Deep burn index as a significant prognostic factor of patients with burns ≥ 70 % TBSA: A retrospective study

Burn injuries represent a major global health concern with prognosis closely linked to the size and depth of the burn. Previous studies have shed light on the correlations between deep burn injuries and prognosis. Nevertheless, studies establishing and consolidating the prognostic value of deep burn injuries remains inadequate.

We included 144 patients with severe burns ≥ 70 % TBSA from January 1, 2010, to December 31, 2020 in Changhai hospital. Maximally selected log-rank statistics, Kaplan-Meier (K-M) survival analysis, and log-rank test were used to determine the optimal cutoff point and prognostic value of the deep burn index (DBI). DBI is defined as the proportion of third and fourth degree burns in the total body surface area burned.. Subgroup analysis, multivariable Cox regression analysis, and model diagnostics were performed to assess the statistical independence of this prognostic factor. Additional Chi-square tests were conducted to explore potential mechanisms. Finally, 185 patients from the Kunshan cohort were included to externally validate the prognostic value of the DBI in severely burned patients.

The DBI was identified as a significant prognostic factor, with an optimal cutoff point of 0.38 in severely burned patients with total burn area ≥ 70 % TBSA in the Changhai cohort. Clinical characteristics concerning infection, organ dysfunction, invasive procedures, and skin grafting showed significant correlations with DBI in these patients. Moreover, DBI > 0.38 was further validated as a significant risk factor in severely burned patients in the Kunshan cohort.

Our findings suggest that greater emphasis should be placed on assessing burn depth, particularly the DBI, than total burn area alone when evaluating prognosis and guiding treatment strategies for patients with severe burns.