Ketamine Use in the Cardiovascular Intensive Care Unit (CVICU)

Mechanism and Benefits

Ketamine functions as an N-methyl-D-aspartate/glutamate receptor (NMDA) antagonist that interferes with normal excitatory effects of glutamate and aspartate while also interacting with opioid receptors 1

For sedation and analgesia: Sub-anesthetic doses (0.1-0.5 mg/minute as a microdrip infusion) can be administered with opioids to help reduce the overall opioid dose 1
For continuous infusion: 0.5 mg/kg IV bolus followed by 1-2 μg/kg/min infusion as an adjunct to opioid therapy 2

Opioid-sparing effect: Ketamine can decrease the overall quantity of opioids administered and reduce the incidence and severity of opioid-related side effects 3
Refractory pain management: Particularly useful when pain is refractory to opioids and other agents 1, 3

Psychotomimetic side effects (dysphoria, nightmares, hallucinations) may occur, especially at higher ketamine doses 1, 4
Use with caution in patients with ischemic heart disease, cerebrovascular disease, or hypertension 2

Track for emergence phenomena and psychotomimetic effects, particularly when discontinuing infusions 1, 4

The American College of Emergency Physicians notes that ketamine can produce sympathomimetic activation and psychotomimetic effects, which can manifest as restlessness, agitation, and inability to relax, in patients receiving a standard antidepressant/analgesic dose of 0.5 mg/kg IV 5, 6, 7
Recovery agitation has been documented in 7.1% of patients receiving ketamine alone in pediatric studies, though rates vary by age and individual susceptibility, according to the American Academy of Pediatrics 8, 9

The American College of Emergency Physicians recommends that benzodiazepines, such as midazolam, can reduce ketamine-induced emergence delirium and psychotomimetic effects, particularly in older patients, with a strength of evidence level of moderate 8, 9