Procedural Sedation — Adult

Pre-sedation assessment

• Focused history: indication and urgency, allergies, current medications, previous sedation/anaesthetic problems, relevant comorbidities and exercise tolerance.
• ASA grade: document ASA physical status. ASA I–II are straightforward; ASA III or above (or a difficult airway) should prompt senior/anaesthetic involvement and a lower threshold for a second experienced clinician.
• Airway assessment: mouth opening, dentition, neck mobility, Mallampati impression, beard, body habitus — anticipate difficulty before you sedate, not after you lose the airway.
• Fasting status: record time since last oral intake, but per RCEM Best Practice this is not an absolute barrier to emergency ED sedation — the decision balances procedural urgency against aspiration risk, sedation depth and target (aim for the lightest sedation that permits the procedure), not a fixed fasting time.
• Baseline observations, weight (for weight-based dosing), and IV access secured before any drug is given.

Team & environment

• Dedicated sedationist whose sole role is sedation and monitoring, separate and distinct from the clinician performing the procedure.
• Minimum of three staff: sedationist, proceduralist, and a nurse/ODP assisting and documenting.
• Perform in a resuscitation-capable area with immediate access to airway equipment, suction, oxygen, reversal agents and a crash trolley.
• Full monitoring running before the first drug is given and continued through recovery: continuous pulse oximetry, ECG, non-invasive blood pressure, and waveform capnography — capnography detects apnoea and hypoventilation earlier than pulse oximetry alone, especially with supplemental oxygen running.
• Verbal contact maintained with the patient throughout where the sedation depth allows.

Equipment

Drug options & typical adult doses

Sedation depth targets

• Aim for the minimum depth that allows the procedure — moderate ("conscious") sedation for most reductions and cardioversion; deeper dissociative or general-anaesthetic-like states only when the procedure demands it.
• Use a recognised sedation scale to document depth at intervals (e.g. Ramsay or a local equivalent) alongside vital signs.
• Deeper sedation carries progressively higher risk of airway obstruction and apnoea — match monitoring intensity to depth, not just to the drug used.

Recovery & discharge criteria

• Continue full monitoring until the patient returns to their baseline level of consciousness and observations are stable.
• Discharge criteria: baseline mental status, stable observations off supplemental oxygen, able to tolerate oral fluids, pain controlled, able to mobilise safely (with assistance as needed).
• A responsible adult should escort the patient home; advise against driving, operating machinery, drinking alcohol or signing legal documents for 24 hours.
• Document the whole episode: drugs and doses, monitoring findings, depth achieved, complications, and discharge checks.

Complications

Pitfalls & pearls

• The sedationist should never also be the proceduralist — attention divided between drugs and the procedure is how complications are missed.
• Don't chase a fixed fasting time in a genuine emergency; instead document the risk discussion and choose a lighter sedation strategy if aspiration risk is a concern.
• Give opioids first, then titrate sedative — reversing this order increases apnoea risk.
• Capnography waveform loss with preserved chest movement can mean airway obstruction, not apnoea — look at the patient, not just the number.
• Recovery takes as long as it takes — rushing discharge criteria is a common source of post-discharge re-attendance.

Capnography waveform

A normal waveform confirms ventilation breath-by-breath; a flattening or disappearing trace is the earliest sign of apnoea or airway obstruction — often before oxygen saturation falls.

References