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Pain is the most common symptom of disease. It is defined as an unpleasant sensory and emotional experience, associated with actual or potential tissue damage. There are sound medical and legal reasons to treat pain aggressively in hospitalized patients. The Joint Commission, which certifies all health care institutions in the United States, mandates that all patients have the right to adequate pain assessment and management (Table 49-1).
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In the inpatient setting, patients may be more concerned about pain relief than the outcome of their underlying illness. Poor pain control has adverse physiologic consequences that lead to worse outcomes (Table 49-2).
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In postoperative patients, better analgesia improves cardiovascular, respiratory, endocrine, immunologic, gastrointestinal, and hematologic status. Acute pain that is not satisfactorily treated may become persistent.
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Nociception, the perception of noxious stimuli, is a preconscious neural activity that is normally necessary, but not sufficient, for pain. It is more accurate to refer to nociceptive pathways, rather than pain pathways. The peripheral nerve fibers acting as nociceptors are lightly myelinated A-delta and unmyelinated C fibers, which are triggered or sensitized (peripheral sensitization) by several substances, ...