Density Spectral Array Enables Precise Sedation Control for Supermicrosurgical Lymphaticovenous Anastomosis: A Retrospective Observational Cohort Study

Supermicrosurgical lymphaticovenous anastomosis (LVA) is a minimally invasive surgical technique that creates bypasses between lymphatic vessels and veins, thereby improving lymphatic drainage and reducing lymphedema. This retrospective single-center study included 137 patients who underwent non-intubated LVA in southern Taiwan. A total of 119 patients were enrolled and assigned to two study groups: the geriatric (age ≥ 75 years, n = 23) and non-geriatric groups (age < 75 years, n = 96). The primary outcome was to investigate and compare the arousal and maintenance of the propofol effect-site concentration (Ce) using an electroencephalographic density spectral array (EEG DSA) in both groups. The results showed that the geriatric group required less propofol (4.05 [3.73–4.77] mg/kg/h vs. 5.01 [4.34–5.92] mg/kg/h, p = 0.001) and alfentanil (4.67 [2.53–5.82] μg/kg/h vs. 6.68 [3.85–8.77] μg/kg/h, p = 0.047). The median arousal Ce of propofol among the geriatric group (0.6 [0.5–0.7] μg/mL) was significantly lower than that in patients aged ≤ 54 years (1.3 [1.2–1.4] μg/mL, p < 0.001), 55–64 years (0.9 [0.8–1.0] μg/mL, p < 0.001), and <75 years (0.9 [0.8–1.2] μg/mL, p < 0.001). In summary, the combined use of EEG DSA provides the objective and depth of adequate sedation for extensive non-intubated anesthesia in late-elderly patients who undergo LVA without perioperative complications.