II. Precautions

  1. Procedural Sedation risks respiratory and cardiovascular depression
    1. Ketamine does not appear to cause significant apnea at typical doses (when used as only sedative)
    2. However, apnea may still occur, especially when combined with Opioids, Benzodiazepines or other sedatives
    3. IV doses may impair respiratory drive if >5 mg/kg IV or infused faster than over 30-45 seconds
  2. Monitoring is critical
    1. See Procedural Sedation and Analgesia
  3. Recheck Ketamine concentration
    1. Multiple Ketamine concentrations may cause confusion and over-dosage
    2. Ketamine IV concentration is typically 10 mg/ml, whereas IM concentration is 50-100 mg/ml
  4. Do not use with Atropine (to dry secretions)
    1. Previously used to decrease Ketamine-induced Hypersalivation
    2. Worsens increased airway secretions by thickening them

III. Mechanism

  1. Synthetic derivative of Phencyclidine (PCP) first developed in 1962
    1. N-Methyl-D-Aspartate Antagonist (NMDA Antagonist)
    2. Blocks glutamate binding in the central nervous system
  2. Dissociative anesthetic
    1. Prevents CNS from perceiving visual, auditory, and painful stimuli
    2. Produces a trance-like state
  3. Additional effects (beyond anesthetic effect)
    1. Analgesic effect
    2. Amnestic effect
    3. Bronchodilation and minimal respiratory depression
    4. Increases Blood Pressure and Heart Rate
  4. Effects are dose dependent
    1. Pure Analgesic effects
      1. Dose: 0.1 to 0.2 mg/kg IV
      2. Strong Analgesic without significant Intoxication or altered perception or emotion
    2. Intoxicant effects
      1. Dose: 0.2 to 0.5 mg/kg IV
      2. See Ketamine Abuse
      3. Very strong Analgesic effects
      4. Intoxicated with altered perception and Hallucinations
      5. May require redirection to calm patient
    3. Partial dissociative effects
      1. Dose: 0.4 to 0.8 mg/kg IV
      2. Partially aware of outside stimuli and able to follow some commands and direction
      3. Potentially distressing
        1. Give additional Ketamine if patient distressed soon after Ketamine initiation
        2. Emergence reactions may be treated with Benzodiazepines (e.g. Midazolam)
    4. Complete dissociative effects
      1. Dose: 0.8 mg/kg IV and higher
      2. Dosing used in Procedural Sedation and Rapid Sequence Intubation
      3. Patient is completely unaware of external stimuli
      4. Cardiopulmonary function is minimally affected
    5. Higher doses
      1. Doses above complete dissociation extend duration but do not have additional adverse effects

IV. Dosing: Analgesia

  1. Single dose protocol
    1. Ketamine 0.3 mg/kg (0.15 to 0.6 mg/kg) IV push over 1-2 min (or IV infused over 10 minutes) OR
    2. Ketamine 0.75 to 1 mg/mg intranasally
    3. Consider in combination with Fentanyl (see below)
    4. Lester (2010) Am J Emerg Med 28(7): 820-7 [PubMed]
    5. Ahern (2015) Am J Emerg Med 33(2): 197-201 [PubMed]
  2. Continuous subdissociative analgesia
    1. Initial: 0.2 to 0.3 mg/kg IV
    2. Maintenance: 0.2 to 0.3 mg/kg/hour IV infusion
    3. Drake (2015) Acad Emerg Med 22(7): 887-9 [PubMed]
    4. Motov (2015) Ann Emerg Med 66(3): 222-9 [PubMed]

