The 1970s were a dark time for ketamine use in patients with intracranial pathology. In patients with non-traumatic lesions, ketamine was suggested to increase intracranial pressure (ICP) using various markers as end-points to suggest this (see references below). Although this concern still remains with traditionalists, we have since seen multiple studies debunking this myth.
Now there is finally a meta-analysis supporting the suggestion that ketamine certainly does not seem to increase ICP. A systematic review of RCTs comparing the effects of ketamine vs opioids on 24-hour ICPs found that ketamine produced similar changes to ICP, MAP and CPP when compared to opioids. Surprised? Me neither.
Although this paper has some obvious flaws (small numbers, only 5 trials included, different choice of opioids, trials took place over 17 years, boluses vs infusions not addressed), this is one of the first meta-analysis to look at this surprisingly commonly misunderstood practice.
It is probably time for those Anaesthetics/Emergency Medicine/Pharmacology text books to be rewritten. And it is probably time to stop discussing whether ketamine can be used as an induction agent in TBI.