Introduction
Every year, many children and adolescents (both groups are referred to as “children” in our study) are injured in accidents and they are often treated in the trauma resuscitation room (trauma room) of the Emergency Department. In a trauma room, a multidisciplinary team of medical specialists and nurses take care of the initial assessment and treatment of trauma patients. Patients are referred to the trauma room in cases with a high-energy trauma mechanism involving a risk of severe and/or potentially life-threatening injuries. A high-energy trauma mechanism refers to mechanisms of injury associated with a high-energy impact such as a fall from height (> 10 ft or 2–3 times the height of the child) or a high-risk automobile crash or a pedestrian/bicycle versus automobile collision (American College of Surgeons,
2012). The accident itself, the injury, the pain, and medical procedures can all be frightening and potentially traumatic (Kahana, Feeny, Youngstrom, & Drotar,
2006; Price, Kassam-Adams, Alderfer, Christofferson, & Kazak,
2016). As a result, children may develop acute stress symptoms. These symptoms disappear spontaneously in the majority of the children in the weeks following traumatic events, but 8–14% develop posttraumatic stress disorder (PTSD) following unintentional injury (Alisic et al.,
2014; van Meijel et al.,
2015) and up to 18% develop severe posttraumatic stress symptoms (PTSS; Landolt, Vollrath, Timm, Gnehm, & Sennhauser,
2005). According to the DSM-5 classification, PTSD includes symptoms of re-experiencing, avoidance, negative alterations in cognitions and mood and increased arousal, resulting in substantial distress or impairment in functioning (APA,
2013). Acute stress disorder (ASD) can be diagnosed if symptoms persist for no longer than 1 month after the traumatic event; PTSD can be diagnosed if symptoms persist for longer than 1 month (APA,
2013). PTSD is a debilitating psychiatric disorder, often involving the development of co-morbid disorders (Stallard, Salter, & Velleman,
2004) and affecting children’s functioning and physical recovery from injury (Kahana et al.,
2006). Since ASD or PTSD at a subsyndromal level can also result in substantial impairment in functioning, it is appropriate to also evaluate and treat children reporting clinically significant persistent PTSS (Gold, Kant, & Kim,
2008).
Most injured patients experience pain, either as a direct consequence of the accident or later on from medical diagnostics and treatment (Baxt, Kassam-Adams, Nance, Vivarelli-O'neill, & Winston,
2004; Keene, Rea, & Aldington,
2011; Melby, McBride, & McAfee,
2011). In a study examining the relationship between acute pain and PTSS in children 8–17 years following traffic-related injury, acute pain was a predictor of PTSS 6 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, Marsac, Daly, Chute, & Kassam-Adams,
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, Hoefling, & Faust,
2011; van Meijel et al.,
2015; Winston, Kassam-Adams, Garcia-Espana, Ittenbach, & Cnaan,
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 account clinical and demographic factors (gender, presence of an extremity fracture, injury severity, length of hospitalization) potentially related to pain or posttraumatic stress. As the prevalence and the risk of PTSD differs between boys and girls (Alisic et al.,
2014; Stallard et al.,
2004; Winston et al.,
2003), we also examined associations between the variables of interest separately for boys and girls.
Discussion
In this study, we found an association between acute pain after accidental injury and PTSS 3 months later. The findings of our study confirm the findings of other studies, in that pain after accidental injury contributes to or is a risk factor for later PTSD or PTSS in children and adolescents (Hildenbrand et al.,
2016; Saxe et al.,
2005). However, the difference in outcome related to gender had not been specified previously. Furthermore, the association between acute pain and severity of posttraumatic stress was strongest in the group of children that reported severe pain. This result supports the finding of Hildenbrand et al. (
2016) that the most severe pain predicted subsequent PTSS. In the group of children with severe pain, pain may account for around 10% of the variance in the severity of the PTSS after 3 months.
In our study, girls reported more severe PTSS than boys. This finding is consistent with a previous study which found that girls have a greater risk for PTSD then boys (Alisic et al.,
2014). Injury severity and the presence of an extremity fracture were moderately associated and influenced the amount of acute pain. In boys, we found an association between the presence of an extremity fracture and pain. A possible explanation is that an extremity fracture causes more pain than other injuries. This is in line with the findings of Baxt et al. (
2004) in which extremity fracture was associated with greater “worst pain” ratings. Pain management may not always fit the need for pain medication that accompanies the presence of an extremity fracture, at least not immediately. Except for the gender difference that emerged from our study, our results are in line with previous findings (Winston et al.,
2003), i.e., that the presence of one or more extremity fractures is considered to be a risk factor for persistent posttraumatic stress. Although previous research has shown that injury severity is not a predictor of PTSD (Brosbe et al.,
2011), we found a negative association between injury severity and pain. A possible explanation might be that more severely injured children are likely to receive more adequate pain medication. The negative association was only found in girls.
