A therapy that combines midazolam, ketamine, and ondansetron is more effective for sedation in cataract surgery than standard therapy, according to a study presented here at the 2018 Annual Meeting of the American Academy of Ophthalmology (AAO).
In addition, the combination therapy decreased patient anxiety and reduced the need intravenous medications, reported Maggie Jeffries, MD, Avanti Anesthesia, Houston, Texas.
“As technology advances in cataract surgery with things like the femtosecond laser, the patient needs to be more awake and more cooperative during surgery,” explained Dr. Jeffries. “That has been a challenge for anaesthesiology.”
The need for conscious sedation has motivated the study of novel agents like midazolam, ketamine, and ondansetron, she added.
The study compared 3 types of sedation: diazepam, diazepam combined with tramadol and ondansetron, and midazolam, ketamine, and ondansetron, with the latter being administered as a sublingual tablet.
Patients were randomised to 1 of the 3 types of sedation and were matched by age, health status, age, and co-axial length.
Additional intravenous medications were administered in 38% of diazepam-treated patients, 32% of patients in the of diazepam/tramadol/ondansetron group, and in 27% of patients exposed to the combination of midazolam, ketamine, and ondansetron. Anxiety was cited as being the leading reason for the use of additional intravenous medications.
“Fentanyl or intravenous narcotic would be given if the patient was uncomfortable,” said Dr. Jeffries.
Patients who were treated with midazolam, ketamine, and ondansetron had a statistically significant decreased incidence of anxiety and reliance on intravenous medications, she said.
No significant differences were observed in surgical or discharge times or surgeon or patient satisfaction nor toxicities across the three arms.
“The great thing about this [novel combination] is that it is opioid-sparing,” said Dr. Jeffries. “This means that you are sparing patients from the risk of respiratory depression and breathing problems.”
More research is needed to determine the optimal dose of the medication, she noted.