V. Dose: Sedation

  1. Intravenous
    1. Initial
      1. Adult: 1.0 mg/kg slow IV over 1-2 min (some start at 1.5 mg/kg)
      2. Child: 1.5 mg/kg slow IV over 1-2 min
    2. Next
      1. Administer 1/2 of intial dose every 10 min as needed
  2. Intramuscular (esp. for Excited Delirium as Chemical Restraint)
    1. Initial: 4-5 mg/kg IM (adult and child)
    2. Repeat 4-5 mg/kg IM after 10 min for one dose if needed
  3. Intranasal
    1. Ketamine 2 mg/kg intranasal
  4. Consider concurrent Midazolam (especially in adults)
    1. Blunts Sympathomimetic effect
    2. Reduces agitation (emergence reaction) on recovery from Ketamine
    3. Midazolam (Versed) dosing: 0.03 mg/kg IV (Max dose: 4.0 mg)

VI. Dosing: Induction for Rapid Sequence Intubation (RSI)

  1. Ketamine 1.5 mg/kg (120 mg for an 80 kg adult)

VII. Preparations: Combinations

  1. Ketaphol (Ketamine with Propofol)
    1. Postulated to reduce risk of Hypotension and apnea of Propofol by cutting dose with Ketamine
      1. Initial studies recommended ratio of 4:1 Propofol to Ketamine for adequate effect
      2. Some protocols start 1:1 ratio Propofol to Ketamine 0.5 then add Propofol to effect
    2. Typical protocol
      1. Start: Administer mix of Propofol 0.5 mg/kg AND Ketamine 0.5 mg/kg
      2. Next: Administer additional Propofol 0.5 mg/kg every 90 seconds as needed to adequate effect
    3. Most studies show no significant benefit over Propofol alone (similar efficacy and safety)
      1. Andolfatto (2012) Ann Emerg Med 59(6): 504-12 [PubMed]
      2. Nejati (2011) Acad Emerg Med 18(8): 800 [PubMed]
      3. Ferguson (2016) Ann Emerg Med 86(5): 574-82 [PubMed]
  2. Ketamine with Fentanyl
    1. May offer excellent Analgesic effect without Ketamine intoxicant effects
    2. Dosing
      1. Ketamine 0.1 mg/kg IV
      2. Fentanyl 1.5 mg/kg IV

VIII. Pharmacokinetics

  1. Intravenous dosing
    1. Onset: 1 minute
    2. Dissociation: 15 minutes
    3. Recovery: 60 minutes
  2. Intramuscular dosing
    1. Onset: 5 minutes
    2. Dissociation: 15-30 minutes
    3. Recovery: 90-150 minutes

IX. Indications

  1. Indicated for ASA Physical Status Score 2 and 3
  2. 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
  3. Conscious Sedation in adults
    1. Excellent Procedural Sedation in single provider procedures or resource poor environments
    2. No Hypotension and low apnea risk compared with Propofol, which is typically used for adult Procedural Sedation
  4. Sedation in Excited Delirium
    1. Excellent first-line sedative to allow for controlled evaluation and management (Ketamine 4-5 mg/kg IM)
  5. Sedation in Rapid Sequence Intubation
    1. Useful in Status Asthmaticus (Bronchodilator)
    2. Ketamine is the only sedative induction agent with Analgesic properties
  6. Analgesia
    1. Low dose Ketamine (0.1 to 0.6 mg/kg) as adjunct for analgesia in Emergency Department
      1. Lester (2010) Am J Emerg Med 28(7): 820-7 [PubMed]

X. Contraindications

  1. Absolute contraindications
    1. Ketamine hypersensitivity
    2. Schizophrenia or other Psychosis
    3. Age <3 months (risk of respiratory complication)
  2. Relative Contraindications
    1. Posterior oropharynx procedures
    2. Tracheal surgery or tracheal stenosis
    3. Significant upper respiratory tract infection
    4. Uncontrolled Hypertension

