title: Lessons learned from a multiple-dose post-operative analgesic trial.
abstract: Patients undergoing major surgery often require several days of post-operative analgesic management. However, little data are available on the course of post-operative pain during this period. Such data would be extremely helpful in planning treatment, formulating pain management guidelines, and determining how to construct multiple-dose post-operative analgesic clinical trials. The objectives of this study were to determine (1) if post-operative pain severity, as measured by a modified version of the Brief Pain Inventory (BPI), can be categorized as mild, moderate, or severe in terms of modified BPI pain interference scores, (2) the relationship between modified BPI pain ratings and responses to a categorical item that specifically measures post-sternotomy pain, and (3) the relationship between global ratings of study medication effectiveness and other pain measures. This study is a reanalysis of data from patients who underwent coronary artery bypass graft procedures. We found that the pain severity level cut points developed for chronic pain apply equally well to post-operative pain. Based on this classification scheme, 18% of patients reported moderate pain after day 3, while 14% reported severe pain. Only 9% of patients reported experiencing moderate-to-severe pain approximately 2 weeks later, at the end of the study. Describing pain as mild, moderate, or severe could be a simple, meaningful clinical trial outcome measure. Because most patients experience only mild pain 6 days after surgery, long-term clinical trials of post-operative pain control may be more efficient and cost-effective if they focus on the subset of patients with persistent moderate or severe pain.
authors.affiliation: Pain Research Group, Department of Symptom Research, The University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Blvd, Box 221, Houston, TX 77030, USA. tmendoza@mdanderson.org
authors.forename: Tito R
authors.initials: TR
authors.lastname: Mendoza
authors.forename: Connie
authors.initials: C
authors.lastname: Chen
authors.forename: Andrew
authors.initials: A
authors.lastname: Brugger
authors.forename: Richard
authors.initials: R
authors.lastname: Hubbard
authors.forename: Michael
authors.initials: M
authors.lastname: Snabes
authors.forename: Stephen N
authors.initials: SN
authors.lastname: Palmer
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhang
authors.forename: Charles S
authors.initials: CS
authors.lastname: Cleeland
mesh_terms: D000368:Aged; D000700:Analgesics; D000704:Analysis of Variance; D001026:Coronary Artery Bypass / Q000523:psychology; D003710:Demography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement / Q000379:methods; D010149:Postoperative Pain / Q000145:classification / Q000628:therapy*; D011184:Postoperative Period; D011594:Psychometrics; D012680:Sensitivity and Specificity; D013997:Time Factors
chemical_list: D000700:Analgesics