Dexmedetomidine vs. Remifentanil Undergoing Cataract Surgery in Geriatrics

The Comparison of Dexmedetomidine and Remifentanil Infusion in Geriatric Patients Undergoing Outpatient Cataract Surgery: A Prospective, Randomized, Blinded Study

Dexmedetomidine is an α2-adrenergic receptor agonist used for its sympatholytic effect, providing sedation, analgesia, and cardiovascular stabilization in the perioperative period. Remifentanil is a µ opioid agonist with a rapid onset and short duration of action, which is degraded by plasma esterase in tissues. Investigators aimed to compare the effects of dexmedetomidine and remifentanil infusions on sedation quality, side effects, and surgeon's satisfaction in geriatric outpatients who underwent cataract surgery.

Dexmedetomidine is an α2 agonist and remifentanil is a short-acting μ, opioid agonist. The aim of this study was to compare dexmedetomidine and remifentanil infusions used for conscious sedation in geriatric patients undergoing outpatient cataract surgery in terms of sedation quality, hemodynamic stability, and surgeon satisfaction. Eighty patients were divided into two groups according to the administration of dexmedetomidine (Group D) and remifentanil (Group R) infusion in this randomized, prospective, double-blinded study. In group D (n = 40), after a loading of 1 µg/kg dexmedetomidine in 10 minutes, 0.4 µg/kg/h-1 infusion was administered. In Group R (n = 40), remifentanil at a dose of 0.05 µg/kg-1 was administered for 10 minutes, and then 0.05 µg/kg/min-1 infusion was continued.

geriatrics, ambulatory surgery, cataract, anesthesia, conscious sedation, dexmedetomidine, remifentanil

The surgeon who performed the surgery, the participants included in the study, and the technician who collected the study data were unaware of the study groups and the type of drugs used for sedation.

Dexmedetomidine (Precedex, Meditera, USA) was administered at a loading dose of 1 µg/kg for 10 minutes before local anesthesia to be applied to the eye by the surgeon. During the surgical procedure, it was administered at a dose of 0.4 µg/kg/h-1 infusion.

Remifentanil (Ultiva, Glaxo SmithKline, Turkey) infusion was started at a dose of 0.05 µg/kg/min-1, 10 minutes before the start of the surgery as baseline infusion and continued at the same infusion dose throughout the surgical procedure.

After Dexmedetomidine infusion was given for 10 minutes, local anesthesia was applied by the surgeon. Peribulbar block and periorbital infiltration application were performed by applying a mixture of lidocaine (Jetokain, Adeka, Turkey) and 1/200000 adrenaline. After the local anesthetic agent was applied by the surgeon, orbital compression was provided for 5 minutes with maximum pressure to block the eyelid movements. Cataract surgery procedures of all patients included in the study were performed by the same surgeon.

After Remifentanil infusion was given for 10 minutes, local anesthesia was applied by the surgeon. Peribulbar block and periorbital infiltration application were performed by applying a mixture of lidocaine (Jetokain, Adeka, Turkey) and 1/200000 adrenaline. After the local anesthetic agent was applied by the surgeon, orbital compression was provided for 5 minutes with maximum pressure to block the eyelid movements. Cataract surgery procedures of all patients included in the study were performed by the same surgeon.

The Observer Assessment Warning/Sedation Scale (OAA/S) was used to determine the sedation quality of each patient. The minimum and maximum values of OAA/S scale was between 0 and 5. Lower scores mean a better sedation quality.

Time interval immediately after the start of the surgery and before the patient is transferred to the postoperative care unit.

Bispectral Index (BIS) was used to determine the sedation level of each patient. The minimum and maximum values for BIS were between 0 and 100. Lower scores mean a deep sedation level.

The Verbal Rating Scale was used to determine severity of the pain in the perioperative period. VRS is a 5-point scale including expressions defining the level of pain intensity (no pain, mild pain, moderate pain, intense pain and maximum pain). Higher scores mean intense pain.

The Vissual Analogue Scale (VAS) was used to measure the frequency and severity of nausea and vomiting in the perioperative period. The VAS score is discovered by measuring the distance (mm) on the 100-mm line. Patients scoring 75 mm or more were considered to have clinically significant nausea and vomiting.

The surgeon's satisfaction in terms of the patient's sedation level, cooperation, and anesthesia management was evaluated using a questionnaire. The clinician satisfaction questionnaire was also classified as follows; 0: Not satisfied, 1: Less Satisfied, 2: Satisfied.

The Visual Analogue Scale (VAS) was used to determine the pain intensity in the postoperative period. The pain score is discovered by measuring the distance (mm) on the 100-mm line. Pain level was classified as follows; no pain (0-4 mm), mild pain (5-44 mm), moderate pain (45-74 mm), and severe pain (75-100 mm).

Immediately after the surgical procedure is completed and the patient is transferred to the postoperative care unit and before the patient is transferred to the outpatient service.

Inclusion Criteria: Patients between the ages of 65-80, Who will undergo cataract surgery, With the American Society of Anesthesiologists (ASA) score I-III. Exclusion Criteria: Second or third-degree heart block, Chronic α2-agonist use, Inability to communicate with the patient, Uncontrolled systemic disease, Allergy to local anesthetics, Chronic analgesic or sedative drug use, History of alcohol or substance addiction.

Kumar CM, Seet E, Eke T, Irwin MG, Joshi GP. Peri-operative considerations for sedation-analgesia during cataract surgery: a narrative review. Anaesthesia. 2019 Dec;74(12):1601-1610. doi: 10.1111/anae.14845. Epub 2019 Sep 19.