XI. Contraindications: Disproven Relative Contraindications

  1. See Adverse Effects as below
  2. Coronary Artery Disease
    1. Theoretical risk of worsening severe coronary ischemia
    2. However improves cardiac contractility as well as improving stunned Myocardium
    3. Not contraindicated in Coronary Artery Disease, Congestive Heart Failure or Hypertension
  3. Increased Intracranial Pressure
    1. Older data recommends avoiding in Closed Head Injury (risk of Increased Intracranial Pressure)
      1. Newer data suggests safe in Head Injury (in fact neuroprotective with increased Cerebral Perfusion Pressure)
      2. No adverse effects on Intracranial Pressure, Cerebral Perfusion Pressure, neurologic outcomes in critically ill adults
        1. Cohen (2014) Ann Emerg Med [PubMed]
  4. Eye Injury or increased Intraocular Pressure
    1. ACEP 2011 guidelines lists Glaucoma and acute globe injury as contraindications for Ketamine use in children
    2. Ketamine does increase Intraocular Pressure in children
      1. However these changes appear to mild (typically <3-5 mmHg) at standard Procedural Sedation doses
      2. Halstead (2012) Acad Emerg Med 19(10):1145-50 [PubMed]

XII. Efficacy and Safety

  1. Sedation
    1. Results in >90% of children with adequate Sedation
  2. Analgesia
    1. Ketamine 0.3 mg/kg as effective as 0.1 mg/kg IV Morphine in acute moderate to severe pain
      1. More Dizziness and Disorientation occurred with Ketamine
      2. Motov (2015) Ann Emerg Med 66(3):222-9 +PMID:25817884 [PubMed]
  3. Induction agent for Rapid Sequence Intubation (RSI)
    1. Asthma or Angioedema
      1. Variable efficacy in studies, but theoretically this should be a Ketamine strong suit
      2. Bronchodilatory effects are unique to Ketamine (among the RSI induction agents)
      3. Ketamine is not associated with apnea, regardless of dose
    2. Safe and effective alternative to Etomidate for adults with Sepsis
      1. Jabre (2009) Lancet 374(9686): 293-300 [PubMed]
    3. Appears safe in Head Trauma even with increased ICP
      1. Appears to be neuroprotective by increasing Cerebral Perfusion Pressure
      2. Does not lower Seizure threshold
      3. Himmelseher (2005) Anesth Analg 101(2): 524-34 [PubMed]
  4. Pregnancy and Lactation
    1. Not recommended
    2. Minimal to no data for either pregnancy or Lactation

XIII. Adverse Effects: General

  1. Blood Pressure elevation
  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. Emergence Reaction (Agitation on recovery from agent)
    1. Acheive adequate analgesia before procedure
    2. Frequently reorient and calm patient with mild distress
    3. Consider concurrent or prn Midazolam in adults (0.03 mg/kg) to counter emergence reaction
      1. However, risk of respiratory depression, especially in children
      2. PRN dosing is preferred instead (have Benzodiazepine ready in case of moderate to severe emergence)
      3. Sener (2011) Ann Emerg Med 57(2):109-114 [PubMed]
  7. Transient laryngospasm
    1. Occurs in 0.3 to 0.4% of cases, especially children
    2. Manage with airway repositioning, Jaw Thrust, or two person bag-valve mask
    3. Laryngospasm Notch Maneuver may also be used with relief within 1-2 breaths
    4. In severe, persistent cases, paralyze (Rocuronium or Succinylcholine) and intubate
  8. Skeletal muscle hypertonicity and rigidity
  9. Vomiting
    1. Typically occurs during recovery
    2. Peak Incidence in teen years
    3. Occurs in up to 20% of cases when used IM and 10% with IV use
    4. Consider prophylaxis with Ondansetron (Zofran)
  10. Ptyalism (Hypersalivation)
    1. Drooling and increased oral secretions
    2. Manage with suction or wiping away secretions with gauze
    3. Avoid Anticholinergics such as Atropine or Diphenhydramine
      1. Simply thickens the increased secretions
  11. Respiratory depression
    1. Respiratory drive is typically preserved, however, transient apnea (10-20 s) may occur with rapid infusion
      1. Administer Ketamine slowly (over 1-2 minutes)
    2. Brief Positive Pressure Ventilation may be needed
    3. Start by repositioning head and neck, and Jaw Thrust maneuver
    4. Mild Oxygen desaturation (most common side effect)
      1. Significant oxygen desaturation <85% occurred in <1%
      2. Most cases: Return to baseline within 2 minutes

