Agents for sedation in ophthalmic surgery: A review of the pharmacodynamics and clinical applications

Effectiveness and safety of intravenous dexmedetomidine sedation for ophthalmic surgery under regional anesthesia

PURPOSE

To assess the effectiveness and safety of intravenous (IV) dexmedetomidine for sedation in ophthalmic surgery.

METHODS

Prospective, observational, uncontrolled, single-center study. Patients were sedated with a continuous dexmedetomidine IV infusion started 15 min before regional anesthesia administration and maintained up to the end of surgery. Effectiveness of dexmedetomidine was assessed by the Modified Observer's Assessment of Alertness and Sedation (MOAA/S) targeted at 5. Safety was assessed by the incidence of patients' movements/snoring and by the incidence of respiratory and haemodynamic complications. An eleven-point numerical rating scale (NRS) was used to assess the level of satisfaction of both the surgeon and the patient.

RESULTS

123 patients (73 males, mean age: 63 ± 13) were included; 81 (81/123; 65.8%) patients reached the requested MOAA/S score of 5. Any intraoperative movement - mostly voluntary - occurred in 34 (34/123; 27.6%) cases with no need for a switch to general anaesthesia; no ocular complications related to the intraoperative movements occurred. Intraoperative snoring occurred in 30 (30/123; 24.4%) patients and it did not affect the surgical manoeuvres. Respiratory drive depression requiring manual or mechanical ventilation never occurred. Bradycardia occurred in 14 (14/123; 11.3%), cases but only 4 (4/123; 3.2%) patients required atropine administration, which was always effective. Intraoperative analgesia was consistently obtained and both the surgeons and the patients reported a high NRS satisfaction score.

CONCLUSION

Dexmedetomidine provided adequate sedation in patients undergoing ocular surgery under local anaesthesia and showed a good effectiveness and safety profile. Upper airway obstruction, apnoea and snoring can occur.

Comparison of the Sedation Quality of Etomidate, Propofol, and Midazolam in Combination with Fentanyl During Phacoemulsification Cataract Surgery: A Double-Blind, Randomized, Controlled, Clinical Trial

Background

According to the favorable effects of combination therapy to provide better sedation during phacoemulsification and lack of any studies investigating the sedative effect of etomidate, propofol, and midazolam in combination with fentanyl during the procedure.

Objectives

The current study aimed at comparing the sedative properties of the mentioned three combination therapies in this field.

Methods

The current double-blind, randomized, controlled clinical trial was conducted on patients referred for elective phacoemulsification surgery under sedation. They were randomly allocated to the three groups to receive fentanyl plus one of the following medications: Propofol, midazolam, and etomidate. Demographic characteristics, medical condition, and hemodynamic parameters before, during, and after surgery, sedation level, anesthetic complications, sedation-related adverse events, and patients' and surgeons' satisfaction were evaluated and recorded by the anesthesiologist and compared in the three studied groups.

Results

In the current study, out of 150 enrolled patients, 98 completed the study. Frequency of different levels of Ramsay scores was not significantly different between the groups (P = 0.41). Frequency of Ramsay scores 3 and 4 was 92%, 79.4%, and 88.2% in etomidate, midazolam and propofol groups, respectively (P = 0.32). The median recovery time was significantly higher in the midazolam group than the propofol group (P = 0.04); intergroup comparisons indicated that the patients' mean score of satisfaction in the propofol group was significantly higher than that of the etomidate group (P = 0.006).

Conclusions

The current study findings indicated that though the quality of sedation during phacoemulsification cataract surgery was acceptable in the three agents and the results had no significantly differences among the groups, and considering other factors including recovery time, hemodynamic evaluation, sedation-related complications, and patients' satisfication scores, it is suggested that propofol was superior to the other two agents.