Preliminary study of the impact of elevated circulating plasma levels of catecholamines on opioid requirements for acute surgical pain

INTRODUCTION: The objective of this study is to determine whether elevated circulating plasma catecholamine levels significantly impact opioid requirements during the first 24 hours postoperative period in individuals with acute surgical pain. METHODS: We retrospectively reviewed 15 electronic medical records (EMRs) from adults 18 years and older, with confirmed elevated plasma catecholamine levels (experimental) and 15 electronic health records (EHRs) from matched-controls for age, gender, race and type of surgery, with a follow up of 24 hours postoperatively. RESULTS: The total morphine milligram equivalents (MMEs) requirements from the experimental group were not statistically different when compared with controls [44.1 (13 to 163) mg versus 47.5 (13 to 151) mg respectively; p 0.4965]. However, the intraoperative MMEs showed a significant difference, among the two groups; [(experimental) 32.5 (13. to 130) mg, (control) 15 (6.5 to 130) mg; p 0.0734]. The intraoperative dosage of midazolam showed a highly significant positive correlation to the total MMEs (p 0.0005). The subjects with both elevated plasma catecholamines and hypertension used significantly higher intraoperative MMEs compared to controls [34.1 (13 to 130) mg versus 15 (6.5 to 130) mg, respectively; p 0.0292)]. Those 51 years and younger, with elevated circulating levels of catecholamines, required significantly higher levels of both the postoperative MMEs [29.1 (0 to 45) mg versus 12 (0 to 71.5) mg; (p 0.0553)] and total MMEs [544.05 (13 to 81) mg versus 29.42 (13 to 92.5) mg; (p 0.00018), when compared to controls with history of nicotine and alcohol use. CONCLUSION: This preliminary study evaluated a biologic factor, which have promising clinical usefulness for predicting analgesic requirements that can drive clinical decisions on acute surgical pain.