Clinical Research On The Enhancement Of Dexmedetomidine In Local Anesthesia For Ophthalmic Surgery

Dexmedetomidine is a new type of high selectiveα₂-adrenergic receptor agonists, which has sedative, analgesic and anxiolytic effects, can maintain hemodynamic stability, has no respiratory depression, amnesia after surgery and son on. Therefore it has applications in many fields of clinical medicine, especially as an adjuvant in anesthesia, providing the anesthesiologist a new choice. However, there is little research about giving the dexmedetomidine in ophthalmic surgery.Objective: Evaluate the effects of sedative, analgesic, maintaining hemodynamic stability and forgotten, when dexmedetomidine was applicated to patients in ophthalmic surgery under local anesthesia.Methods: Select 100 patients who were undergoing ophthalmic surgery with local anesthesia as the research object, 50 patients with vitrectomy, 50 patients with trabeculectomy. All the patients were ASAⅠ-Ⅱ, aged 16-80 years, weight 35-80 kg, of Which 50 patients with vitrectomy and the other 50 ones with trabeculectomy. Patients were divided into two groups, the experimental group(dexmedetomidine group) and control group (placebo group). Each group has 50 patients. The patients of the experimental group before surgery 10 min were given dexmedetomidine loading dose of 0.5μg/kg, the infusion time is greater than 10 min, followed by 0.5μg /(kg·h) for maintenance; control group received an equal volume of physiological salt. When the surgeon with 2% lidocaine for peribulbar anesthesia, the two groups of patients were given intravenous injection of half the amount of fentany-droperidol mixture (fentanyl 50μg+droperidol 2.5mg). Routine monitoring and recording the respiratory rate (RR), heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), main arterial blood pressure(MAP), VAS score and Ramsay score of patients in each group at 10 min before surgery (T₀), the time of starting surgery(T₁), 10 min after the start of surgery(T₂), 30 min after the start of surgery(T₃), 60 min after the start of surgery(T₄) and at the end of surgery (T₅), at the same time, recording the level of cooperation between intraoperative, the degree of surgical forgotten and postoperative adverse. Use SPSS 13.0 statistical software for statistical processing.Results:1. The difference between experimental group and control group in age, gender, weight and operation tine was not statistically significant. The two group had comparability.2. Ramsay score was not significantly different between two groups at T₀, while was at T₁～T₅. Furthermore, Ramsay score in experimental group was significantly higher than control group.3. VAS score was not significantly different between two groups at T₀, while was at T₁～T₅. Furthermore, VAS score in experimental group was significantly lower than control group.4. At the time of T₀, SBP was not significantly different between experimental group and control group, while HR, DBP and MAP were. Furthermore, HR, DBP and MAP in experimental group were significantly lower than control group. At the time of T₁, HR, DBP and MAP were not significantly different between two groups, while SBP was. Furthermore, SBP in experimental group was significantly lower than control group. At the time of T₁～T₅, HR, SBP, DBP and MAP were significantly different between two groups, and all of them in experimental group were significantly lower than control group.5. RR was not significantly different between two groups at T₀, while was at T₁～T₅. Furthermore, RR in experimental group was significantly higher than control group.6. Cooperation degree of patients was not significantly different between experimental group and control group during surgery. The degree of postoperative forgotten was significantly different between two groups, and the rate of completely forgotten in experimental group (68%) was statistically higher than control group (0%).7. The number of cases of nausea, vomiting, respiratory depression, bradycardia, restlessness and drowsiness were not significantly different between experimental group and control group.Conclusion:1. The application of dexmedetomidine in ophthalmic surgery under local anesthesia could make the Ramsay score of experimental group significantly higher, with providing comfortable calm for patients and not decreasing the cooperation degree during surgery.2. Dexmedetomidine had analgesic effect, which can increase tolerability to pain for patients with ophthalmic surgery under local anesthesia.3. Dexmedetomidine could maintain hemodynamic stability.4. Dexmedetomidine could eliminate poor memory appearing because of anesthesia and operation of surgery in ophthalmic surgery under local anesthesia. Therefore, dexmedetomodine had a certain line of the forgotten role.5. The application of dexmedetomidine in ophthalmic surgery under local anesthesia will not produce nausea, vomiting, respiratory inhibition, bradycardia, restlessness and drowsiness.