Ketamine

Contraindications

Absolute

• <3 month old
• Known or suspected schizophrenia, even if currently stable or controlled with medications

Relative

• Major procedures involving posterior pharynx (e.g. endoscopy)
  • Typical minor ED oropharyngeal procedures are okay
• Airway instability (e.g. tracheal stenosis, tracheal surgery)
• Active pulmonary infection, including URI or asthma (unless for induction)
• CAD, HTN, CHF
• CNS masses, hydrocephalus (head trauma okay)
• Glaucoma/acute globe injury
• Thyroid disorder or on thyroid medication

Preparation

• Monitor
• BVM (ready)
• Suction
• Atropine
  • Only recommended for patients with impaired ability to mobilize secretions
  • 0.01 mg/kg IVP; min 0.1mg, max 0.5mg
• Versed
  • Pretreatment is nonmandatory in both adults and children
  • Consider 0.03mg/kg IVP if pt has unpleasant recovery reaction
• "Happy Place"

Administration

• Given as a slow push bolus.
  • Rapid bolus increases risk for apnea.
• IV preferred over IM (faster recovery, less emesis)
• Nystagmus is seen as an effect of the medication

Procedural Sedation or Induction

IV

• Children: 1.5-2 mg/kg (over 30-60sec)
• Adults: 1 mg/kg (over 30-60sec)
• Repeat dose 0.5-1 mg/kg q5-15 PRN

IM

• Children: 4-5 mg/kg
• Adult: 4-5 mg/kg
• Repeat dose 2-4 mg/kg if sedation inadequate 10min after initial dose

Intranasal

• Children: 3-6 mg/kg

Analgesia

IV

• Intermittent dosing at 0.1-0.5 mg/kg

Ketamine "Dart" (IM) for Sedation

• May be an option for combative special needs patients; originally studied in pediatric pts with facial trauma in ED
• IM ketamine (3 mg/kg), midazolam (0.05 mg/kg), glycopyrrolate (0.005 mg/kg)

Side Effects

• Airway misalignment requiring re-positioning of head (occasional)
• Laryngospasm (0.3%)
  • Only associated with unusually high IV doses
  • Tx = BVM ventilation; intubation is rarely needed
• Apnea or respiratory depression (0.8%)
  • Associated with rapid IV push
  • Transient
• Hypersalivation (rare)
• Emesis, usually well into recovery (8.4%)
• Recovery agitation, aka emergence reaction (mild in 6.3%, clinically important in 1.4%)
• Muscular hypertonicity and random, purposeless movements (common)
• Clonus, hiccuping, or short-lived nonallergic rash of face and neck
• May increase intraocular pressure

Intracranial pressure elevation

• Cerebral perfusion pressure (CPP) was compromised only in the patients with pre-existing intracranial hypertension and obstruction to the flow of cerebral spinal fluid. This has, however, led to the persistent belief that ketamine is contraindicated in patients with traumatic head injuries. Studies done subsequently have shown, however, that the effects of ketamine on cerebral haemodynamics and ICP are in fact variable and depend on both the presence of additional anaesthetic agents and PaCO2 values. Meta-analysis also suggests that Ketamine does not increase ICP and provides favorable hemodynamics.

Neurologic Injury

• Metaanalysis has shown that when ketamine is used in the presence of controlled ventilation, in conjunction with anaesthetics which reduce cerebral metabolism such as GABA receptor agonists, ICP is not increased.

Pediatrics

• In ventilated children with prior intracranial hypertension, ketamine decreased intracranial pressure (ICP) and prevented elevations during interventions without lowering blood pressure and CPP.

Prehospital

• In prehospital head trauma patients in Vietnam, no adverse effects on consciousness were observed when Ketamine was uses for analgesia

Disposition

Discharge Criteria

• Return to pretreatment level of verbalization/awareness
• Return to pretreatment level of purposeful neuromuscular activity
• Do NOT have to wait until the pt can ambulate or tolerate PO

Discharge Instructions

• NPO for 2hr
• No independent ambulation for 2hr

See Also

• Sedation (Main)
• Procedural Sedation
• Intranasal Sedation
• Sympathomimetic Toxicity
• Ketofol