Research on gender differences in pain suggests a difference between genders in their response to pain. Gender has been reported as a critical factor in the perception of pain; males and females experience pain differently (Paller, Campbell, Edwards, & Dobs,
2009). In that study, increased pain sensitivity and risk for clinical pain were more common in women. The specific basis for the differences between genders is still unknown, but research suggests that multiple biological and psychosocial processes are involved (Bartley & Fillingim,
2013). Furthermore, differences between genders might be related to a difference in communication and openness about the degree of pain. This is in line with the suggestion in Paller et al. (
2009) that boys and girls are reinforced differently for their expression of pain-related experiences. Another possible explanation is that medical staff evaluates the degree of pain differently in boys and girls. Although girls generally have a greater risk for PTSD than boys (Alisic et al.,
2014; Stallard et al.,
2004; Winston et al.,
2003), our results suggest that the risk for PTSD in injured children might be influenced by injury severity, pain, and pain management.
In the context of our findings, the subjectivity of reported pain should be addressed. Besides the injury itself, psychological mechanisms, like fear and loss of control, play a role in mediating the pain. Many people report pain for psychological reasons (International Association for the Study of Pain [IASP],
2017). There is no way to distinguish the subjective reporting of pain from pain that is due to tissue damage. According to the IASP, if people regard their experience as pain, it should be accepted as pain. This definition avoids tying pain to the stimulus. This clearly indicates the importance of pain measurement and subsequent pain medication according to the patient’s report as stated in pain protocols. In a review of the availability and content of acute pain protocols in emergency departments in the Netherlands, the authors emphasized the importance of adequate acute pain control, not only from the perspective of good patient care, but also due to adverse physical effects and the risk of developing chronic pain (Gaakeer, van Lieshout, & Bierens,
2010). The latter is strongly associated with chronic PTSD (Chossegros et al.,
2011). From the responding Dutch emergency departments, 35% did not have a pain management protocol for children (Gaakeer et al.,
2010), which heightens the risk of misjudgment and undertreatment. Several studies lend further support to the relationship between pain and later PTSD development by describing how aggressive pharmacological pain management at the time of initial hospitalization can reduce the likelihood of PTSD development (Gold et al.,
2008).
In addition to medication, the use of psychological strategies (e.g., distraction) by the medical staff can be of great help in reducing the subjective experience of pain, whether or not mediated by relief of anxiety. They can be applied dependent on the situation and the child’s characteristics and preferences (Koller & Goldman,
2012; Langeland & Olff,
2008). Furthermore, Trauma Informed Care (TIC) offers a multidisciplinary approach to reduce the risk for persisting posttraumatic stress and PTSD following injury (Marsac et al.,
2016; Weiss et al.,
2017). TIC is characterized by realizing the effect of trauma, recognizing how trauma can affect those involved, bringing trauma-related knowledge into practice and preventing further negative reactions (Marsac et al.,
2016). Implementing TIC can increase medical staff awareness of stressors following injury and can provide them with strategies that can help minimize the adverse effect of these stressors.
Strengths and Limitations
Due to the nature of our study and the acute situation after an accident, a retrospective pain rating was used, which increases the chance of unreliable ratings. Some of the children may have reported less reliably on the worst experienced pain, due to a period of unconsciousness or amnesia. Since we only used a single pain scale, we could not perform sensitivity analyses using another instrument. Moreover, pain medication could have had a confounding effect on the outcome but we were unable to account for this possible effect. The administration of pain medication was reported in the medical records, but children reported the worst experienced pain retrospectively. They did not report the exact moment in time that they experienced this pain. Therefore, we were unable to relate pain to information on pain medication. Additionally, we did not assess pain over time, although this could have provided more insight into the relationship between pain and the other variables. Furthermore, only the presence or absence of an extremity fracture was specifically registered as part of the STEPP study. We therefore did not include other types of injury classifications as an independent variable in the current study. Baseline acute stress may have contributed to the report of pain at baseline and to posttraumatic stress at 3 months but this was not assessed in our study.
Ideally, we would have examined the relationship between acute pain and a diagnosis of PTSD or significant PTSS. In this case, logistic regression analysis would have been appropriate. We would then have examined differences between the relationships between these variables for boys and girls using interaction effects. However, the number of children with significant PTSS (
n = 20) or PTSD (van Meijel et al.,
2015) in our sample was too low to perform logistic regression analysis, including a correction for gender and other potentially relevant factors (Peduzzi, Concato, Kemper, Holford, & Feinstein,
1996). Because of skewness of the data (many children without symptoms and few children with low pain scores), a transformation of the data offered no solution. The use of bivariate correlation precludes corrections for multiple factors. However, the use of Spearman’s rho correlation coefficients was the best alternative to obtain a reliable answer to the research question, certainly because there is a definite ordering of most of the variables in time. Although correlation coefficients should be interpreted as associations, the succession in time of the variables creates possibilities for additional interpretations. However, only an association, and not causation, can be inferred from cross-sectional data (Sedgwick,
2014). An advantage of the method we used was that pain and severity of posttraumatic stress were reported directly by the children and therefore were not biased by the interpretation of parents or professionals.
Acknowledgements
We gratefully acknowledge and thank Joost Daams, clinical librarian, Academic Medical Center, University of Amsterdam, the Netherlands, for his help with the literature search; Rebecca Holman, clinical statistician at Clinical Research Unit, Academic Medical Center, University of Amsterdam, the Netherlands for her statistical advice and her help with the interpretation of the data, and Charles Frink, (Frink Communications, Nijmegen, the Netherlands) for his contribution to text editing. This work was carried out as part of the Amsterdam Public Health research institute, Amsterdam, the Netherlands.