Patients who have no pulse and have apnea or those with severe obtundation can (and should) be intubated without pharmacologic assistance. Other patients are given sedating and paralytic medications to minimize discomfort and facilitate intubation (termed rapid sequence intubation) (see table ). (See also Overview of Respiratory Arrest, Airway Establishment and Control, and Tracheal Intubation.)
Sedation and analgesia for intubation
Laryngoscopy and intubation are uncomfortable; in patients who are conscious, a short-acting IV medication with sedative or combined sedative and analgesic properties is mandatory.
Etomidate 0.3mg/kg is a nonbarbiturate sedative-hypnotic frequently used for induction. There are concerns that etomidate may increase mortality in some critically ill patients, but current evidence is not definitive, and etomidate is still a recommended agent for rapid sequence intubation (1, 2, 3, 4).
Fentanyl is a fast-acting synthetic opioid that can be used to reduce the hypertensive and tachycardic response to stimulation from the intubation procedure (5). Fentanyl dose IV for adults is 5 mcg/kg ideal body weight (2 to 5 mcg/kg in children). NOTE: This dose is higher than the analgesic dose and needs to be reduced if used in combination with a sedative-hypnotic (eg, propofol, etomidate). Fentanyl is an opioid and has analgesic as well as sedative properties. However, at higher doses, chest wall rigidity may occur (6).
Ketamine 1 to 2 mg/kg IV is a dissociative anesthetic with cardiostimulatory properties. It is generally safe but may cause hallucinations or bizarre behavior on awakening. These adverse effects can be managed with low doses of prophylactic benzodiazepines. Use of ketamine and etomidate results in similar post-intubation 28-day survival rates in patients who are critically ill and require intubation (2, 7).
Propofol, a sedative and amnesic, is commonly used in induction at doses of 1.5 to 3 mg/kg IV but can cause cardiovascular depression leading to hypotension.
Atropine may be used to prevent bradycardia during emergency intubation of infants and children (8).
Barbiturates are not commonly used because they tend to cause hypotension.
Sedative and Analgesic Medications for Induction of Intubation
Medication | Dose (IV) | Considerations |
|---|---|---|
Propofol* | 0.5–1 mg/kg (loading dose) and 0.25–0.5 mg/kg (subsequent maintenance doses) | A medication that is used to induce sedation and amnesia very quickly (< 1 minute) |
Etomidate† | 0.1–0.15 mg/kg over 1 minute (loading dose) | Etomidate does not provide pain relief and may require the use of a short-acting synthetic opioid |
Midazolam‡ | 0.02–0.03 mg/kg (as 0.5–1 mg loading dose) | A short-acting analgesic (minimal sedation); the maximum single dose should not exceed 2.5 mg |
Fentanyl§, ¶ | 0.5 - 2 mcg/kg | A short-acting synthetic opioid;the initial dose is 50-100 mcg for adults, and the maximum total dose is 5 mcg/kg (or approximately 250 mcg) May cause hypotension |
Ketamine¶ | 1–2 mg/kg over 1–2 minutes (loading dose) and 0.25–0.5 mg/kg (maintenance dose) | Ketamine a short-acting dissociative sedative; doses should be adjusted when used in combination with other sedatives or in patients with obesity (based on ideal body weight not actual weight) |
* Data from Miner JR, Burton JH. Clinical practice advisory: Emergency department procedural sedation with propofol. Ann Emerg Med. 2007;50(2):182-187.e1. doi:10.1016/j.annemergmed.2006.12.017 | ||
† Data from Miner JR, Danahy M, Moch A, Biros M. Randomized clinical trial of etomidate versus propofol for procedural sedation in the emergency department. Ann Emerg Med. 2007;49(1):15-22. doi:10.1016/j.annemergmed.2006.06.042 | ||
‡ Data from Horn E, Nesbit SA. Pharmacology and pharmacokinetics of sedatives and analgesics. Gastrointest Endosc Clin N Am. 2004;14(2):247-268. doi:10.1016/j.giec.2004.01.001 | ||
§ Data from American College of Emergency Physicians Clinical Policies Subcommittee (Writing Committee) on Airway Management, Godwin SA, Hahn SA, et al. Clinical Policy: Critical Issues in the Management of Adult Patients Requiring Endotracheal Intubation in the Emergency Department. Ann Emerg Med. 2025;86(2):e29-e68. doi:10.1016/j.annemergmed.2025.04.003. and from Brown TB, Lovato LM, Parker D. Procedural sedation in the acute care setting. Am Fam Physician. 2005;71(1):85-90. | ||
¶ Data from David H, Shipp J. A randomized controlled trial of ketamine/propofol versus propofol alone for emergency department procedural sedation. Ann Emerg Med. 2011;57(5):435-441. doi:10.1016/j.annemergmed.2010.11.025 and from Brown TB, Lovato LM, Parker D: Procedural sedation in the acute care setting. Am Fam Physician. 2005;71(1):85-90. | ||
Neuromuscular blocking agents for intubation
Skeletal muscle relaxation with an IV neuromuscular blocker (NMBA) facilitates intubation (9, 10) and improves first-pass success (ie, successful intubation on the first attempt) (1).
