Emergency department procedural sedation

Guidelines

The Australasian College for Emergency Medicine (ACEM), the Royal College of Emergency Medicine, American College of Emergency Physicians (ACEP) and the Canadian Association of Emergency Physicians (CAEP) have all published on the underlying principles for successful procedural sedation and analgesia. All guidelines cover presedation preparation and assessment, presedation fasting, physician skills, staffing, equipment and environment, patient monitoring, documentation and postsedation care. There has been a gradual change in the perception accorded to EDPS being performed in EDs over the past decade, and the use of intravenous ‘anaesthetic agents’ for EDPS is widely accepted and is now part of mainstream emergency medicine specialist training.

Best practice guidelines require that two medical attendants, one of whom should be a specialist or advanced trainee with sedation competency, be present. Nursing staff are also required, and the procedure must be performed in a resuscitation-capable area of the ED. Physiologic monitoring is mandated during the procedure and extending into the recovery phase. The practitioner must understand the agents available and choose based on the procedure being performed (e.g. the potential for pain, the likely duration of sedation and pain relief required and staff familiarity with the agent and its effects).

Depth and duration of sedation

The optimal end point of any sedation episode depends on the procedure being performed and patient’s characteristics. Sedation state classification ranging from minimal sedation (anxiolysis) through moderate sedation (formerly conscious sedation), deep sedation and general anaesthesia. Dissociative sedation is a separate state induced by ketamine. The exact characteristics of respiratory and/or airway reflex depression in relation to depth of sedation are not well defined and can be quite variable.

Titration of drug and constant verbal and tactile reassessment of the patient reduce the risk of oversedation. Some degree of responsiveness to painful stimuli should indicate preservation of airway reflexes, decreasing the risk of aspiration if vomiting occurs.

The duration of sedation is largely determined by the choice and dose of agent used and the procedure itself, as to whether this will be brief (e.g. shoulder reduction) or longer (e.g. compound scrub, or manipulation of fractures), with most ED procedures taking less than 20 minutes. The longer the sedation, the greater the risk of an adverse event.

Indications

Indications include, but are not limited to, fracture and dislocation reduction, incision and drainage of abscesses and cardioversion. Less painful but anxiety-provoking procedures in children will also be facilitated by the use of dissociative sedation (e.g. lumbar puncture, suturing, ocular or auditory canal FB removal or IV cannulation in an uncooperative and anxious child).

Departmental procedures and logistics

All departments that perform EDPS should have written guidelines, standardized data collection and suitably trained staff. Patient selection is informed by the pre-procedural risk assessment, by available departmental resources to successfully and safely perform the procedure and the sedation without jeopardizing patient care elsewhere in the department and by the ability to monitor and safely discharge the patient.

Age

A young patient’s level of anxiety and cooperation will depend upon past medical experiences, anxiety of the parent/s and the reassurance given by medical staff.

Children often present the challenge of initial lack of cooperation with the sedation process. Elderly patients, whilst mostly cooperative, may have underlying impairment of cardiorespiratory reserve and are at greater risk of respiratory depression or hypotension.

American Society of Anesthesiologists classification

The American Society of Anesthesiologists (ASA) classification system is a global score used to classify the physical status of patients before planned surgery ( Box 22.3.1 ). ASA class I and ASA II patients are usually preferred as candidates for procedural sedation in the ED. If an ASA class III patient requires sedation out of necessity, this should not preclude performance of the procedure. The management of respiratory depression becomes a more active issue with increasing ASA in all age groups.

Airway

An adverse past anaesthetic history or a focussed airway assessment with attention to mouth opening, pharyngeal visualization (Mallampati score), neck movement, thyromental distance and dentition may signal potential difficulty should active airway intervention be required. An airway assessment checklist can be found in Box 22.3.2 and Fig. 22.3.1 .

Past medical history

Some conditions predispose to gastro-oesophageal reflux (such as pregnancy or hiatus hernia), raising the theoretical risk of aspiration events during deep sedation. Unstable acute medical/neurological conditions (with the exception of arrhythmia requiring cardioversion) may carry too high a risk to justify proceeding with EDPS. Allergies to any agent in the past precludes use of that agent, and egg and/or soy allergy will preclude the use of propofol in particular.

Occasionally a patient with significant comorbidities will present for a procedure requiring sedation. A careful assessment of the patient, the urgency of the procedure and the available alternatives, in consultation with anaesthetic or ICU colleagues, would be appropriate. Often only very small doses or sedation are required in the elderly to safely perform procedures in a painless fashion.

Fasting status