Kristi Tinsbloom, PharmD candidate 2015, Mercer University College of Pharmacy
There are several agents in the benzodiazepine drug class that are approved by the Food and Drug Administration (FDA) for use as premedication in surgical patients undergoing general anesthesia. Examples of these include lorazepam and midazolam; they are used primarily for their ability to relieve anxiety prior to surgery as well as induce amnesia (diminish recall) after the procedure.1
According to the package insert for lorazepam, recommended intravenous dosing for premedication in surgical patients is 2 mg total or 0.044 mg/kg, whichever dose is smaller. However, in patients in whom a lack of recall is highly desired, doses of 0.05 mg/kg up to 4 mg total can be given. In patients older than 50, it is recommended not to exceed a 2 mg total dose. Amnesia effects from intravenous administration are optimal about 15 to 20 minutes after injection and last anywhere from 6 to 8 hours.2
|Title: Effect of Sedative Premedication on Patient Experience After General Anesthesia: A Randomized Clinical Trial|
|Design||Randomized, placebo-controlled; 1062 participants|
|Objective||To assess the efficacy of sedative premedication on perioperative patient experience|
|Study groups||Three groups:
• Lorazepam 2.5 mg
• No premedication
|Methods||Patients undergoing elective surgery using general anesthesia were enrolled in the study. Patients were not included if they were having neurosurgery, obstetric, cardiac, or outpatient surgery. Patients were excluded if they requested anxiolytic premedication. All patients enrolled that were on chronic benzodiazepine therapy were allowed to take their medication until the day before surgery.|
|Duration||January 2013 through June 2014||Primary Outcome Measure||Perioperative patient experience assessed 24 hours after surgery with a validated questionnaire (Evaluation du Vécu de l’Anesthésie Generale; EVAN-G)|
|Baseline Characteristics||All patients:
• Below the age of 70
• Weight of 45 kg or more
• Having elective surgery under general anesthesia
• Capable of completing a self-report questionnaire
|Results||The EVAN-G mean global index (measuring overall patient satisfaction from 0-100 with 100 being a high satisfaction) for the lorazepam groups was 72, while the mean satisfaction score was 73 and 71 for the no premedication and placebo groups, respectively (p=0.38).|
|Adverse Events||Common Adverse Events: Not assessed|
|Serious Adverse Events: Not assessed|
|Percentage that Discontinued due to Adverse Events: 0%|
|Study Author Conclusions||Sedative premedication with lorazepam in patients undergoing elective surgery did not improve self-reported patient experience the day after surgery when compared with no premedication or placebo. However, lorazepam was associated with prolonged time to extubation and lower rate of early cognitive recovery. The findings of the study suggest a lacking benefit with using lorazepam as a routine sedative premedication in patients undergoing surgery with general anesthesia.|
This study showed no benefit in patient reported experience 24 hours after surgery with the use of lorazepam as premedication. The results of this study are not likely to impact current practice as the use of benzodiazepines for premedication prior to surgery is commonplace for their ability to relieve anxiety and produce amnesia. However, it is interesting that the study used a 2.5 mg dose in all patients in the lorazepam study group as opposed to a weight or age (patients older than 50) based approach.
1. Lorazepam. Mayo Clinic. http://www.mayoclinic.org/drugs-supplements/lorazepam-injection-route/description/drg-20072326. Accessed March 9, 2015.
2. Ativan (lorazepam) injection. Package Insert. http://www.accessdata.fda.gov/ drugsatfda_docs/label/2006/018140s028lbl.pdf. Accessed March 10, 2015.
3. Maurice-szamburski A, Auquier P, Viarre-oreal V, et al. Effect of sedative premedication on patient experience after general anesthesia: a randomized clinical trial. JAMA. 2015;313(9):916-25.