Propofol in emergency medicine: Pushing the sedation frontier

Abstract

Is propofol an appropriate agent for use as part of emergency department (ED) procedural sedation and analgesia? Few questions in emergency medicine are currently as controversial. No one disputes that propofol exhibits numerous exceptionally desirable characteristics as a procedural sedation and analgesia agent. First, its clinical effect is essentially immediate after intravenous administration (“one arm–brain circulatory time”). Second, its marked potency reliably produces effective procedural sedation and analgesia conditions, even for very painful procedures. Third, recovery after sedation is extremely short, typically between 5 and 15 minutes. Finally, patient satisfaction is high because propofol has anti-emetic and apparent euphoric properties. It is no wonder that this agent has revolutionized anesthesiology practice. Many emergency physicians have already extrapolated this proven operating room success to our setting, using propofol as a single agent or in combination with an opioid, to successfully induce brief but potent sedation for short, painful procedures such as orthopedic manipulations, cardioversion, and abscess drainage. However, this application is based on limited experience because, thus far, only 8 small series of ED propofol use have been formally reported (Table).1-8 Despite this, proponents believe that there are sufficient studies in the anesthesia literature demonstrating the safety and efficacy of propofol to justify its use in the ED.9 Although hypotension, apnea, pain on injection, and bacterial contamination of the lipid emulsion have been reported, the primary criticism of propofol for procedural sedation and analgesia has focused on the greater sedation depth that typically results from propofol. Using the traditional propofol for procedural sedation and analgesia combination of midazolam and fentanyl, emergency physicians can reliably (albeit laboriously) titrate patients to either a state of “moderate sedation” (ie, purposeful responsive to verbal or tactile stimulation)10 or “deep sedation” (ie, purposeful responsive to repeated or painful stimulation).10 It is widely accepted that such moderate sedation is unlikely to be associated with impairment of protective airway reflexes, and thus aspiration risk in this setting is minimized.11 In contrast, however, the ultrarapid onset and high potency of propofol make it more difficult to titrate and prone to potentially substantial overshoot. Within 30 seconds of a single intravenous dose of propofol, a patient’s sedation depth could, without always a high level of predictability, be compatible with moderate sedation, deep sedation, or perhaps general anesthesia.12 Although all nondissociative sedatives can induce depth at all levels of the sedation continuum, in practice, propofol is primarily used for deep sedation.3-8,13 Anesthesiologists have been especially concerned about propofol use by nonanesthesiologists14 and have not differentiated such practitioners by skill set, lumping together emergency physicians with dentists, radiologists, and gastroenterologists.15,16 Pharmacy and therapeutics committees in many hospitals have blocked use of propofol for ED procedural sedation and analgesia because of objection by anesthesiologists on the committee. The paucity of data on the safety of propofol for ED procedural sedation and analgesia has made it difficult at times to overcome these objections. Four years ago, one of us characterized propofol as “not yet ready for prime time” in emergency medicine.12 This cautionary commentary raised concerns regarding the risk of inadvertent oversedation with propofol, personnel requirements, Joint Commission on Accreditation of Healthcare Organizations (JCAHO) standards, and fasting in the setting of deep sedation. Large case P A I N M A N A G E M E N T / E D I T O R I A L