Oral Low-Dose Midazolam as Premedication for Intraocular Surgery in Retrobulbar Anesthesia: Cardiovascular Effects and Relief of Perioperative Anxiety

Abstract

The aim was to investigate the efficacy and practicability of oral low-dose premedication with 3.75 mg midazolam (1/2 tablet Dormicum 7.5 mg) for selective intraocular surgery with retrobulbar anesthesia. Forty-six ASA II-III patients were randomly assigned to either group I: midazolam (n = 24) or group II: placebo (n = 22). Sedation was objectively quantified with a scale derived from the Glasgow-Coma-Scale and a verbal self-rating scale. Trait-anxiety was studied with the State-Trait Inventory by Spielberger, perioperative situative anxiety with the Erlanger Anxiety Scale. Cardiovascular variables and oxygenation were automatically monitored. Midazolam produced significant and sufficient sedation and significant anxiolysis. Systolic, diastolic and mean blood pressure were moderately but significantly, reduced. The effect on diastolic pressure was more pronounced. There was no effect on heart-rate. Oxygenation at all times remained well above 90% SpO2. In conclusion low-dose oral midazolam proved to be a single and effective premedication before intraocular surgery under local anesthesia.

Oral premedication with low dose midazolam modifies the immunological stress reaction after the setting of retrobulbar anaesthesia

“…In our study, oral low dose midazolam was chosen for premedication in order to minimise the patient's risk, as "standard dose" administration of benzodiazepines might predispose to respiratory depression. In accordance with previous studies, 4 3.75 mg midazolam fulfilled the main goals of premedication for ophthalmosurgery, as it tended to induce anxiolysis and light to moderate sedation without causing too strong sedation that would result in a drowsy uncooperative patient, rendering the surgeon's handling of the patient difficult. Even though we did not compare short term memory loss between the two study groups, oral premedication with 3.75 mg midazolam has been shown before by us and by others 17 18 to induce significant anterograde amnesia.…”

“…21 It has been shown by us recently that male and female patients differ in the situative preoperative anxiety before intraocular surgery. 4 In order to increase the homogeneity of our patient groups, our study was restricted to women. In a strict sense, our results thus apply only to female patients, and may not be extrapolated to male patients.…”

“…4 It combines sufficient preoperative anxiolysis, amnesia, and only moderate sedation with greatest possible safety. 4 …”

Determinants of surgery related anxiety in cataract patients

“…5 This finding emphasises the need for postoperative counselling by the ophthalmologist. It remains unclear compared to former studies [13][14][15] why differences in anxiety related to anaesthesia did not exist between hospitals in advance of the retrobulbar block; keeping in mind that REH patients could anticipate sedation before local anaesthesia. To obtain a greater reduction of anxiety during the days before surgery, patients should be better informed about the calming effects of Dormicum.…”

The cardiovascular effects of midazolam co-induction to propofol for induction in aged patients

“…It has been widely used recently as the premedication agent of anesthesia because it was effective in resolving anxiety of surgery and in stabilizing the cardiovascular system during the perioperative period [22,23]. When performing the co-induction of anesthesia by combining midazolam with propofol, the single intravenous bolus administration of propofol or its gradual additional intravenous administration had shown the synergistic action of sleep effectiveness, indicating that such co-induction presents the effect of approximately 25-35% higher dose reduction in comparison to single respective doses of each medication [24].…”