Ketamine Procedural Sedation

Ketamine is a dissociative anesthetic that works by binding NMDA receptors. It is commonly used for procedural sedation that provides sedation, analgesia, and amnesia, while maintaining protective airway reflexes and breathing, making it suitable for numerous procedures such as wound repairs (lacerations, burns, fractures).

Initial Dose: 1 - 1.5 mg/kg | PRN Dose: 0.5 - 1 mg/kg q5-10 min | Max Total dose 5 mg/kg

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Advantages:

Disadvantages:

• Rapid onset of action

  Onset in 30 to 60 seconds and lasts for 10 to 20 minutes.

• Does not suppress respiratory drive

  • Preserves upper airway tone, airway reflexes, and spontaneous breathing.

  • Also acts as a bronchodilator which may benefit asthmatics.

• Hemodynamically favorable

  • Can induce hypertension and tachycardia as a side effect.

  • Be careful in catecholamine-depleted patients as it can cause myocardial depression.

  • Increases in blood pressure and heart rate, can be concerning for patients with underlying cardiovascular conditions.

• Increased secretions, Apnea, and Laryngospasm

  Occur in <1% of children receiving ketamine. Increased risk in children <2 yo or >12 yo, higher doses, and coadministration of benzodiazepines.
  

  Laryngospasm management

  In complete glottic closure, no sounds may be heard and the chest is often silent. In partial closure, there may be stridor, guttural noises or paradoxical chest movement in effort against the partially closed cords. Apnea identified by chest wall movement or end-tidal CO2 may be the only indication of laryngospasm.

  1. Positive pressure via BVM with 100% FiO2.

  2. Ensure positive pressure with an adequate seal, jaw-thrust maneuver, and neck extension.

  3. Apply pressure to Larson's point (laryngospasm notch): Soft tissue located behind the ear lobe and the mastoid process. Press both sides firmly inward and simultaneously push anteriorly in a jaw-thrust manuever. Periosteal pain results in autonomic nervous system reflex and vocal cord relaxation.

  4. Propofol (1-2mg/kg) has been shown to treat 80% of laryngospasm by deepening anesthesia.

  5. Succinylcholine is considered the gold standard for treatment (0.1 to 0.5 mg/kg). Low doses may offer the benefit of maintenance of spontaneous breathing. Be prepared to ventilate or intubate until neuromuscular blockade runs out.

  6. Observation for 2-3 hours after laryngospasm for reported post-obstructive pulmonary edema, bradycardia, or pulmonary aspiration.

• Nausea/Vomiting

  Emesis post-procedure will cause discomfort, parental stress, and increase your patient’s LOS while you wait for them to tolerate PO! Pre-medicate with ondansetron to mitigate this effect.

• Hallucination and Agitation

  Patients can have emergence reactions marked by hallucinations, confusion, and vivid dreams during the recovery period.

  Higher risk in older patients and patients with psychiatric or neurodevelopmental problems.

Relative Contraindications:

• Conditions worsened by an increase in blood pressure or heart rate, such as poorly controlled high blood pressure.

• Psychiatric disorders: Ketamine may exacerbate the symptoms of certain psychiatric disorders.

• Penetrating eye injury/Raised intraocular pressure (IOP): Ketamine can further increase IOP
  

Sedation Checklist:

1. Assess the patient for any potential contraindications/side effects to ketamine or prior personal or familial adverse reactions to anesthesia. If concerning history or abnormalities on the exam (ie high ASA, difficult airway, cardiac hx, etx), consider consulting anesthesia prior to procedural sedation.

2. Ensure that room is set up appropriately with BVM, ETCO2, oxygen, and suction. During the procedure, continuous monitoring of vital signs, such as blood pressure, heart rate, and oxygen saturation, is necessary.

3. Check to make sure Zofran and all ketamine doses are ordered appropriately.