Principles & Practice of Pain Medicine > Part V. Pain Syndromes > C. Pain in the Terminally Ill > Chapter 45. Medical Management of Cancer Pain Stuart W. Hough and Russell K. Portenoy

Pain Assessment

"Pain is often underrecognized in cancer patients. Cleeland et al surveyed outpatients with metastatic cancer and physicians from 54 treatment centers.³ They found that 42% of 597 patients with pain were not receiving adequate analgesia by the WHO guidelines (Fig. 45-1). Insufficient pain relief was particularly common among minorities, women, and the aged. An important barrier to effective pain management was a discrepancy between the patient's and physician's assessments of the extent to which pain was interfering with daily activities. The data underscore the importance of accurate pain assessment in providing adequate cancer pain relief.Although there is no quantitative biochemical or neurophysiologic test for pain, tools have been devised to assess pain intensity ⁴ (See Chapter 6, Evaluating the Patient with Chronic Pain). Categorical scales, which ask patients to rate pain using adjectives such as "mild" and "excruciating," are simple to use, but assume an understanding of the adjectives. Pain relief may also be rated with a categorical or percentage scale. The verbal numeric scale, rating pain from zero for "no pain" to 10 for "the worst imaginable pain," is easily implemented and recorded during frequent assessments. The use of numbers removes any linguistic misunderstanding of categorical descriptors. Similarly, a 100-mm visual analog scale may be used, with or without intensity descriptors (Fig. 45-2). Although a visual analog pain score may not mean the same thing to different..."