AB0577 EFFECT OF TRANSCUTANEOUS CARBON DIOXIDE THERAPY FOR WOUND HEALING AFTER FOREFOOT SURGERY IN RHEUMATOID ARTHRITIS PATIENTS
Authors: A. Uefuji, S. Takahara, R. Yoshihara, M. Murata, N. Amano, M. Nishida, Y. Tanaka, K. Shiozawa, N. Nakagawa
Journal: Annals of the Rheumatic Diseases (2024)

<h3>Background:</h3> Rheumatoid arthritis (RA) patients often experience forefoot deformity. While mild deformity cases can be treated conservatively, cases with severe deformity or pain are treated with forefoot surgery. The complication of forefoot surgery, such as delayed wound healing (delay), is reported to occur at a relatively high rate of 4 to 24%. Conversely, the wound-healing effects of carbon dioxide have been documented over time, and transcutaneous carbon dioxide therapy (CO2 therapy) has gained attention in recent years. CO2 therapy involves applying a hydrogel that absorbs carbon dioxide to the extremities. The treated area is then wrapped in a plastic bag, and carbon dioxide gas is delivered (Figure 1). Studies have indicated that the absorption of CO2 leads to the dilation of blood vessels, enhancing blood flow in the extremities. Additionally, it contributes to an increase in oxygen concentration through the artificial Bohr effect. This therapeutic approach holds promise for wound healing. <h3>Objectives:</h3> In our hospital, we expect the effect of CO2 therapy will enhance wound healing. Since September 2019, we have been using CO2 therapy after forefoot surgery after obtaining approval from the Ethics Committee. This study investigated the factors influencing delayed wound healing after forefoot surgery. <h3>Methods:</h3> Subjects comprised 81 patients diagnosed with rheumatoid arthritis (RA) who underwent plastic surgery between April 2016 and August 2023. The cohort consisted of 8 men and 73 women, with an average age of 68.6 years at the time of surgery. CO2 therapy was administered daily for 20 minutes, starting from the second postoperative day until discharge. At the 3-week mark post-surgery, cases exhibiting healed wounds were categorized as the "cured" group, while those manifesting wound abnormalities were classified as the "delayed" group. Factors considered were age (years), disease duration (years), preoperative C-reactive protein (CRP) levels (mg/dL), glucocorticoids (prednisolone, PSL) usage, daily PSL intake (mg/day), biological agents (Bio) usage, forefoot deformity evident in preoperative X-rays (deformity), and the presence or absence of CO2 therapy. For assessing deformity, the hallux valgus angle (HV angle) (degree) and the total overlap length of the first to fifth toe metatarsal-proximal phalanx at the metatarsophalangeal (MTP) joint (overlap)(mm) on the standing frontal X-ray image were utilized. A comparative analysis of factors between the cured and delayed groups employed the T-test and chi-square test. Factors exhibiting significant differences were further scrutinized for their impact on delayed occurrence through logistic regression analysis. Significance was set at p ≤ 0.05. <h3>Results:</h3> In this study, the cure group comprised 61 patients with 87 feet, while the delayed group included 20 patients with 21 feet, resulting in a delayed complication rate of 19.4%. No significant differences were observed in age, preoperative CRP levels, usage of PSL and Bio, and preoperative HV angle between the two groups. However, a significant difference was found in disease duration (p=0.032), daily PSL intake (p=0.010), overlap (p&lt;0.001), and the presence or absence of CO2 therapy (p=0.028). Logistic regression analysis revealed that a substantial PSL intake (p=0.006), a prolonged overlap length (p=0.022), and the absence of CO2 therapy (p=0.050) significantly influenced the occurrence of delayed wound healing (Table 1). <h3>Conclusion:</h3> Factors influencing delay after forefoot surgery include substantial prednisolone (PSL) intake, prolonged overlap length, and the absence of CO2 therapy. CO2 therapy was deemed effective in preventing delays. <h3>REFERENCES:</h3> [1] Sakai Y et al., PLoS One. 2011; 6(9) <h3>Acknowledgements:</h3> <b>NIL.</b> <h3>Disclosure of Interests:</h3> <b>None declared.</b>