Clinical outcomes of isolated lower extremity or foot burns in diabetic versus non-diabetic patients: a 10-year retrospective analysis

Abstract

Introduction: The incidence of diabetes mellitus (DM) in the United States is expected to increase from 8 per 1000 in 2008 to 15 per 1000 by 2050 [20]. As a result, DM patients will constitute a large proportion of Burn Center admissions, with burns typically due to contact burn or scalding. Peripheral vascular disease (PVD) and peripheral neuropathy (PN) are far more common in DM patients, particularly in those with poorly controlled disease, and are often associated with worse outcomes than non-diabetic (nDM) burn patients. This study sought to analyze whether the outcome of isolated leg and foot burns among DM and nDM individuals differed significantly.

Materials and methods: Retrospective data on 207 consecutive patients (>18 years old) admitted to a Burn Center with isolated leg or foot burns between 1999 and 2009 was collected and analyzed for this study. Age, gender, ethnicity, total body surface area (TBSA), degree of burn, etiology, hospital and burn intensive care unit (ICU), length of stay (LOS), and status at discharge were reviewed. Patients were grouped as diabetic (DM) or non-diabetic (nDM). Differences were analyzed using either the Student's t-test or Chi-square.

Results: 43 DM and 164 nDM patients with isolated lower extremity or foot burns were treated during the study period (1999-2009). The mean age of DM and nDM patients was 54.6 and 43.7 years, respectively (p<0.001). The most common burn etiology was scalding, flame, or contact burn. Percentage of total body surface area (TBSA) burn in DM patients averaged±standard deviation 1.8±1.3% compared to 1.8±1.6% in nDM (p<0.9). Among DM patients, 86% (N=37) of patients suffered third degree burns and 14% (N=6) of patients had second degree burns compared to 76% (N=125) of patients and 24% (N=39) of patients among nDM patients, respectively (p<0.16). The DM group had significantly higher burn ICU admission rates, 16.3% of patients versus 8.5% of patients (p<0.001), total length of hospital stay (mean±standard deviation), 14.1±10 versus 9.8±9.3 days (p<0.01) and renal failure, 4.7% of patients versus 0.6% of patients (p<0.05) compared to the nDM group. 93% of DM patients were discharged to home without further medical attention while 4.7% of patients underwent further treatment. In comparison, 85.4% of the nDM patients were discharged home with no further treatment while 8.5% of patients received home care (p<0.01).

Conclusion: DM patients who suffer isolated burns to the feet or lower extremities have poorer clinical outcomes and more complicated and protracted hospital courses when compared to nDM patients with similar burns. Although diabetics in the current study did not experience larger or more severe burns than nDM patients, they were nearly twice as likely to be admitted to the ICU, spent an average of four days longer in the hospital, and had a higher likelihood of developing renal failure compared to nDM patients.