Els van Meijel

42 Chapter 3 | Acute pain and posttraumatic stress symptoms six months after the injury, even after controlling for demographic and empirically based risk factors (age, gender, ethnicity, heart rate at triage, prior trauma history, acute stress symptoms and perceived life threat (Hildenbrand et al., 2016). Pain was identified as a risk factor for ASD in 7- to 18-year-old children after intentional and unintentional injury (Saxe et al., 2005). In turn, ASD is considered to be a risk factor for PTSD (Dalgleish et al., 2008; Saxe et al., 2005). A study of young children with burns identified pain as a factor positively associated with posttraumatic stress outcome (Stoddard et al., 2006). The association between acute pain and later PTSS may be based on shared neurobiological stress mechanisms, enhanced hypothalamic–pituitary–adrenal axis and noradrenergic activation (Asmundson, Coons, Taylor, & Katz, 2002; Hildenbrand et al., 2016; McLean, Clauw, Abelson, & Liberzon, 2005; Norman, Stein, Dimsdale, & Hoyt, 2008). These stress mechanisms, which trigger acute pain, may also serve to encode the memory of the trauma and trigger a posttraumatic stress-related process. Memories of painful events are readily retrievable, indicating that strong encoding occurs at the time the pain was experienced (Morley, 1993; Norman et al., 2008). Pain associated with traumatic injury may act as a reminder of the traumatic event, which may further reinforce memories associated with the traumatic event (Gold et al., 2008). Additionally, the finding that aggressive pharmacological pain management can reduce the likelihood of PTSD lends further support to the relationship between pain and later PTSD development (Gold et al., 2008). Studies on prediction of, and risk factors for, PTSD generally use clusters of factors and study their combined predictive value or combined risk for PTSD. So far, acute pain has not been included in a screening instrument for risk for PTSD in children following accidental injury (Brosbe et al., 2011; van Meijel et al., 2015; Winston et al., 2003) nor has it been used as stand-alone screener for risk of PTSS. However, the assessment of acute pain is, or easily can be, included in ambulance and emergency care protocols, thus offering an opportunity to identify children at risk for PTSD or PTSS. Research on the relationship between acute pain and PTSS following child accidental injury is still scarce. If we confirmed or further clarified the above-mentioned initial research findings on the role of acute pain in later child PTSS, we would be able to contribute to screening methods for identifying children at risk and consequently to the prevention of PTSD and PTSS. The aim of this study was to examine the association between acute pain after accidental child injury and PTSS 3 months later, taking into