17.6 Acute Pain Management & Procedural Sedation and Analgesia in the ED
Key Takeaways
Ketorolac 10 mg IV relieves pain about as well as 15 or 30 mg, and ibuprofen 400 mg about as well as 600 or 800 mg; higher doses mainly add adverse effects.
Sub-dissociative ketamine (0.1 to 0.3 mg/kg IV) is an opioid-sparing analgesic, and infusing it over 10 to 15 minutes causes less dysphoria than an IV push.
ACEP's 2014 procedural sedation policy says sedation should not be delayed solely because of recent oral intake.
Ketamine sedation has two absolute contraindications in ACEP's ketamine guideline: age under 3 months and known or suspected schizophrenia.
Capnography detects hypoventilation during procedural sedation earlier than pulse oximetry, especially when supplemental oxygen is given.
17.6 Acute Pain Management & Procedural Sedation and Analgesia in the ED
Note
Exam scope: 2025 outline subtopic 2B9 (Pharmacotherapy for Pain and Sedation). Intubation drugs and post-intubation analgosedation are covered in Chapter 4, sickle cell pain in Section 10.3, and discharge opioid stewardship in Section 14.2.
Principles of ED Analgesia
Pain is one of the most common reasons for an ED visit, and undertreatment is well documented, with documented disparities by race and ethnicity. Good practice is:
- Assess and reassess with a validated scale and treat promptly; giving analgesia does not mask surgical diagnoses.
- Use multimodal therapy: combine drugs with different mechanisms (acetaminophen, NSAIDs, local or regional anesthesia, ketamine), with opioids added when needed.
- Choose the route that is fastest but least invasive. Intranasal fentanyl or ketamine works quickly in children without an IV.
Non-Opioid Analgesics
| Agent | Typical ED dose | Key points |
|---|---|---|
| Acetaminophen | 1 g orally or IV (adult) | Oral works as well as IV when the patient can swallow; IV costs more |
| Ibuprofen | 400 mg orally | 400, 600 and 800 mg gave similar pain relief in an ED trial |
| Ketorolac | 10 mg IV | 10, 15 and 30 mg IV gave similar relief: a ceiling effect |
| Topical NSAIDs | Diclofenac gel | Useful for sprains and strains with less systemic exposure |
| Sub-dissociative ketamine | 0.1 to 0.3 mg/kg IV over 10 to 15 minutes | Comparable to morphine 0.1 mg/kg in trials; infusion causes less dysphoria and fewer feelings of unreality than a push |
| IV lidocaine | About 1.5 mg/kg over 10 minutes | Studied for renal colic, with mixed results; avoid in heart block and with other sodium-channel blockers |
| Suzetrigine (FDA-approved 2025) | 100 mg orally, then 50 mg every 12 hours | First selective NaV1.8 blocker for moderate to severe acute pain; avoid with strong CYP3A inhibitors; modest efficacy |
NSAIDs are avoided in AKI or advanced CKD, active GI bleeding, late pregnancy and when bleeding risk is high. Older adults usually tolerate short courses with appropriate precautions.
Opioids
| Opioid | Typical IV starting dose | Notes |
|---|---|---|
| Morphine | 0.1 mg/kg | Active metabolite (M6G) accumulates in kidney failure; histamine release |
| Hydromorphone | 0.015 mg/kg (often 0.5 mg in older or opioid-naive patients) | About 5 to 7 times as potent as morphine; dose errors are common |
| Fentanyl | 1 mcg/kg IV; 1.5 mcg/kg intranasal (maximum 100 mcg) | Fast onset, little histamine release; preferred with hypotension or kidney impairment |
- In kidney impairment, avoid morphine, codeine, meperidine and tramadol accumulation; fentanyl and cautious hydromorphone are preferred.
- Older adults: start low (often half the usual dose) and watch for delirium and respiratory depression.
- Discharge prescriptions: the 2022 CDC guideline says nonopioid therapy is at least as effective as opioids for many acute pain conditions. When an opioid is needed, prescribe an immediate-release product, the lowest effective dose, and no more than the expected duration of severe pain. Check the prescription drug monitoring program and co-prescribe naloxone for patients at risk (Section 14.2).
Regional Anesthesia
Ultrasound-guided nerve blocks give strong analgesia with little systemic effect:
- Fascia iliaca or femoral nerve block for hip fracture reduces opioid use and is associated with less delirium in older adults.
- Hematoma blocks for distal radius fractures, digital blocks, and serratus anterior blocks for rib fractures.
The pharmacist checks the total local anesthetic dose across all sites against maximum doses and keeps lipid emulsion available (Section 9.4).
Procedural Sedation and Analgesia (PSA)
The Sedation Continuum (ASA)
| Level | Response | Airway and breathing | Circulation |
|---|---|---|---|
| Minimal (anxiolysis) | Normal response to voice | Unaffected | Unaffected |
| Moderate | Purposeful response to voice or light touch | No intervention needed | Usually maintained |
| Deep | Purposeful response only to repeated or painful stimulation | Intervention may be needed | Usually maintained |
| General anesthesia | Not rousable | Intervention often needed | May be impaired |
| Dissociative (ketamine) | Trance-like state with analgesia and amnesia | Airway reflexes and breathing usually preserved | Usually maintained or increased |
Sedation is a continuum, so the team must be able to rescue a patient from one level deeper than intended.
