Circadian pain patterns in human pain conditions - A systematic review.

Background: Chronobiology is the science of how physiological processes in the body follow a pattern of time. Pain has been shown to follow a circadian rhythm, with different types of pain having variable expression along this rhythm.

Objective: This article reviews the nature of diurnal variations in pain along with a discussion of the mechanisms of circadian rhythm of pain.

Intraoperative Nerve Blocks Fail to Improve Quality of Recovery after Tissue Expander Breast Reconstruction: A Prospective, Double-Blinded, Randomized, Placebo-Controlled Clinical Trial.

Background: The authors' study represents the first level I evidence to assess whether intraoperative nerve blocks improve the quality of recovery from immediate tissue expander/implant breast reconstruction.

Methods: A prospective, randomized, double-blinded, placebo-controlled clinical trial was conducted in which patients undergoing immediate tissue expander/implant breast reconstruction were randomized to either (1) intraoperative intercostal and pectoral nerve blocks with 0.25% bupivacaine with 1:200,000 epinephrine and 4 mg of dexamethasone or (2) sham nerve blocks with normal saline.