XIV. Adverse Effects: Disproven or not thought to be Clinically Significant

  1. Increased Intracranial Pressure (ICP)
    1. Consider alternatives in Intracranial Mass or Hydrocephalus (although not an absolute contraindication)
    2. ICP not found to be increased with Ketamine
      1. Cohen (2015) Ann Emerg Med 65(1):43-51 [PubMed]
  2. Increased Intraocular Pressure (IOP)
    1. Consider alternatives in Glaucoma and globe injury (although not an absolute contraindication)
    2. IOP not increased in adults and only minimally increased in children
      1. Drayna (2012) Am J Emerg Med 30(7): 1215-8 [PubMed]
      2. Halstead (2012) Acad Emerg Med 19(10): 1145-50 [PubMed]

XV. References

  1. Acker, Koval and Leeper (2017) Crit Dec Emerg Med 31(4): 3-13
  2. Hipskind and Kamboj (2016) Crit Dec Emerg Med 30(10): 15-23
  3. Kay (2015) Crit Dec Emerg Med 29(8): 11-17
  4. Mell in Herbert (2015) EM:Rap 15(5): 4-5
  5. Brown (2005) Am Fam Physician 71:85-90 [PubMed]
  6. Gahlinger (2004) Am Fam Physician 69:2619-27 [PubMed]
  7. Green (1998) Ann Emerg Med 31:688-97 [PubMed]
  8. Jansen (1993) BMJ 306:601-2 [PubMed]
  9. Parker (1997) Pediatrics 99:427-31 [PubMed]

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Ontology: Ketalar (C0022613)

Concepts Pharmacologic Substance (T121) , Organic Chemical (T109)
MSH D007649
English ketalar, Ketalar

Ontology: Ketamine (C0022614)

Definition (CHV) a kind of anesthetic drug
Definition (NCI) A cyclohexanone derivative with analgesic and anesthetic properties. Although its mechanism of action is not well understood, ketamine appears exerts complex pharmacological actions including inhibition of biogenic amine uptake, binding to opioid receptors, and inhibition of N-methyl D-aspartate (NMDA) receptors. Because of the involvement of spinal NMDA receptors in the process of central sensitization, this agent may reduce pain perception and induce sedation.
Definition (NCI_NCI-GLOSS) A drug used to cause a loss of feeling and awareness and to induce sleep in patients having surgery. It is also being studied in the treatment of nerve pain caused by chemotherapy. Ketamine blocks pathways to the brain that are involved in sensing pain. It is a type of general anesthetic.
Definition (MSH) A cyclohexanone derivative used for induction of anesthesia. Its mechanism of action is not well understood, but ketamine can block NMDA receptors (RECEPTORS, N-METHYL-D-ASPARTATE) and may interact with sigma receptors.
Definition (CSP) rapid-acting general anesthetic, animal anesthetic, and emerging drug of abuse.
Concepts Pharmacologic Substance (T121) , Organic Chemical (T109)
MSH D007649
SnomedCT 31706007, 333847008, 373464007
LNC LP15032-3, MTHU002347
English Cyclohexanone, 2-(2-chlorophenyl)-2-(methylamino)-, (+-)-, Ketamine [Chemical/Ingredient], 2-(2-Chlorophenyl)-2-(methylamino)cyclohexanone, KETAMINE, ketamine, Ketamine (product), Ketamine (substance), Ketamine
Swedish Ketamin
Czech ketamin
Finnish Ketamiini
Italian 2-(2-clorofenil)-2-(metilamino) cicloesanone, Chetamina
Russian KETAMIN, CI-581, КЕТАМИН
Japanese ケタミン
Croatian KETAMIN
Spanish Ketamina, Cetamina, Quetamina, cetamina, ketamina (producto), ketamina (sustancia), ketamina
Polish Ketamina
Portuguese Quetamina, Cetamina, Ketamina
French Kétamine
German Ketamin