Effect of intravenous sedation on patients’ visual experience and vital signs during cataract surgery under topical anesthesia: A randomized controlled trial

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.