Rocuronium is a non-depolarizing, reversible NMBA; when used in an adequate dose for rapid onset it has a significantly longer duration of action (> 30 minutes) than succinylcholine (1, 11). It is used as a first-line neuromuscular blocker for intubation, or as an alternative to succinylcholine when succinylcholine is contraindicated.
Succinylcholine (1.5 mg/kg IV, 2.0 mg/kg for infants), a depolarizing neuromuscular blocker, has the most rapid onset (30 seconds to 1 minute) and shortest duration (3 to 5 minutes). It should be avoided in patients with burns, muscle crush injuries > 1 to 2 days old, and acute kidney injury because of potential concerns about hyperkalemia (12). Succinylcholine should also be avoided in patients with spinal cord injury and certain neuromuscular diseases (eg, multiple sclerosis, muscular dystrophy) because of the risk of iatrogenic hyperkalemia (1, 13). Other NMBAs should also be considered in patients with possible penetrating eye injury because of concerns about increased intraocular pressures due to fasciculations. Malignant hyperthermia can be caused by depolarizing neuromuscular blockers as well as certain anesthetics. Malignant hyperthermia accounts for a small percentage of overall anesthesia-related deaths (14, 15). Pretreatment with small doses of nondepolarizing NMBAs prior to succinylcholine administration is suggested to prevent fasciculations and myalgias (16).
The 2023 SCCM Clinical Practice Guideline for rapid sequence intubation (RSI) in critically ill adults advises the use of either rocuronium or succinylcholine, provided there are no contraindications to succinylcholine (1). In current practice, rocuronium has emerged as the preferred option for several reasons. Complications during intubation, especially cardiovascular issues, are reported less frequently with rocuronium than with succinylcholine. In addition, a low dose of rocuronium (0.6 mg/kg) has been shown to result in fewer adverse effects when combined with pretreatment with magnesium sulfate (60 mg/kg) (17). However, this method requires a slow (approximately 15-minute) infusion, making it less suitable for urgent situations. The reversal agent sugammadex, which can reverse a full RSI dose of rocuronium more quickly than the natural recovery from succinylcholine (18), significantly alleviates concerns about prolonged action duration.
Other non-depolarizing NBMAs include atracurium, cisatracurium, and vecuronium.
It is important to exercise caution with patients who have comorbid conditions or obesity and cannot be ventilated. The primary focus in managing these patients who cannot ventilate should be on re-establishing airway patency and ensuring oxygenation, which includes surgical airway procedures, rather than depending solely on pharmacological reversal (19).
Topical anesthesia for intubation
Intubation of an awake patient requires anesthesia of the nose and pharynx. A commercial aerosol preparation of benzocaine, tetracaine, butyl aminobenzoate (butamben), is available (20). Alternatively, 4% lidocaine can be nebulized and inhaled via face mask. Caution is needed when benzocaine is used because it can cause methemoglobinemia (21).
Post-intubation sedation and analgesia
Appropriate medications should also be immediately available for post-intubation sedation and analgesia. Combinations of opioids and benzodiazepines (eg, fentanyl and midazolam) can be quickly administered as bolus doses. Continuous infusion of sedatives such as propofol or dexmedetomidine can also be used.
After initial intubation and resuscitation, clinical practice guidelines recommend the use of light sedation (rather than deep sedation) in adult critically ill patients and recommend the use of propofol or dexmedetomidine over benzodiazepines (22). Benzodiazepines have a higher incidence of delirium.
