Clinical features and gallium scan in the detection of post-surgical infection in the elderly

Common signs of infection, such as an elevated level of C-reactive protein (CRP), raised white blood cell (WBC) count and increased temperature, may not be present in elderly patients when infection occurs. In addition, these typical signs may be normal events during the postoperative period. Therefore, early detection of post-surgical infection may be difficult in the elderly population. In this study, we evaluated the usefulness of gallium scan in the detection of infection in elderly patients after colorectal surgery and compared it with CRP, WBC count and ear temperature (ET) examinations. Thirty-three patients undergoing colorectal surgery and aged over 60 years were enrolled in the study. All patients underwent a gallium scan and CRP, WBC and ET examinations. Of the 33 patients, 18 (54.5%) were diagnosed with infection. The diagnostic sensitivity was 100% for both gallium scan and the CRP test, but only 44.4% and 61.1% for the WBC count and ET, respectively. The diagnostic specificity of the gallium scan, WBC count and ET was 80% or more, whereas that of the CRP test was only 53.3%. The diagnostic accuracy of gallium scan, CRP test, WBC count and ET was 90.9%, 78.8%, 60.6% and 72.7%, respectively. In conclusion, both WBC and ET examinations show low sensitivity in the detection of infection in the elderly population after colorectal surgery. The CRP test has good sensitivity but low specificity. Of the four diagnostic modalities, gallium scan had the highest overall diagnostic accuracy (90.9%) while the WBC test had the lowest (60.6%).