The Efficacy of Continuous Intravenous Ketamine in Refractory Pediatric Headaches
Scott Rosenthal1, Angelina Koehler1, Elizabeth Ackley2, Marcy Yonker3
1University of Colorado, 2University of Colorado School of Medicine, Dept Neurology, 3Children's Hospital of Colorado
Objective:
To examine the efficacy of intravenous (IV) ketamine in refractory pediatric headaches.
Background:
IV Ketamine, a NMDA receptor antagonist, has emerged as potential therapeutic option for headache patients who fail typical rescue options. There is a paucity of literature available about the use of IV ketamine in the treatment of severe and refractory pediatric headaches.
Design/Methods:

Retrospective chart review of patients 5-21 years old, admitted between 2019-2022 for the treatment of refractory headache with continuous intravenous ketamine.  Primary outcome measures were percent pain reduction ([Initial Pain -Repeat Pain Score]/Initial Pain Score*100) at discharge and after each subsequent day of ketamine, serious adverse events, and headache recurrence defined as representation to neurology care via phone, clinic, or hospital encounter.

Results:
64 encounters comprised of 38 unique patients were included for analysis.  The median age was 16.3 years (IQR 13.5-17.6) and 76.5% (49/64) identified as female.  The median duration of headache exacerbation at presentation was 14 days (IQR 4-23).  The median percent pain reduction at discharge was 40% (IQR 19.4-66.7) and 45% (29/64) of encounters had ≥50% pain reduction at discharge.  There was a ≥50% pain reduction in 17.2% (11/64) on day 1, 35.5% (22/62) day 2, and 43.9% (18/41) day 3.  64% (41/64) did not have headache recurrence within 1 month. There were no serious adverse events.  7.8% (5/64) encounters terminated therapy early due to side effects.
Conclusions:
Intravenous ketamine is an effective, safe and well tolerated treatment option for refractory pediatric headaches and status migrainosus.  There was a median pain reduction of 40% at discharge and 45% of patients had ≥50% pain reduction.  There was increasing benefit of each serial day of ketamine with the rate of ≥50% pain reduction increasing from 17% on day 1 to 44% on day 3. The majority of patients did not have headache recurrence within 1 month.  
10.1212/WNL.0000000000205749