Acute pain and posttraumatic stress after pediatric injury

Background: Unintentional injury is a leading health concern for children across the globe (Peden, 2008). In the United States alone, 20 million children suffer injuries each year (Borse et al., 2009). After an injury, many children experience persistent posttraumatic stress symptoms (PTSS) that negatively impact functioning and recovery (Balluffi et al., 2004; Daviss et al., 2000; DeVries et al., 1999; Holbrook et al., 2005; Kazak et al., 2001; Kean, Kelsay, Wamboldt, & Wamboldt, 2006; Mintzer et al., 2005; Rennick et al., 2004; Stoddard & Saxe, 2001; Winston, Kassam-Adams, Garcia-Espana, Ittenbach, & Cnaan, 2003). Although prior research on risk factors for PTSS has advanced our understanding of emotional recovery after pediatric injury, most investigations have focused on processes in the post-trauma period. Acute pain during the peri-trauma phase represents a promising avenue for identifying children who may be at risk for developing PTSS. Acute pain and PTSS share neurobiological pathways and commonly present after pediatric injury, yet their interactions are poorly understood given the paucity of research in this area (Gold, Kant, & Kim, 2008; Langeland & Olff, 2008). Investigations examining the association between pain and posttraumatic stress have largely focused on adults or small samples primarily composed of pediatric burn patients. As such, much remains unknown regarding the complex interactions between acute pain and PTSS among children who have sustained injuries. Aims: This research aims to add to our understanding of the development of PTSS and contribute to more effective screening and prevention approaches for children who have experienced medical trauma. Specifically, the current study examined the relationship between acute pain and PTSS and investigated whether pain medications conferred a protective effect against PTSS. Methods: This study utilized data collected as part of two large, prospective longitudinal studies of children following injury (Kassam-Adams et al., 2011; Kassam-Adams & Winston, 2004). In Study 1, children ages 8 - 17 years who had sustained an injury (N = 243) and their parents participated in baseline interviews to assess children's current and worst pain since the injury. Approximately six months later, children and parents completed follow-up interviews to assess child PTSS. In Study 2, children hospitalized for unintentional injury (N = 292) and their parents completed baseline assessments of traumatic stress symptoms. Approximately six weeks and six months later, follow-up assessments were conducted to assess PTSS. Children's pain ratings and opiate medications administered during hospitalization were obtained via chart reviews. Results: Worst pain as assessed by the Color Analogue Pain Scale predicted child PTSS six months post-injury, even when controlling for demographic and empirically-based risk factors (e.g., heart rate, prior trauma history, acute stress symptoms). In contrast, pain as assessed by the Faces Pain Rating Scale and a numeric 0-10 rating system did not emerge as significant independent predictors of persistent PTSS. Opiate medication use during hospitalization did not moderate the relationship between acute pain and PTSS six weeks or six months following pediatric injury. Conclusions: The Color Analogue Pain Scale may be a useful addition to existing screening tools for PTSS among children. Additional research is needed to examine differences between pain assessment tools as well as the impact of opiate medication use during hospitalization with regards to the development of PTSS. Further research is also warranted to better understand underlying mechanisms linking acute pain and subsequent PTSS in order to improve assessment, prevention, and treatment approaches and promote optimal recovery to pediatric injury.