Pain locations in the postoperative period after cardiac surgery: Chronology of pain and response to treatment.

INTRODUCTION: Postoperative pain after cardiac surgery (CS) can be generated at several foci besides the sternotomy.

METHODS: Prospective descriptive longitudinal study on the chronological evolution of pain in 11 sites after CS including consecutive patients submitted to elective CS through sternotomy. The primary endpoints were to establish the main origins of pain, and to describe its chronological evolution during the first postoperative week. Secondary endpoints were to describe pain characteristics in the sternotomy area and to correlate pain intensity with other variables. Numerical Pain Rating Scale from 0 to 10 at rest and at movement on postoperative days 1, 2, 4 and 6. Numerical Pain Rating Scale>3 was considered moderate pain. Statistical analysis consisted in Mann-Whitney U-test, a Chi-squared, a Fisher exact text and Pearson's correlations.

RESULTS: Forty-seven patients were enrolled. In 4 of 11 locations pain was reported as Numerical Pain Rating Scale>3 (sternotomy, oropharynx, saphenectomy and musculoskeletal pain in the back and shoulders). Maximum intensity of pain on postoperative days 1 and 2 was reported in the sternotomy area, while on postoperative days 4 and 6 it was reported at the saphenectomy. Pain at rest and at movement differed considerably in the sternotomy, saphenectomy and oropharynx. Pain at back and shoulders and at central venous catheter entry were not influenced by movement. Pain in the sternotomy was mainly described as oppressive. Patients with arthrosis and younger patients presented higher intensity of pain (P=.004; P=.049, respectively).

CONCLUSIONS: Four locations were identified as the main sources of pain after CS: sternotomy, oropharynx, saphenectomy, and back and shoulders. Pain in different focuses presented differences in chronologic evolution and was differently influenced by movement.