Ketamine

1. Mechanism
   1. Derived from Phencyclidine (PCP)
   2. Dissociative anesthetic with Analgesic effect
   3. Anesthesia with rare respiratory depression
2. Dose: Sedation
   1. Intravenous: 1-2 mg/kg IV
   2. Intramuscular: 2-4 mg/kg IM
   3. Consider concurrent Midazolam (especially in adults)
      1. Blunts Sympathomimetic effect
      2. Reduces agitation on recovery from Ketamine
      3. Versed dosing: 0.05 to 0.1 mg/kg IV (MAX 4.0 mg)
3. Pharmacokinetics
   1. Intravenous dosing
      1. Onset: 1 minutes
      2. Duration: 10-20 minutes
   2. Intramuscular dosing
      1. Onset: 5 minutes
      2. Duration: 15-45 minutes
4. Indications
   1. Drug of choice for Conscious Sedation in children
      1. Not FDA approved
      2. Ear Foreign Body
      3. Entrapment of penis in zipper
      4. Abscess Incision and Drainage
      5. Imaging studies
      6. Laceration Repair or Wound Debridement
      7. Fracture or dislocation reduction
   2. Sedation in Rapid Sequence Intubation
      1. Useful in Status Asthmaticus (Bronchodilator)
5. Contraindications
   1. Increased Intracranial Pressure
      1. Use Fentanyl with Midazolam if ICP is of concern
   2. Coronary Artery Disease
   3. Ketamine hypersensitivity
6. Efficacy and Safety
   1. Results in >90% of children with adequate Sedation
7. Pregnancy
   1. Pregnancy Category C
8. Adverse Effects
   1. Blood Pressure elevation
      1. Consider concurrent Midazolam in adults
   2. Confusion or Delirium
   3. Anterograde amnesia
   4. Visual hallucinations
      1. Floating outside the body
      2. Dream-like state
   5. Flashbacks may occur weeks after use
   6. Agitation on recovery from agent
      1. Consider concurrent Midazolam in adults
   7. Transient laryngospasm (occurs in 0.4% of cases)
   8. Ptyalism
      1. Treat with anticholinergics (e.g. Diphenhydramine)
   9. Respiratory depression
      1. Brief Positive Pressure Ventilation may be needed
      2. Mild Oxygen desaturation (most common side effect)
         1. Most cases: Return to baseline within 2 minutes
9. Adverse Effects
   1. Significant oxygen desaturation <85% occurred in <1%
10. Illicit use
    1. Club Drug
    2. Date Rape Drug used for Sedation
    3. Use
       1. Smoked as powder with Tobacco or Marijuana
       2. Inhaled intranasally
    4. Illicit use is often in combination with other agents
       1. Methamphetamine
       2. Cocaine
       3. Sildenafil
       4. Heroin
11. Street Names when used illicitly
    1. Special K
    2. Super K
    3. Kit-Kat
    4. Keets
    5. Super acid
    6. Jet
    7. Cat Valiums
    8. Vitamin K
12. Toxicology: Detection of illicit use
    1. Specific tests to detect Ketamine usually not available
    2. Ketamine will cause positive PCP on Urine Tox Screen
13. References
    1. Brown (2005) Am Fam Physician 71:85-90
    2. Gahlinger (2004) Am Fam Physician 69:2619-27
    3. Green (1998) Ann Emerg Med 31:688-97
    4. Jansen (1993) BMJ 306:601-2
    5. Parker (1997) Pediatrics 99:427-31