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The major shift in preoperative assessment and management from within the hospital to outside the hospital has prompted new efforts to coordinate preoperative care. Much of this can be accomplished with the introduction of a preadmission testing center. Under the direction of a physician (typically an anesthesiologist), the Pre-Admission Testing Center staff performs necessary assessments and coordinates necessary information about the presurgical patient. This assessment should include features essential to the general history and physical examination, as well as the specific issues related to anesthesia and surgery. The preoperative visit is also an opportunity to perform directed laboratory testing (as opposed to across the board batteries of tests) and to carefully plan out the continuance, discontinuance, or initiation of medications in the perioperative period. It also may be beneficial to stabilize disorders such as hypertension and, when indicated, initiate preoperative optimization of patients with advanced disease. The ultimate goal is to provide safe and "efficient" care, without exhausting highly valued intensive care resources.

Pain reduces itch-a commonly known effect of scratching the skin. Experimentally produced itch from histamine is sometimes accompanied by secondary sensations of pain. The present study investigated the effects of eliminating this pain, by means of a local anesthetic, on the itch and the enhanced mechanically evoked itch and pain that occur after an intradermal injection of histamine. In ten human subjects, the volar forearm was injected with either 20 microl of 2% chloroprocaine (experimental arm), or 20 microl of saline (control arm). Histamine 10 microl was injected into each bleb, and the resulting magnitude of itch estimated. The borders of three cutaneous areas were mapped within which mechanical stimulation of the skin surrounding the bleb elicited abnormal sensations (dysesthesiae): alloknesis, defined as itch evoked by innocuous stroking, and hyperalgesia and hyperknesis, characterized, respectively, by enhanced pain and enhanced itch evoked by pricking the skin with a fine tipped filament. The magnitude and duration of itch were significantly greater and the areas of dysesthesia significantly larger for the experimental than for the control arm. It is hypothesized that there exist two classes of histamine-sensitive primary afferent neurons. One class is "pruritic", and mediates itch whereas the other is "antipruritic", and evokes a centrally mediated reduction in histamine-evoked itch and dysesthesiae. It is further suggested that the anesthetic blocked the discharges of the antipruritic afferents, preventing the central inhibition from occurring and thereby unmasking the effects of the pruritic afferents.