References
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2. Casey JD, Seitz KP, Driver BE, et al. Ketamine or Etomidate for Tracheal Intubation of Critically Ill Adults. N Engl J Med. 2026;394(16):1608-1620. doi:10.1056/NEJMoa2511420
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8. Lasa JJ, Dhillon GS, Duff JP, et al. Part 8: Pediatric Advanced Life Support: 2025 American Heart Association and American Academy of Pediatrics Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Pediatrics. 2026;157(1):e2025074351. doi:10.1542/peds.2025-074351
9. Lundstrøm LH, Duez CHV, Nørskov AK, et al. Effects of avoidance or use of neuromuscular blocking agents on outcomes in tracheal intubation: a Cochrane systematic review. Br J Anaesth. 2018;120(6):1381-1393. doi:10.1016/j.bja.2017.11.106
10. Vanlinthout LE, Geniets B, Driessen JJ, et al. Neuromuscular-blocking agents for tracheal intubation in pediatric patients (0-12 years): A systematic review and meta-analysis. Paediatr Anaesth. 2020;30(4):401-414. doi:10.1111/pan.13806
11. Plaud B, Baillard C, Bourgain JL, et al. Guidelines on muscle relaxants and reversal in anaesthesia. Anaesth Crit Care Pain Med. 2020;39(1):125-142. doi:10.1016/j.accpm.2020.01.005
12. Blanié A, Ract C, Leblanc PE, et al. The limits of succinylcholine for critically ill patients. Anesth Analg. 2012;115(4):873-879. doi:10.1213/ANE.0b013e31825f829d
13. Cooperman LH. Succinylcholine-induced hyperkalemia in neuromuscular disease. JAMA. 1970;213(11):1867-1871.
14. Hirshey Dirksen SJ, Larach MG, Rosenberg H, et al. Special article: Future directions in malignant hyperthermia research and patient care. Anesth Analg. 2011;113(5):1108-1119. doi:10.1213/ANE.0b013e318222af2e
15. Rosenberg H, Davis M, James D, Pollock N, Stowell K. Malignant hyperthermia. Orphanet J Rare Dis. 2007;2:21. doi:10.1186/1750-1172-2-21
16. Schreiber JU, Lysakowski C, Fuchs-Buder T, Tramèr MR: Prevention of succinylcholine-induced fasciculation and myalgia: a meta-analysis of randomized trials. Anesthesiology. 2005;103(4):877-884. doi:10.1097/00000542-200510000-00027
17. Czarnetzki C, Albrecht E, Masouyé P, et al. Rapid Sequence Induction With a Standard Intubation Dose of Rocuronium After Magnesium Pretreatment Compared With Succinylcholine: A Randomized Clinical Trial. Anesth Analg. 2021;133(6):1540-1549. doi:10.1213/ANE.0000000000005324
18. Abrishami A, Ho J, Wong J, Yin L, Chung F. Sugammadex, a selective reversal medication for preventing postoperative residual neuromuscular blockade. Cochrane Database Syst Rev. 2009;(4):CD007362. doi:10.1002/14651858.CD007362.pub2
19. Abou Nafeh NG, Aouad MT, Khalili AF, Serhan FG, Sokhn AM, Kaddoum RN. Use of Sugammadex in "Cannot Intubate, Cannot Ventilate" Scenarios: A Systematic Review of Case Reports. Anesth Analg. 2025;140(4):931-937. doi:10.1213/ANE.0000000000007199
20. Hersh EV, Secreto S, Wang S, et al. A Proof-of-concept Study Using Quantitative Sensory Threshold Analysis to Compare Two Intraoral Topical Anesthetics. Clin Ther. 2019;41(2):291-302. doi:10.1016/j.clinthera.2018.12.009
21. Wills BK, Cumpston KL, Downs JW, Rose SR. Causative Agents in Clinically Significant Methemoglobinemia: A National Poison Data System Study. Am J Ther. 2020;28(5):e548-e551. doi:10.1097/MJT.0000000000001277
22. Devlin JW, Skrobik Y, Gélinas C, et al. Clinical Practice Guidelines for the Prevention and Management of Pain, Agitation/Sedation, Delirium, Immobility, and Sleep Disruption in Adult Patients in the ICU. Crit Care Med. 2018;46(9):e825-e873. doi:10.1097/CCM.0000000000003299
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