FIGURE 54.1 Back pain algorithm Laboratory studies Laboratory investigation is not routinely required and should be directed by the history and physical examination A complete blood count, C-reactive protein, and erythrocyte sedimentation rate are indicated if there is suspicion for infectious, neoplastic, or rheumatologic process Blood cultures should be obtained if there is concern for infection Antinuclear antibody, HLAB27 and rheumatoid factor may help in determination of a rheumatologic process and a basic metabolic panel, liver tests, lactose dehydrogenase, and uric acid should be added if neoplasia is a concern If history and physical examination are suggestive of other etiologies, additional tests (e.g., urinalysis and urine culture, pancreatic enzymes, liver tests) may be indicated Imaging Imaging for evaluation of back pain should only be utilized if a specific disease process is suspected and confirmation on imaging would alter