Ketamine Dosing for Rapid Sequence Intubation
For RSI in adults, administer ketamine 2 mg/kg IV over 60 seconds; for children, use 1.5-2 mg/kg IV. These doses provide optimal intubation conditions while minimizing adverse events.
Adult Dosing
The FDA-approved dosing range for ketamine induction is 1-4.5 mg/kg IV, with 2 mg/kg producing 5-10 minutes of surgical anesthesia within 30 seconds 1. The 2 mg/kg dose represents the evidence-based standard for RSI in critically ill adults and has been validated in multiple clinical trials 2, 3.
Key Administration Points:
- Administer slowly over 60 seconds to avoid respiratory depression and enhanced vasopressor response 1
- The 100 mg/mL concentration must be diluted before IV use 1
- Consider antisialagogue pretreatment due to potential for increased salivation 1
Dosing Cautions:
Avoid doses exceeding 2 mg/kg in the prehospital or emergency setting. A 2021 study demonstrated that ketamine doses >2 mg/kg were associated with significantly increased odds of adverse events including:
- Hypotension (OR 7.0)
- Laryngospasm (OR 10.8)
- Bradycardia (OR 7.5)
- Oxygen desaturation (OR 6.0)
- Multiple intubation attempts (OR 3.2)
- Failed airway (OR 3.6) 4
There is no evidence supporting dose reduction in hemodynamically unstable patients. A 2023 analysis of 12,175 intubations found no association between ketamine dose (median 1.33 mg/kg) and postintubation hypotension 5. The 2023 Society of Critical Care Medicine guidelines note that while ketamine has sympathomimetic properties, critically ill patients with depleted catecholamine stores may still experience hypotension 6.
Pediatric Dosing
For children, use ketamine 1.5-2 mg/kg IV for RSI. A 2019 prospective randomized trial in children aged 2-12 years demonstrated that doses ≥1.5 mg/kg (when combined with low-dose rocuronium 0.3 mg/kg) provided clinically acceptable intubation conditions in 65% of patients, compared to only 30% with 1 mg/kg 7. The 1.5-2 mg/kg range also reduced postoperative analgesic requirements 7.
Alternative IM Route:
If IV access unavailable, ketamine 9-13 mg/kg IM produces surgical anesthesia within 3-4 minutes, lasting 12-25 minutes 1.
Comparative Evidence
Recent high-quality evidence comparing ketamine to etomidate shows:
- No mortality difference: The 2025 NEJM trial (n=2365) found 28.1% mortality with ketamine vs 29.1% with etomidate (risk difference -0.8%, 95% CI -4.5 to 2.9) 8
- Increased peri-intubation hemodynamic instability with ketamine: 22.1% vs 17.0% cardiovascular collapse (risk difference 5.1%) 8
- Less need for continuous vasopressor initiation with ketamine (RR 0.75) 9
- Equivalent first-pass success rates between agents 9, 8
The 2023 SCCM guidelines suggest no difference between etomidate and ketamine regarding mortality or hypotension, providing conditional recommendation for either agent 6.
Clinical Pitfalls
- Rapid IV push increases adverse events: Always administer over 60 seconds 1
- Higher doses do not improve intubation success: Doses >2 mg/kg increase complications without benefit 4
- Catecholamine depletion risk: In profoundly shocked patients, ketamine's sympathomimetic effects may fail, potentially causing cardiovascular collapse 6
- Dilution requirement: The 100 mg/mL concentration requires 1:1 dilution before IV administration 1