Pharmacology of Procedural Sedation

M unpleasant, uncomfortable, and painful procedures take place throughout various areas in the hospital, including the emergency department, intensive care units, general medicine floors, and procedural areas. These procedures can include, but are not limited to, cardioversion, orthopedic injury reduction, burn debridement, endoscopy, bronchoscopy, and interventional imaging.1,2 Patients may experience anxiety about undergoing these procedures as they can cause pain and discomfort. This anxiety can occur in both adults and children and can lead to agitation, an increased stress response, and ultimately a patient who is unable to cooperate.2 The care provider’s goal is to minimize pain and anxiety experienced by patients, to ensure a safer environment for both the patient and the health care team, and to increase the chance of a successful procedure.1,2 Currently, procedural sedation is one of the best ways to accomplish this goal. Procedural sedation, previously known as conscious sedation, is defined as “a technique of administering sedatives or dissociative agents with or without analgesics to induce a state that allows patients to tolerate unpleasant procedures while maintaining cardiorespiratory function.”2(p861) Multiple pharmacological agents are capable of providing procedural sedation and/or analgesia. Commonly used agents include propofol, benzodiazepines, ketamine, opioids, and etomidate. To facilitate the initiation of a procedure and timely recovery from sedation, clinicians want to choose agents that have a fast onset of action and a short duration of action, in addition to minimal adverse effects. The duration of action of these commonly used agents varies; therefore, the anticipated length of the procedure and the duration of sedation required should be considered for dosing and monitoring purposes.1 Medications are commonly administered as bolus doses over continuous infusions to account for the length of the procedure. The potential adverse effects, most significantly hemodynamic changes and respiratory depression, of these sedative, analgesic, and dissociative agents should also be monitored.3 Emergency equipment must be readily available, and all patients undergoing procedural sedation should be appropriately monitored. In this column, we discuss the commonly used agents and highlight pertinent differences in characteristics and appropriate monitoring practices for procedural sedation.