Researchers from the Division of Child Psychiatry at North Shore-Long Island Jewish Hospital evaluated the effectiveness of teaching guided imagery to acutely injured pediatric patients in the PICU, as compared to a one-on-one inquiry about pain-related experiences.
Forty-four hospitalized children and adolescents were assigned to one of two intervention groups, the imagery arm (N = 24) or the inquiry arm (N = 20).  Pain was assessed pre- and post-intervention using the Wong-Baker Faces Pain Rating Scale and a 0-10 Likert pain rating scale, while the Pediatric Trauma Score was given to assess the severity of each child's injuries.

Boys in the imagery condition had a significant decrease in average pain ratings [t(38) = 3.41, p = .0015] while girls showed a non-significant decrease in average pain ratings.
The study concludes that teaching acutely injured children in the use of guided imagery for pain management in the intensive-care setting has merit.  One-on-one inquiry with boys was not effective.
Citation: Kline WH, Turnbull A, Labruna VE, Haufler L, DeVivio S, Ciminera P. Enhancing pain management in the PICU by teaching guided mental imagery: a quality-improvement project. Journal of Pediatric Psychology. 2010 Jan-Feb; 35 (1): pages 25-31. Epub 2009 Apr 22. [email protected]