What is the recommended dosing for ketamine (ketamine hydrochloride) conscious sedation?

Ketamine Dosing for Conscious Sedation

For conscious sedation, ketamine should be administered at 1.5 mg/kg IV or 4 mg/kg IM, with continuous monitoring of vital signs and airway status. 1

Intravenous (IV) Administration

• Initial dose of 1.5 mg/kg IV is recommended as it provides more effective sedation than 1.0 mg/kg, with only 5.5% of patients requiring additional doses compared to 54% with the lower dose 1, 2
• Onset of action is rapid (30-96 seconds), allowing for quick procedural intervention 1
• Additional doses of 0.5 mg/kg can be administered if needed to maintain adequate sedation 2
• Average recovery time after IV ketamine administration is approximately 84 minutes (range: 22-215 minutes) 1, 2
• For adult procedural sedation, studies have shown that 0.5-1.0 mg/kg IV provides adequate sedation in 98.9% of cases 3

Intramuscular (IM) Administration

• Standard dose is 4 mg/kg IM, with repeat doses of 2-4 mg/kg allowed after 5-10 minutes if needed 1
• Onset of action is slower than IV (average 4-5 minutes) 2
• Average duration until recovery is approximately 90 minutes (range: 60-130 minutes) 2
• IM administration may be preferred when IV access is difficult or not available 1

Adjunctive Medications

• Midazolam (0.05-0.1 mg/kg IV) may be co-administered to reduce the risk of emergence reactions, particularly in patients over 10 years of age 2
• Atropine (0.01 mg/kg, minimum 0.1 mg, maximum 0.5 mg) or glycopyrrolate may be administered to reduce hypersalivation 2, 1

Monitoring Requirements

• Continuous monitoring of vital signs, including oxygen saturation, heart rate, and blood pressure is required during ketamine administration 1, 4
• Patients should maintain oxygen saturation >93% on room air during the procedure 1
• Practitioners must be able to identify and rescue patients from unintended deep sedation or general anesthesia 4
• Maintain vascular access throughout the procedure until the patient is no longer at risk for cardiorespiratory depression 4

Side Effects and Management

• Mild recovery agitation occurs in approximately 17.6% of patients, with moderate-to-severe agitation in about 1.6% 1
• Emergence reactions (floating sensations, vivid dreams, hallucinations) occur in 10-30% of adults and can be treated with midazolam 2, 3
• Emesis without aspiration is reported in 6.7-7% of cases 1, 2
• Transient increases in heart rate (18%) and respiratory rate (13%) are common 2

Contraindications

• Ketamine should be avoided in patients with:
  • Uncontrolled cardiovascular disease 4
  • Ischemic heart disease 2
  • Cerebrovascular disease 2
  • Hypertension 2
  • Active psychosis 4
  • Severe liver dysfunction 4
  • High intracranial or ocular pressure 4

Special Considerations

• Lower initial doses (0.5 mg/kg IV) may be appropriate for adults, with titration as needed 3
• Pediatric patients often respond well to ketamine, with 88% successfully sedated at initial doses of 1 mg/kg or less 5
• Recovery agitation is associated with higher ASA status (>I) and decreasing age 1
• Emesis is associated with increasing age 1

Practical Administration Algorithm

1. Assess patient for contraindications 2, 4
2. Establish IV access and monitoring equipment 4
3. Administer:
   • IV route: 1.5 mg/kg (adults and children) 1, 2
   • IM route: 4 mg/kg (if IV access unavailable) 1
4. Consider adjunctive medications:
   • Midazolam 0.05-0.1 mg/kg IV to reduce emergence reactions 2
   • Atropine 0.01 mg/kg or glycopyrrolate for hypersalivation 2
5. Assess sedation level and proceed with procedure when adequate 1
6. Monitor vital signs continuously throughout procedure 1, 4
7. If additional sedation needed, administer 0.5 mg/kg IV ketamine 2
8. Continue monitoring during recovery until discharge criteria met 1, 4