FUTURE RESEARCH QUESTIONS

FUTURE RESEARCH QUESTIONS
The ED ketamine literature in children is robust, with few
major issues remaining unstudied. Although larger, multicenter
studies would always be welcome, there is already a strong
evidentiary basis in place for indications, dosing, route, and
adjunctive medications and for the safety of this drug in the ED.
The high-priority study questions at this time are as follows.
Adult Use
Although the existing evidence is supportive of the safety and
efficacy of ED dissociative sedation in adults, it will take larger
and more focused studies to approach the rigor of what is
known in children. For what indications might ketamine be
preferred to other sedatives? Can we better define the adverse
event profile of ketamine in adults and identify any predictors of
such events? What are the optimal strategies for mitigating

hallucinatory dysphoria during recovery? Is there an upper age
limit beyond which ketamine imposes undue cardiac risk?
When can ketamine induce myocardial ischemia?
Ketamine Versus Propofol
Many emergency physicians are increasingly administering
propofol in settings in which they would have previously used
ketamine. Propofol has fewer contraindications than ketamine
and exhibits rapid recoveries generally free of recovery agitation
or vomiting. Does propofol possess a safety profile sufficient to
ultimately replace ketamine in most situations?
Ketamine and Propofol Combined
Several ED studies now describe the combined use of
ketamine and propofol as safe and effective.77,100-102 But does
this offer clinically important advantages over either drug alone,
propofol in particular?
Subdissociative Ketamine
Some emergency physicians administer ketamine in lower
doses that produce analgesia, disorientation, and obtundation
rather than dissociation either because the procedure does not
require such dissociation or because satisfactory conditions can
be achieved with adjunctive local anesthesia or physical
immobilization.103 Faster recovery should be expected with such
lower dosing. Further research is needed to identify what ED
indications are appropriate for such dosing and to quantify the
relative advantages and disadvantages of dissociative versus
subdissociative dosing.
In other settings, ketamine has been administered in doses
below the dissociative threshold to achieve pure analgesia and to
reduce opioid use.104-108 A strategy of “preemptive” ketamine
may decrease postoperative opioid requirements beyond
ketamine’s duration of effect.105 It remains unclear whether any
such benefits might be observed in the ED setting or whether
such low-dose ketamine offers any advantages over traditional
opioids for these indications.