Evaluating the Patient Before Anesthesia - Day of Surgery Premedication

Sedatives and analgesics

Sedatives and analgesics. The goal for administering sedatives and analgesics before surgery is to allay the patient’s anxiety, to decrease pain during administration of regional anesthesia or preoperative line placement, and to facilitate smooth induction of anesthesia. The dose of sedatives and analgesics should be reduced or withheld for the elderly, debilitated, or acutely intoxicated patient. The dose should also be decreased in a patient with upper airway obstruction, central apnea, neurologic deterioration, or severe pulmonary disease.

1. Benzodiazepines.
   1. Midazolam. Midazolam, 1 to 3 mg intravenously or intramuscularly, is a short-acting benzodiazepine that provides excellent anterograde amnesia and anxiolysis. It plays a role in preventing PONV. It is known to cause delirium in the elderly and to be synergistic with opioids in causing respiratory depression.
   2. Lorazepam. Lorazepam, 1 to 2 mg orally or intravenously, may cause more prolonged amnesia and postoperative sedation than midazolam.
2. Opioids. Opioids may be given preoperatively to a patient who has, or is anticipated to have, significant pain or to a patient who is opioid dependent. The opioid-dependent patient should receive sufficient premedication to overcome tolerance and to prevent perioperative withdrawal. Intravenous fentanyl is ideally dosed at least 2 to 5 minutes prior to airway instrumentation so that its effect blunts the reaction from laryngoscopy.