Diagnostics & Procedures · Topic 15 of 16

Procedural Sedation

Procedures · sedation and analgesia

Procedural Sedation

Classify ASA risk, pick a depth, monitor with capnography and a dedicated observer, and be ready to rescue one level deeper than planned.

Key numbers

ASA class I–VI, plus EASA I–VI (+E)

Elective: clear liquids 2 h, meal 6 hclears 2 h · meal 6 h

01 · What it isMinimal, moderate, deep, then general anesthesia

Sedation is a continuum: minimal (anxiolysis, interacts normally), moderate (responds to voice or touch), deep (arousable only by repeated or painful stimuli, airway and breathing may falter), then general anesthesia (unresponsive).

02 · Defined byASA class I–VI, plus E

ASA physical status: I healthy; II mild systemic disease; III severe systemic disease; IV severe disease that constantly threatens life; V moribund, will not survive without surgery; VI brain-dead organ donor; add E for emergencies.

03 · The ruleED: don't delay sedation for fasting

ACEP: do not delay emergency department procedural sedation based on fasting time — preprocedural fasting for any duration has not been shown to reduce vomiting or aspiration.

Causes & risk factors

Why it happens

High risk: lower doses, consider ketamineSevere cardiopulmonary disease, obstructive sleep apnea, a predicted difficult airway, age over 60 and intoxication raise risk: lower the doses, consult anesthesia, or choose ketamine, which does not depress respiration.

Diagnosis & monitoring

Work-up

Capnography plus a dedicated observer must knowMonitor pulse oximetry, capnography, blood pressure and ECG throughout, with a dedicated observer who is not the proceduralist; capnography detects hypoventilation before oximetry falls, especially when supplemental oxygen is running.

Management

Orders

Ketamine 1–1.5 mg/kg IV preserves airway reflexesKetamine 1–1.5 mg/kg IV pushed slowly over at least 30–60 seconds (repeat 0.5–0.75 mg/kg after 10 minutes): dissociative sedation with analgesia that preserves breathing, airway reflexes and blood pressure; watch for laryngospasm and emergence reactions.

Propofol 0.5–1 mg/kg: fast, but hypotension and apneaPropofol 0.5–1 mg/kg IV, then 0.25–0.5 mg/kg every 1–3 minutes: rapid, ultra-short deep sedation with no analgesia; expect brief hypotension and respiratory depression, and avoid it in hypotensive patients.

Etomidate 0.1–0.15 mg/kg when blood pressure is lowEtomidate 0.1–0.15 mg/kg IV gives deep sedation without changing blood pressure or pulse, suiting hypotensive or cardiac patients; it gives no analgesia and causes brief myoclonus and transient adrenal suppression.

Midazolam plus fentanyl for moderate sedationMidazolam 0.5–2 mg IV over ≥ 2 minutes (5 mg cumulative maximum; 3.5 mg if ≥ 60 years), plus fentanyl 50–100 mcg IV for pain; use smaller doses together, waiting ≥ 2 minutes between doses.

Apnea: stimulate, reposition, bag-mask ventilateFor hypoventilation or apnea: stimulate the patient, reposition the airway, add oxygen and nasal or oral airways, bag-mask ventilate, and give reversal agents if needed — advanced airway support is seldom required.

Reverse with naloxone or flumazenilReverse opioids with naloxone and benzodiazepines with flumazenil 0.2 mg IV, repeated in 0.2-mg doses to 1 mg; flumazenil can provoke seizures in benzodiazepine-dependent patients or cyclic antidepressant overdose, and resedation can occur.

Red flags & don'ts

Avoid harm

Ketamine: not under 3 months; caution in CAD avoidKetamine is contraindicated under 3 months of age (airway compromise), and its sympathomimetic rise in heart rate and blood pressure is risky with ischemic heart disease or uncontrolled hypertension.

The rules

Know these

Be ready to rescue one level deeper must knowBe able to rescue a patient who goes deeper than intended: for moderate sedation, manage an obstructed airway and hypoventilation; PSA providers must be able to support a patient who reaches general anesthesia.

Discharge only when awake, with an escortDo not give naloxone or flumazenil just to speed recovery; observe until normal wakefulness returns, discharge adults only when they walk unaided and with an accompanying adult, and restrict driving and decisions for 12 hours.

Elective: clear liquids 2 h, meal 6 hElective procedures follow ASA fasting: clear liquids up to 2 hours and a light meal or nonhuman milk up to 6 hours before; fried or fatty food or meat may need 8 hours or more.

Ketamine or propofol?

Commonly confused

Sedation type	Dissociative
Analgesia	Yes
Breathing and airway reflexes	Preserved
Blood pressure	Rises modestly
Initial IV dose	1–1.5 mg/kg, slow push
Watch for	Laryngospasm, emergence reactions, vomiting

More detail

Reference

Show 5 reference facts

Respiratory depression is most common at the start of sedation and during recovery; procedural hypotension usually responds to IV fluid.

Sub-dissociative ketamine (0.1–0.2 mg/kg) gives substantial analgesia without dissociation and can spare opioid; at full PSA doses, do not add another analgesic to ketamine.

Egg or soy allergy is no longer a contraindication to propofol; nitrous oxide is contraindicated with pneumothorax, bowel obstruction or an intraocular gas bubble because it expands closed air spaces.

ACEP rates propofol safe for ED sedation in adults and children (Level A) and ketamine safe in children (Level A) and adults (Level C); ketamine-propofol combinations are also considered safe.

If capnography is unavailable, consider withholding supplemental oxygen, because oxygen masks hypoventilation by delaying the fall in oxygen saturation.

Pearl

Plan for the level deeper than you intend — and watch the capnograph, not just the saturation.

Sources · Merck Manual Professional — How To Do Procedural Sedation and Analgesia · Practice Guidelines for Moderate Procedural Sedation and Analgesia 2018 (ASA Task Force with AAOMS, ACR, ADA, ASDA, SIR). Anesthesiology 2018;128:437–479 · American Society of Anesthesiologists Statement on ASA Physical Status Classification System. Anesthesiology Open · Godwin SA et al. ACEP Clinical Policy: Procedural Sedation and Analgesia in the Emergency Department. Ann Emerg Med 2014;63:247–258 (MDCalc recommendation summary) · ASA Practice Guidelines for Preoperative Fasting and the Use of Pharmacologic Agents to Reduce the Risk of Pulmonary Aspiration. Anesthesiology 2017;126:376–393 · Flumazenil injection prescribing information — DailyMed · OpenAnesthesia — NPO guidelines (ASA 2017 fasting guideline and 2023 modular update summary) · Starter sheet built from the verified AGACNP fact map (facts reviewed 2026-10-15).