Comparing the preventive effect of 2 percent topical lidocaine and intravenous atropine on oculocardiac reflex in ophthalmological surgeries under general anesthesia

The current study aimed to determine preventive effect of 2 percent topical xylocaine on oculocardiac reflex in ophthalmological surgeries except strabismus, including retinal detachment and vitrectomy with scleral buckling under general anesthesia. A randomized controlled clinical trial was carried out on 150 patients aged 18-90 years undergoing ophthalmological surgeries under general anesthesia. Samples randomly divided into the experimental group [received four drops of 2 percent topical xylocaine instilled in desired eye] and control group [received 0.5 mg atropine sulfate injection]. Systolic, diastolic and mean arterial blood pressure of patients and baseline heart rate were recorded. They were compared regarding the incidence of bradycardia, heart rate less than 60 beats/minute, hypotension and blood pressure less than 90 mm/Hg. Data were analyzed by Statistical Package for the Social Sciences software version 20 using Chi-square and ANOVA. The difference between two groups was not statistically significant regarding demographic and basic variables. The incidence of bradycardia in both groups was respectively [90.7 percent vs. 17.3 percent], heart rate less than 60 beats/minute [40 percent vs. 13.3 percent], hypotension [76 percent vs. 32 percent] and blood pressure less than 90 mmHg was [28 percent vs. 8 percent]. Accordingly, the differences between both groups were statistically significant [P > 0.001]. The preventive impact of topical xylocaine upon oculocardiac reflex in ophthalmological surgeries such as retinal detachment and vitrectomy with scleral buckling under general anesthesia was less effective than that of atropine injection. Therefore, to avoid this reflex in high risk patients, injecting atropine would be safer.

Adjunctive local application of lidocaine during scleral buckling under general anesthesia

To evaluate the effect of local lidocaine application on the incidence of the oculocardiac reflex [OCR] during scleral buckling [SB] for rhegmatogenous retinal detachment [RRD] under general anesthesia. In a randomized clinical trial, eyes with RRD scheduled for SB under general anesthesia were randomized to adjunctive local application of 1 ml lidocaine 2% versus normal saline to the muscles after conjunctival opening. Surgical stimulation was initiated 5 minutes afterwards. Additionally, 100 mg of lidocaine 2% was added to 50 ml of normal saline in the treatment group which was used for irrigation during surgery; control eyes were irrigated with normal saline. The incidence of the OCR, rate of postoperative nausea/vomiting [PONV], total intravenous [IV] analgesic dose, duration of surgery, and period of hospitalization were compared between the study groups. Thirty eyes of 30 patients including 22 [73.3%] male and 8 [26.7%] subjects with mean age of 49.4 +/- 16.3 years were operated. OCR and PONV occurred less frequently, and total intravenous analgesic dose was significantly lower in the lidocaine group [P < 0.05 for all comparisons]. However, no significant difference was noted between the study groups in terms of duration of surgery and period of hospitalization. Adjunctive local application of lidocaine during SB under GA for RRD decreases the rate of OCR and PONV, reduces the intravenous analgesic dose, but does not affect the duration of surgery or hospitalization