Analgesic and Sedative Effects of Dezocine and Midazolam During Vitrectomy

To evaluate the analgesic and sedative effectiveness of dezocine and midazolam in vitrectomy.

One hundred and sixty patients undergoing vitrectomy were randomized into four groups. The control group was given local anesthetic in retrobulbar nerve block only, while the other three groups received a single dose of 0.1 mg/kg dezocine or/and 0.05 mg/kg midazolam (groups D, M, DM), respectively, at 10 min before retrobulbar block. Mean arterial pressure (MAP), heart rate (HR), and oxygen saturation (SpO₂) were recorded prior to local anesthesia (Tp), at the start of surgery (T0), 5, 15, 30 min during (T1-T3), and at the end of surgery (T4). Pain at T2 and T4 was assessed by Numeric Rating Scale (NRS). Level of sedation at T2 was assessed using the Ramsay scale. Postoperative nausea and vomiting (PONV) events were recorded for 24 h.

Group DM showed a decrease in HR during T0-T4 compared to Tp (p < 0.001). The MAP of all groups decreased significantly at T0 compared to Tp (p < 0.05), but remained unchanged at T1-T4. At T2, all groups have lower pain level than control (p < 0.001), while group DM showed the lowest pain level. At T4, groups D and DM showed a lower pain level than control (p < 0.01). Groups M and DM showed a higher Ramsay score than group C (p < 0.01). Compared with control, group D had a higher PONV rate (p < 0.1). Groups M and DM showed a lower PONV rate than group D (p < 0.0001), and group M had a lower PONV rate than group C (p < 0.01).

Combinatory use of dezocine and midazolam in addition to local anesthetic in retrobulbar nerve block can help relief pain and anxiety during vitrectomy and reduce PONV.