Procedural sedation and analgesia (PSA) has been proven safe and efficacious within the ED environment, and should be utilized when patients undergo painful procedures. The most important step beyond monitoring the patient involves extensive preparation, and at conclusion of the procedure, patients should return to their mental and physiologic baseline. In scenarios where the patient's severity of illness questions the applicability of ED sedation, one must judiciously review the risks and consider consultation with the anesthesiologist. Although the degrees of sedation can at times be ambiguous, observing the patient's progression and remaining vigilant for respiratory depression can diminish untoward effects and facilitate successful recovery and disposition.
Sedation is often utilized to facilitate care in the ED. PSA has replaced the previous nomenclature of “conscious sedation.” The American College of Emergency Physicians (ACEP) defines PSA as the “administration of sedatives or dissociative agents with or without analgesics to induce a state that allows the patient to tolerate unpleasant procedures while maintaining cardiorespiratory function. Procedural sedation and analgesia is intended to result in a depressed level of consciousness that allows the patient to maintain oxygenation and airway control independently.”
The controversy over nonanesthesiologists providing PSA primarily involves this last statement. Patients can easily progress to each successive stage of sedation to the point of apnea and respiratory arrest. The practitioner's goal should be to avoid progressive unconsciousness and remain capable in managing their cardiopulmonary function when necessary. Despite concerns, the efficacy and safety of ED procedural sedations have been demonstrated in numerous studies, and PSA has become a core skill in emergency medicine training and practice.
PSA is a spectrum involving light, moderate, deep, and general anesthesia levels necessitating the practitioner to be capable of recognizing the levels of sedation, and be prepared to rescue the next level of sedation if necessary. Some experts have proposed adding a separate category for dissociative anesthetics such as ketamine since its performance and side-effect profile differ a great deal from other forms of sedation. Each degree of sedation increases risk of cardiopulmonary instability with a likely need for aggressive intervention.
- Minimal sedation (anxiolysis)
A drug-induced state during which patients respond normally to verbal commands. Although cognitive function and physical coordination may be impaired, airway reflexes, and ventilatory and cardiovascular functions are unaffected.
- Moderate sedation/analgesia (“conscious sedation”)
A drug-induced depression of consciousness during which patients respond purposefully to verbal commands, either alone or accompanied by light tactile stimulation. No interventions are required to maintain a patent airway, and spontaneous ventilation is adequate. Cardiovascular function is usually maintained.
A drug-induced depression of consciousness during which patients cannot be easily aroused but respond purposefully following repeated or painful stimulation. Reflex withdrawal from a painful stimulus is not considered a purposeful response. The ability to independently maintain ventilatory function may ...