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.