Acute Pain Characteristics in Patients with and without Chronic Pain following Lower Extremity Injury.

Many patients with injuries to lower extremities report chronic pain. High pain intensity at time of admission for injury is a risk factor for chronic pain, but it is not clear whether specific acute pain patterns following injury influence the development of chronic pain. To examine the relationship between the pain trajectory, the mean pain score, and the frequency of pain documentation during the immediate hospitalization following injury, with the report of chronic pain. This was a descriptive, retrospective cohort study of adults admitted with lower extremity fractures to an academic urban trauma center. Participants, 6-45 months postinjury, rated their current pain, worst pain, and average pain over the last 3 months. Pain scores from hospitalization associated with the injury were obtained through a retrospective chart review. The pain trajectory, mean pain score, and frequency of pain documentation was compared between patients with and without chronic pain. A total of 129 patients were enrolled in this study and 78% reported chronic pain at the site of injury. The mean pain score (5.1 vs. 4.2) and first pain score (5.6 vs. 3.4) were higher for patients with chronic pain compared to patients with no chronic pain. Consistent with other studies, high pain intensity at time of injury was associated with chronic pain. The findings contribute valuable information about acute pain characteristics associated with chronic pain and provide insight into the importance of early and adequate acute pain treatment.