The effects of acute pain on cognitive skills in emergency department patients

Introduction: Effective pain management results in improved patient satisfaction, reduced anxiety, and improved comfort. However, concern exists regarding the effects of pain medications on cognition and patient ability to consent for procedures, hospital admission, or to refuse recommended medical interventions. Methods: This prospective, case-control study was conducted at a Level 1 Trauma Center. Eligible subjects included ED patients ages 18 and older with a triage pain score of 1 or higher, who received non-narcotic analgesic agents. Cognition was measured before and after non-narcotic pain medication using the Digit Symbol Substitution Test (DSST). A control group consisted of 35 healthy volunteers who completed the DSST at baseline and one hour. Results: Among 46 subjects, the mean age was 33. The mean triage pain score was 7. Before medication, the average DSST score was 39.5. After medication, the average DSST score was 42.9. There was a significant within-subject average change in DSST score (pre-post) of 3.4 (95% confidence interval: 1.6, 5.2), p < 0.001. Among the control group, the mean baseline DSST score was 64.2 (SD 10.7). One hour later the mean DSST score had increased to 71.1 (SD 10.4). Overall, the mean within-subject change over time in DSST was 6.9 (SD 8.0) with 95% CI 4.2 to 9.7. There was not enough evidence to detect relationships between change in DSST scores and age, triage pain, triage HR, triage RR, change in pain scores, gender, ethnicity, mode of arrival nor insurance (all with p > 0.05). Conclusions: We found significant variation in DSST scores among ED patients with pain. Treatment of pain with nonsedating analgesic agents was not associated with improved scores on the Digit Symbol Substitution Test among ED patients with acute painful conditions, compared to control subjects.