This post was contributed by Lauren Riney, one of the excellent Pediatric Emergency Medicine Fellows at Cincinnati Children’s Hospital Medical Center.
So you’ve got another procedural sedation to do in the pediatric emergency department. If your ED is anything like ours, your options for sedation include ketamine, ketamine, and, well, more ketamine.
The pharmacology of ketamine is totally different from any other sedative. It works by dissociating the CNS from outside stimuli causing a cataleptic trancelike state. This amazing medication does not blunt the respiratory drive nor cause hypotension, and at the same time allows for effective sedation, amnesia, and analgesia. It is almost too good to be true!
The dissociation induced by ketamine does not follow the progression of increasing depth of sedation followed by cardiorespiratory depression. Patients either are or are not dissociated; there is no increased depth response to increase in dose.
So what exactly is dissociative sedation? And what should you be telling parents about this type of sedation? For starters, the patient will be in a trancelike state of mind where they do not respond to stimuli but the eyes may remain open, they may make noises, and they may move their extremities. Nystagmus is common and muscular clonus may be seen. The patient will have substantial or complete analgesia as well as total amnesia all while maintaining their respiratory drive and cardiovascular stability.
You should include parents and family members (older children) in the sedation process. For example, have the family talk with the patient to think of topics for dreaming during sedation, which has been shown to decrease recovery reactions. Just before induction, I often have the patient think about a recent trip they went on: describe what they saw, how they felt, who went with them, and their favorite part. The more calm and relaxed the patient is during induction with ketamine, the more likely their recovery will be pleasant.