Ketamine

Contraindications

Absolute

1. <3 mo old
2. Known or suspected schizophrenia, even if currently stable or controlled w/ meds

Relative

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

Preparation

1. Monitor
2. BVM (ready)
3. Suction
4. Atropine
   1. Only recommended for pts w/ impaired ability to mobilize secretions
   2. 0.01 mg/kg IVP; min 0.1mg, max 0.5mg
5. Versed
   1. Pretreatment is nonmandatory in both adults and children
   2. Consider 0.03mg/kg IVP if pt has unpleasant recovery reaction
6. "Happy Place"

Administration

1. Give initial bolus
   1. IV prefered over IM (faster recovery, less emesis)
   2. IV
      1. Children: 1.5-2 mg/kg (over 30-60sec)
      2. Adults: 1 mg/kg (over 30-60sec)
      3. Repeat dose 0.5-1 mg/kg q5-15 PRN
   3. IM
      1. Children: 4-5 mg/kg
      2. Adult: 4-5 mg/kg
      3. Repeat dose 2-4 mg/kg if sedation inadequate 10min after initial dose
2. Nystagmus = effect

Side Effects

1. Airway misalignment requiring repositioning of head (occasional)
2. Laryngospasm (0.3%)
   1. Only associated with unusually high IV doses
   2. Tx = BVM ventilation; intubation is rarely needed
3. Apnea or respiratory depression (0.8%)
   1. Associated with rapid IV push
   2. Transient
4. Hypersalivation (rare)
5. Emesis, usually well into recovery (8.4%)
6. Recovery agitation (mild in 6.3%, clinically important in 1.4%)
7. Muscular hypertonicity and random, purposeless movements (common)
8. Clonus, hiccupping, or short-lived nonallergic rash of face and neck
9. Elevated Intracranial pressure

Discharge Criteria

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

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

Discharge Instructions

1. NPO for 2hr
2. No independent ambulation for 2hr

See Also

Procedural Sedation

Source

Annals of EM. Clinical Practice Guideline for ED Ketamine Dissociative Sedation: 2011 Update