Self-reported Pain Scores in the Emergency Department: Lack of Association with Vital Signs

Background: Some practitioners and investigators have presumed relationships between pain scores and heart rate, blood pressure, or respiratory rate. Previous literature has not adequately addressed the association of pain and vital signs. Objectives: To identify any association between self-reported pain and heart rate, blood pressure, or respiratory rate. Methods: In this retrospective, observational study, emergency department patients older than 17 years of age presenting between May 2004 and April 2005 with verifiable painful diagnoses (including nephrolithiasis, myocardial infarction, small bowel obstruction, fracture, burn, crush injury, stab wound, amputation, corneal abrasion, and dislocation) were identified. Data were extracted from the hospital's database, including patients' age, gender, emergency department diagnosis, self-reported pain score, heart rate, blood pressure, and respiratory rate. Results: Among 1,063 subjects, the most common diagnoses were nephrolithiasis (25%; n = 267) and fracture (23%; n = 249). The mean (±SD) triage pain score was 7 (±3). The mean (±SD) heart rate was 85 (±16) beats/min, mean (±SD) systolic blood pressure was 141 (±23) mm Hg, and mean (±SD) respiratory rate was 19 (±3) breaths/min. There were no clinically significant differences in mean vital signs across the individual pain scores, as demonstrated by overlapping confidence intervals across pain scores. Conclusions: No clinically significant associations were identified between self-reported triage pain scores and heart rate, blood pressure, or respiratory rate.