Presedation Assessment
- ASA physical status class, airway exam (signs of difficult bag-mask ventilation or intubation), allergies, prior sedation problems, and current medications.
- Fasting: ACEP's 2014 clinical policy states that procedural sedation should not be delayed solely because of recent oral intake. Aspiration during ED sedation is very rare.
- Informed consent and a plan for the depth needed.
Sedative Agents
| Agent | Typical IV dose | Strengths | Pitfalls |
|---|---|---|---|
| Ketamine | 1 to 2 mg/kg IV (dissociation above about 1 to 1.5 mg/kg); 4 to 5 mg/kg IM | Analgesia, preserved breathing and airway reflexes, stable blood pressure | Vomiting (ondansetron helps), emergence agitation in adults (pretreatment with low-dose midazolam helps), laryngospasm (rare), rise in BP and heart rate |
| Propofol | 1 mg/kg, then 0.5 mg/kg every 3 to 5 minutes | Rapid onset and recovery, antiemetic | Apnea, hypotension; no analgesia |
| Ketofol (ketamine plus propofol) | For example 0.5 mg/kg of each | Ketamine offsets propofol's hypotension, and propofol offsets ketamine's vomiting | Two drugs means a higher risk of mixing errors |
| Etomidate | 0.1 to 0.15 mg/kg | Stable hemodynamics | Myoclonus, brief sedation, no analgesia |
| Midazolam plus fentanyl | Midazolam about 0.02 to 0.05 mg/kg plus fentanyl 0.5 to 1 mcg/kg, titrated | Reversible (flumazenil, naloxone) | Respiratory depression is additive; slower to titrate |
| Dexmedetomidine | Loading 0.5 to 1 mcg/kg over 10 minutes, then infusion | Calm, cooperative sedation for imaging | Bradycardia, hypotension, slow onset; poor for painful procedures |
ACEP ketamine guideline (2011) absolute contraindications: age under 3 months (higher airway risk) and known or suspected schizophrenia, even when stable. Relative concerns include procedures that stimulate the back of the throat, active respiratory infection, significant coronary disease or uncontrolled hypertension, and porphyria or thyroid disease. Routine atropine or glycopyrrolate premedication is no longer recommended.
Laryngospasm with ketamine is rare (well under 1%). Treat it with jaw thrust, bag-mask ventilation with positive pressure and, rarely, a small dose of succinylcholine.
Monitoring and Rescue
- A dedicated clinician watches the patient continuously, separate from the person doing the procedure.
- Continuous pulse oximetry, cardiac monitoring and blood pressure every 3 to 5 minutes.
- Capnography shows hypoventilation (rising end-tidal CO2, flattening waveform, apnea) before pulse oximetry falls, especially when the patient is receiving supplemental oxygen. ACEP supports its use.
- Have suction, bag-mask, airway equipment, naloxone and flumazenil at the bedside.
Recovery and discharge: return to baseline mental status and vital signs, adequate pain control, and a responsible adult escort, with written instructions to avoid driving and hazardous activities for the rest of the day.
Which patient has an absolute contraindication to ketamine for procedural sedation, according to ACEP's 2011 ketamine clinical practice guideline?
A 25-year-old with stable schizophrenia who needs a fracture reduction
A 7-year-old with a simple forearm fracture who ate lunch 2 hours ago
A 4-year-old with an upper respiratory infection needing a laceration repair
A 60-year-old with controlled hypertension needing a shoulder reduction
A 9-year-old needs closed reduction of a displaced forearm fracture. He ate a sandwich 2 hours ago. He is otherwise healthy, with a normal airway exam. What does ACEP's 2014 procedural sedation clinical policy advise about timing?
Sedation need not be delayed solely because he ate recently
Wait 6 hours after solids before any sedation
Use propofol instead of ketamine because propofol prevents aspiration
Proceed only after placing a nasogastric tube to empty the stomach
A 35-year-old with a closed tibial fracture still has severe pain after morphine. The team adds ketamine 0.3 mg/kg IV for analgesia. Which administration method best reduces the dysphoria and feelings of unreality often seen with this dose?
Give lorazepam 2 mg IV first, then the ketamine as a push
Give the dose as a rapid IV push over 15 seconds
Double the dose to 0.6 mg/kg to produce full dissociation
Infuse the dose over 10 to 15 minutes in a small IV bag
During propofol sedation for a hip reduction, a patient receiving 4 L/min oxygen by nasal cannula has an SpO2 of 99%. Which monitoring finding gives the earliest warning of hypoventilation?
A rising end-tidal CO2 with a flattening waveform
Development of sinus bradycardia
A drop in systolic blood pressure of 20 mmHg
A fall in SpO2 below 94%
Sections you finish are checked off in the contents.