Objective  To compare and analyze the clinical efficacy of negative pressure wound therapy (NPWT) combined with lavage system in the treatment of Wagner grade 3-5 diabetic foot ulcers combined with infections.

  Methods  The clinical data of 100 patients with Wagner grade 3-5 diabetic foot ulcers combined with infections admitted to our department between January 2016 and January 2020 were retrospectively analyzed. According to the methods of surgical wound management, they were divided into two groups, a combination treatment group treated by NPWT plus a lavage system and a single treatment group receiving NPWT only. Patients were studied for the types of bacterial infection found in the wounds, the amount of time it took for the wound bacterial culture to turn negative, and the status of blood inflammatory indicators, including white blood cell count and C-reactive protein (CRP). Data concerning hospitalization were collected, including the waiting time before the first operation, the number of operations, length of hospital stay, NPWT usage time, and wound closure time. In addition, data concerning patient condition after discharge were also collected, including the duration of out-of-hospital antibiotic use, the final wound healing rate, the final wound healing time, and long-term wound complications, which include wound dehiscence, new ulcer, infection recurrence, readmission, reoperation, and amputation.

  Results  There were no statistically significant differences in age, sex, course of disease, lesion side, lesion size and combined diseases between the two groups. Likewise, there was no significant difference in the species and genus, or the composition of bacteria found in the wounds (P>0.05). However, the combination treatment group showed better results than the single treatment group did in the amount of time it took for wound bacterial culture to turn negative (P<0.05). As for the blood inflammatory indicators, there was no significant difference between the two groups except that the CRP of the combination group decreased more significantly than that of the single treatment group did at one week postop. The number of surgeries, length of hospital stay, NPWT use time, and wound closure time were lower in the combination treatment group than those in the single treatment group (P<0.05). However, there was no significant difference in long-term wound complications between the two groups.

  Conclusion  When applying NPWT plus lavage system in the treatment of Wagner grade 3-5 diabetic foot ulcers combined with infection, wound infection can be controlled effectively at an early stage and the amount of time needed for wound bacterial culture to turn negative can also be reduced. In addition, the combination treatment stimulates granulation growth of the wounds to effectively cover the wound at an early stage.