Should we be scoring pain differently for rib fractures? A comparison of two scoring systems.

Introduction: Uncontrolled rib fracture pain can lead to hypoventilation, impaired airway clearance, and progression to respiratory failure and death. Pain control is a mainstay of treatment, but pain assessments are most commonly obtained while a patient is at rest. A novel approach is to assess movement-evoked pain in order to better capture pain that limits physical function. We hypothesized that movement-evoked pain scores (MPS) for patients with rib fractures would be higher than resting pain scores (RPS) and would better correlate with opioid administration.

Methods: A retrospective observational study was performed at a single Level 1 trauma center. Adult trauma patients (≥18 years old) admitted between January and March of 2022 with at least one rib fracture were included. Patients with other significant injuries (non-chest AIS >2) or those unable to self-report pain scores were excluded. Pain was scored on a 0-10 scale, with 10 indicating the most severe pain. RPS and MPS obtained at the same time during the first ten hospital days were averaged, and the means were compared using paired t-tests. Additionally, mean daily morphine milligram equivalents (MME) were analyzed.

Results: The cohort consisted of 80 patients (median age 69 [IQR 48-79]; 65 % male; 88 % white). The majority were involved in blunt trauma (95 %) with a median length of admission of 4 days (IQR 2-8). The median number of rib fractures was 4 (IQR 2-6), and the median injury severity score was 10 (IQR 9-14). A total of 1692 paired pain scores from 416 patient hospital days were analyzed with higher mean daily MPS across all hospital days (p < 0.001). MPS and RPS differed for 79 % of patient hospital days, with a mean difference of 2.3 (SD 1.4, p < 0.001). Higher mean daily MPS were correlated with higher mean daily opioid use (R²=0.54), and days with differing scores had higher mean MME [42.5 (SD 49.6) vs 23.6 (56.1)].

Conclusions: Resting and movement-evoked pain scores for patients with rib fractures varied significantly, and movement-evoked pain scores were consistently higher. Opioid use was positively correlated with movement-evoked pain scores. Utilization of movement-evoked pain scores may improve patient pain control and outcomes.