Abstract
Category:
Diabetes; Other
Introduction/Purpose:
The incidence of Streptococcus agalactiae (Group B Streptococcus, GBS) infection in diabetic foot ulcers (DFU) has been on the rise. Severe soft tissue damage, which often leads to septicemia and amputation, has been reported in many cases. With the paucity of literature, we aimed to investigate the clinical outcome of GBS infected DFU patients. We hypothesize that GBS patients have a greater severity of infection as indicated by elevated inflammatory markers, more frequent wound complication, and a higher rate of unplanned readmission and reoperation.
Methods:
Data was retrospectively collected in a single academic orthopedic surgeon’s practice from February 2015 to October 2019. Seventy-eight patients with infected DFUs who underwent surgical treatment formed the basis of this study. Infected bone samples were obtained intraoperatively and sent for standard culture. The microbe data, demographic data (age, gender, race, ethnicity, and BMI), comorbidities, and initial lab values (HgA1C, CRP, ESR, WBC, and glucose) were recorded for all patients. Sixteen GBS infected DFU patients (20.5%) were identified. Among them, GBS infection occurred in 9 acute (<2 wks), 2 subacute (4-6 wks), and 5 chronic (>6 wks) DFUs. Clinical outcome was assessed by surgical outcome, wound healing status, post-operative complications, unplanned readmission, and unplanned reoperation within 3 months following initial surgery. Mean, standard deviation, percentage and range were calculated for patient demographics and inflammatory markers. Statistical significance of inflammatory markers between patients with and without GBS was also calculated.
Results:
The initial procedures were irrigation and debridement (n=11), toe amputation (n=1), ray amputation (n=2), transmetatarsal amputation (n=1), and a partial calcanectomy (n=1). Five GBS patients (31.3%), as compared to eighteen (29%) DFU patients without GBS, developed post-surgical complications (wound dehiscence, recurrent infection, septicemia) which required unplanned readmission and reoperation. Repeat operations were irrigation and debridement (n=1), metatarsal ray amputation (n=1), ray amputation (n=1), and below knee amputation (n=2) with average number of 2 repeat operations (range: 1 - 5). Hemoglobin A1C (p=.0067) was statistically higher in GBS patients. When comparing acute GBS ulcers (n=9) and acute ulcers without GBS (n=18), CRP (p=.037), HgA1C (p=.026), and blood glucose (p=.046) were all found to be significantly higher in patients with GBS DFUs.
Conclusion:
GBS infected DFU patients generally showed more extensive and severe soft tissue inflammation, as indicated by higher inflammatory markers at initial presentation. Compared to other patients with DFUs, GBS patients had significantly higher HgA1C values, and in those experiencing acute ulcers, had higher CRP, HgA1C, and blood glucose values. They have higher rates of post-operative complications that required unplanned readmission and reoperation at more proximal level. Surgeons should consider time sensitive and aggressive surgical treatment for GBS infected DFUs and counsel patients on the high risk of post- operative complications and repeat surgery.
