The Efficacy of Local Insulin Versus Topical Phenytoin or Normal Saline in Diabetic Foot Ulcer Management: A Prospective Comparative Study

Introduction During an individual's lifetime, around 15% to 25% of patients with diabetes mellitus develop foot ulcers, and about 1% of patients end up with an amputation. For the past two decades, we have treated diabetic foot ulcers with a variety of methods including cleansing and dressing after debridement of the lesion, where the dressing is applied using local insulin, topical phenytoin, normal saline dressing, etc. We conducted the present study to compare the efficacy of diabetic foot ulcer management between local injectable insulin, topical phenytoin, and normal saline among diabetic patients. Methodology We conducted a prospective study of 60 patients with diabetic foot ulcers who sought outpatient care at the Department of General Surgery, in a tertiary care hospital in Perambalur, from September 2021 to August 2022. We included all patients who provided informed written consent and had ulcers ranging from grade 1-2. We excluded patients with foot ulcers caused by other etiologies such as osteomyelitis and renal failure. We divided the selected study participants into three groups using the number lot method (randomization). Twenty study participants made up each group; there were three groups in total - groups 1, 2, and 3. Group 1 was treated with local insulin; group 2 with topical phenytoin; and group 3 with normal saline dressing. Before the start of the study, we measured the wound size and depth of the wound and followed up at seven days intervals for one month. The results were analyzed using SPSS, version 21 (IBM Corp., Armonk, NY). Results The mean age, duration of diabetes, and mean fasting blood sugar values of the study participants in the three groups were almost similar. The mean difference in wound size before and after treatment in the insulin, normal saline, and phenytoin groups was 4.98, 3.74, and 3.805 square centimeters, respectively. This difference in mean among the above three groups was statistically significant (P < 0.001). The mean difference in wound depth before and after treatment in the insulin, normal saline, and phenytoin groups was 47.005, 4.945, and 4.820 square centimeters, respectively. This difference in mean among the above three groups was statistically significant (P < 0.001). Thus, wound healing was better in the local insulin group than in the other two groups, with statistical significance. The mean number of days taken for wound healing in the insulin, normal saline, and phenytoin groups was 20, 26, and 23 days, respectively. This difference in mean among the above three groups was statistically significant (P < 0.001).  Conclusion The current study, which lasted a year in a tertiary care hospital, found that local injectable insulin heals diabetic foot ulcers more rapidly than local topical phenytoin, which is superior to the standard treatment of using normal saline.