Abstract: Objective　To explore the influence of different laboratory indexes for different prognosis of diabetic foot amputation and evaluate its predictive value for poor prognosis.　Methods 　The clinical data of 69 patients with diabetic foot amputation at the Second Xiangya Hospital of Central South University from January 2016 to March 2018 were retrospectively collected. All the patients were followed up for 1 year. The patients were classified into a poor prognosis group (patients with exacerbation) and a favorable prognosis group (patients with on exacerbation and good wound healing). Kaplan-Meier survival curve was drawn to observe the one-year poor prognosis rate. Univariate and multivariate analysis were used to screen out the independent influencing factors that lead to poor prognosis. The predictive ability of the adverse reactions after diabetic foot amputation was calculated and evaluated by the ROC curve. In the prognostic group, patients were sub-grouped according to the number of debridement to screen out the independent risk factors that affecting the number of debridement before amputation surgery.　Results　Univariate analysis showed that for diabetic foot amputation, D-dimer、CRP、ESR、NLR、ALB of the poor prognosis group have better statistical difference than that of the favorable prognosis group (P<0.05). Multivariate analysis showed D-dimer、CRP and NLR were the independent factors that influencing the prognosis of diabetic foot amputation. Kaplan-Meier survival curve showed that one-year poor prognosis rate was 40.6%. Area under the curve of the combined diagnosis of D-dimer, CRP and NLR was 0.902, which was higher than that of D-dimer or CRP or NLR. Delong test showed there were statistical difference between the area under the curve and D-dimer (P<0.05). CRP was the independent risk factor that affecting the number of debridement before amputation in the favorable prognosis group (P<0.05).　Conclusions　D-dimer, CRP, NLR and the combined diagnosis of the three have favorable predictive ability for the prognosis of diabetic foot amputation. The efficiency of the combined diagnosis was higher than that of D-dimer, but not significantly better than that of CRP and NLR. CRP was the independent risk factor that affecting the number of debridement before amputation in the favorable prognosis group.

Key words: Diabetic foot amputation, 　Prognosis analysis, 　D-dimer, 　CRP, 　NLR