Abstract
PURPOSE: Effect of intravenous sedation on patients' visual experience and vital signs during cataract surgery under topical anesthesia: a randomized controlled trial. DESIGN: Prospective, double masked, randomized controlled trial. METHODS: 150 eyes of 150 patients undergoing phacoemulsification and IOL implantation under topical anesthesia were randomized to receive either intravenous midazolam (0.015 mg/kg) or normal saline. The patients' experience was evaluated using a questionnaire. Vital signs including blood pressure and heart rate were measured before, during and after surgery. Mean arterial pressure (MAP) was calculated. RESULTS: Both groups were comparable except that fewer patients in the control group were pseudophakic in the fellow eye (25.3% vs. 41.3%). More patients in the control group perceived hand movements (p < 0.01), surgeon/medical staff (p = 0.04) and sudden increase in vision during surgery (p < 0.01) compared to midazolam group. More control group patients experienced fear (p < 0.001), pain (p = 0.06) and unpleasant surgical experience (20.3% vs. 1.3%, p < 0.001). They also experienced greater fluctuation in MAP (16.9 ± 7.9 vs.7.2 ± 5.3, p < 0.001) and this was accentuated in hypertensives. After adjusting for age, gender, hypertension status and other eye lens status, multivariable logistic regression analysis revealed that subjects in the control arm (OR = 11.7, 95% [CI] = 1.3-108, p = 0.03), had a longer duration of surgery, experienced pain and more likely to report unpleasant experience. Adjusting for similar covariates, multivariable linear regression analysis showed that control group patients (β = 8.5 mmHg, 95% CI = 6.2-10.8, p = 0.03) had hypertension, experienced fear during surgery and greater fluctuations in the MAP. CONCLUSIONS: A sedative dose of intravenous midazolam during phacoemulsification under topical anesthesia significantly reduces patients' visual experience, fear and fluctuations in MAP and improves overall surgical experience.