the visual analog scale (VAS) score at each time point and the Montreal cognitive assessment (MoCA) score before surgery and after discharge from the hospital (or seventh day postoperative). Secondary outcomes included drug consumption, vital signs, blood gas analysis, malondialdehyde, superoxide dismutase, and serum cortisol levels. Results Sixty patients were eventually enrolled in this study. The VAS scores were significantly lower in the DSPB group than in the local block group (all P < 0.05). The difference in blood gas analysis index TCO2 (27.71 ± 3.49 vs 29.31 ± 2.26) in the two groups was statistically significant (P < 0.05). The length of hospitalization in the DSPB group was shorter than that in the local block group (6.03 ± 1.35 vs 7.20 ± 1.49), and the difference was statistically significant (P < 0.05). There were no statistically significant differences in MoCA scores before surgery and after hospitalization (or the seventh day postoperative), stress indices, vital signs, bispectral index value, blood gas analysis (except TCO2), and drug addiction during extubation at each time point (all P > 0.05). Conclusion Compared with local block, DSPB provided a superior analgesic effect with a lower VAS score and shorter length of hospitalization in elderly ptalatients undergoing thoracic surgery. It does not require ultrasound equipment, making it simpler and easier to operate, and is especially suitable for widespread implementation in grassroots hospitals.