Early Diagnosis of Surgical Wound Infection following Spinal Instrumentation Surgery: Usefulness of White Blood Cell Differential pp. 423-431
Authors: (Jun Takahashi, Hiroyuki Kato, Dept. of Orthopaedic Surgery, Shinshu University, School of Medicine, Nagano, Japan)
Abstract: Renewed elevation of C-reactive protein (CRP) or White blood cell (WBC) counts, gallium scan, and CRP/ transthyretin mass concentration ratio were reported for early diagnosis of surgical wound infection. The purpose of this study is to investigate the usefulness of white blood cell differential for early diagnosis of surgical wound infection after spinal instrumentation surgery. A total of 39 patients were enrolled in this study: 13 patients who developed wound infection within 2 weeks after spinal instrumentation surgery (infection group) and 26 patients who were comparable to those patients included in the infection group with regard to age, sex, a surgical techniques used (control group). The WBC count and WBC differential were determined before and after surgery. In the both groups, WBC, percentage and number of neutrophils showed nearly same change until postoperative 4 days (Day 4). However, in the infection group, these parameters had increased after Day 4. Especially Neutrophil percentages in the infection group were significantly higher values were observed on Days 4 (more than 80%), 7, and 11 compared with the values of the control group. In both groups, the percentage and number of lymphocytes decreased to 10% or less and 800/l or less on Day 1, respectively. These lymphocyte parameters began to gradually normalize on Day 4 and returned to the pre-operative level 3 weeks after surgery in the control group. On the other hand, these parameters remained 10% or less and 1000/l or less until Day 11 in the infection group. In patients with infection, the percentage and number of lymphocytes significantly decreased as early as on Day 4. Less than 10% of the percentage of lymphocytes, 800/l of the number of lymphocytes and more than 80% of the percentage of neutrophils on Day 4 are early diagnosis of surgical wound infection after spinal instrumentation surgery.